rescaler_mips32: disable ImportRowShrink

this function is failing the 'accum == 0' assert on skia bots for
rescaling to 13x13

BUG=skia:6682

Change-Id: I9f9f3adf28cec63ad6e38ed3128f18825d5b70cc

.gitattributes

@@ -0,0 +1,5 @@
+.gitattributes export-ignore
+.gitignore export-ignore
+.mailmap export-ignore
+*.pdf -text -diff
+*.ppm -text -diff

.gitignore

@@ -1,18 +1,41 @@
 *.l[ao]
-*.o
+*.[ao]
+*.pc
 .deps
 .libs
 /aclocal.m4
+/ar-lib
 /autom4te.cache
 /compile
 /config.*
 /configure
 /depcomp
+/dist
 /install-sh
 /libtool
 /ltmain.sh
 /missing
+/mkinstalldirs
 /stamp-h1
 Makefile
 Makefile.in
-examples/[cd]webp
+examples/anim_diff
+examples/[cdv]webp
+examples/gif2webp
+examples/img2webp
+examples/webpmux
+src/webp/config.h*
+src/webp/stamp-h1
+/output
+/doc/output
+*.idb
+*.pdb
+/iosbuild
+/WebP.framework
+CMakeCache.txt
+CMakeFiles/
+cmake_install.cmake
+.gradle
+/build
+extras/get_disto
+extras/webp_quality

.mailmap

@@ -0,0 +1,12 @@
+<johann.koenig@duck.com> <johannkoenig@google.com>
+Mikołaj Zalewski <mikolajz@google.com>
+Pascal Massimino <pascal.massimino@gmail.com>
+<pascal.massimino@gmail.com> <skal@google.com>
+Vikas Arora <vikasa@google.com>
+<vikasa@google.com> <vikasa@gmail.com>
+<vikasa@google.com> <vikaas.arora@gmail.com>
+<slobodan.prijic@imgtec.com> <Slobodan.Prijic@imgtec.com>
+<vrabaud@google.com> <vincent.rabaud@gmail.com>
+Tamar Levy <tamar.levy@intel.com>
+<qrczak@google.com> <qrczak>
+Hui Su <huisu@google.com>

AUTHORS

@@ -1,7 +1,38 @@
 Contributors:
+- Charles Munger (clm at google dot com)
+- Christian Duvivier (cduvivier at google dot com)
+- Djordje Pesut (djordje dot pesut at imgtec dot com)
+- Hui Su (huisu at google dot com)
+- James Zern (jzern at google dot com)
 - Jan Engelhardt (jengelh at medozas dot de)
+- Jehan (jehan at girinstud dot io)
+- Johann (johann dot koenig at duck dot com)
+- Jovan Zelincevic (jovan dot zelincevic at imgtec dot com)
+- Jyrki Alakuijala (jyrki at google dot com)
+- Lode Vandevenne (lode at google dot com)
+- Lou Quillio (louquillio at google dot com)
+- Mans Rullgard (mans at mansr dot com)
+- Marcin Kowalczyk (qrczak at google dot com)
+- Martin Olsson (mnemo at minimum dot se)
 - Mikołaj Zalewski (mikolajz at google dot com)
+- Mislav Bradac (mislavm at google dot com)
+- Nico Weber (thakis at chromium dot org)
+- Noel Chromium (noel at chromium dot org)
+- Owen Rodley (orodley at google dot com)
+- Parag Salasakar (img dot mips1 at gmail dot com)
 - Pascal Massimino (pascal dot massimino at gmail dot com)
-- pierre.php@gmail.com
-- Somnath Banerjee (somnath at google dot com)
+- Paweł Hajdan, Jr (phajdan dot jr at chromium dot org)
+- Pierre Joye (pierre dot php at gmail dot com)
+- Sam Clegg (sbc at chromium dot org)
+- Scott Hancher (seh at google dot com)
+- Scott LaVarnway (slavarnway at google dot com)
+- Scott Talbot (s at chikachow dot org)
+- Slobodan Prijic (slobodan dot prijic at imgtec dot com)
+- Somnath Banerjee (somnath dot banerjee at gmail dot com)
+- Sriraman Tallam (tmsriram at google dot com)
+- Tamar Levy (tamar dot levy at intel dot com)
+- Timothy Gu (timothygu99 at gmail dot com)
+- Urvang Joshi (urvang at google dot com)
 - Vikas Arora (vikasa at google dot com)
+- Vincent Rabaud (vrabaud at google dot com)
+- Yang Zhang (yang dot zhang at arm dot com)

Android.mk

@@ -1,35 +1,266 @@
-LOCAL_PATH:= $(call my-dir)
+LOCAL_PATH := $(call my-dir)
+
+WEBP_CFLAGS := -Wall -DANDROID -DHAVE_MALLOC_H -DHAVE_PTHREAD -DWEBP_USE_THREAD
+WEBP_CFLAGS += -fvisibility=hidden
+
+ifeq ($(APP_OPTIM),release)
+  WEBP_CFLAGS += -finline-functions -ffast-math \
+                 -ffunction-sections -fdata-sections
+  ifeq ($(findstring clang,$(NDK_TOOLCHAIN_VERSION)),)
+    WEBP_CFLAGS += -frename-registers -s
+  endif
+endif
+
+ifneq ($(findstring armeabi-v7a, $(TARGET_ARCH_ABI)),)
+  # Setting LOCAL_ARM_NEON will enable -mfpu=neon which may cause illegal
+  # instructions to be generated for armv7a code. Instead target the neon code
+  # specifically.
+  NEON := c.neon
+  USE_CPUFEATURES := yes
+else
+  NEON := c
+endif
+
+dec_srcs := \
+    src/dec/alpha_dec.c \
+    src/dec/buffer_dec.c \
+    src/dec/frame_dec.c \
+    src/dec/idec_dec.c \
+    src/dec/io_dec.c \
+    src/dec/quant_dec.c \
+    src/dec/tree_dec.c \
+    src/dec/vp8_dec.c \
+    src/dec/vp8l_dec.c \
+    src/dec/webp_dec.c \
+
+demux_srcs := \
+    src/demux/anim_decode.c \
+    src/demux/demux.c \
+
+dsp_dec_srcs := \
+    src/dsp/alpha_processing.c \
+    src/dsp/alpha_processing_mips_dsp_r2.c \
+    src/dsp/alpha_processing_neon.$(NEON) \
+    src/dsp/alpha_processing_sse2.c \
+    src/dsp/alpha_processing_sse41.c \
+    src/dsp/argb.c \
+    src/dsp/argb_mips_dsp_r2.c \
+    src/dsp/argb_sse2.c \
+    src/dsp/cpu.c \
+    src/dsp/dec.c \
+    src/dsp/dec_clip_tables.c \
+    src/dsp/dec_mips32.c \
+    src/dsp/dec_mips_dsp_r2.c \
+    src/dsp/dec_msa.c \
+    src/dsp/dec_neon.$(NEON) \
+    src/dsp/dec_sse2.c \
+    src/dsp/dec_sse41.c \
+    src/dsp/filters.c \
+    src/dsp/filters_mips_dsp_r2.c \
+    src/dsp/filters_msa.c \
+    src/dsp/filters_neon.$(NEON) \
+    src/dsp/filters_sse2.c \
+    src/dsp/lossless.c \
+    src/dsp/lossless_mips_dsp_r2.c \
+    src/dsp/lossless_msa.c \
+    src/dsp/lossless_neon.$(NEON) \
+    src/dsp/lossless_sse2.c \
+    src/dsp/rescaler.c \
+    src/dsp/rescaler_mips32.c \
+    src/dsp/rescaler_mips_dsp_r2.c \
+    src/dsp/rescaler_msa.c \
+    src/dsp/rescaler_neon.$(NEON) \
+    src/dsp/rescaler_sse2.c \
+    src/dsp/upsampling.c \
+    src/dsp/upsampling_mips_dsp_r2.c \
+    src/dsp/upsampling_msa.c \
+    src/dsp/upsampling_neon.$(NEON) \
+    src/dsp/upsampling_sse2.c \
+    src/dsp/yuv.c \
+    src/dsp/yuv_mips32.c \
+    src/dsp/yuv_mips_dsp_r2.c \
+    src/dsp/yuv_sse2.c \
+
+dsp_enc_srcs := \
+    src/dsp/cost.c \
+    src/dsp/cost_mips32.c \
+    src/dsp/cost_mips_dsp_r2.c \
+    src/dsp/cost_sse2.c \
+    src/dsp/enc.c \
+    src/dsp/enc_avx2.c \
+    src/dsp/enc_mips32.c \
+    src/dsp/enc_mips_dsp_r2.c \
+    src/dsp/enc_msa.c \
+    src/dsp/enc_neon.$(NEON) \
+    src/dsp/enc_sse2.c \
+    src/dsp/enc_sse41.c \
+    src/dsp/lossless_enc.c \
+    src/dsp/lossless_enc_mips32.c \
+    src/dsp/lossless_enc_mips_dsp_r2.c \
+    src/dsp/lossless_enc_msa.c \
+    src/dsp/lossless_enc_neon.$(NEON) \
+    src/dsp/lossless_enc_sse2.c \
+    src/dsp/lossless_enc_sse41.c \
+
+enc_srcs := \
+    src/enc/alpha_enc.c \
+    src/enc/analysis_enc.c \
+    src/enc/backward_references_enc.c \
+    src/enc/config_enc.c \
+    src/enc/cost_enc.c \
+    src/enc/delta_palettization_enc.c \
+    src/enc/filter_enc.c \
+    src/enc/frame_enc.c \
+    src/enc/histogram_enc.c \
+    src/enc/iterator_enc.c \
+    src/enc/near_lossless_enc.c \
+    src/enc/picture_enc.c \
+    src/enc/picture_csp_enc.c \
+    src/enc/picture_psnr_enc.c \
+    src/enc/picture_rescale_enc.c \
+    src/enc/picture_tools_enc.c \
+    src/enc/predictor_enc.c \
+    src/enc/quant_enc.c \
+    src/enc/syntax_enc.c \
+    src/enc/token_enc.c \
+    src/enc/tree_enc.c \
+    src/enc/vp8l_enc.c \
+    src/enc/webp_enc.c \
+
+mux_srcs := \
+    src/mux/anim_encode.c \
+    src/mux/muxedit.c \
+    src/mux/muxinternal.c \
+    src/mux/muxread.c \
+
+utils_dec_srcs := \
+    src/utils/bit_reader_utils.c \
+    src/utils/color_cache_utils.c \
+    src/utils/filters_utils.c \
+    src/utils/huffman_utils.c \
+    src/utils/quant_levels_dec_utils.c \
+    src/utils/random_utils.c \
+    src/utils/rescaler_utils.c \
+    src/utils/thread_utils.c \
+    src/utils/utils.c \
+
+utils_enc_srcs := \
+    src/utils/bit_writer_utils.c \
+    src/utils/huffman_encode_utils.c \
+    src/utils/quant_levels_utils.c \
+
+################################################################################
+# libwebpdecoder
 
 include $(CLEAR_VARS)
+
 LOCAL_SRC_FILES := \
-	src/dec/bits.c \
-	src/dec/dsp.c \
-	src/dec/frame.c \
-	src/dec/idec.c \
-	src/dec/quant.c \
-	src/dec/tree.c \
-	src/dec/vp8.c \
-	src/dec/webp.c \
-	src/dec/yuv.c \
-	src/enc/analysis.c \
-	src/enc/bit_writer.c \
-	src/enc/config.c \
-	src/enc/dsp.c \
-	src/enc/filter.c \
-	src/enc/frame.c \
-	src/enc/iterator.c \
-	src/enc/picture.c \
-	src/enc/quant.c \
-	src/enc/syntax.c \
-	src/enc/tree.c \
-	src/enc/webpenc.c
-
-LOCAL_CFLAGS := -Wall -DANDROID -DHAVE_MALLOC_H -DHAVE_PTHREAD \
-                -finline-functions -frename-registers -ffast-math \
-                -s -fomit-frame-pointer -Isrc/webp
+    $(dec_srcs) \
+    $(dsp_dec_srcs) \
+    $(utils_dec_srcs) \
 
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/src
 
-LOCAL_MODULE:= webp
+# prefer arm over thumb mode for performance gains
+LOCAL_ARM_MODE := arm
+
+ifeq ($(USE_CPUFEATURES),yes)
+  LOCAL_STATIC_LIBRARIES := cpufeatures
+endif
+
+LOCAL_MODULE := webpdecoder_static
 
 include $(BUILD_STATIC_LIBRARY)
+
+ifeq ($(ENABLE_SHARED),1)
+include $(CLEAR_VARS)
+
+LOCAL_WHOLE_STATIC_LIBRARIES := webpdecoder_static
+
+LOCAL_MODULE := webpdecoder
+
+include $(BUILD_SHARED_LIBRARY)
+endif  # ENABLE_SHARED=1
+
+################################################################################
+# libwebp
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    $(dsp_enc_srcs) \
+    $(enc_srcs) \
+    $(utils_enc_srcs) \
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/src
+
+# prefer arm over thumb mode for performance gains
+LOCAL_ARM_MODE := arm
+
+LOCAL_WHOLE_STATIC_LIBRARIES := webpdecoder_static
+
+LOCAL_MODULE := webp
+
+ifeq ($(ENABLE_SHARED),1)
+  include $(BUILD_SHARED_LIBRARY)
+else
+  include $(BUILD_STATIC_LIBRARY)
+endif
+
+################################################################################
+# libwebpdemux
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := $(demux_srcs)
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/src
+
+# prefer arm over thumb mode for performance gains
+LOCAL_ARM_MODE := arm
+
+LOCAL_MODULE := webpdemux
+
+ifeq ($(ENABLE_SHARED),1)
+  LOCAL_SHARED_LIBRARIES := webp
+  include $(BUILD_SHARED_LIBRARY)
+else
+  LOCAL_STATIC_LIBRARIES := webp
+  include $(BUILD_STATIC_LIBRARY)
+endif
+
+################################################################################
+# libwebpmux
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := $(mux_srcs)
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/src
+
+# prefer arm over thumb mode for performance gains
+LOCAL_ARM_MODE := arm
+
+LOCAL_MODULE := webpmux
+
+ifeq ($(ENABLE_SHARED),1)
+  LOCAL_SHARED_LIBRARIES := webp
+  include $(BUILD_SHARED_LIBRARY)
+else
+  LOCAL_STATIC_LIBRARIES := webp
+  include $(BUILD_STATIC_LIBRARY)
+endif
+
+################################################################################
+
+WEBP_SRC_PATH := $(LOCAL_PATH)
+include $(WEBP_SRC_PATH)/imageio/Android.mk
+include $(WEBP_SRC_PATH)/examples/Android.mk
+
+ifeq ($(USE_CPUFEATURES),yes)
+  $(call import-module,android/cpufeatures)
+endif

CMakeLists.txt

@@ -0,0 +1,189 @@
+cmake_minimum_required(VERSION 2.8.7)
+
+project(libwebp C)
+
+# Options for coder / decoder executables.
+option(WEBP_BUILD_CWEBP "Build the cwebp command line tool." OFF)
+option(WEBP_BUILD_DWEBP "Build the dwebp command line tool." OFF)
+option(WEBP_BUILD_GIF2WEBP "Build the gif2webp conversion tool." OFF)
+option(WEBP_BUILD_IMG2WEBP "Build the img2webp animation tool." OFF)
+option(WEBP_EXPERIMENTAL_FEATURES "Build with experimental features." OFF)
+option(WEBP_ENABLE_SWAP_16BIT_CSP "Enable byte swap for 16 bit colorspaces." OFF)
+
+set(WEBP_DEP_LIBRARIES)
+set(WEBP_DEP_INCLUDE_DIRS)
+
+if(NOT CMAKE_BUILD_TYPE)
+  set(CMAKE_BUILD_TYPE "Release" CACHE
+    "Build type: Release, Debug or RelWithDebInfo" STRING FORCE
+  )
+endif()
+
+include(cmake/config.h.cmake)
+
+################################################################################
+# Options.
+if(WEBP_ENABLE_SWAP_16BIT_CSP)
+  add_definitions(-DWEBP_SWAP_16BIT_CSP)
+endif()
+
+################################################################################
+# Android only.
+if(ANDROID)
+  include_directories(${ANDROID_NDK}/sources/android/cpufeatures)
+  add_library(cpufeatures STATIC
+    ${ANDROID_NDK}/sources/android/cpufeatures/cpu-features.c
+  )
+  target_link_libraries(cpufeatures dl)
+  set(WEBP_DEP_LIBRARIES ${WEBP_DEP_LIBRARIES} cpufeatures)
+  set(WEBP_DEP_INCLUDE_DIRS ${WEBP_DEP_INCLUDE_DIRS}
+    ${ANDROID_NDK}/sources/android/cpufeatures
+  )
+endif()
+
+################################################################################
+# WebP source files.
+# Read the Makefile.am to get the source files.
+
+function(parse_Makefile_am FOLDER VAR)
+  file(READ ${FOLDER}/Makefile.am MAKEFILE_AM)
+  string(REGEX MATCHALL "_SOURCES \\+= [^\n]*"
+    FILES_PER_LINE ${MAKEFILE_AM}
+  )
+  set(SRCS ${${VAR}})
+  foreach(FILES ${FILES_PER_LINE})
+    string(SUBSTRING ${FILES} 12 -1 FILES)
+    string(REGEX MATCHALL "[0-9a-z\\._]+"
+      FILES ${FILES}
+    )
+    foreach(FILE ${FILES})
+      list(APPEND SRCS ${FOLDER}/${FILE})
+    endforeach()
+  endforeach()
+  set(${VAR} ${SRCS} PARENT_SCOPE)
+endfunction()
+
+set(WEBP_SRCS)
+parse_Makefile_am(${CMAKE_CURRENT_SOURCE_DIR}/src/dec "WEBP_SRCS")
+parse_Makefile_am(${CMAKE_CURRENT_SOURCE_DIR}/src/demux "WEBP_SRCS")
+parse_Makefile_am(${CMAKE_CURRENT_SOURCE_DIR}/src/dsp "WEBP_SRCS")
+parse_Makefile_am(${CMAKE_CURRENT_SOURCE_DIR}/src/enc "WEBP_SRCS")
+parse_Makefile_am(${CMAKE_CURRENT_SOURCE_DIR}/src/utils "WEBP_SRCS")
+
+# Remove the files specific to SIMD we don't use.
+foreach(FILE ${WEBP_SIMD_FILES_NOT_TO_INCLUDE})
+  list(REMOVE_ITEM WEBP_SRCS ${FILE})
+endforeach()
+
+# Build the library.
+add_definitions(-Wall)
+include_directories(${CMAKE_CURRENT_SOURCE_DIR}/src/ ${WEBP_DEP_INCLUDE_DIRS})
+add_library(webp ${WEBP_SRCS})
+target_link_libraries(webp ${WEBP_DEP_LIBRARIES})
+
+# Change the compile flags for SIMD files we use.
+list(LENGTH WEBP_SIMD_FILES_TO_INCLUDE WEBP_SIMD_FILES_TO_INCLUDE_LENGTH)
+math(EXPR WEBP_SIMD_FILES_TO_INCLUDE_RANGE
+  "${WEBP_SIMD_FILES_TO_INCLUDE_LENGTH}-1"
+)
+
+foreach(I_FILE RANGE ${WEBP_SIMD_FILES_TO_INCLUDE_RANGE})
+  list(GET WEBP_SIMD_FILES_TO_INCLUDE ${I_FILE} FILE)
+  list(GET WEBP_SIMD_FLAGS_TO_INCLUDE ${I_FILE} SIMD_COMPILE_FLAG)
+  set_source_files_properties(${FILE} PROPERTIES
+    COMPILE_FLAGS ${SIMD_COMPILE_FLAG}
+  )
+endforeach()
+
+# Build the executables if asked for.
+if(WEBP_BUILD_CWEBP OR WEBP_BUILD_DWEBP OR
+   WEBP_BUILD_GIF2WEBP OR WEBP_BUILD_IMG2WEBP)
+  # Example utility library.
+  set(exampleutil_SRCS
+    ${CMAKE_CURRENT_SOURCE_DIR}/examples/stopwatch.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/examples/example_util.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/examples/example_util.h)
+  add_library(exampleutil ${exampleutil_SRCS})
+  target_link_libraries(exampleutil webp ${WEBP_DEP_LIBRARIES})
+
+  set(imageioutil_SRCS
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/imageio_util.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/imageio_util.h)
+  add_library(imageioutil ${imageioutil_SRCS})
+  target_link_libraries(imageioutil ${WEBP_DEP_LIBRARIES})
+
+  # Image-decoding utility library.
+  set(imagedec_SRCS
+    ${CMAKE_CURRENT_SOURCE_DIR}/examples/gifdec.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/examples/gifdec.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/image_dec.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/image_dec.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/jpegdec.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/jpegdec.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/metadata.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/metadata.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/pngdec.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/pngdec.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/tiffdec.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/tiffdec.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/webpdec.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/webpdec.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/wicdec.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/wicdec.h)
+  add_library(imagedec ${imagedec_SRCS})
+  target_link_libraries(imagedec webp ${WEBP_DEP_LIBRARIES}
+    ${WEBP_DEP_IMG_LIBRARIES})
+
+  # Image-encoding utility library.
+  set(imageenc_SRCS
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/image_enc.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/image_enc.h)
+  add_library(imageenc ${imageenc_SRCS})
+  target_link_libraries(imageenc webp imageioutil
+    ${WEBP_DEP_LIBRARIES} ${WEBP_DEP_IMG_LIBRARIES})
+endif()
+
+if(WEBP_BUILD_DWEBP)
+  # dwebp
+  include_directories(${WEBP_DEP_IMG_INCLUDE_DIRS})
+  add_executable(dwebp
+    ${CMAKE_CURRENT_SOURCE_DIR}/examples/dwebp.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/examples/stopwatch.h)
+  target_link_libraries(dwebp imagedec imageenc webp
+    exampleutil imageioutil
+    ${WEBP_DEP_LIBRARIES} ${WEBP_DEP_IMG_LIBRARIES}
+  )
+endif()
+
+if(WEBP_BUILD_CWEBP)
+  # cwebp
+  include_directories(${WEBP_DEP_IMG_INCLUDE_DIRS})
+  add_executable(cwebp
+    ${CMAKE_CURRENT_SOURCE_DIR}/examples/cwebp.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/examples/stopwatch.h)
+  target_link_libraries(cwebp imagedec webp exampleutil imageioutil
+    ${WEBP_DEP_LIBRARIES} ${WEBP_DEP_IMG_LIBRARIES}
+  )
+endif()
+
+if(WEBP_BUILD_GIF2WEBP)
+  # gif2webp
+  include_directories(${WEBP_DEP_IMG_INCLUDE_DIRS})
+  set(GIF2WEBP_SRCS ${CMAKE_CURRENT_SOURCE_DIR}/examples/gif2webp.c)
+  parse_Makefile_am(${CMAKE_CURRENT_SOURCE_DIR}/src/mux "GIF2WEBP_SRCS")
+  add_executable(gif2webp ${GIF2WEBP_SRCS})
+  target_link_libraries(gif2webp imagedec webp exampleutil imageioutil
+    ${WEBP_DEP_LIBRARIES} ${WEBP_DEP_IMG_LIBRARIES}
+  )
+endif()
+
+if(WEBP_BUILD_IMG2WEBP)
+  # img2webp
+  include_directories(${WEBP_DEP_IMG_INCLUDE_DIRS})
+  set(IMG2WEBP_SRCS ${CMAKE_CURRENT_SOURCE_DIR}/examples/img2webp.c)
+  parse_Makefile_am(${CMAKE_CURRENT_SOURCE_DIR}/src/mux "IMG2WEBP_SRCS")
+  add_executable(img2webp ${IMG2WEBP_SRCS})
+  target_link_libraries(img2webp imagedec webp exampleutil imageioutil
+    ${WEBP_DEP_LIBRARIES} ${WEBP_DEP_IMG_LIBRARIES}
+  )
+endif()

Makefile.am

@@ -1,3 +1,9 @@
 ACLOCAL_AMFLAGS = -I m4
-SUBDIRS = src examples man
+SUBDIRS = src imageio man
 EXTRA_DIST = COPYING autogen.sh
+
+if WANT_EXTRAS
+  SUBDIRS += extras
+endif
+
+SUBDIRS += examples

Makefile.vc

@@ -1,37 +1,50 @@
 #
 # Stem for static libs and DLLs
 #
-LIB_NAME       = libwebp_a
-LIB_NAME_DEBUG = libwebp_a_debug
-
-#
-# Stem for DLL import libs
-#
-IMPLIB_NAME       = libwebp
-IMPLIB_NAME_DEBUG = libwepb_debug
-
-!IFNDEF DEP_PATH
-DEPS_PATH   = ../../deps
-!ENDIF
+LIBWEBPDECODER_BASENAME = libwebpdecoder
+LIBWEBP_BASENAME = libwebp
+LIBWEBPMUX_BASENAME = libwebpmux
+LIBWEBPDEMUX_BASENAME = libwebpdemux
 
 !IFNDEF ARCH
-ARCH  = x86
+!IF ! [ cl 2>&1 | find "x86" > NUL ]
+ARCH = x86
+!ELSE IF ! [ cl 2>&1 | find "x64" > NUL ]
+ARCH = x64
+!ELSE IF ! [ cl 2>&1 | find "ARM" > NUL ]
+ARCH = ARM
+!ELSE
+!ERROR Unable to auto-detect toolchain architecture! \
+If cl.exe is in your PATH rerun nmake with ARCH=<arch>.
+!ENDIF
+!ENDIF
+
+!IF "$(ARCH)" == "x86"
+PLATFORM_LDFLAGS = /SAFESEH
 !ENDIF
 
 #############################################################
 ## Nothing more to do below this line!
 
-MT         = mt.exe
-CCNODBG    = cl.exe /nologo /O2 /DNDEBUG
-CCDEBUG    = cl.exe /nologo /Od /Gm /Zi /D_DEBUG /RTC1
-CFLAGS     = /Isrc /nologo /W3 /EHsc /DWIN32 /FD /c /GS /D_CRT_SECURE_NO_WARNINGS
-LDFLAGS    = /LARGEADDRESSAWARE /MANIFEST /NXCOMPAT /SAFESEH /DYNAMICBASE
-CFLAGSLIB  = /DLIBWEBP_STATICLIB
-LNKDLL     = link.exe /DLL
-LNKLIB     = link.exe /lib
-LNKEXE     = link.exe
-LFLAGS     = /nologo /machine:$(ARCH)
-CFLAGS     = $(CFLAGS)
+NOLOGO     = /nologo
+CCNODBG    = cl.exe $(NOLOGO) /O2 /DNDEBUG
+CCDEBUG    = cl.exe $(NOLOGO) /Od /Gm /Zi /D_DEBUG /RTC1
+CFLAGS     = /Isrc $(NOLOGO) /W3 /EHsc /c
+CFLAGS     = $(CFLAGS) /DWIN32 /D_CRT_SECURE_NO_WARNINGS /DWIN32_LEAN_AND_MEAN
+LDFLAGS    = /LARGEADDRESSAWARE /MANIFEST /NXCOMPAT /DYNAMICBASE
+LDFLAGS    = $(LDFLAGS) $(PLATFORM_LDFLAGS)
+LNKDLL     = link.exe /DLL $(NOLOGO)
+LNKEXE     = link.exe $(NOLOGO)
+LNKLIB     = lib.exe $(NOLOGO)
+MT         = mt.exe $(NOLOGO)
+RCNODBG    = rc.exe $(NOLOGO) /l"0x0409"  # 0x409 = U.S. English
+RCDEBUG    = $(RCNODBG) /D_DEBUG
+
+!IF "$(ARCH)" == "ARM"
+CFLAGS = $(CFLAGS) /DWINAPI_FAMILY=WINAPI_FAMILY_PHONE_APP /DWEBP_USE_THREAD
+!ELSE
+CFLAGS = $(CFLAGS) /DHAVE_WINCODEC_H /DWEBP_USE_THREAD
+!ENDIF
 
 CFGSET     = FALSE
 !IF "$(OBJDIR)" == ""
@@ -40,11 +53,21 @@ OUTDIR = ..\obj\
 OUTDIR = $(OBJDIR)
 !ENDIF
 
+!IF "$(HAVE_AVX2)" == "1"
+CFLAGS = $(CFLAGS) /DWEBP_HAVE_AVX2
+AVX2_FLAGS = /arch:AVX2
+!ENDIF
+
 ##############################################################
 # Runtime library configuration
 !IF "$(RTLIBCFG)" == "static"
 RTLIB  = /MT
 RTLIBD = /MTd
+!ELSE IF "$(RTLIBCFG)" == "legacy"
+RTLIBCFG = static
+RTLIB  = /MT
+RTLIBD = /MTd
+CFLAGS = $(CFLAGS) /GS- /arch:IA32
 !ELSE
 RTLIB   = /MD
 RTLIBD  = /MDd
@@ -54,20 +77,60 @@ DIROBJ = $(DIRBASE)\obj
 DIRLIB = $(DIRBASE)\lib
 DIRINC = $(DIRBASE)\include
 DIRBIN = $(DIRBASE)\bin
+LIBWEBP_PDBNAME = $(DIROBJ)\$(LIBWEBP_BASENAME).pdb
+OUTPUT_DIRS = $(DIRBIN) $(DIRINC) $(DIRLIB) \
+              $(DIROBJ)\dec \
+              $(DIROBJ)\demux \
+              $(DIROBJ)\dsp \
+              $(DIROBJ)\enc \
+              $(DIROBJ)\examples \
+              $(DIROBJ)\extras \
+              $(DIROBJ)\imageio \
+              $(DIROBJ)\mux \
+              $(DIROBJ)\utils \
 
-# release-static
+# Target configuration
 !IF "$(CFG)" == "release-static"
-TARGET = $(LIB_NAME).lib
-LNK    = $(LNKLIB) /out:$(DIRLIB)\$(TARGET)
-CC     = $(CCNODBG) $(RTLIB) $(CFLAGSLIB)
-CFGSET = TRUE
+CC             = $(CCNODBG)
+STATICLIBBUILD = TRUE
+!ELSE IF "$(CFG)" == "debug-static"
+CC             = $(CCDEBUG)
+RTLIB          = $(RTLIBD)
+STATICLIBBUILD = TRUE
+LIBWEBPDECODER_BASENAME = $(LIBWEBPDECODER_BASENAME)_debug
+LIBWEBP_BASENAME = $(LIBWEBP_BASENAME)_debug
+LIBWEBPMUX_BASENAME = $(LIBWEBPMUX_BASENAME)_debug
+LIBWEBPDEMUX_BASENAME = $(LIBWEBPDEMUX_BASENAME)_debug
+!ELSE IF "$(CFG)" == "release-dynamic"
+CC        = $(CCNODBG)
+RC        = $(RCNODBG)
+DLLBUILD  = TRUE
+!ELSE IF "$(CFG)" == "debug-dynamic"
+CC        = $(CCDEBUG)
+RC        = $(RCDEBUG)
+RTLIB     = $(RTLIBD)
+DLLBUILD  = TRUE
+LIBWEBPDECODER_BASENAME = $(LIBWEBPDECODER_BASENAME)_debug
+LIBWEBP_BASENAME = $(LIBWEBP_BASENAME)_debug
+LIBWEBPMUX_BASENAME = $(LIBWEBPMUX_BASENAME)_debug
+LIBWEBPDEMUX_BASENAME = $(LIBWEBPDEMUX_BASENAME)_debug
 !ENDIF
 
-# debug-static
-!IF "$(CFG)" == "debug-static"
-TARGET = $(LIB_NAME_DEBUG).lib
-LNK    = $(LNKLIB) /out:$(DIRLIB)\$(TARGET)
-CC     = $(CCDEBUG) $(RTLIBD) $(CFLAGSLIB)
+!IF "$(STATICLIBBUILD)" == "TRUE"
+CC     = $(CC) $(RTLIB)
+CFGSET = TRUE
+LIBWEBPDECODER = $(DIRLIB)\$(LIBWEBPDECODER_BASENAME).lib
+LIBWEBP = $(DIRLIB)\$(LIBWEBP_BASENAME).lib
+LIBWEBPMUX = $(DIRLIB)\$(LIBWEBPMUX_BASENAME).lib
+LIBWEBPDEMUX = $(DIRLIB)\$(LIBWEBPDEMUX_BASENAME).lib
+!ELSE IF "$(DLLBUILD)" == "TRUE"
+DLLINC = webp_dll.h
+CC     = $(CC) /I$(DIROBJ) /FI$(DLLINC) $(RTLIB) /DWEBP_DLL
+LIBWEBPDECODER = $(DIRLIB)\$(LIBWEBPDECODER_BASENAME)_dll.lib
+LIBWEBP = $(DIRLIB)\$(LIBWEBP_BASENAME)_dll.lib
+LIBWEBPMUX = $(DIRLIB)\$(LIBWEBPMUX_BASENAME)_dll.lib
+LIBWEBPDEMUX = $(DIRLIB)\$(LIBWEBPDEMUX_BASENAME)_dll.lib
+LIBWEBP_PDBNAME = $(DIROBJ)\$(LIBWEBP_BASENAME)_dll.pdb
 CFGSET = TRUE
 !ENDIF
 
@@ -75,16 +138,28 @@ CFGSET = TRUE
 # Usage
 #
 !IF "$(CFGSET)" == "FALSE"
-!MESSAGE Usage: nmake /f makefile.vc9 [CFG=<config>] [OBJDIR=<path>] [RTLIBCFG=<rtlib>] [<target>]
+!MESSAGE Usage: nmake /f Makefile.vc [CFG=<config>]
+!MESSAGE .          [OBJDIR=<path>] [RTLIBCFG=<rtlib>] [<target>]
+!MESSAGE
 !MESSAGE where <config> is one of:
 !MESSAGE -  release-static                - release static library
 !MESSAGE -  debug-static                  - debug static library
-!MESSAGE -  (empty)                       - perform a clean
+!MESSAGE -  release-dynamic               - release dynamic link library (DLL)
+!MESSAGE -  debug-dynamic                 - debug dynamic link library (DLL)
 !MESSAGE
-!MESSAGE <rtlibcfg> controls the runtime library likage - can be 'static' or 'dynamic'.
-!MESSAGE <target> can be left blank in which case all is assumed
-!MESSAGE <path> is the path where you like to build (obj, bins, etc.)
-!MESSAGE   default to ..\obj\
+!MESSAGE <target> may be:
+!MESSAGE -  clean                         - perform a clean for CFG
+!MESSAGE -  experimental                  - build CFG with experimental
+!MESSAGE .                                  features enabled.
+!MESSAGE - (empty)                        - build libwebp-based targets for CFG
+!MESSAGE - all                            - build (de)mux-based targets for CFG
+!MESSAGE - gif2webp                       - requires libgif & >= VS2013
+!MESSAGE - anim_diff                      - requires libgif & >= VS2013
+!MESSAGE
+!MESSAGE RTLIBCFG controls the runtime library linkage - 'static' or 'dynamic'.
+!MESSAGE   'legacy' will produce a Windows 2000 compatible library.
+!MESSAGE OBJDIR is the path where you like to build (obj, bins, etc.),
+!MESSAGE   defaults to ..\obj
 
 !IF "$(CFG)" != ""
 !MESSAGE
@@ -93,99 +168,332 @@ CFGSET = TRUE
 !ENDIF
 
 #######################
-# Only the clean target can be used if a config was not provided.
+# Rules
 #
-!IF "$(CFGSET)" == "FALSE"
-!MESSAGE
-!MESSAGE No configuration provided - performing a clean.
-clean:
-	@-erase /s *.dll 2> NUL
-	@-erase /s *.exp 2> NUL
-	@-erase /s *.idb 2> NUL
-	@-erase /s *.lib 2> NUL
-	@-erase /s *.obj 2> NUL
-	@-erase /s *.pch 2> NUL
-	@-erase /s *.pdb 2> NUL
-	@-erase /s *.res 2> NUL
-!ELSE
+!IF "$(CFGSET)" == "TRUE"
 # A config was provided, so the library can be built.
 #
 
-X_OBJS= \
-	$(DIROBJ)\dec\bits.obj \
-	$(DIROBJ)\dec\dsp.obj \
-	$(DIROBJ)\dec\frame.obj \
-	$(DIROBJ)\dec\quant.obj \
-	$(DIROBJ)\dec\tree.obj \
-	$(DIROBJ)\dec\vp8.obj \
-	$(DIROBJ)\dec\webp.obj \
-	$(DIROBJ)\dec\yuv.obj \
-	$(DIROBJ)\dec\idec.obj \
-	$(DIROBJ)\enc\analysis.obj \
-	$(DIROBJ)\enc\bit_writer.obj \
-	$(DIROBJ)\enc\config.obj \
-	$(DIROBJ)\enc\cost.obj \
-	$(DIROBJ)\enc\dsp.obj \
-	$(DIROBJ)\enc\frame.obj \
-	$(DIROBJ)\enc\filter.obj \
-	$(DIROBJ)\enc\iterator.obj \
-	$(DIROBJ)\enc\picture.obj \
-	$(DIROBJ)\enc\quant.obj \
-	$(DIROBJ)\enc\syntax.obj \
-	$(DIROBJ)\enc\tree.obj \
-	$(DIROBJ)\enc\webpenc.obj \
-	$(RESOURCE)
+DEC_OBJS = \
+    $(DIROBJ)\dec\alpha_dec.obj \
+    $(DIROBJ)\dec\buffer_dec.obj \
+    $(DIROBJ)\dec\frame_dec.obj \
+    $(DIROBJ)\dec\idec_dec.obj \
+    $(DIROBJ)\dec\io_dec.obj \
+    $(DIROBJ)\dec\quant_dec.obj \
+    $(DIROBJ)\dec\tree_dec.obj \
+    $(DIROBJ)\dec\vp8_dec.obj \
+    $(DIROBJ)\dec\vp8l_dec.obj \
+    $(DIROBJ)\dec\webp_dec.obj \
 
-EXAMPLES_OBJS = \
-	$(DIROBJ)\examples\cwebp.obj \
-	$(DIROBJ)\examples\dwebp.obj
+DEMUX_OBJS = \
+    $(DIROBJ)\demux\anim_decode.obj \
+    $(DIROBJ)\demux\demux.obj \
 
-all: $(DIRLIB)\$(TARGET) $(DIRBIN)\dwebp.exe $(DIRBIN)\cwebp.exe
+DSP_DEC_OBJS = \
+    $(DIROBJ)\dsp\alpha_processing.obj \
+    $(DIROBJ)\dsp\alpha_processing_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\alpha_processing_neon.obj \
+    $(DIROBJ)\dsp\alpha_processing_sse2.obj \
+    $(DIROBJ)\dsp\alpha_processing_sse41.obj \
+    $(DIROBJ)\dsp\cpu.obj \
+    $(DIROBJ)\dsp\dec.obj \
+    $(DIROBJ)\dsp\dec_clip_tables.obj \
+    $(DIROBJ)\dsp\dec_mips32.obj \
+    $(DIROBJ)\dsp\dec_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\dec_msa.obj \
+    $(DIROBJ)\dsp\dec_neon.obj \
+    $(DIROBJ)\dsp\dec_sse2.obj \
+    $(DIROBJ)\dsp\dec_sse41.obj \
+    $(DIROBJ)\dsp\filters.obj \
+    $(DIROBJ)\dsp\filters_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\filters_msa.obj \
+    $(DIROBJ)\dsp\filters_neon.obj \
+    $(DIROBJ)\dsp\filters_sse2.obj \
+    $(DIROBJ)\dsp\lossless.obj \
+    $(DIROBJ)\dsp\lossless_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\lossless_msa.obj \
+    $(DIROBJ)\dsp\lossless_neon.obj \
+    $(DIROBJ)\dsp\lossless_sse2.obj \
+    $(DIROBJ)\dsp\rescaler.obj \
+    $(DIROBJ)\dsp\rescaler_mips32.obj \
+    $(DIROBJ)\dsp\rescaler_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\rescaler_msa.obj \
+    $(DIROBJ)\dsp\rescaler_neon.obj \
+    $(DIROBJ)\dsp\rescaler_sse2.obj \
+    $(DIROBJ)\dsp\upsampling.obj \
+    $(DIROBJ)\dsp\upsampling_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\upsampling_msa.obj \
+    $(DIROBJ)\dsp\upsampling_neon.obj \
+    $(DIROBJ)\dsp\upsampling_sse2.obj \
+    $(DIROBJ)\dsp\yuv.obj \
+    $(DIROBJ)\dsp\yuv_mips32.obj \
+    $(DIROBJ)\dsp\yuv_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\yuv_sse2.obj \
 
-$(DIRLIB)\$(TARGET): $(X_OBJS)
-	$(LNK) $(LFLAGS) $(X_OBJS)
-	-xcopy $(DIROBJ)\$(LIB_NAME).dll       $(DIRBIN) /y
-	-xcopy $(DIROBJ)\$(LIB_NAME).lib       $(DIRLIB) /y
-	-xcopy $(DIROBJ)\$(LIB_NAME_DEBUG).dll $(DIRBIN) /y
-	-xcopy $(DIROBJ)\$(LIB_NAME_DEBUG).lib $(DIRLIB) /y
-	-xcopy $(DIROBJ)\$(IMPLIB_NAME).lib    $(DIRLIB) /y
-	-xcopy $(DIROBJ)\$(IMPLIB_NAME_DEBUG).lib $(DIRLIB) /y
-	-xcopy $(DIROBJ)\*.exp                 $(DIRLIB) /y
-	-xcopy $(DIROBJ)\*.pdb                 $(DIRLIB) /y
+DSP_ENC_OBJS = \
+    $(DIROBJ)\dsp\argb.obj \
+    $(DIROBJ)\dsp\argb_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\argb_sse2.obj \
+    $(DIROBJ)\dsp\cost.obj \
+    $(DIROBJ)\dsp\cost_mips32.obj \
+    $(DIROBJ)\dsp\cost_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\cost_sse2.obj \
+    $(DIROBJ)\dsp\enc.obj \
+    $(DIROBJ)\dsp\enc_avx2.obj \
+    $(DIROBJ)\dsp\enc_mips32.obj \
+    $(DIROBJ)\dsp\enc_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\enc_msa.obj \
+    $(DIROBJ)\dsp\enc_neon.obj \
+    $(DIROBJ)\dsp\enc_sse2.obj \
+    $(DIROBJ)\dsp\enc_sse41.obj \
+    $(DIROBJ)\dsp\lossless_enc.obj \
+    $(DIROBJ)\dsp\lossless_enc_mips32.obj \
+    $(DIROBJ)\dsp\lossless_enc_mips_dsp_r2.obj \
+    $(DIROBJ)\dsp\lossless_enc_msa.obj \
+    $(DIROBJ)\dsp\lossless_enc_neon.obj \
+    $(DIROBJ)\dsp\lossless_enc_sse2.obj \
+    $(DIROBJ)\dsp\lossless_enc_sse41.obj \
 
-$(X_OBJS): $(DIROBJ)\enc $(DIROBJ)\dec $(DIRLIB) $(DIRINC) $(DIRBIN)
+EX_ANIM_UTIL_OBJS = \
+    $(DIROBJ)\examples\anim_util.obj \
 
-$(EXAMPLES_OBJS): $(DIROBJ)\examples $(DIRLIB)\$(TARGET)
+IMAGEIO_DEC_OBJS = \
+    $(DIROBJ)\imageio\image_dec.obj \
+    $(DIROBJ)\imageio\jpegdec.obj \
+    $(DIROBJ)\imageio\metadata.obj \
+    $(DIROBJ)\imageio\pngdec.obj \
+    $(DIROBJ)\imageio\tiffdec.obj \
+    $(DIROBJ)\imageio\webpdec.obj \
+    $(DIROBJ)\imageio\wicdec.obj \
 
-$(DIROBJ)\enc:
-	@if not exist "$(DIROBJ)\enc" mkdir $(DIROBJ)\enc
+IMAGEIO_ENC_OBJS = \
+    $(DIROBJ)\imageio\image_enc.obj \
 
-$(DIROBJ)\examples:
-	@if not exist "$(DIROBJ)\examples" mkdir $(DIROBJ)\examples
+EX_GIF_DEC_OBJS = \
+    $(DIROBJ)\examples\gifdec.obj \
 
-$(DIROBJ)\dec:
-	@if not exist "$(DIROBJ)\dec" mkdir $(DIROBJ)\dec
+EX_UTIL_OBJS = \
+    $(DIROBJ)\examples\example_util.obj \
 
-$(DIRLIB):
-	@if not exist "$(DIRLIB)" mkdir $(DIRLIB)
+ENC_OBJS = \
+    $(DIROBJ)\enc\alpha_enc.obj \
+    $(DIROBJ)\enc\analysis_enc.obj \
+    $(DIROBJ)\enc\backward_references_enc.obj \
+    $(DIROBJ)\enc\config_enc.obj \
+    $(DIROBJ)\enc\cost_enc.obj \
+    $(DIROBJ)\enc\delta_palettization_enc.obj \
+    $(DIROBJ)\enc\filter_enc.obj \
+    $(DIROBJ)\enc\frame_enc.obj \
+    $(DIROBJ)\enc\histogram_enc.obj \
+    $(DIROBJ)\enc\iterator_enc.obj \
+    $(DIROBJ)\enc\near_lossless_enc.obj \
+    $(DIROBJ)\enc\picture_enc.obj \
+    $(DIROBJ)\enc\picture_csp_enc.obj \
+    $(DIROBJ)\enc\picture_psnr_enc.obj \
+    $(DIROBJ)\enc\picture_rescale_enc.obj \
+    $(DIROBJ)\enc\picture_tools_enc.obj \
+    $(DIROBJ)\enc\predictor_enc.obj \
+    $(DIROBJ)\enc\quant_enc.obj \
+    $(DIROBJ)\enc\syntax_enc.obj \
+    $(DIROBJ)\enc\token_enc.obj \
+    $(DIROBJ)\enc\tree_enc.obj \
+    $(DIROBJ)\enc\vp8l_enc.obj \
+    $(DIROBJ)\enc\webp_enc.obj \
 
-$(DIRINC):
-	@if not exist "$(DIRINC)" mkdir $(DIRINC)
+EXTRAS_OBJS = \
+    $(DIROBJ)\extras\extras.obj \
+    $(DIROBJ)\extras\quality_estimate.obj \
 
-$(DIRBIN):
-	@if not exist "$(DIRBIN)" mkdir $(DIRBIN)
+IMAGEIO_UTIL_OBJS = \
+    $(DIROBJ)\imageio\imageio_util.obj \
+
+MUX_OBJS = \
+    $(DIROBJ)\mux\anim_encode.obj \
+    $(DIROBJ)\mux\muxedit.obj \
+    $(DIROBJ)\mux\muxinternal.obj \
+    $(DIROBJ)\mux\muxread.obj \
+
+UTILS_DEC_OBJS = \
+    $(DIROBJ)\utils\bit_reader_utils.obj \
+    $(DIROBJ)\utils\color_cache_utils.obj \
+    $(DIROBJ)\utils\filters_utils.obj \
+    $(DIROBJ)\utils\huffman_utils.obj \
+    $(DIROBJ)\utils\quant_levels_dec_utils.obj \
+    $(DIROBJ)\utils\rescaler_utils.obj \
+    $(DIROBJ)\utils\random_utils.obj \
+    $(DIROBJ)\utils\thread_utils.obj \
+    $(DIROBJ)\utils\utils.obj \
+
+UTILS_ENC_OBJS = \
+    $(DIROBJ)\utils\bit_writer_utils.obj \
+    $(DIROBJ)\utils\huffman_encode_utils.obj \
+    $(DIROBJ)\utils\quant_levels_utils.obj \
+
+LIBWEBPDECODER_OBJS = $(DEC_OBJS) $(DSP_DEC_OBJS) $(UTILS_DEC_OBJS)
+LIBWEBP_OBJS = $(LIBWEBPDECODER_OBJS) $(ENC_OBJS) $(DSP_ENC_OBJS) \
+               $(UTILS_ENC_OBJS) $(DLL_OBJS)
+LIBWEBPMUX_OBJS = $(MUX_OBJS) $(LIBWEBPMUX_OBJS)
+LIBWEBPDEMUX_OBJS = $(DEMUX_OBJS) $(LIBWEBPDEMUX_OBJS)
+
+OUT_LIBS = $(LIBWEBPDECODER) $(LIBWEBP)
+!IF "$(ARCH)" == "ARM"
+ex: $(OUT_LIBS)
+all: ex
+!ELSE
+OUT_EXAMPLES = $(DIRBIN)\cwebp.exe $(DIRBIN)\dwebp.exe
+EXTRA_EXAMPLES = $(DIRBIN)\vwebp.exe $(DIRBIN)\webpmux.exe \
+                 $(DIRBIN)\img2webp.exe $(DIRBIN)\get_disto.exe \
+                 $(DIRBIN)\webp_quality.exe
+
+ex: $(OUT_LIBS) $(OUT_EXAMPLES)
+all: ex $(EXTRA_EXAMPLES)
+# NB: gif2webp.exe and anim_diff.exe are excluded from 'all' as libgif requires
+# C99 support which is only available from VS2013 onward.
+gif2webp: $(DIRBIN)\gif2webp.exe
+anim_diff: $(DIRBIN)\anim_diff.exe
+
+$(DIRBIN)\anim_diff.exe: $(DIROBJ)\examples\anim_diff.obj $(EX_ANIM_UTIL_OBJS)
+$(DIRBIN)\anim_diff.exe: $(EX_UTIL_OBJS) $(IMAGEIO_UTIL_OBJS)
+$(DIRBIN)\anim_diff.exe: $(EX_GIF_DEC_OBJS) $(LIBWEBPDEMUX) $(LIBWEBP)
+$(DIRBIN)\cwebp.exe: $(DIROBJ)\examples\cwebp.obj $(IMAGEIO_DEC_OBJS)
+$(DIRBIN)\cwebp.exe: $(IMAGEIO_UTIL_OBJS)
+$(DIRBIN)\dwebp.exe: $(DIROBJ)\examples\dwebp.obj $(IMAGEIO_DEC_OBJS)
+$(DIRBIN)\dwebp.exe: $(IMAGEIO_ENC_OBJS)
+$(DIRBIN)\dwebp.exe: $(IMAGEIO_UTIL_OBJS)
+$(DIRBIN)\gif2webp.exe: $(DIROBJ)\examples\gif2webp.obj $(EX_GIF_DEC_OBJS)
+$(DIRBIN)\gif2webp.exe: $(EX_UTIL_OBJS) $(IMAGEIO_UTIL_OBJS) $(LIBWEBPMUX)
+$(DIRBIN)\gif2webp.exe: $(LIBWEBP)
+$(DIRBIN)\vwebp.exe: $(DIROBJ)\examples\vwebp.obj $(EX_UTIL_OBJS)
+$(DIRBIN)\vwebp.exe: $(IMAGEIO_UTIL_OBJS) $(LIBWEBPDEMUX) $(LIBWEBP)
+$(DIRBIN)\webpmux.exe: $(DIROBJ)\examples\webpmux.obj $(LIBWEBPMUX)
+$(DIRBIN)\webpmux.exe: $(EX_UTIL_OBJS) $(IMAGEIO_UTIL_OBJS) $(LIBWEBP)
+$(DIRBIN)\img2webp.exe: $(DIROBJ)\examples\img2webp.obj $(LIBWEBPMUX)
+$(DIRBIN)\img2webp.exe: $(IMAGEIO_DEC_OBJS)
+$(DIRBIN)\img2webp.exe: $(EX_UTIL_OBJS) $(IMAGEIO_UTIL_OBJS) $(LIBWEBP)
+$(DIRBIN)\get_disto.exe: $(DIROBJ)\extras\get_disto.obj
+$(DIRBIN)\get_disto.exe: $(IMAGEIO_DEC_OBJS) $(IMAGEIO_UTIL_OBJS) $(LIBWEBP)
+
+$(DIRBIN)\webp_quality.exe: $(DIROBJ)\extras\webp_quality.obj
+$(DIRBIN)\webp_quality.exe: $(IMAGEIO_UTIL_OBJS)
+$(DIRBIN)\webp_quality.exe: $(EXTRAS_OBJS) $(LIBWEBP)
+
+$(OUT_EXAMPLES): $(EX_UTIL_OBJS) $(LIBWEBP)
+$(EX_UTIL_OBJS) $(IMAGEIO_UTIL_OBJS): $(OUTPUT_DIRS)
+$(IMAGEIO_DEC_OBJS) $(IMAGEIO_ENC_OBJS) $(EXTRAS_OBJS): $(OUTPUT_DIRS)
+!ENDIF  # ARCH == ARM
+
+experimental:
+	$(MAKE) /f Makefile.vc \
+	    CFG=$(CFG) \
+	    CFLAGS="$(CFLAGS) /DWEBP_EXPERIMENTAL_FEATURES" /$(MAKEFLAGS)
+
+$(LIBWEBPDECODER): $(LIBWEBPDECODER_OBJS)
+$(LIBWEBP): $(LIBWEBP_OBJS)
+$(LIBWEBPMUX): $(LIBWEBPMUX_OBJS)
+$(LIBWEBPDEMUX): $(LIBWEBPDEMUX_OBJS)
+
+$(LIBWEBP_OBJS) $(LIBWEBPMUX_OBJS) $(LIBWEBPDEMUX_OBJS): $(OUTPUT_DIRS)
+
+!IF "$(DLLBUILD)" == "TRUE"
+$(LIBWEBP_OBJS) $(LIBWEBPMUX_OBJS) $(LIBWEBPDEMUX_OBJS): \
+    $(DIROBJ)\$(DLLINC)
+
+{$(DIROBJ)}.c{$(DIROBJ)}.obj:
+	$(CC) $(CFLAGS) /Fd$(LIBWEBP_PDBNAME) /Fo$@  $<
+
+{src}.rc{$(DIROBJ)}.res:
+	$(RC) /fo$@ $<
+{src\demux}.rc{$(DIROBJ)\demux}.res:
+	$(RC) /fo$@ $<
+{src\mux}.rc{$(DIROBJ)\mux}.res:
+	$(RC) /fo$@ $<
+
+$(LIBWEBP): $(DIROBJ)\$(LIBWEBP_BASENAME:_debug=).res
+$(LIBWEBPDECODER): $(DIROBJ)\$(LIBWEBPDECODER_BASENAME:_debug=).res
+$(LIBWEBPMUX): $(LIBWEBP) $(DIROBJ)\mux\$(LIBWEBPMUX_BASENAME:_debug=).res
+$(LIBWEBPDEMUX): $(LIBWEBP) $(DIROBJ)\demux\$(LIBWEBPDEMUX_BASENAME:_debug=).res
+
+$(LIBWEBPDECODER) $(LIBWEBP) $(LIBWEBPMUX) $(LIBWEBPDEMUX):
+	$(LNKDLL) /out:$(DIRBIN)\$(@B:_dll=.dll) /implib:$@ $(LFLAGS) $**
+	-xcopy $(DIROBJ)\*.pdb $(DIRLIB) /y
+
+clean::
+	@-erase /s $(DIROBJ)\$(DLLINC) 2> NUL
+!ELSE
+$(LIBWEBPDECODER) $(LIBWEBP) $(LIBWEBPMUX) $(LIBWEBPDEMUX):
+	$(LNKLIB) /out:$@ $**
+	-xcopy $(DIROBJ)\*.pdb $(DIRLIB) /y
+!ENDIF
+
+$(OUTPUT_DIRS):
+	@if not exist "$(@)" mkdir "$(@)"
+
+# generate a helper include to define WEBP_EXTERN suitable for the DLL build
+$(DIROBJ)\$(DLLINC):
+	@echo #ifndef WEBP_DLL_H_ > $@
+	@echo #define WEBP_DLL_H_ >> $@
+	@echo #define WEBP_EXTERN(type) __declspec(dllexport) type >> $@
+	@echo #endif  /* WEBP_DLL_H_ */ >> $@
 
 .SUFFIXES: .c .obj .res .exe
-{examples}.c{$(DIROBJ)\examples}.obj:
-	$(CC) $(CFLAGS) /Fo"$@"  $<
-{src\dec}.c{$(DIROBJ)\dec}.obj:
-	$(CC) $(CFLAGS) /Fo"$@"  $<
-{src\enc}.c{$(DIROBJ)\enc}.obj:
-	$(CC) $(CFLAGS) /Fo"$@"  $<
+# File-specific flag builds. Note batch rules take precedence over wildcards,
+# so for now name each file individually.
+$(DIROBJ)\dsp\enc_avx2.obj: src\dsp\enc_avx2.c
+	$(CC) $(CFLAGS) $(AVX2_FLAGS) /Fd$(LIBWEBP_PDBNAME) /Fo$(DIROBJ)\dsp\ \
+	  src\dsp\$(@B).c
+$(DIROBJ)\examples\anim_diff.obj: examples\anim_diff.c
+	$(CC) $(CFLAGS) /DWEBP_HAVE_GIF /Fd$(LIBWEBP_PDBNAME) \
+	  /Fo$(DIROBJ)\examples\ examples\$(@B).c
+$(DIROBJ)\examples\anim_util.obj: examples\anim_util.c
+	$(CC) $(CFLAGS) /DWEBP_HAVE_GIF /Fd$(LIBWEBP_PDBNAME) \
+	  /Fo$(DIROBJ)\examples\ examples\$(@B).c
+$(DIROBJ)\examples\gif2webp.obj: examples\gif2webp.c
+	$(CC) $(CFLAGS) /DWEBP_HAVE_GIF /Fd$(LIBWEBP_PDBNAME) \
+	  /Fo$(DIROBJ)\examples\ examples\$(@B).c
+$(DIROBJ)\examples\gifdec.obj: examples\gifdec.c
+	$(CC) $(CFLAGS) /DWEBP_HAVE_GIF /Fd$(LIBWEBP_PDBNAME) \
+	  /Fo$(DIROBJ)\examples\ examples\$(@B).c
+# Batch rules
+{examples}.c{$(DIROBJ)\examples}.obj::
+	$(CC) $(CFLAGS) /Fd$(DIROBJ)\examples\ /Fo$(DIROBJ)\examples\ $<
+{extras}.c{$(DIROBJ)\extras}.obj::
+	$(CC) $(CFLAGS) /Fd$(DIROBJ)\extras\ /Fo$(DIROBJ)\extras\ $<
+{imageio}.c{$(DIROBJ)\imageio}.obj::
+	$(CC) $(CFLAGS) /Fd$(DIROBJ)\imageio\ /Fo$(DIROBJ)\imageio\ $<
+{src\dec}.c{$(DIROBJ)\dec}.obj::
+	$(CC) $(CFLAGS) /Fd$(LIBWEBP_PDBNAME) /Fo$(DIROBJ)\dec\ $<
+{src\demux}.c{$(DIROBJ)\demux}.obj::
+	$(CC) $(CFLAGS) /Fd$(LIBWEBP_PDBNAME) /Fo$(DIROBJ)\demux\ $<
+{src\dsp}.c{$(DIROBJ)\dsp}.obj::
+	$(CC) $(CFLAGS) /Fd$(LIBWEBP_PDBNAME) /Fo$(DIROBJ)\dsp\ $<
+{src\enc}.c{$(DIROBJ)\enc}.obj::
+	$(CC) $(CFLAGS) /Fd$(LIBWEBP_PDBNAME) /Fo$(DIROBJ)\enc\ $<
+{src\mux}.c{$(DIROBJ)\mux}.obj::
+	$(CC) $(CFLAGS) /Fd$(LIBWEBP_PDBNAME) /Fo$(DIROBJ)\mux\ $<
+{src\utils}.c{$(DIROBJ)\utils}.obj::
+	$(CC) $(CFLAGS) /Fd$(LIBWEBP_PDBNAME) /Fo$(DIROBJ)\utils\ $<
 
 {$(DIROBJ)\examples}.obj{$(DIRBIN)}.exe:
-	$(LNKEXE) $(LDFLAGS) /OUT:"$@" $<  ole32.lib windowscodecs.lib shlwapi.lib $(DIRLIB)\$(TARGET)
+	$(LNKEXE) $(LDFLAGS) /OUT:$@ $** \
+	    ole32.lib windowscodecs.lib shlwapi.lib
 	$(MT) -manifest $@.manifest -outputresource:$@;1
 	del $@.manifest
 
+{$(DIROBJ)\extras}.obj{$(DIRBIN)}.exe:
+	$(LNKEXE) $(LDFLAGS) /OUT:$@ $** \
+	    ole32.lib windowscodecs.lib shlwapi.lib
+	$(MT) -manifest $@.manifest -outputresource:$@;1
+	del $@.manifest
+
+clean::
+	@-erase /s $(DIROBJ)\*.dll 2> NUL
+	@-erase /s $(DIROBJ)\*.exp 2> NUL
+	@-erase /s $(DIROBJ)\*.idb 2> NUL
+	@-erase /s $(DIROBJ)\*.lib 2> NUL
+	@-erase /s $(DIROBJ)\*.obj 2> NUL
+	@-erase /s $(DIROBJ)\*.pch 2> NUL
+	@-erase /s $(DIROBJ)\*.pdb 2> NUL
+	@-erase /s $(DIROBJ)\*.res 2> NUL
+
 !ENDIF  # End of case where a config was provided.

NEWS

@@ -1,3 +1,173 @@
+- 1/26/2017: version 0.6.0
+  * lossless performance and compression improvements
+  * miscellaneous performance improvements (SSE2, NEON, MSA)
+  * webpmux gained a -duration option allowing for frame timing modification
+  * new img2webp utility allowing a sequence of images to be converted to
+    animated webp
+  * API changes:
+    - libwebp:
+      WebPPictureSharpARGBToYUVA
+      WebPPlaneDistortion
+    - libwebpmux / gif2webp:
+      WebPAnimEncoderOptions: kmax <= 0 now disables keyframes, kmax == 1
+                              forces all keyframes. See mux.h and the gif2webp
+                              manpage for details.
+
+- 12/13/2016: version 0.5.2
+  This is a binary compatible release.
+  This release covers CVE-2016-8888 and CVE-2016-9085.
+  * further security related hardening in the tools; fixes to
+    gif2webp/AnimEncoder (issues #310, #314, #316, #322), cwebp/libwebp (issue
+    #312)
+  * full libwebp (encoder & decoder) iOS framework; libwebpdecoder
+    WebP.framework renamed to WebPDecoder.framework (issue #307)
+  * CMake support for Android Studio (2.2)
+  * miscellaneous build related fixes (issue #306, #313)
+  * miscellaneous documentation improvements (issue #225)
+  * minor lossy encoder fixes and improvements
+
+- 6/14/2016: version 0.5.1
+  This is a binary compatible release.
+  * miscellaneous bug fixes (issues #280, #289)
+  * reverted alpha plane encoding with color cache for compatibility with
+    libwebp 0.4.0->0.4.3 (issues #291, #298)
+  * lossless encoding performance improvements
+  * memory reduction in both lossless encoding and decoding
+  * force mux output to be in the extended format (VP8X) when undefined chunks
+    are present (issue #294)
+  * gradle, cmake build support
+  * workaround for compiler bug causing 64-bit decode failures on android
+    devices using clang-3.8 in the r11c NDK
+  * various WebPAnimEncoder improvements
+
+- 12/17/2015: version 0.5.0
+  * miscellaneous bug & build fixes (issues #234, #258, #274, #275, #278)
+  * encoder & decoder speed-ups on x86/ARM/MIPS for lossy & lossless
+    - note! YUV->RGB conversion was sped-up, but the results will be slightly
+      different from previous releases
+  * various lossless encoder improvements
+  * gif2webp improvements, -min_size option added
+  * tools fully support input from stdin and output to stdout (issue #168)
+  * New WebPAnimEncoder API for creating animations
+  * New WebPAnimDecoder API for decoding animations
+  * other API changes:
+    - libwebp:
+      WebPPictureSmartARGBToYUVA() (-pre 4 in cwebp)
+      WebPConfig::exact (-exact in cwebp; -alpha_cleanup is now the default)
+      WebPConfig::near_lossless (-near_lossless in cwebp)
+      WebPFree() (free'ing webp allocated memory in other languages)
+      WebPConfigLosslessPreset()
+      WebPMemoryWriterClear()
+    - libwebpdemux: removed experimental fragment related fields and functions
+    - libwebpmux: WebPMuxSetCanvasSize()
+  * new libwebpextras library with some uncommon import functions:
+    WebPImportGray/WebPImportRGB565/WebPImportRGB4444
+
+- 10/15/15: version 0.4.4
+  This is a binary compatible release.
+  * rescaling out-of-bounds read fix (issue #254)
+  * various build fixes and improvements (issues #253, #259, #262, #267, #268)
+  * container documentation update
+  * gif2webp transparency fix (issue #245)
+
+- 3/3/15: version 0.4.3
+  This is a binary compatible release.
+  * Android / gcc / iOS / MSVS build fixes and improvements
+  * lossless decode fix (issue #239 -- since 0.4.0)
+  * documentation / vwebp updates for animation
+  * multi-threading fix (issue #234)
+
+- 10/13/14: version 0.4.2
+  This is a binary compatible release.
+  * Android / gcc build fixes
+  * (Windows) fix reading from stdin and writing to stdout
+  * gif2webp: miscellaneous fixes
+  * fix 'alpha-leak' with lossy compression (issue #220)
+  * the lossless bitstream spec has been amended to reflect the current code
+
+- 7/24/14: version 0.4.1
+  This is a binary compatible release.
+  * AArch64 (arm64) & MIPS support/optimizations
+  * NEON assembly additions:
+    - ~25% faster lossy decode / encode (-m 4)
+    - ~10% faster lossless decode
+    - ~5-10% faster lossless encode (-m 3/4)
+  * dwebp/vwebp can read from stdin
+  * cwebp/gif2webp can write to stdout
+  * cwebp can read webp files; useful if storing sources as webp lossless
+
+- 12/19/13: version 0.4.0
+  * improved gif2webp tool
+  * numerous fixes, compression improvement and speed-up
+  * dither option added to decoder (dwebp -dither 50 ...)
+  * improved multi-threaded modes (-mt option)
+  * improved filtering strength determination
+  * New function: WebPMuxGetCanvasSize
+  * BMP and TIFF format output added to 'dwebp'
+  * Significant memory reduction for decoding lossy images with alpha.
+  * Intertwined decoding of RGB and alpha for a shorter
+    time-to-first-decoded-pixel.
+  * WebPIterator has a new member 'has_alpha' denoting whether the frame
+    contains transparency.
+  * Container spec amended with new 'blending method' for animation.
+
+- 6/13/13: version 0.3.1
+  This is a binary compatible release.
+  * Add incremental decoding support for images containing ALPH and ICCP chunks.
+  * Python bindings via swig for the simple encode/decode interfaces similar to
+    Java.
+
+- 3/20/13: version 0.3.0
+  This is a binary compatible release.
+  * WebPINewRGB/WebPINewYUVA accept being passed a NULL output buffer
+    and will perform auto-allocation.
+  * default filter option is now '-strong -f 60'
+  * encoding speed-up for lossy methods 3 to 6
+  * alpha encoding can be done in parallel to lossy using 'cwebp -mt ...'
+  * color profile, metadata (XMP/EXIF) and animation support finalized in the
+    container.
+  * various NEON assembly additions
+  Tool updates / additions:
+    * gif2webp added
+    * vwebp given color profile & animation support
+    * cwebp can preserve color profile / metadata with '-metadata'
+
+- 10/30/12: version 0.2.1
+  * Various security related fixes
+  * cwebp.exe: fix import errors on Windows XP
+  * enable DLL builds for mingw targets
+
+- 8/3/12: version 0.2.0
+  * Add support for ARGB -> YUVA conversion for lossless decoder
+    New functions: WebPINewYUVA, WebPIDecGetYUVA
+  * Add stats for lossless and alpha encoding
+  * Security related hardening: allocation and size checks
+  * Add PAM output support to dwebp
+
+- 7/19/12: version 0.1.99
+  * This is a pre-release of 0.2.0, not an rc to allow for further
+    incompatible changes based on user feedback.
+  * Alpha channel encode/decode support.
+  * Lossless encoder/decoder.
+  * Add TIFF input support to cwebp.
+  Incompatible changes:
+    * The encode ABI has been modified to support alpha encoding.
+    * Deprecated function WebPINew() has been removed.
+    * Decode function signatures have changed to consistently use size_t over
+      int/uint32_t.
+    * decode_vp8.h is no longer installed system-wide.
+    * cwebp will encode the alpha channel if present.
+
+- 9/19/11: version 0.1.3
+  * Advanced decoding APIs.
+  * On-the-fly cropping and rescaling of images.
+  * SSE2 instructions for decoding performance optimizations on x86 based
+    platforms.
+  * Support Multi-threaded decoding.
+  * 40% improvement in Decoding performance.
+  * Add support for RGB565, RGBA4444 & ARGB image colorspace.
+  * Better handling of large picture encoding.
+
 - 3/25/11: version 0.1.2
   * Incremental decoding: picture can be decoded byte-by-byte if needs be.
   * lot of bug-fixes, consolidation and stabilization

PATENTS

@@ -1,22 +1,23 @@
 Additional IP Rights Grant (Patents)
+------------------------------------
 
-"This implementation" means the copyrightable works distributed by
-Google as part of the WebM Project.
+"These implementations" means the copyrightable works that implement the WebM
+codecs distributed by Google as part of the WebM Project.
 
-Google hereby grants to you a perpetual, worldwide, non-exclusive,
-no-charge, royalty-free, irrevocable (except as stated in this section)
-patent license to make, have made, use, offer to sell, sell, import,
-transfer, and otherwise run, modify and propagate the contents of this
-implementation of VP8, where such license applies only to those patent
-claims, both currently owned by Google and acquired in the future,
-licensable by Google that are necessarily infringed by this
-implementation of VP8. This grant does not include claims that would be
-infringed only as a consequence of further modification of this
-implementation. If you or your agent or exclusive licensee institute or
-order or agree to the institution of patent litigation against any
-entity (including a cross-claim or counterclaim in a lawsuit) alleging
-that this implementation of VP8 or any code incorporated within this
-implementation of VP8 constitutes direct or contributory patent
-infringement, or inducement of patent infringement, then any patent
-rights granted to you under this License for this implementation of VP8
-shall terminate as of the date such litigation is filed.
+Google hereby grants to you a perpetual, worldwide, non-exclusive, no-charge,
+royalty-free, irrevocable (except as stated in this section) patent license to
+make, have made, use, offer to sell, sell, import, transfer, and otherwise
+run, modify and propagate the contents of these implementations of WebM, where
+such license applies only to those patent claims, both currently owned by
+Google and acquired in the future, licensable by Google that are necessarily
+infringed by these implementations of WebM. This grant does not include claims
+that would be infringed only as a consequence of further modification of these
+implementations. If you or your agent or exclusive licensee institute or order
+or agree to the institution of patent litigation or any other patent
+enforcement activity against any entity (including a cross-claim or
+counterclaim in a lawsuit) alleging that any of these implementations of WebM
+or any code incorporated within any of these implementations of WebM
+constitute direct or contributory patent infringement, or inducement of
+patent infringement, then any patent rights granted to you under this License
+for these implementations of WebM shall terminate as of the date such
+litigation is filed.

README

@@ -4,22 +4,23 @@
           \__\__/\____/\_____/__/ ____  ___
                 / _/ /    \    \ /  _ \/ _/
                /  \_/   / /   \ \   __/  \__
-               \____/____/\_____/_____/____/v0.1.2
+               \____/____/\_____/_____/____/v0.6.0
 
 Description:
 ============
 
-WEBP codec: Library to encode and decode images in WebP format. This package
+WebP codec: library to encode and decode images in WebP format. This package
 contains the library that can be used in other programs to add WebP support,
 as well as the command line tools 'cwebp' and 'dwebp'.
 
-See http://code.google.com/speed/webp
+See http://developers.google.com/speed/webp
 
-Latest sources are available from http://www.webmproject.org/code/
+The latest source tree is available at
+https://chromium.googlesource.com/webm/libwebp
 
 It is released under the same license as the WebM project.
 See http://www.webmproject.org/license/software/ or the
-file "COPYING" file for details. An additional intellectual
+"COPYING" file for details. An additional intellectual
 property rights grant can be found in the file PATENTS.
 
 Building:
@@ -32,9 +33,11 @@ By running:
 
   nmake /f Makefile.vc CFG=release-static RTLIBCFG=static OBJDIR=output
 
-the directory output\release-static\x86\bin will contain the tools
-cweb.exe and dweb.exe. The directory output\release-static\x86\lib will
-contains the libwebp static library.
+the directory output\release-static\(x64|x86)\bin will contain the tools
+cwebp.exe and dwebp.exe. The directory output\release-static\(x64|x86)\lib will
+contain the libwebp static library.
+The target architecture (x86/x64) is detected by Makefile.vc from the Visual
+Studio compiler (cl.exe) available in the system path.
 
 Unix build using makefile.unix:
 -------------------------------
@@ -47,22 +50,26 @@ will build the binaries examples/cwebp and examples/dwebp, along
 with the static library src/libwebp.a. No system-wide installation
 is supplied, as this is a simple alternative to the full installation
 system based on the autoconf tools (see below).
-Please refer the makefile.unix for additional details and customizations.
+Please refer to makefile.unix for additional details and customizations.
 
 Using autoconf tools:
 ---------------------
-./autogen.sh
+Prerequisites:
+A compiler (e.g., gcc), make, autoconf, automake, libtool.
+On a Debian-like system the following should install everything you need for a
+minimal build:
+$ sudo apt-get install gcc make autoconf automake libtool
+
+When building from git sources, you will need to run autogen.sh to generate the
+configure script.
+
 ./configure
 make
 make install
 
-Note: In case './configure' step fails, try generating configure & appropriate
-Makefile(s) via command 'aclocal && autoconf && automake -a -c;'.
-
 should be all you need to have the following files
 
 /usr/local/include/webp/decode.h
-/usr/local/include/webp/decode_vp8.h
 /usr/local/include/webp/encode.h
 /usr/local/include/webp/types.h
 /usr/local/lib/libwebp.*
@@ -71,10 +78,119 @@ should be all you need to have the following files
 
 installed.
 
-Note: The encoding and decoding libraries are compiled separately
-(as src/dec/libwebpdecode.* and src/dec/libwebpencode.*). They
-can be installed independently using a minor modifications in the
-corresponding Makefile.am configure files (see comments there).
+Note: A decode-only library, libwebpdecoder, is available using the
+'--enable-libwebpdecoder' flag. The encode library is built separately and can
+be installed independently using a minor modification in the corresponding
+Makefile.am configure files (see comments there). See './configure --help' for
+more options.
+
+Building for MIPS Linux:
+------------------------
+MIPS Linux toolchain stable available releases can be found at:
+https://community.imgtec.com/developers/mips/tools/codescape-mips-sdk/available-releases/
+
+# Add toolchain to PATH
+export PATH=$PATH:/path/to/toolchain/bin
+
+# 32-bit build for mips32r5 (p5600)
+HOST=mips-mti-linux-gnu
+MIPS_CFLAGS="-O3 -mips32r5 -mabi=32 -mtune=p5600 -mmsa -mfp64 \
+  -msched-weight -mload-store-pairs -fPIE"
+MIPS_LDFLAGS="-mips32r5 -mabi=32 -mmsa -mfp64 -pie"
+
+# 64-bit build for mips64r6 (i6400)
+HOST=mips-img-linux-gnu
+MIPS_CFLAGS="-O3 -mips64r6 -mabi=64 -mtune=i6400 -mmsa -mfp64 \
+  -msched-weight -mload-store-pairs -fPIE"
+MIPS_LDFLAGS="-mips64r6 -mabi=64 -mmsa -mfp64 -pie"
+
+./configure --host=${HOST} --build=`config.guess` \
+  CC="${HOST}-gcc -EL" \
+  CFLAGS="$MIPS_CFLAGS" \
+  LDFLAGS="$MIPS_LDFLAGS"
+make
+make install
+
+CMake:
+------
+The support for CMake is minimal: it only helps you compile libwebp, cwebp and
+dwebp.
+
+Prerequisites:
+A compiler (e.g., gcc with autotools) and CMake.
+On a Debian-like system the following should install everything you need for a
+minimal build:
+$ sudo apt-get install build-essential cmake
+
+When building from git sources, you will need to run cmake to generate the
+configure script.
+
+mkdir build && cd build && cmake ../
+make
+make install
+
+If you also want cwebp or dwebp, you will need to enable them through CMake:
+
+cmake -DWEBP_BUILD_CWEBP=ON -DWEBP_BUILD_DWEBP=ON ../
+
+or through your favorite interface (like ccmake or cmake-qt-gui).
+
+Gradle:
+-------
+The support for Gradle is minimal: it only helps you compile libwebp, cwebp and
+dwebp and webpmux_example.
+
+Prerequisites:
+A compiler (e.g., gcc with autotools) and gradle.
+On a Debian-like system the following should install everything you need for a
+minimal build:
+$ sudo apt-get install build-essential gradle
+
+When building from git sources, you will need to run the Gradle wrapper with the
+appropriate target, e.g. :
+
+./gradlew buildAllExecutables
+
+SWIG bindings:
+--------------
+
+To generate language bindings from swig/libwebp.swig at least swig-1.3
+(http://www.swig.org) is required.
+
+Currently the following functions are mapped:
+Decode:
+  WebPGetDecoderVersion
+  WebPGetInfo
+  WebPDecodeRGBA
+  WebPDecodeARGB
+  WebPDecodeBGRA
+  WebPDecodeBGR
+  WebPDecodeRGB
+
+Encode:
+  WebPGetEncoderVersion
+  WebPEncodeRGBA
+  WebPEncodeBGRA
+  WebPEncodeRGB
+  WebPEncodeBGR
+  WebPEncodeLosslessRGBA
+  WebPEncodeLosslessBGRA
+  WebPEncodeLosslessRGB
+  WebPEncodeLosslessBGR
+
+See swig/README for more detailed build instructions.
+
+Java bindings:
+
+To build the swig-generated JNI wrapper code at least JDK-1.5 (or equivalent)
+is necessary for enum support. The output is intended to be a shared object /
+DLL that can be loaded via System.loadLibrary("webp_jni").
+
+Python bindings:
+
+To build the swig-generated Python extension code at least Python 2.6 is
+required. Python < 2.6 may build with some minor changes to libwebp.swig or the
+generated code, but is untested.
 
 Encoding tool:
 ==============
@@ -84,9 +200,13 @@ decoding (dwebp) images.
 
 The easiest use should look like:
   cwebp input.png -q 80 -o output.webp
-which will convert the input PNG or JPEG file to a WebP one using a
-quality factor of 80 on a 0->100 scale (0 being the lowest quality,
-100 being the best. Default value is 75).
+which will convert the input file to a WebP file using a quality factor of 80
+on a 0->100 scale (0 being the lowest quality, 100 being the best. Default
+value is 75).
+You might want to try the -lossless flag too, which will compress the source
+(in RGBA format) without any loss. The -q quality parameter will in this case
+control the amount of processing time spent trying to make the output file as
+small as possible.
 
 A longer list of options is available using the -longhelp command line flag:
 
@@ -94,41 +214,77 @@ A longer list of options is available using the -longhelp command line flag:
 Usage:
  cwebp [-preset <...>] [options] in_file [-o out_file]
 
-If input size (-s) for an image is not specified, it is assumed to be a either
-  PNG or JPEG format file.
-options:
-  -h / -help  ............ short help
-  -H / -longhelp  ........ long help
-  -q <float> ............. quality factor (0:small..100:big)
-  -preset <string> ....... Preset setting, one of:
+If input size (-s) for an image is not specified, it is
+assumed to be a PNG, JPEG, TIFF or WebP file.
+
+Options:
+  -h / -help ............. short help
+  -H / -longhelp ......... long help
+  -q <float> ............. quality factor (0:small..100:big), default=75
+  -alpha_q <int> ......... transparency-compression quality (0..100),
+                           default=100
+  -preset <string> ....... preset setting, one of:
                             default, photo, picture,
                             drawing, icon, text
-     -preset must come first, as it overwrites other parameters.
-  -m <int> ............... compression method (0=fast, 6=slowest)
-  -segments <int> ........ number of segments to use (1..4)
+     -preset must come first, as it overwrites other parameters
+  -z <int> ............... activates lossless preset with given
+                           level in [0:fast, ..., 9:slowest]
 
-  -s <int> <int> ......... Input size (width x height) for YUV
-  -sns <int> ............. Spatial Noise Shaping (0:off, 100:max)
-  -f <int> ............... filter strength (0=off..100)
-  -sharpness <int> ....... filter sharpness (0:most .. 7:least sharp)
-  -strong ................ use strong filter instead of simple.
+  -m <int> ............... compression method (0=fast, 6=slowest), default=4
+  -segments <int> ........ number of segments to use (1..4), default=4
+  -size <int> ............ target size (in bytes)
+  -psnr <float> .......... target PSNR (in dB. typically: 42)
+
+  -s <int> <int> ......... input size (width x height) for YUV
+  -sns <int> ............. spatial noise shaping (0:off, 100:max), default=50
+  -f <int> ............... filter strength (0=off..100), default=60
+  -sharpness <int> ....... filter sharpness (0:most .. 7:least sharp), default=0
+  -strong ................ use strong filter instead of simple (default)
+  -nostrong .............. use simple filter instead of strong
+  -sharp_yuv ............. use sharper (and slower) RGB->YUV conversion
+  -partition_limit <int> . limit quality to fit the 512k limit on
+                           the first partition (0=no degradation ... 100=full)
   -pass <int> ............ analysis pass number (1..10)
-  -partitions <int> ...... number of partitions to use (0..3)
   -crop <x> <y> <w> <h> .. crop picture with the given rectangle
-  -map <int> ............. print map of extra info.
-  -d <file.pgm> .......... dump the compressed output (PGM file).
+  -resize <w> <h> ........ resize picture (after any cropping)
+  -mt .................... use multi-threading if available
+  -low_memory ............ reduce memory usage (slower encoding)
+  -map <int> ............. print map of extra info
+  -print_psnr ............ prints averaged PSNR distortion
+  -print_ssim ............ prints averaged SSIM distortion
+  -print_lsim ............ prints local-similarity distortion
+  -d <file.pgm> .......... dump the compressed output (PGM file)
+  -alpha_method <int> .... transparency-compression method (0..1), default=1
+  -alpha_filter <string> . predictive filtering for alpha plane,
+                           one of: none, fast (default) or best
+  -exact ................. preserve RGB values in transparent area, default=off
+  -blend_alpha <hex> ..... blend colors against background color
+                           expressed as RGB values written in
+                           hexadecimal, e.g. 0xc0e0d0 for red=0xc0
+                           green=0xe0 and blue=0xd0
+  -noalpha ............... discard any transparency information
+  -lossless .............. encode image losslessly, default=off
+  -near_lossless <int> ... use near-lossless image
+                           preprocessing (0..100=off), default=100
+  -hint <string> ......... specify image characteristics hint,
+                           one of: photo, picture or graph
+
+  -metadata <string> ..... comma separated list of metadata to
+                           copy from the input to the output if present.
+                           Valid values: all, none (default), exif, icc, xmp
 
   -short ................. condense printed message
-  -quiet ................. don't print anything.
+  -quiet ................. don't print anything
+  -version ............... print version number and exit
+  -noasm ................. disable all assembly optimizations
   -v ..................... verbose, e.g. print encoding/decoding times
+  -progress .............. report encoding progress
 
 Experimental Options:
-  -size <int> ............ Target size (in bytes)
-  -psnr <float> .......... Target PSNR (in dB. typically: 42)
-  -af <int> .............. adjust filter strength (0=off, 1=on)
+  -jpeg_like ............. roughly match expected JPEG size
+  -af .................... auto-adjust filter strength
   -pre <int> ............. pre-processing filter
 
-
 The main options you might want to try in order to further tune the
 visual quality are:
  -preset
@@ -137,7 +293,7 @@ visual quality are:
  -m
 
 Namely:
-  * 'preset' will set up a default encoding configuration targetting a
+  * 'preset' will set up a default encoding configuration targeting a
      particular type of input. It should appear first in the list of options,
      so that subsequent options can take effect on top of this preset.
      Default value is 'default'.
@@ -149,10 +305,11 @@ Namely:
      but with better quality.
      Typical value is around '75'.
   * 'f' option directly links to the filtering strength used by the codec's
-     in-loop processing. The higher, the smoother will highly-compressed area
-     look. This is particularly useful when aiming at very small files.
-     Typical values are around 20-30. Note that using the option -strong will
-     change the type of filtering. Use "-f 0" to turn filtering off.
+     in-loop processing. The higher the value, the smoother the
+     highly-compressed area will look. This is particularly useful when aiming
+     at very small files. Typical values are around 20-30. Note that using the
+     option -strong/-nostrong will change the type of filtering. Use "-f 0" to
+     turn filtering off.
   * 'm' controls the trade-off between encoding speed and quality. Default is 4.
      You can try -m 5 or -m 6 to explore more (time-consuming) encoding
      possibilities. A lower value will result in faster encoding at the expense
@@ -161,7 +318,7 @@ Namely:
 Decoding tool:
 ==============
 
-There is a decoding sample code as examples/dwebp.c which will take
+There is a decoding sample in examples/dwebp.c which will take
 a .webp file and decode it to a PNG image file (amongst other formats).
 This is simply to demonstrate the use of the API. You can verify the
 file test.webp decodes to exactly the same as test_ref.ppm by using:
@@ -170,9 +327,190 @@ file test.webp decodes to exactly the same as test_ref.ppm by using:
  ./dwebp test.webp -ppm -o test.ppm
  diff test.ppm test_ref.ppm
 
+The full list of options is available using -h:
+
+> dwebp -h
+Usage: dwebp in_file [options] [-o out_file]
+
+Decodes the WebP image file to PNG format [Default]
+Use following options to convert into alternate image formats:
+  -pam ......... save the raw RGBA samples as a color PAM
+  -ppm ......... save the raw RGB samples as a color PPM
+  -bmp ......... save as uncompressed BMP format
+  -tiff ........ save as uncompressed TIFF format
+  -pgm ......... save the raw YUV samples as a grayscale PGM
+                 file with IMC4 layout
+  -yuv ......... save the raw YUV samples in flat layout
+
+ Other options are:
+  -version ..... print version number and exit
+  -nofancy ..... don't use the fancy YUV420 upscaler
+  -nofilter .... disable in-loop filtering
+  -nodither .... disable dithering
+  -dither <d> .. dithering strength (in 0..100)
+  -alpha_dither  use alpha-plane dithering if needed
+  -mt .......... use multi-threading
+  -crop <x> <y> <w> <h> ... crop output with the given rectangle
+  -resize <w> <h> ......... scale the output (*after* any cropping)
+  -flip ........ flip the output vertically
+  -alpha ....... only save the alpha plane
+  -incremental . use incremental decoding (useful for tests)
+  -h ........... this help message
+  -v ........... verbose (e.g. print encoding/decoding times)
+  -quiet ....... quiet mode, don't print anything
+  -noasm ....... disable all assembly optimizations
+
+Visualization tool:
+===================
+
+There's a little self-serve visualization tool called 'vwebp' under the
+examples/ directory. It uses OpenGL to open a simple drawing window and show
+a decoded WebP file. It's not yet integrated in the automake build system, but
+you can try to manually compile it using the recommendations below.
+
+Usage: vwebp in_file [options]
+
+Decodes the WebP image file and visualize it using OpenGL
+Options are:
+  -version ..... print version number and exit
+  -noicc ....... don't use the icc profile if present
+  -nofancy ..... don't use the fancy YUV420 upscaler
+  -nofilter .... disable in-loop filtering
+  -dither <int>  dithering strength (0..100), default=50
+  -noalphadither disable alpha plane dithering
+  -mt .......... use multi-threading
+  -info ........ print info
+  -h ........... this help message
+
+Keyboard shortcuts:
+  'c' ................ toggle use of color profile
+  'i' ................ overlay file information
+  'd' ................ disable blending & disposal (debug)
+  'q' / 'Q' / ESC .... quit
+
+Building:
+---------
+
+Prerequisites:
+1) OpenGL & OpenGL Utility Toolkit (GLUT)
+  Linux:
+    $ sudo apt-get install freeglut3-dev mesa-common-dev
+  Mac + XCode:
+    - These libraries should be available in the OpenGL / GLUT frameworks.
+  Windows:
+    http://freeglut.sourceforge.net/index.php#download
+
+2) (Optional) qcms (Quick Color Management System)
+  i. Download qcms from Mozilla / Chromium:
+    http://hg.mozilla.org/mozilla-central/file/0e7639e3bdfb/gfx/qcms
+    http://src.chromium.org/viewvc/chrome/trunk/src/third_party/qcms
+  ii. Build and archive the source files as libqcms.a / qcms.lib
+  iii. Update makefile.unix / Makefile.vc
+    a) Define WEBP_HAVE_QCMS
+    b) Update include / library paths to reference the qcms directory.
+
+Build using makefile.unix / Makefile.vc:
+$ make -f makefile.unix examples/vwebp
+> nmake /f Makefile.vc CFG=release-static \
+    ../obj/x64/release-static/bin/vwebp.exe
+
+Animation creation tool:
+========================
+The utility 'img2webp' can turn a sequence of input images (PNG, JPEG, ...)
+into an animated WebP file. It offers fine control over duration, encoding
+modes, etc.
+
+Usage:
+
+  img2webp [file-level options] [image files...] [per-frame options...]
+
+File-level options (only used at the start of compression):
+ -min_size ............ minimize size
+ -loop <int> .......... loop count (default: 0, = infinite loop)
+ -kmax <int> .......... maximum number of frame between key-frames
+                        (0=only keyframes)
+ -kmin <int> .......... minimum number of frame between key-frames
+                        (0=disable key-frames altogether)
+ -mixed ............... use mixed lossy/lossless automatic mode
+ -v ................... verbose mode
+ -h ................... this help
+
+Per-frame options (only used for subsequent images input):
+ -d <int> ............. frame duration in ms (default: 100)
+ -lossless  ........... use lossless mode (default)
+ -lossy ... ........... use lossy mode
+ -q <float> ........... quality
+ -m <int> ............. method to use
+
+example: img2webp -loop 2 in0.png -lossy in1.jpg
+                  -d 80 in2.tiff -o out.webp
+
+Animated GIF conversion:
+========================
+Animated GIF files can be converted to WebP files with animation using the
+gif2webp utility available under examples/. The files can then be viewed using
+vwebp.
+
+Usage:
+ gif2webp [options] gif_file -o webp_file
+Options:
+  -h / -help ............. this help
+  -lossy ................. encode image using lossy compression
+  -mixed ................. for each frame in the image, pick lossy
+                           or lossless compression heuristically
+  -q <float> ............. quality factor (0:small..100:big)
+  -m <int> ............... compression method (0=fast, 6=slowest)
+  -min_size .............. minimize output size (default:off)
+                           lossless compression by default; can be
+                           combined with -q, -m, -lossy or -mixed
+                           options
+  -kmin <int> ............ min distance between key frames
+  -kmax <int> ............ max distance between key frames
+  -f <int> ............... filter strength (0=off..100)
+  -metadata <string> ..... comma separated list of metadata to
+                           copy from the input to the output if present
+                           Valid values: all, none, icc, xmp (default)
+  -mt .................... use multi-threading if available
+
+  -version ............... print version number and exit
+  -v ..................... verbose
+  -quiet ................. don't print anything
+
+Building:
+---------
+With the libgif development files installed, gif2webp can be built using
+makefile.unix:
+$ make -f makefile.unix examples/gif2webp
+
+or using autoconf:
+$ ./configure --enable-everything
+$ make
+
+Comparison of animated images:
+==============================
+Test utility anim_diff under examples/ can be used to compare two animated
+images (each can be GIF or WebP).
+
+Usage: anim_diff <image1> <image2> [options]
+
+Options:
+  -dump_frames <folder> dump decoded frames in PAM format
+  -min_psnr <float> ... minimum per-frame PSNR
+  -raw_comparison ..... if this flag is not used, RGB is
+                        premultiplied before comparison
+
+Building:
+---------
+With the libgif development files and a C++ compiler installed, anim_diff can
+be built using makefile.unix:
+$ make -f makefile.unix examples/anim_diff
+
+or using autoconf:
+$ ./configure --enable-everything
+$ make
 
 Encoding API:
-===========
+=============
 
 The main encoding functions are available in the header src/webp/encode.h
 The ready-to-use ones are:
@@ -188,10 +526,26 @@ size_t WebPEncodeBGRA(const uint8_t* bgra, int width, int height, int stride,
 They will convert raw RGB samples to a WebP data. The only control supplied
 is the quality factor.
 
+There are some variants for using the lossless format:
+
+size_t WebPEncodeLosslessRGB(const uint8_t* rgb, int width, int height,
+                             int stride, uint8_t** output);
+size_t WebPEncodeLosslessBGR(const uint8_t* bgr, int width, int height,
+                             int stride, uint8_t** output);
+size_t WebPEncodeLosslessRGBA(const uint8_t* rgba, int width, int height,
+                              int stride, uint8_t** output);
+size_t WebPEncodeLosslessBGRA(const uint8_t* bgra, int width, int height,
+                              int stride, uint8_t** output);
+
+Of course in this case, no quality factor is needed since the compression
+occurs without loss of the input values, at the expense of larger output sizes.
+
+Advanced encoding API:
+----------------------
 
 A more advanced API is based on the WebPConfig and WebPPicture structures.
 
-WebPConfig contains the encoding settings and is not tied a to a particular
+WebPConfig contains the encoding settings and is not tied to a particular
 picture.
 WebPPicture contains input data, on which some WebPConfig will be used for
 compression.
@@ -210,7 +564,7 @@ The encoding flow looks like:
   // ... additional tuning
   config.sns_strength = 90;
   config.filter_sharpness = 6;
-  config_error = WebPValidateConfig(&config);  // not mandartory, but useful
+  config_error = WebPValidateConfig(&config);  // not mandatory, but useful
 
   // Setup the input data
   WebPPicture pic;
@@ -223,50 +577,51 @@ The encoding flow looks like:
   if (!WebPPictureAllocate(&pic)) {
     return 0;   // memory error
   }
-  // add that point, 'pic' has been initialized as a container,
+  // at this point, 'pic' has been initialized as a container,
   // and can receive the Y/U/V samples.
   // Alternatively, one could use ready-made import functions like
   // WebPPictureImportRGB(), which will take care of memory allocation.
   // In any case, past this point, one will have to call
   // WebPPictureFree(&pic) to reclaim memory.
 
-
   // Set up a byte-output write method. WebPMemoryWriter, for instance.
   WebPMemoryWriter wrt;
+  WebPMemoryWriterInit(&wrt);     // initialize 'wrt'
+
   pic.writer = MyFileWriter;
   pic.custom_ptr = my_opaque_structure_to_make_MyFileWriter_work;
-  // initialize 'wrt' here...
 
   // Compress!
-  int ok = WebPEncode(&config, &pic);   // ok = 0 => error occured!
+  int ok = WebPEncode(&config, &pic);   // ok = 0 => error occurred!
   WebPPictureFree(&pic);  // must be called independently of the 'ok' result.
 
   // output data should have been handled by the writer at that point.
+  // -> compressed data is the memory buffer described by wrt.mem / wrt.size
+
+  // deallocate the memory used by compressed data
+  WebPMemoryWriterClear(&wrt);
 
 -------------------------------------- END PSEUDO EXAMPLE
 
-
 Decoding API:
 =============
 
 This is mainly just one function to call:
 
 #include "webp/decode.h"
-uint8_t* WebPDecodeRGB(const uint8_t* data, uint32_t data_size,
-                       int *width, int *height);
+uint8_t* WebPDecodeRGB(const uint8_t* data, size_t data_size,
+                       int* width, int* height);
 
 Please have a look at the file src/webp/decode.h for the details.
-There are variants for decoding in BGR/RGBA/BGRA order, along with decoding to
-raw Y'CbCr samples. One can also decode the image directly into a pre-allocated
-buffer.
+There are variants for decoding in BGR/RGBA/ARGB/BGRA order, along with
+decoding to raw Y'CbCr samples. One can also decode the image directly into a
+pre-allocated buffer.
 
-To detect a WebP file and gather picture's dimensions, the function:
-  int WebPGetInfo(const uint8_t* data, uint32_t data_size,
-                  int *width, int *height);
+To detect a WebP file and gather the picture's dimensions, the function:
+  int WebPGetInfo(const uint8_t* data, size_t data_size,
+                  int* width, int* height);
 is supplied. No decoding is involved when using it.
 
-A lower-level API is available from the header file <webp/decode_vp8.h>
-
 Incremental decoding API:
 =========================
 
@@ -276,7 +631,11 @@ is stored into an instance of the WebPIDecoder object. This object can be
 created with the purpose of decoding either RGB or Y'CbCr samples.
 For instance:
 
-  WebPIDecoder* idec = WebPINew(MODE_BGR);
+  WebPDecBuffer buffer;
+  WebPInitDecBuffer(&buffer);
+  buffer.colorspace = MODE_BGR;
+  ...
+  WebPIDecoder* idec = WebPINewDecoder(&buffer);
 
 As data is made progressively available, this incremental-decoder object
 can be used to decode the picture further. There are two (mutually exclusive)
@@ -290,31 +649,97 @@ or by just mentioning the new size of the transmitted data:
 
   WebPIUpdate(idec, buffer, size_of_transmitted_buffer);
 
-Note that 'buffer' can be modified between each calls to WebPIUpdate, in
-particular when the buffer is resized to accomodate larger data.
+Note that 'buffer' can be modified between each call to WebPIUpdate, in
+particular when the buffer is resized to accommodate larger data.
 
 These functions will return the decoding status: either VP8_STATUS_SUSPENDED if
-decoding is not finished yet, or VP8_STATUS_OK when decoding is done.
-Any other status is an error condition.
+decoding is not finished yet or VP8_STATUS_OK when decoding is done. Any other
+status is an error condition.
 
-The idec object must always be released (even upon an error condition)
-by calling: WebPDelete(idec)
+The 'idec' object must always be released (even upon an error condition) by
+calling: WebPDelete(idec).
 
 To retrieve partially decoded picture samples, one must use the corresponding
-method: WebPIDecGetRGB or WebPIDecGetYUV.
+method: WebPIDecGetRGB or WebPIDecGetYUVA.
 It will return the last displayable pixel row.
 
 Lastly, note that decoding can also be performed into a pre-allocated pixel
 buffer. This buffer must be passed when creating a WebPIDecoder, calling
-WebPINewRGB() or WebPINewYUV().
+WebPINewRGB() or WebPINewYUVA().
 
 Please have a look at the src/webp/decode.h header for further details.
 
+Advanced Decoding API:
+======================
+
+WebP decoding supports an advanced API which provides on-the-fly cropping and
+rescaling, something of great usefulness on memory-constrained environments like
+mobile phones. Basically, the memory usage will scale with the output's size,
+not the input's, when one only needs a quick preview or a zoomed in portion of
+an otherwise too-large picture. Some CPU can be saved too, incidentally.
+
+-------------------------------------- BEGIN PSEUDO EXAMPLE
+     // A) Init a configuration object
+     WebPDecoderConfig config;
+     CHECK(WebPInitDecoderConfig(&config));
+
+     // B) optional: retrieve the bitstream's features.
+     CHECK(WebPGetFeatures(data, data_size, &config.input) == VP8_STATUS_OK);
+
+     // C) Adjust 'config' options, if needed
+     config.options.no_fancy_upsampling = 1;
+     config.options.use_scaling = 1;
+     config.options.scaled_width = scaledWidth();
+     config.options.scaled_height = scaledHeight();
+     // etc.
+
+     // D) Specify 'config' output options for specifying output colorspace.
+     // Optionally the external image decode buffer can also be specified.
+     config.output.colorspace = MODE_BGRA;
+     // Optionally, the config.output can be pointed to an external buffer as
+     // well for decoding the image. This externally supplied memory buffer
+     // should be big enough to store the decoded picture.
+     config.output.u.RGBA.rgba = (uint8_t*) memory_buffer;
+     config.output.u.RGBA.stride = scanline_stride;
+     config.output.u.RGBA.size = total_size_of_the_memory_buffer;
+     config.output.is_external_memory = 1;
+
+     // E) Decode the WebP image. There are two variants w.r.t decoding image.
+     // The first one (E.1) decodes the full image and the second one (E.2) is
+     // used to incrementally decode the image using small input buffers.
+     // Any one of these steps can be used to decode the WebP image.
+
+     // E.1) Decode full image.
+     CHECK(WebPDecode(data, data_size, &config) == VP8_STATUS_OK);
+
+     // E.2) Decode image incrementally.
+     WebPIDecoder* const idec = WebPIDecode(NULL, NULL, &config);
+     CHECK(idec != NULL);
+     while (bytes_remaining > 0) {
+       VP8StatusCode status = WebPIAppend(idec, input, bytes_read);
+       if (status == VP8_STATUS_OK || status == VP8_STATUS_SUSPENDED) {
+         bytes_remaining -= bytes_read;
+       } else {
+         break;
+       }
+     }
+     WebPIDelete(idec);
+
+     // F) Decoded image is now in config.output (and config.output.u.RGBA).
+     // It can be saved, displayed or otherwise processed.
+
+     // G) Reclaim memory allocated in config's object. It's safe to call
+     // this function even if the memory is external and wasn't allocated
+     // by WebPDecode().
+     WebPFreeDecBuffer(&config.output);
+
+-------------------------------------- END PSEUDO EXAMPLE
+
 Bugs:
 =====
 
-Please report all bugs to our issue tracker:
-    http://code.google.com/p/webp/issues
+Please report all bugs to the issue tracker:
+    https://bugs.chromium.org/p/webp
 Patches welcome! See this page to get started:
     http://www.webmproject.org/code/contribute/submitting-patches/
 
@@ -322,3 +747,4 @@ Discuss:
 ========
 
 Email: webp-discuss@webmproject.org
+Web: http://groups.google.com/a/webmproject.org/group/webp-discuss

README.mux

@@ -0,0 +1,223 @@
+          __   __  ____  ____  ____  __ __  _     __ __
+         /  \\/  \/  _ \/  _ \/  _ \/  \  \/ \___/_ / _\
+         \       /   __/  _  \   __/      /  /  (_/  /__
+          \__\__/\_____/_____/__/  \__//_/\_____/__/___/v0.4.0
+
+
+Description:
+============
+
+WebPMux: set of two libraries 'Mux' and 'Demux' for creation, extraction and
+manipulation of an extended format WebP file, which can have features like
+color profile, metadata and animation. Reference command-line tools 'webpmux'
+and 'vwebp' as well as the WebP container specification
+'doc/webp-container-spec.txt' are also provided in this package.
+
+WebP Mux tool:
+==============
+
+The examples/ directory contains a tool (webpmux) for manipulating WebP
+files. The webpmux tool can be used to create an extended format WebP file and
+also to extract or strip relevant data from such a file.
+
+A list of options is available using the -help command line flag:
+
+> webpmux -help
+Usage: webpmux -get GET_OPTIONS INPUT -o OUTPUT
+       webpmux -set SET_OPTIONS INPUT -o OUTPUT
+       webpmux -duration DURATION_OPTIONS [-duration ...]
+               INPUT -o OUTPUT
+       webpmux -strip STRIP_OPTIONS INPUT -o OUTPUT
+       webpmux -frame FRAME_OPTIONS [-frame...] [-loop LOOP_COUNT]
+               [-bgcolor BACKGROUND_COLOR] -o OUTPUT
+       webpmux -info INPUT
+       webpmux [-h|-help]
+       webpmux -version
+
+GET_OPTIONS:
+ Extract relevant data:
+   icc       get ICC profile
+   exif      get EXIF metadata
+   xmp       get XMP metadata
+   frame n   get nth frame
+
+SET_OPTIONS:
+ Set color profile/metadata:
+   icc  file.icc     set ICC profile
+   exif file.exif    set EXIF metadata
+   xmp  file.xmp     set XMP metadata
+   where:    'file.icc' contains the ICC profile to be set,
+             'file.exif' contains the EXIF metadata to be set
+             'file.xmp' contains the XMP metadata to be set
+
+DURATION_OPTIONS:
+ Set duration of selected frames:
+   duration            set duration for each frames
+   duration,frame      set duration of a particular frame
+   duration,start,end  set duration of frames in the
+                        interval [start,end])
+   where: 'duration' is the duration in milliseconds
+          'start' is the start frame index
+          'end' is the inclusive end frame index
+           The special 'end' value '0' means: last frame.
+
+STRIP_OPTIONS:
+ Strip color profile/metadata:
+   icc       strip ICC profile
+   exif      strip EXIF metadata
+   xmp       strip XMP metadata
+
+FRAME_OPTIONS(i):
+ Create animation:
+   file_i +di+[xi+yi[+mi[bi]]]
+   where:    'file_i' is the i'th animation frame (WebP format),
+             'di' is the pause duration before next frame,
+             'xi','yi' specify the image offset for this frame,
+             'mi' is the dispose method for this frame (0 or 1),
+             'bi' is the blending method for this frame (+b or -b)
+
+LOOP_COUNT:
+ Number of times to repeat the animation.
+ Valid range is 0 to 65535 [Default: 0 (infinite)].
+
+BACKGROUND_COLOR:
+ Background color of the canvas.
+  A,R,G,B
+  where:    'A', 'R', 'G' and 'B' are integers in the range 0 to 255 specifying
+            the Alpha, Red, Green and Blue component values respectively
+            [Default: 255,255,255,255]
+
+INPUT & OUTPUT are in WebP format.
+
+Note: The nature of EXIF, XMP and ICC data is not checked and is assumed to be
+valid.
+
+Visualization tool:
+===================
+
+The examples/ directory also contains a tool (vwebp) for viewing WebP files.
+It decodes the image and visualizes it using OpenGL. See the libwebp README
+for details on building and running this program.
+
+Mux API:
+========
+The Mux API contains methods for adding data to and reading data from WebP
+files. This API currently supports XMP/EXIF metadata, ICC profile and animation.
+Other features may be added in subsequent releases.
+
+Example#1 (pseudo code): Creating a WebPMux object with image data, color
+profile and XMP metadata.
+
+  int copy_data = 0;
+  WebPMux* mux = WebPMuxNew();
+  // ... (Prepare image data).
+  WebPMuxSetImage(mux, &image, copy_data);
+  // ... (Prepare ICC profile data).
+  WebPMuxSetChunk(mux, "ICCP", &icc_profile, copy_data);
+  // ... (Prepare XMP metadata).
+  WebPMuxSetChunk(mux, "XMP ", &xmp, copy_data);
+  // Get data from mux in WebP RIFF format.
+  WebPMuxAssemble(mux, &output_data);
+  WebPMuxDelete(mux);
+  // ... (Consume output_data; e.g. write output_data.bytes to file).
+  WebPDataClear(&output_data);
+
+
+Example#2 (pseudo code): Get image and color profile data from a WebP file.
+
+  int copy_data = 0;
+  // ... (Read data from file).
+  WebPMux* mux = WebPMuxCreate(&data, copy_data);
+  WebPMuxGetFrame(mux, 1, &image);
+  // ... (Consume image; e.g. call WebPDecode() to decode the data).
+  WebPMuxGetChunk(mux, "ICCP", &icc_profile);
+  // ... (Consume icc_profile).
+  WebPMuxDelete(mux);
+  free(data);
+
+
+For a detailed Mux API reference, please refer to the header file
+(src/webp/mux.h).
+
+Demux API:
+==========
+The Demux API enables extraction of images and extended format data from
+WebP files. This API currently supports reading of XMP/EXIF metadata, ICC
+profile and animated images. Other features may be added in subsequent
+releases.
+
+Code example: Demuxing WebP data to extract all the frames, ICC profile
+and EXIF/XMP metadata.
+
+  WebPDemuxer* demux = WebPDemux(&webp_data);
+  uint32_t width = WebPDemuxGetI(demux, WEBP_FF_CANVAS_WIDTH);
+  uint32_t height = WebPDemuxGetI(demux, WEBP_FF_CANVAS_HEIGHT);
+  // ... (Get information about the features present in the WebP file).
+  uint32_t flags = WebPDemuxGetI(demux, WEBP_FF_FORMAT_FLAGS);
+
+  // ... (Iterate over all frames).
+  WebPIterator iter;
+  if (WebPDemuxGetFrame(demux, 1, &iter)) {
+    do {
+      // ... (Consume 'iter'; e.g. Decode 'iter.fragment' with WebPDecode(),
+      // ... and get other frame properties like width, height, offsets etc.
+      // ... see 'struct WebPIterator' below for more info).
+    } while (WebPDemuxNextFrame(&iter));
+    WebPDemuxReleaseIterator(&iter);
+  }
+
+  // ... (Extract metadata).
+  WebPChunkIterator chunk_iter;
+  if (flags & ICCP_FLAG) WebPDemuxGetChunk(demux, "ICCP", 1, &chunk_iter);
+  // ... (Consume the ICC profile in 'chunk_iter.chunk').
+  WebPDemuxReleaseChunkIterator(&chunk_iter);
+  if (flags & EXIF_FLAG) WebPDemuxGetChunk(demux, "EXIF", 1, &chunk_iter);
+  // ... (Consume the EXIF metadata in 'chunk_iter.chunk').
+  WebPDemuxReleaseChunkIterator(&chunk_iter);
+  if (flags & XMP_FLAG) WebPDemuxGetChunk(demux, "XMP ", 1, &chunk_iter);
+  // ... (Consume the XMP metadata in 'chunk_iter.chunk').
+  WebPDemuxReleaseChunkIterator(&chunk_iter);
+  WebPDemuxDelete(demux);
+
+
+For a detailed Demux API reference, please refer to the header file
+(src/webp/demux.h).
+
+AnimEncoder API:
+================
+The AnimEncoder API can be used to create animated WebP images.
+
+Code example:
+
+  WebPAnimEncoderOptions enc_options;
+  WebPAnimEncoderOptionsInit(&enc_options);
+  // ... (Tune 'enc_options' as needed).
+  WebPAnimEncoder* enc = WebPAnimEncoderNew(width, height, &enc_options);
+  while(<there are more frames>) {
+    WebPConfig config;
+    WebPConfigInit(&config);
+    // ... (Tune 'config' as needed).
+    WebPAnimEncoderAdd(enc, frame, duration, &config);
+  }
+  WebPAnimEncoderAssemble(enc, webp_data);
+  WebPAnimEncoderDelete(enc);
+  // ... (Write the 'webp_data' to a file, or re-mux it further).
+
+
+For a detailed AnimEncoder API reference, please refer to the header file
+(src/webp/mux.h).
+
+
+Bugs:
+=====
+
+Please report all bugs to the issue tracker:
+    https://bugs.chromium.org/p/webp
+Patches welcome! See this page to get started:
+    http://www.webmproject.org/code/contribute/submitting-patches/
+
+Discuss:
+========
+
+Email: webp-discuss@webmproject.org
+Web: http://groups.google.com/a/webmproject.org/group/webp-discuss

build.gradle

@@ -0,0 +1,404 @@
+// Define dependencies.
+buildscript {
+  repositories {
+    maven {
+      url "https://jcenter.bintray.com"
+    }
+  }
+  dependencies {
+    classpath "com.android.tools.build:gradle:${ANDROID_GRADLE_PLUGIN_VERSION}"
+  }
+}
+
+// Define versions in the project.
+project.ext {
+  buildToolsVersion = "${BUILD_TOOLS_VERSION}"
+  compileSdkVersion = COMPILE_SDK_VERSION.toInteger()
+}
+
+// Core libraries and executables.
+apply plugin: "c"
+def NEON
+model {
+  buildTypes {
+    debug
+    release
+  }
+  platforms {
+    arm {
+      architecture "arm"
+    }
+    arm64 {
+      architecture "arm64"
+    }
+    x86 {
+      architecture "x86"
+    }
+    x64 {
+      architecture "x86_64"
+    }
+    mips32r2
+    mips32r5
+    mips64r6
+  }
+  toolChains {
+    gcc(Gcc) {
+      target("mips32r2") {
+        cCompiler.args "-mips32r2"
+      }
+      target("mips32r5") {
+        cCompiler.args "-mips32r5"
+      }
+      target("mips64r6") {
+        cCompiler.args "-mips64r6"
+      }
+    }
+  }
+  binaries {
+    all {
+      if (toolChain in Gcc) {
+        cCompiler.args "-fPIC"
+        cCompiler.args "-Wall"
+        cCompiler.define "ANDROID"
+        cCompiler.define "HAVE_MALLOC_H"
+      }
+      // Optimizations.
+      if (buildType == buildTypes.release) {
+        if (toolChain in Gcc) {
+          cCompiler.args "-finline-functions"
+          cCompiler.args "-ffast-math"
+          cCompiler.args "-ffunction-sections"
+          cCompiler.args "-fdata-sections"
+        }
+        if (toolChain in Clang) {
+          cCompiler.args "-frename-registers -s"
+        }
+      }
+      // Check for NEON usage.
+      if (getTargetPlatform() == "arm" || getTargetPlatform() == "arm64") {
+        NEON = "c.neon"
+      } else {
+        NEON = "c"
+      }
+    }
+    // Link to pthread for shared libraries.
+    withType(SharedLibraryBinarySpec) {
+      if (toolChain in Gcc) {
+        cCompiler.define "HAVE_PTHREAD"
+        cCompiler.define "WEBP_USE_THREAD"
+        linker.args "-pthread"
+      }
+    }
+  }
+  components {
+    webp(NativeLibrarySpec) {
+      sources {
+        c {
+          source {
+            srcDir "src/dec"
+            include "alpha_dec.c"
+            include "buffer_dec.c"
+            include "frame_dec.c"
+            include "idec_dec.c"
+            include "io_dec.c"
+            include "quant_dec.c"
+            include "tree_dec.c"
+            include "vp8_dec.c"
+            include "vp8l_dec.c"
+            include "webp_dec.c"
+            srcDir "src/dsp"
+            include "alpha_processing.c"
+            include "alpha_processing_mips_dsp_r2.c"
+            include "alpha_processing_neon.$NEON"
+            include "alpha_processing_sse2.c"
+            include "alpha_processing_sse41.c"
+            include "argb.c"
+            include "argb_mips_dsp_r2.c"
+            include "argb_sse2.c"
+            include "cpu.c"
+            include "dec.c"
+            include "dec_clip_tables.c"
+            include "dec_mips32.c"
+            include "dec_mips_dsp_r2.c"
+            include "dec_msa.c"
+            include "dec_neon.$NEON"
+            include "dec_sse2.c"
+            include "dec_sse41.c"
+            include "filters.c"
+            include "filters_mips_dsp_r2.c"
+            include "filters_msa.c"
+            include "filters_neon.$NEON"
+            include "filters_sse2.c"
+            include "lossless.c"
+            include "lossless_mips_dsp_r2.c"
+            include "lossless_msa.c"
+            include "lossless_neon.$NEON"
+            include "lossless_sse2.c"
+            include "rescaler.c"
+            include "rescaler_mips32.c"
+            include "rescaler_mips_dsp_r2.c"
+            include "rescaler_msa.c"
+            include "rescaler_neon.$NEON"
+            include "rescaler_sse2.c"
+            include "upsampling.c"
+            include "upsampling_mips_dsp_r2.c"
+            include "upsampling_msa.c"
+            include "upsampling_neon.$NEON"
+            include "upsampling_sse2.c"
+            include "yuv.c"
+            include "yuv_mips32.c"
+            include "yuv_mips_dsp_r2.c"
+            include "yuv_sse2.c"
+            srcDir "src/utils"
+            include "bit_reader_utils.c"
+            include "color_cache_utils.c"
+            include "filters_utils.c"
+            include "huffman_utils.c"
+            include "quant_levels_dec_utils.c"
+            include "random_utils.c"
+            include "rescaler_utils.c"
+            include "thread_utils.c"
+            include "utils.c"
+            srcDir "src/dsp"
+            include "cost.c"
+            include "cost_mips32.c"
+            include "cost_mips_dsp_r2.c"
+            include "cost_sse2.c"
+            include "enc.c"
+            include "enc_avx2.c"
+            include "enc_mips32.c"
+            include "enc_mips_dsp_r2.c"
+            include "enc_msa.c"
+            include "enc_neon.$NEON"
+            include "enc_sse2.c"
+            include "enc_sse41.c"
+            include "lossless_enc.c"
+            include "lossless_enc_mips32.c"
+            include "lossless_enc_mips_dsp_r2.c"
+            include "lossless_enc_msa.c"
+            include "lossless_enc_neon.$NEON"
+            include "lossless_enc_sse2.c"
+            include "lossless_enc_sse41.c"
+            srcDir "src/enc"
+            include "alpha_enc.c"
+            include "analysis_enc.c"
+            include "backward_references_enc.c"
+            include "config_enc.c"
+            include "cost_enc.c"
+            include "delta_palettization_enc.c"
+            include "filter_enc.c"
+            include "frame_enc.c"
+            include "histogram_enc.c"
+            include "iterator_enc.c"
+            include "near_lossless_enc.c"
+            include "picture_enc.c"
+            include "picture_csp_enc.c"
+            include "picture_psnr_enc.c"
+            include "picture_rescale_enc.c"
+            include "picture_tools_enc.c"
+            include "predictor_enc.c"
+            include "quant_enc.c"
+            include "syntax_enc.c"
+            include "token_enc.c"
+            include "tree_enc.c"
+            include "vp8l_enc.c"
+            include "webp_enc.c"
+            srcDir "src/utils"
+            include "bit_writer_utils.c"
+            include "huffman_encode_utils.c"
+            include "quant_levels_utils.c"
+          }
+          exportedHeaders {
+            srcDir "src"
+          }
+        }
+      }
+    }
+
+    webpdemux(NativeLibrarySpec) {
+      sources {
+        c {
+          source {
+            srcDir "src/demux"
+            include "anim_decode.c"
+            include "demux.c"
+          }
+        }
+      }
+    }
+
+    webpmux(NativeLibrarySpec) {
+      sources {
+        c {
+          source {
+            srcDir "src/mux/"
+            include "anim_encode.c"
+            include "muxedit.c"
+            include "muxinternal.c"
+            include "muxread.c"
+          }
+        }
+      }
+    }
+
+    // Executables from examples.
+    example_util(NativeLibrarySpec) {
+      binaries {
+        all {
+          lib library: "webp", linkage: "static"
+        }
+      }
+      sources {
+        c {
+          source {
+            srcDir "./examples"
+            include "example_util.c"
+          }
+        }
+      }
+    }
+
+    imageio_util(NativeLibrarySpec) {
+      binaries {
+        all {
+          lib library: "webp", linkage: "static"
+        }
+      }
+      sources {
+        c {
+          source {
+            srcDir "./imageio"
+            include "imageio_util.c"
+          }
+        }
+      }
+    }
+
+    imagedec(NativeLibrarySpec) {
+      binaries {
+        all {
+          lib library: "webp", linkage: "static"
+        }
+      }
+      sources {
+        c {
+          source {
+            srcDir "./imageio"
+            include "image_dec.c"
+            include "jpegdec.c"
+            include "metadata.c"
+            include "pngdec.c"
+            include "tiffdec.c"
+            include "webpdec.c"
+          }
+        }
+      }
+    }
+
+    imageenc(NativeLibrarySpec) {
+      binaries {
+        all {
+          lib library: "webp", linkage: "static"
+          lib library: "imageio_util", linkage: "static"
+        }
+      }
+      sources {
+        c {
+          source {
+            srcDir "./imageio"
+            include "image_enc.c"
+          }
+        }
+      }
+    }
+
+    cwebp(NativeExecutableSpec) {
+      binaries {
+        all {
+          lib library: "example_util", linkage: "static"
+          lib library: "imagedec", linkage: "static"
+          lib library: "imageio_util", linkage: "static"
+          lib library: "webp", linkage: "static"
+        }
+      }
+      sources {
+        c {
+          source {
+            srcDir "./examples"
+            include "cwebp.c"
+          }
+        }
+      }
+    }
+
+    dwebp(NativeExecutableSpec) {
+      binaries {
+        all {
+          lib library: "example_util", linkage: "static"
+          lib library: "imagedec", linkage: "static"
+          lib library: "imageenc", linkage: "static"
+          lib library: "imageio_util", linkage: "static"
+          lib library: "webp"
+        }
+      }
+      sources {
+        c {
+          source {
+              srcDir "./examples"
+              include "dwebp.c"
+          }
+        }
+      }
+    }
+
+    webpmux_example(NativeExecutableSpec) {
+      binaries {
+        all {
+          lib library: "example_util", linkage: "static"
+          lib library: "imageio_util", linkage: "static"
+          lib library: "webpmux", linkage: "static"
+          lib library: "webp"
+        }
+      }
+      sources {
+        c {
+          source {
+            srcDir "./examples"
+            include "webpmux.c"
+          }
+        }
+      }
+    }
+
+    img2webp_example(NativeExecutableSpec) {
+      binaries {
+        all {
+          lib library: "example_util", linkage: "static"
+          lib library: "imagedec", linkage: "static"
+          lib library: "imageio_util", linkage: "static"
+          lib library: "webpmux", linkage: "static"
+          lib library: "webp"
+        }
+      }
+      sources {
+        c {
+          source {
+            srcDir "./examples"
+            include "img2webp.c"
+          }
+        }
+      }
+    }
+  }
+  tasks {
+    // Task to test all possible configurations.
+    buildAllExecutables(Task) {
+      dependsOn $.binaries.findAll { it.buildable }
+    }
+  }
+}
+
+// Task to generate the wrapper.
+task wrapper(type: Wrapper) {
+  gradleVersion = '2.13'
+}

cmake/config.h.cmake

@@ -0,0 +1,141 @@
+# Generate the config.h to compile with specific intrinsics / libs.
+
+## Check for compiler options.
+include(CheckCSourceCompiles)
+check_c_source_compiles("
+    int main(void) {
+      (void)__builtin_bswap16(0);
+      return 0;
+    }
+  "
+  HAVE_BUILTIN_BSWAP16
+)
+check_c_source_compiles("
+    int main(void) {
+      (void)__builtin_bswap32(0);
+      return 0;
+    }
+  "
+  HAVE_BUILTIN_BSWAP32
+)
+check_c_source_compiles("
+    int main(void) {
+      (void)__builtin_bswap64(0);
+      return 0;
+    }
+  "
+  HAVE_BUILTIN_BSWAP64
+)
+
+## Check for libraries.
+find_package(Threads)
+if(Threads_FOUND)
+  if(CMAKE_USE_PTHREADS_INIT)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pthread")
+  endif()
+  foreach(PTHREAD_TEST HAVE_PTHREAD_PRIO_INHERIT PTHREAD_CREATE_UNDETACHED)
+    check_c_source_compiles("
+        #include <pthread.h>
+        int main (void) {
+          int attr = ${PTHREAD_TEST};
+          return attr;
+        }
+      " ${PTHREAD_TEST}
+    )
+  endforeach()
+  list(APPEND WEBP_DEP_LIBRARIES ${CMAKE_THREAD_LIBS_INIT})
+endif()
+set(WEBP_USE_THREAD ${Threads_FOUND})
+
+# TODO: this seems unused, check with autotools.
+set(LT_OBJDIR ".libs/")
+
+# Only useful for vwebp, so useless for now.
+# find_package(OpenGL)
+# set(WEBP_HAVE_GL ${OPENGL_FOUND})
+# set(WEBP_DEP_INCLUDE_DIRS ${WEBP_DEP_INCLUDE_DIRS} ${OPENGL_INCLUDE_DIRS})
+# set(WEBP_DEP_LIBRARIES ${WEBP_DEP_LIBRARIES} ${OPENGL_LIBRARIES})
+
+# Find the standard C math library.
+find_library(MATH_LIBRARY NAMES m)
+if(MATH_LIBRARY)
+  list(APPEND WEBP_DEP_LIBRARIES ${MATH_LIBRARY})
+endif()
+
+# Find the standard image libraries.
+set(WEBP_DEP_IMG_LIBRARIES)
+set(WEBP_DEP_IMG_INCLUDE_DIRS)
+foreach(I_LIB PNG JPEG TIFF GIF)
+  find_package(${I_LIB})
+  set(WEBP_HAVE_${I_LIB} ${${I_LIB}_FOUND})
+  if(${I_LIB}_FOUND)
+    list(APPEND WEBP_DEP_IMG_LIBRARIES ${${I_LIB}_LIBRARIES})
+    list(APPEND WEBP_DEP_IMG_INCLUDE_DIRS ${${I_LIB}_INCLUDE_DIRS})
+  endif()
+endforeach()
+
+## Check for specific headers.
+include(CheckIncludeFiles)
+check_include_files("stdlib.h;stdarg.h;string.h;float.h" STDC_HEADERS)
+check_include_files(dlfcn.h HAVE_DLFCN_H)
+check_include_files(GLUT/glut.h HAVE_GLUT_GLUT_H)
+check_include_files(GL/glut.h HAVE_GL_GLUT_H)
+check_include_files(inttypes.h HAVE_INTTYPES_H)
+check_include_files(memory.h HAVE_MEMORY_H)
+check_include_files(OpenGL/glut.h HAVE_OPENGL_GLUT_H)
+check_include_files(shlwapi.h HAVE_SHLWAPI_H)
+check_include_files(stdint.h HAVE_STDINT_H)
+check_include_files(stdlib.h HAVE_STDLIB_H)
+check_include_files(strings.h HAVE_STRINGS_H)
+check_include_files(string.h HAVE_STRING_H)
+check_include_files(sys/stat.h HAVE_SYS_STAT_H)
+check_include_files(sys/types.h HAVE_SYS_TYPES_H)
+check_include_files(unistd.h HAVE_UNISTD_H)
+check_include_files(wincodec.h HAVE_WINCODEC_H)
+check_include_files(windows.h HAVE_WINDOWS_H)
+
+# Windows specifics
+if(HAVE_WINCODEC_H)
+  list(APPEND WEBP_DEP_LIBRARIES shlwapi ole32 windowscodecs)
+endif()
+
+## Check for SIMD extensions.
+include(${CMAKE_CURRENT_LIST_DIR}/cpu.cmake)
+
+## Define extra info.
+set(PACKAGE ${PROJECT_NAME})
+set(PACKAGE_NAME ${PROJECT_NAME})
+
+# Read from configure.ac.
+file(READ ${CMAKE_CURRENT_SOURCE_DIR}/configure.ac CONFIGURE_AC)
+string(REGEX MATCHALL "\\[([0-9a-z\\.:/]*)\\]"
+  CONFIGURE_AC_PACKAGE_INFO ${CONFIGURE_AC}
+)
+function(strip_bracket VAR)
+  string(LENGTH ${${VAR}} TMP_LEN)
+  math(EXPR TMP_LEN ${TMP_LEN}-2)
+  string(SUBSTRING ${${VAR}} 1 ${TMP_LEN} TMP_SUB)
+  set(${VAR} ${TMP_SUB} PARENT_SCOPE)
+endfunction()
+
+list(GET CONFIGURE_AC_PACKAGE_INFO 1 PACKAGE_VERSION)
+strip_bracket(PACKAGE_VERSION)
+list(GET CONFIGURE_AC_PACKAGE_INFO 2 PACKAGE_BUGREPORT)
+strip_bracket(PACKAGE_BUGREPORT)
+list(GET CONFIGURE_AC_PACKAGE_INFO 3 PACKAGE_URL)
+strip_bracket(PACKAGE_URL)
+
+# Build more info.
+set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+set(PACKAGE_TARNAME ${PACKAGE_NAME})
+set(VERSION ${PACKAGE_VERSION})
+
+## Generate the config.h header.
+configure_file(${CMAKE_CURRENT_LIST_DIR}/config.h.in
+  ${CMAKE_CURRENT_BINARY_DIR}/include/webp/config.h)
+add_definitions(-DHAVE_CONFIG_H)
+# The webp folder is included as we reference config.h as
+# ../webp/config.h or webp/config.h
+include_directories(${CMAKE_CURRENT_BINARY_DIR}/include
+  ${CMAKE_CURRENT_BINARY_DIR}/include/webp
+)

cmake/config.h.in

@@ -0,0 +1,143 @@
+/* Adapted from the autotools src/webp/config.h.in.  */
+
+/* Define if building universal (internal helper macro) */
+/* TODO: handle properly in CMake */
+#cmakedefine AC_APPLE_UNIVERSAL_BUILD 1
+
+/* Set to 1 if __builtin_bswap16 is available */
+#cmakedefine HAVE_BUILTIN_BSWAP16 1
+
+/* Set to 1 if __builtin_bswap32 is available */
+#cmakedefine HAVE_BUILTIN_BSWAP32 1
+
+/* Set to 1 if __builtin_bswap64 is available */
+#cmakedefine HAVE_BUILTIN_BSWAP64 1
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#cmakedefine HAVE_DLFCN_H 1
+
+/* Define to 1 if you have the <GLUT/glut.h> header file. */
+#cmakedefine HAVE_GLUT_GLUT_H 1
+
+/* Define to 1 if you have the <GL/glut.h> header file. */
+#cmakedefine HAVE_GL_GLUT_H 1
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#cmakedefine HAVE_INTTYPES_H 1
+
+/* Define to 1 if you have the <memory.h> header file. */
+#cmakedefine HAVE_MEMORY_H 1
+
+/* Define to 1 if you have the <OpenGL/glut.h> header file. */
+#cmakedefine HAVE_OPENGL_GLUT_H 1
+
+/* Have PTHREAD_PRIO_INHERIT. */
+#cmakedefine HAVE_PTHREAD_PRIO_INHERIT @HAVE_PTHREAD_PRIO_INHERIT@
+
+/* Define to 1 if you have the <shlwapi.h> header file. */
+#cmakedefine HAVE_SHLWAPI_H 1
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#cmakedefine HAVE_STDINT_H 1
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#cmakedefine HAVE_STDLIB_H 1
+
+/* Define to 1 if you have the <strings.h> header file. */
+#cmakedefine HAVE_STRINGS_H 1
+
+/* Define to 1 if you have the <string.h> header file. */
+#cmakedefine HAVE_STRING_H 1
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#cmakedefine HAVE_SYS_STAT_H 1
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#cmakedefine HAVE_SYS_TYPES_H 1
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#cmakedefine HAVE_UNISTD_H 1
+
+/* Define to 1 if you have the <wincodec.h> header file. */
+#cmakedefine HAVE_WINCODEC_H 1
+
+/* Define to 1 if you have the <windows.h> header file. */
+#cmakedefine HAVE_WINDOWS_H 1
+
+/* Define to the sub-directory in which libtool stores uninstalled libraries.
+   */
+/* TODO: handle properly in CMake */
+#cmakedefine LT_OBJDIR "@LT_OBJDIR@"
+
+/* Name of package */
+#cmakedefine PACKAGE "@PROJECT_NAME@"
+
+/* Define to the address where bug reports for this package should be sent. */
+#cmakedefine PACKAGE_BUGREPORT "@PACKAGE_BUGREPORT@"
+
+/* Define to the full name of this package. */
+#cmakedefine PACKAGE_NAME "@PACKAGE_NAME@"
+
+/* Define to the full name and version of this package. */
+#cmakedefine PACKAGE_STRING "@PACKAGE_STRING@"
+
+/* Define to the one symbol short name of this package. */
+#cmakedefine PACKAGE_TARNAME "@PACKAGE_TARNAME@"
+
+/* Define to the home page for this package. */
+#cmakedefine PACKAGE_URL "@PACKAGE_URL@"
+
+/* Define to the version of this package. */
+#cmakedefine PACKAGE_VERSION "@PACKAGE_VERSION@"
+
+/* Define to necessary symbol if this constant uses a non-standard name on
+   your system. */
+#cmakedefine PTHREAD_CREATE_JOINABLE 1
+
+/* Define to 1 if you have the ANSI C header files. */
+#cmakedefine STDC_HEADERS 1
+
+/* Version number of package */
+#cmakedefine VERSION "@VERSION@"
+
+/* Enable experimental code */
+#cmakedefine WEBP_EXPERIMENTAL_FEATURES 1
+
+/* Set to 1 if AVX2 is supported */
+#cmakedefine WEBP_HAVE_AVX2 1
+
+/* Set to 1 if GIF library is installed */
+#cmakedefine WEBP_HAVE_GIF 1
+
+/* Set to 1 if OpenGL is supported */
+#cmakedefine WEBP_HAVE_GL 1
+
+/* Set to 1 if JPEG library is installed */
+#cmakedefine WEBP_HAVE_JPEG 1
+
+/* Set to 1 if PNG library is installed */
+#cmakedefine WEBP_HAVE_PNG 1
+
+/* Set to 1 if SSE2 is supported */
+#cmakedefine WEBP_HAVE_SSE2 1
+
+/* Set to 1 if SSE4.1 is supported */
+#cmakedefine WEBP_HAVE_SSE41 1
+
+/* Set to 1 if TIFF library is installed */
+#cmakedefine WEBP_HAVE_TIFF 1
+
+/* Undefine this to disable thread support. */
+#cmakedefine WEBP_USE_THREAD 1
+
+/* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
+   significant byte first (like Motorola and SPARC, unlike Intel). */
+#if defined AC_APPLE_UNIVERSAL_BUILD
+# if defined __BIG_ENDIAN__
+#  define WORDS_BIGENDIAN 1
+# endif
+#else
+# ifndef WORDS_BIGENDIAN
+#  undef WORDS_BIGENDIAN
+# endif
+#endif

cmake/cpu.cmake

@@ -0,0 +1,113 @@
+## Check for SIMD extensions.
+
+function(webp_check_compiler_flag WEBP_SIMD_FLAG)
+  unset(WEBP_HAVE_FLAG_${WEBP_SIMD_FLAG} CACHE)
+  check_c_source_compiles("
+      #include \"${CMAKE_CURRENT_LIST_DIR}/../src/dsp/dsp.h\"
+      int main(void) {
+        #if !defined(WEBP_USE_${WEBP_SIMD_FLAG})
+        this is not valid code
+        #endif
+        return 0;
+      }
+    " WEBP_HAVE_FLAG_${WEBP_SIMD_FLAG}
+  )
+  if(WEBP_HAVE_FLAG_${WEBP_SIMD_FLAG})
+    set(WEBP_HAVE_${WEBP_SIMD_FLAG} 1 PARENT_SCOPE)
+  else()
+    set(WEBP_HAVE_${WEBP_SIMD_FLAG} 0 PARENT_SCOPE)
+  endif()
+endfunction()
+
+# those are included in the names of WEBP_USE_* in c++ code.
+set(WEBP_SIMD_FLAGS "SSE2;SSE41;AVX2;MIPS32;MIPS_DSP_R2;NEON;MSA")
+set(WEBP_SIMD_FILE_EXTENSIONS "_sse2.c;_sse41.c;_avx2.c;_mips32.c;_mips_dsp_r2.c;_neon.c;_msa.c")
+if(MSVC)
+  # MSVC does not have a SSE4 flag but AVX2 support implies
+  # SSE4 support.
+  set(SIMD_ENABLE_FLAGS "/arch:SSE2;/arch:AVX2;/arch:AVX2;;;;")
+  set(SIMD_DISABLE_FLAGS)
+else()
+  set(SIMD_ENABLE_FLAGS "-msse2;-msse4.1;-mavx2;-mips32;-mdspr2;-mfpu=neon;-mmsa")
+  set(SIMD_DISABLE_FLAGS "-mno-sse2;-mno-sse4.1;-mno-avx2;;-mno-dspr2;;-mno-msa")
+endif()
+
+set(WEBP_SIMD_FILES_TO_NOT_INCLUDE)
+set(WEBP_SIMD_FILES_TO_INCLUDE)
+set(WEBP_SIMD_FLAGS_TO_INCLUDE)
+
+if(${ANDROID})
+  if(${ANDROID_ABI} STREQUAL "armeabi-v7a")
+    # This is because Android studio uses the configuration
+    # "-march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16"
+    # that does not trigger neon optimizations but should
+    # (as this configuration does not exist anymore).
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=neon ")
+  endif()
+endif()
+
+list(LENGTH WEBP_SIMD_FLAGS WEBP_SIMD_FLAGS_LENGTH)
+math(EXPR WEBP_SIMD_FLAGS_RANGE "${WEBP_SIMD_FLAGS_LENGTH} - 1")
+
+foreach(I_SIMD RANGE ${WEBP_SIMD_FLAGS_RANGE})
+  list(GET WEBP_SIMD_FLAGS ${I_SIMD} WEBP_SIMD_FLAG)
+
+  # First try with no extra flag added as the compiler might have default flags
+  # (especially on Android).
+  unset(WEBP_HAVE_${WEBP_SIMD_FLAG} CACHE)
+  set(CMAKE_REQUIRED_FLAGS)
+  webp_check_compiler_flag(${WEBP_SIMD_FLAG})
+  if(NOT WEBP_HAVE_${WEBP_SIMD_FLAG})
+    list(GET SIMD_ENABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)
+    set(CMAKE_REQUIRED_FLAGS ${SIMD_COMPILE_FLAG})
+    webp_check_compiler_flag(${WEBP_SIMD_FLAG})
+  else()
+    set(SIMD_COMPILE_FLAG " ")
+  endif()
+  # Check which files we should include or not.
+  list(GET WEBP_SIMD_FILE_EXTENSIONS ${I_SIMD} WEBP_SIMD_FILE_EXTENSION)
+  file(GLOB SIMD_FILES "${CMAKE_CURRENT_LIST_DIR}/../"
+    "src/dsp/*${WEBP_SIMD_FILE_EXTENSION}"
+  )
+  if(WEBP_HAVE_${WEBP_SIMD_FLAG})
+    # Memorize the file and flags.
+    foreach(FILE ${SIMD_FILES})
+      list(APPEND WEBP_SIMD_FILES_TO_INCLUDE ${FILE})
+      list(APPEND WEBP_SIMD_FLAGS_TO_INCLUDE ${SIMD_COMPILE_FLAG})
+    endforeach()
+  else()
+    # Remove the file from the list.
+    foreach(FILE ${SIMD_FILES})
+      list(APPEND WEBP_SIMD_FILES_NOT_TO_INCLUDE ${FILE})
+    endforeach()
+    # Explicitly disable SIMD.
+    if(SIMD_DISABLE_FLAGS)
+      list(GET SIMD_DISABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)
+      include(CheckCCompilerFlag)
+      if(SIMD_COMPILE_FLAG)
+        unset(HAS_COMPILE_FLAG CACHE)
+        check_c_compiler_flag(${SIMD_COMPILE_FLAG} HAS_COMPILE_FLAG)
+        if(HAS_COMPILE_FLAG)
+          # Do one more check for Clang to circumvent CMake issue 13194.
+          if(COMMAND check_compiler_flag_common_patterns)
+            # Only in CMake 3.0 and above.
+            check_compiler_flag_common_patterns(COMMON_PATTERNS)
+          else()
+            set(COMMON_PATTERNS)
+          endif()
+          set(CMAKE_REQUIRED_DEFINITIONS ${SIMD_COMPILE_FLAG})
+          check_c_source_compiles("int main(void) {return 0;}" FLAG2
+            FAIL_REGEX "warning: argument unused during compilation:"
+            ${COMMON_PATTERNS}
+          )
+          if(NOT FLAG2)
+            unset(HAS_COMPILE_FLAG CACHE)
+          endif()
+        endif()
+        if(HAS_COMPILE_FLAG)
+          set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SIMD_COMPILE_FLAG}")
+        endif()
+      endif()
+    endif()
+  endif()
+endforeach()

configure.ac

@@ -1,73 +1,721 @@
-AC_INIT([webpdecode], [0.1])
+AC_INIT([libwebp], [0.6.0],
+        [https://bugs.chromium.org/p/webp],,
+        [http://developers.google.com/speed/webp])
+AC_CANONICAL_HOST
+AC_PREREQ([2.60])
 AM_INIT_AUTOMAKE([-Wall foreign subdir-objects])
+
+dnl === automake >= 1.12 requires this for 'unusual archivers' support.
+dnl === it must occur before LT_INIT (AC_PROG_LIBTOOL).
+m4_ifdef([AM_PROG_AR], [AM_PROG_AR])
+
 AC_PROG_LIBTOOL
+AC_PROG_SED
 AM_PROG_CC_C_O
 
-AC_ARG_WITH([pkgconfigdir], AS_HELP_STRING([--with-pkgconfigdir=PATH],
-	[Path to the pkgconfig directory [[LIBDIR/pkgconfig]]]),
-	[pkgconfigdir="$withval"], [pkgconfigdir='${libdir}/pkgconfig'])
+dnl === Enable less verbose output when building.
+m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
+
+dnl == test endianness
+AC_C_BIGENDIAN
+
+dnl === SET_IF_UNSET(shell_var, value)
+dnl ===   Set the shell variable 'shell_var' to 'value' if it is unset.
+AC_DEFUN([SET_IF_UNSET], [test "${$1+set}" = "set" || $1=$2])
+
+AC_ARG_ENABLE([everything],
+              AS_HELP_STRING([--enable-everything],
+                             [Enable all optional targets. These can still be
+                              disabled with --disable-target]),
+              [SET_IF_UNSET([enable_libwebpdecoder], [$enableval])
+               SET_IF_UNSET([enable_libwebpdemux], [$enableval])
+               SET_IF_UNSET([enable_libwebpextras], [$enableval])
+               SET_IF_UNSET([enable_libwebpmux], [$enableval])])
+
+dnl === If --enable-asserts is not defined, define NDEBUG
+
+AC_MSG_CHECKING(whether asserts are enabled)
+AC_ARG_ENABLE([asserts],
+              AS_HELP_STRING([--enable-asserts],
+                             [Enable assert checks]))
+if test "x${enable_asserts-no}" = "xno"; then
+  AM_CPPFLAGS="${AM_CPPFLAGS} -DNDEBUG"
+fi
+AC_MSG_RESULT(${enable_asserts-no})
+AC_SUBST([AM_CPPFLAGS])
+
+AC_ARG_WITH([pkgconfigdir], AS_HELP_STRING([--with-pkgconfigdir=DIR],
+            [Path to the pkgconfig directory @<:@LIBDIR/pkgconfig@:>@]),
+            [pkgconfigdir="$withval"], [pkgconfigdir='${libdir}/pkgconfig'])
 AC_SUBST([pkgconfigdir])
 
+dnl === TEST_AND_ADD_CFLAGS(var, flag)
+dnl ===   Checks whether $CC supports 'flag' and adds it to 'var'
+dnl ===   on success.
+AC_DEFUN([TEST_AND_ADD_CFLAGS],
+         [SAVED_CFLAGS="$CFLAGS"
+          CFLAGS="-Werror $2"
+          AC_MSG_CHECKING([whether $CC supports $2])
+          dnl Note AC_LANG_PROGRAM([]) uses an old-style main definition.
+          AC_COMPILE_IFELSE([AC_LANG_SOURCE([int main(void) { return 0; }])],
+                            [AC_MSG_RESULT([yes])]
+                            dnl Simply append the variable avoiding a
+                            dnl compatibility ifdef for AS_VAR_APPEND as this
+                            dnl variable shouldn't grow all that large.
+                            [$1="${$1} $2"],
+                            [AC_MSG_RESULT([no])])
+          CFLAGS="$SAVED_CFLAGS"])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-fvisibility=hidden])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wall])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wdeclaration-after-statement])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wextra])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wfloat-conversion])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wformat -Wformat-nonliteral])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wformat -Wformat-security])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wmissing-declarations])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wmissing-prototypes])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wold-style-definition])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wshadow])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wshorten-64-to-32])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wunreachable-code])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wunused-but-set-variable])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wunused])
+TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-Wvla])
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62040
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61622
+AS_IF([test "$GCC" = "yes" ], [
+       gcc_version=`$CC -dumpversion`
+       gcc_wht_bug=""
+       case "$host_cpu" in
+         aarch64|arm64)
+          case "$gcc_version" in
+            4.9|4.9.0|4.9.1) gcc_wht_bug=yes ;;
+          esac
+       esac
+       AS_IF([test "$gcc_wht_bug" = "yes"], [
+              TEST_AND_ADD_CFLAGS([AM_CFLAGS], [-frename-registers])])])
+# Use -flax-vector-conversions, if available, when building intrinsics with
+# older versions of gcc. The flag appeared in 4.3.x, but if backported, and
+# -fno-lax-vector-conversions is set, errors may occur with the intrinsics
+# files along with the older system includes, e.g., emmintrin.h.
+# Originally observed with cc (GCC) 4.2.1 20070831 patched [FreeBSD] (9.3).
+# https://bugs.chromium.org/p/webp/issues/detail?id=274
+AS_IF([test "$GCC" = "yes" ], [
+       case "$host_cpu" in
+         amd64|i?86|x86_64)
+           AC_COMPILE_IFELSE(
+             dnl only check for -flax-vector-conversions with older gcc, skip
+             dnl clang as it reports itself as 4.2.1, but the flag isn't needed.
+             [AC_LANG_SOURCE([#if !defined(__clang__) && defined(__GNUC__) && \
+                                  ((__GNUC__ << 8) | __GNUC_MINOR__) < 0x403
+                              #error old gcc
+                              #endif
+                              int main(void) { return 0; }
+                             ])],,
+              [TEST_AND_ADD_CFLAGS([INTRINSICS_CFLAGS],
+                                   [-flax-vector-conversions])])
+           ;;
+       esac])
+AC_SUBST([AM_CFLAGS])
+
+dnl === Check for machine specific flags
+AC_ARG_ENABLE([avx2],
+              AS_HELP_STRING([--disable-avx2],
+                             [Disable detection of AVX2 support
+                              @<:@default=auto@:>@]))
+
+AS_IF([test "x$enable_avx2" != "xno" -a "x$enable_sse4_1" != "xno" \
+         -a "x$enable_sse2" != "xno"], [
+  AVX2_CFLAGS="$INTRINSICS_CFLAGS $AVX2_FLAGS"
+  TEST_AND_ADD_CFLAGS([AVX2_FLAGS], [-mavx2])
+  AS_IF([test -n "$AVX2_FLAGS"], [
+    SAVED_CFLAGS=$CFLAGS
+    CFLAGS="$CFLAGS $AVX2_FLAGS"
+    AC_CHECK_HEADER([immintrin.h],
+                    [AC_DEFINE(WEBP_HAVE_AVX2, [1],
+                     [Set to 1 if AVX2 is supported])],
+                    [AVX2_FLAGS=""],
+                    dnl it's illegal to directly include avx2intrin.h, but it's
+                    dnl included conditionally in immintrin.h, tricky!
+                    [#ifndef __AVX2__
+                     #error avx2 is not enabled
+                     #endif
+                    ])
+    CFLAGS=$SAVED_CFLAGS])
+  AC_SUBST([AVX2_FLAGS])])
+
+AC_ARG_ENABLE([sse4.1],
+              AS_HELP_STRING([--disable-sse4.1],
+                             [Disable detection of SSE4.1 support
+                              @<:@default=auto@:>@]))
+
+AS_IF([test "x$enable_sse4_1" != "xno" -a "x$enable_sse2" != "xno"], [
+  SSE41_FLAGS="$INTRINSICS_CFLAGS $SSE41_FLAGS"
+  TEST_AND_ADD_CFLAGS([SSE41_FLAGS], [-msse4.1])
+  AS_IF([test -n "$SSE41_FLAGS"], [
+    SAVED_CFLAGS=$CFLAGS
+    CFLAGS="$CFLAGS $SSE41_FLAGS"
+    AC_CHECK_HEADER([smmintrin.h],
+                    [AC_DEFINE(WEBP_HAVE_SSE41, [1],
+                     [Set to 1 if SSE4.1 is supported])],
+                    [SSE41_FLAGS=""])
+    CFLAGS=$SAVED_CFLAGS])
+  AC_SUBST([SSE41_FLAGS])])
+
+AC_ARG_ENABLE([sse2],
+              AS_HELP_STRING([--disable-sse2],
+                             [Disable detection of SSE2 support
+                              @<:@default=auto@:>@]))
+
+AS_IF([test "x$enable_sse2" != "xno"], [
+  SSE2_FLAGS="$INTRINSICS_CFLAGS $SSE2_FLAGS"
+  TEST_AND_ADD_CFLAGS([SSE2_FLAGS], [-msse2])
+  AS_IF([test -n "$SSE2_FLAGS"], [
+    SAVED_CFLAGS=$CFLAGS
+    CFLAGS="$CFLAGS $SSE2_FLAGS"
+    AC_CHECK_HEADER([emmintrin.h],
+                    [AC_DEFINE(WEBP_HAVE_SSE2, [1],
+                     [Set to 1 if SSE2 is supported])],
+                    [SSE2_FLAGS=""])
+    CFLAGS=$SAVED_CFLAGS])
+  AC_SUBST([SSE2_FLAGS])])
+
+AC_ARG_ENABLE([neon],
+              AS_HELP_STRING([--disable-neon],
+                             [Disable detection of NEON support
+                              @<:@default=auto@:>@]))
+
+AC_ARG_ENABLE([neon_rtcd],
+              AS_HELP_STRING([--disable-neon-rtcd],
+                             [Disable runtime detection of NEON support via
+                              /proc/cpuinfo on Linux hosts
+                              @<:@default=auto@:>@]))
+# For ARM(7) hosts:
+# Both NEON flags unset and NEON support detected = build all modules with NEON
+# NEON detected with the use of -mfpu=neon = build only NEON modules with NEON
+AS_IF([test "x$enable_neon" != "xno"], [
+  case "$host_cpu" in
+    arm|armv7*)
+      # Test for NEON support without flags before falling back to -mfpu=neon
+      for flag in '' '-mfpu=neon'; do
+        LOCAL_NEON_FLAGS="$INTRINSICS_CFLAGS $NEON_FLAGS"
+        TEST_AND_ADD_CFLAGS([LOCAL_NEON_FLAGS], [$flag])
+        SAVED_CFLAGS=$CFLAGS
+        CFLAGS="$CFLAGS $LOCAL_NEON_FLAGS"
+
+        dnl Note AC_LANG_PROGRAM([]) uses an old-style main definition.
+        AC_COMPILE_IFELSE([AC_LANG_SOURCE([
+          #include <arm_neon.h>
+          int main(void) {
+            int8x8_t v = vdup_n_s8(0);
+            (void)v;
+            return 0;
+          }])],
+          [NEON_FLAGS="$(echo $LOCAL_NEON_FLAGS | $SED 's/^ *//')"
+           AS_IF([test -n "$NEON_FLAGS"], [
+             AS_IF([test "${host_os%%-*}" = "linux" -o \
+                         "x$enable_neon_rtcd" = "xno"], [
+               CFLAGS=$SAVED_CFLAGS
+               AC_DEFINE(WEBP_HAVE_NEON, [1], [Set to 1 if NEON is supported])
+               break
+             ],[
+               AC_MSG_WARN(m4_normalize([NEON runtime cpu-detection is
+                                         unavailable for ${host_os%%-*}. Force
+                                         with CFLAGS=-mfpu=neon or
+                                         --disable-neon-rtcd.]))
+               enable_neon_rtcd=no
+               NEON_FLAGS=""
+             ])
+           ],[
+             CFLAGS=$SAVED_CFLAGS
+             AC_DEFINE(WEBP_HAVE_NEON, [1], [Set to 1 if NEON is supported])
+             break
+           ])])
+        CFLAGS=$SAVED_CFLAGS
+      done
+
+      AS_IF([test -n "$NEON_FLAGS"], [
+        # If NEON is available and rtcd is disabled apply NEON_FLAGS globally.
+        AS_IF([test "x$enable_neon_rtcd" = "xno"], [
+          AM_CFLAGS="$AM_CFLAGS $NEON_FLAGS"
+          NEON_FLAGS=""],
+          [AC_DEFINE(WEBP_HAVE_NEON_RTCD, [1],
+                     [Set to 1 if runtime detection of NEON is enabled])])])
+        ;;
+    esac
+    AC_SUBST([NEON_FLAGS])])
+
+dnl === CLEAR_LIBVARS([var_pfx])
+dnl ===   Clears <var_pfx>_{INCLUDES,LIBS}.
+AC_DEFUN([CLEAR_LIBVARS], [$1_INCLUDES=""; $1_LIBS=""])
+
+dnl === WITHLIB_OPTION([opt_pfx], [outvar_pfx])
+dnl ===   Defines --with-<opt_pfx>{include,lib}dir options which set
+dnl ===   the variables <outvar_pfx>_{INCLUDES,LIBS}.
+AC_DEFUN([WITHLIB_OPTION],
+  [AC_ARG_WITH([$1includedir],
+               AS_HELP_STRING([--with-$1includedir=DIR],
+                              [use $2 includes from DIR]),
+               $2_INCLUDES="-I$withval")
+   AC_ARG_WITH([$1libdir],
+               AS_HELP_STRING([--with-$1libdir=DIR],
+                              [use $2 libraries from DIR]),
+               [$2_LIBS="-L$withval"])])
+
+dnl === LIBCHECK_PROLOGUE([var_pfx])
+dnl ===   Caches the current values of CPPFLAGS/LIBS in SAVED_* then
+dnl ===   prepends the current values with <var_pfx>_{INCLUDES,LIBS}.
+AC_DEFUN([LIBCHECK_PROLOGUE],
+         [SAVED_CPPFLAGS=$CPPFLAGS
+          SAVED_LIBS=$LIBS
+          CPPFLAGS="$$1_INCLUDES $CPPFLAGS"
+          LIBS="$$1_LIBS $LIBS"])
+
+dnl === LIBCHECK_EPILOGUE([var_pfx])
+dnl ===   Restores the values of CPPFLAGS/LIBS from SAVED_* and exports
+dnl ===   <var_pfx>_{INCLUDES,LIBS} with AC_SUBST.
+AC_DEFUN([LIBCHECK_EPILOGUE],
+         [AC_SUBST($1_LIBS)
+          AC_SUBST($1_INCLUDES)
+          CPPFLAGS=$SAVED_CPPFLAGS
+          LIBS=$SAVED_LIBS])
+
+dnl === Check for gcc builtins
+
+dnl === CHECK_FOR_BUILTIN([builtin], [param], [define])
+dnl ===   links a C AC_LANG_PROGRAM, with <builtin>(<param>)
+dnl ===   AC_DEFINE'ing <define> if successful.
+AC_DEFUN([CHECK_FOR_BUILTIN],
+         [AC_LANG_PUSH([C])
+          AC_MSG_CHECKING([for $1])
+          AC_LINK_IFELSE([AC_LANG_PROGRAM([], [(void)$1($2)])],
+                         [AC_MSG_RESULT([yes])
+                          AC_DEFINE([$3], [1],
+                                    [Set to 1 if $1 is available])],
+                         [AC_MSG_RESULT([no])]),
+          AC_LANG_POP])
+
+dnl AC_CHECK_FUNC doesn't work with builtin's.
+CHECK_FOR_BUILTIN([__builtin_bswap16], [1u << 15], [HAVE_BUILTIN_BSWAP16])
+CHECK_FOR_BUILTIN([__builtin_bswap32], [1u << 31], [HAVE_BUILTIN_BSWAP32])
+CHECK_FOR_BUILTIN([__builtin_bswap64], [1ull << 63], [HAVE_BUILTIN_BSWAP64])
+
+dnl === Check for pthread support
+AC_ARG_ENABLE([threading],
+              AS_HELP_STRING([--disable-threading],
+                             [Disable detection of thread support]),,
+              [enable_threading=yes])
+if test "$enable_threading" = "yes"; then
+  AC_MSG_NOTICE([checking for threading support...])
+  AX_PTHREAD([AC_DEFINE([WEBP_USE_THREAD], [1],
+                        [Undefine this to disable thread support.])
+              LIBS="$PTHREAD_LIBS $LIBS"
+              CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+              CC="$PTHREAD_CC"
+             ],
+             [AC_CHECK_FUNC([_beginthreadex],
+                            [AC_DEFINE([WEBP_USE_THREAD], [1],
+                                       [Undefine this to disable thread
+                                        support.])],
+                            [enable_threading=no])])
+fi
+AC_MSG_NOTICE([checking if threading is enabled... ${enable_threading-no}])
+
+dnl === check for OpenGL/GLUT support ===
+
+AC_ARG_ENABLE([gl], AS_HELP_STRING([--disable-gl],
+                                   [Disable detection of OpenGL support
+                                    @<:@default=auto@:>@]))
+AS_IF([test "x$enable_gl" != "xno"], [
+  CLEAR_LIBVARS([GL])
+  WITHLIB_OPTION([gl], [GL])
+
+  LIBCHECK_PROLOGUE([GL])
+
+  glut_cflags="none"
+  glut_ldflags="none"
+  case $host_os in
+    darwin*)
+      # Special case for OSX builds. Append these to give the user a chance to
+      # override with --with-gl*
+      glut_cflags="$glut_cflags|-framework GLUT -framework OpenGL"
+      glut_ldflags="$glut_ldflags|-framework GLUT -framework OpenGL"
+      ;;
+  esac
+
+  GLUT_SAVED_CPPFLAGS="$CPPFLAGS"
+  SAVED_IFS="$IFS"
+  IFS="|"
+  for flag in $glut_cflags; do
+    # restore IFS immediately as the autoconf macros may need the default.
+    IFS="$SAVED_IFS"
+    unset ac_cv_header_GL_glut_h
+    unset ac_cv_header_OpenGL_glut_h
+
+    case $flag in
+      none) ;;
+      *) CPPFLAGS="$flag $CPPFLAGS";;
+    esac
+    AC_CHECK_HEADERS([GL/glut.h GLUT/glut.h OpenGL/glut.h],
+                     [glut_headers=yes;
+                      test "$flag" = "none" || GL_INCLUDES="$CPPFLAGS";
+                      break])
+    CPPFLAGS="$GLUT_SAVED_CPPFLAGS"
+    test "$glut_headers" = "yes" && break
+  done
+  IFS="$SAVED_IFS"
+
+  if test "$glut_headers" = "yes"; then
+    AC_LANG_PUSH([C])
+    GLUT_SAVED_LDFLAGS="$LDFLAGS"
+    SAVED_IFS="$IFS"
+    IFS="|"
+    for flag in $glut_ldflags; do
+      # restore IFS immediately as the autoconf macros may need the default.
+      IFS="$SAVED_IFS"
+      unset ac_cv_search_glBegin
+
+      case $flag in
+        none) ;;
+        *) LDFLAGS="$flag $LDFLAGS";;
+      esac
+
+      # find libGL
+      GL_SAVED_LIBS="$LIBS"
+      AC_SEARCH_LIBS([glBegin], [GL OpenGL opengl32])
+      LIBS="$GL_SAVED_LIBS"
+
+      # A direct link to libGL may not be necessary on e.g., linux.
+      GLUT_SAVED_LIBS="$LIBS"
+      for lib in "" "-lglut" "-lglut $ac_cv_search_glBegin"; do
+        LIBS="$lib"
+        AC_LINK_IFELSE(
+          [AC_LANG_PROGRAM([
+             #ifdef __cplusplus
+             # define EXTERN_C extern "C"
+             #else
+             # define EXTERN_C
+             #endif
+             EXTERN_C char glOrtho();
+             EXTERN_C char glutMainLoop();
+            ],[
+             glOrtho();
+             glutMainLoop();
+            ])
+          ],
+          AC_DEFINE(WEBP_HAVE_GL, [1],
+                    [Set to 1 if OpenGL is supported])
+          [glut_support=yes], []
+        )
+        if test "$glut_support" = "yes"; then
+          GL_LIBS="$LDFLAGS $lib"
+          break
+        fi
+      done
+      LIBS="$GLUT_SAVED_LIBS"
+      LDFLAGS="$GLUT_SAVED_LDFLAGS"
+      test "$glut_support" = "yes" && break
+    done
+    IFS="$SAVED_IFS"
+    AC_LANG_POP
+  fi
+
+  LIBCHECK_EPILOGUE([GL])
+
+  if test "$glut_support" = "yes" -a "$enable_libwebpdemux" = "yes"; then
+    build_vwebp=yes
+  fi
+])
+AM_CONDITIONAL([BUILD_VWEBP], [test "$build_vwebp" = "yes"])
+
 dnl === check for PNG support ===
 
-PNG_INCLUDES=""
-PNG_LIBS=""
-AC_PATH_PROG(LIBPNG_CONFIG, libpng-config)
-if test -n "$LIBPNG_CONFIG"; then
-  PNG_INCLUDES=`$LIBPNG_CONFIG --cflags`
-  PNG_PREFIX=`$LIBPNG_CONFIG --prefix`
-  if test "${PNG_PREFIX}/lib" != "/usr/lib" ; then
-    PNG_LIBS="-L${PNG_PREFIX}/lib"
+AC_ARG_ENABLE([png], AS_HELP_STRING([--disable-png],
+                                    [Disable detection of PNG format support
+                                     @<:@default=auto@:>@]))
+AS_IF([test "x$enable_png" != "xno"], [
+  CLEAR_LIBVARS([PNG])
+  AC_PATH_PROGS([LIBPNG_CONFIG],
+                [libpng-config libpng16-config libpng15-config libpng14-config \
+                 libpng12-config])
+  if test -n "$LIBPNG_CONFIG"; then
+    PNG_INCLUDES=`$LIBPNG_CONFIG --cflags`
+    PNG_LIBS="`$LIBPNG_CONFIG --ldflags`"
   fi
-fi
 
-AC_ARG_WITH(pngincludedir,
-            [--with-pngincludedir=DIR use PNG includes from DIR],
-            PNG_INCLUDES="-I$withval")
-AC_ARG_WITH(pnglibdir,
-            [--with-pnglibdir=DIR    use PNG libraries from DIR],
-            [PNG_LIBS="-L$withval"])
+  WITHLIB_OPTION([png], [PNG])
 
-AC_CHECK_HEADER(png.h,
-  AC_CHECK_LIB(png, main,
-               [PNG_LIBS="$PNG_LIBS -lpng"
-                PNG_INCLUDES="$PNG_INCLUDES -DWEBP_HAVE_PNG"
-                AC_DEFINE(WEBP_HAVE_PNG, [1], [Set to 1 if PNG library is installed])
-               ],
-               AC_MSG_WARN(Optional png library not found),
-               [$MATH_LIBS]),
-  AC_MSG_WARN(png library not available - no png.h)
-)
-AC_SUBST(PNG_LIBS)
-AC_SUBST(PNG_INCLUDES)
+  LIBCHECK_PROLOGUE([PNG])
+  AC_CHECK_HEADER(png.h,
+    AC_SEARCH_LIBS(png_get_libpng_ver, [png],
+                   [test "$ac_cv_search_png_get_libpng_ver" = "none required" \
+                      || PNG_LIBS="$PNG_LIBS $ac_cv_search_png_get_libpng_ver"
+                    PNG_INCLUDES="$PNG_INCLUDES -DWEBP_HAVE_PNG"
+                    AC_DEFINE(WEBP_HAVE_PNG, [1],
+                              [Set to 1 if PNG library is installed])
+                    png_support=yes
+                   ],
+                   [AC_MSG_WARN(Optional png library not found)
+                    PNG_LIBS=""
+                    PNG_INCLUDES=""
+                   ],
+                   [$MATH_LIBS]),
+    [AC_MSG_WARN(png library not available - no png.h)
+     PNG_LIBS=""
+     PNG_INCLUDES=""
+    ],
+  )
+  LIBCHECK_EPILOGUE([PNG])
+])
 
 dnl === check for JPEG support ===
 
-JPEG_INCLUDES=""
-JPEG_LIBS=""
-AC_ARG_WITH(jpegincludedir,
-            [--with-jpegincludedir=DIR use JPEG includes from DIR],
-            JPEG_INCLUDES="-I$withval")
-AC_ARG_WITH(jpeglibdir,
-            [--with-jpeglibdir=DIR    use JPEG libraries from DIR],
-            [JPEG_LIBS="-L$withval"])
+AC_ARG_ENABLE([jpeg],
+              AS_HELP_STRING([--disable-jpeg],
+                             [Disable detection of JPEG format support
+                              @<:@default=auto@:>@]))
+AS_IF([test "x$enable_jpeg" != "xno"], [
+  CLEAR_LIBVARS([JPEG])
+  WITHLIB_OPTION([jpeg], [JPEG])
 
-AC_CHECK_HEADER(jpeglib.h,
-  AC_CHECK_LIB(jpeg, jpeg_set_defaults,
-               [JPEG_LIBS="$JPEG_LIBS -ljpeg"
-                JPEG_INCLUDES="$JPEG_INCLUDES -DWEBP_HAVE_JPEG"
-                AC_DEFINE(WEBP_HAVE_JPEG, [1], [Set to 1 if JPEG library is installed])
-               ],
-               AC_MSG_WARN(Optional jpeg library not found),
-               [$MATH_LIBS]),
-  AC_MSG_WARN(jpeg library not available - no jpeglib.h)
-)
-AC_SUBST(JPEG_LIBS)
-AC_SUBST(JPEG_INCLUDES)
+  LIBCHECK_PROLOGUE([JPEG])
+  AC_CHECK_HEADER(jpeglib.h,
+    AC_CHECK_LIB(jpeg, jpeg_set_defaults,
+                 [JPEG_LIBS="$JPEG_LIBS -ljpeg"
+                  JPEG_INCLUDES="$JPEG_INCLUDES -DWEBP_HAVE_JPEG"
+                  AC_DEFINE(WEBP_HAVE_JPEG, [1],
+                            [Set to 1 if JPEG library is installed])
+                  jpeg_support=yes
+                 ],
+                 AC_MSG_WARN(Optional jpeg library not found),
+                 [$MATH_LIBS]),
+    AC_MSG_WARN(jpeg library not available - no jpeglib.h)
+  )
+  LIBCHECK_EPILOGUE([JPEG])
+])
+
+dnl === check for TIFF support ===
+
+AC_ARG_ENABLE([tiff],
+              AS_HELP_STRING([--disable-tiff],
+                             [Disable detection of TIFF format support
+                              @<:@default=auto@:>@]))
+AS_IF([test "x$enable_tiff" != "xno"], [
+  CLEAR_LIBVARS([TIFF])
+  WITHLIB_OPTION([tiff], [TIFF])
+
+  LIBCHECK_PROLOGUE([TIFF])
+  AC_CHECK_HEADER(tiffio.h,
+    AC_CHECK_LIB(tiff, TIFFGetVersion,
+                 [TIFF_LIBS="$TIFF_LIBS -ltiff"
+                  TIFF_INCLUDES="$TIFF_INCLUDES -DWEBP_HAVE_TIFF"
+                  AC_DEFINE(WEBP_HAVE_TIFF, [1],
+                            [Set to 1 if TIFF library is installed])
+                  tiff_support=yes
+                 ],
+                 AC_MSG_WARN(Optional tiff library not found),
+                 [$MATH_LIBS]),
+    AC_MSG_WARN(tiff library not available - no tiffio.h)
+  )
+  LIBCHECK_EPILOGUE([TIFF])
+])
+
+dnl === check for GIF support ===
+
+AC_ARG_ENABLE([gif], AS_HELP_STRING([--disable-gif],
+                                    [Disable detection of GIF format support
+                                     @<:@default=auto@:>@]))
+AS_IF([test "x$enable_gif" != "xno"], [
+  CLEAR_LIBVARS([GIF])
+  WITHLIB_OPTION([gif], [GIF])
+
+  LIBCHECK_PROLOGUE([GIF])
+  AC_CHECK_HEADER(gif_lib.h,
+    AC_CHECK_LIB([gif], [DGifOpenFileHandle],
+                 [GIF_LIBS="$GIF_LIBS -lgif"
+                  AC_DEFINE(WEBP_HAVE_GIF, [1],
+                            [Set to 1 if GIF library is installed])
+                  gif_support=yes
+                 ],
+                 AC_MSG_WARN(Optional gif library not found),
+                 [$MATH_LIBS]),
+    AC_MSG_WARN(gif library not available - no gif_lib.h)
+  )
+  LIBCHECK_EPILOGUE([GIF])
+
+  if test "$gif_support" = "yes" -a \
+          "$enable_libwebpdemux" = "yes"; then
+    build_animdiff=yes
+  fi
+
+  if test "$gif_support" = "yes" -a \
+          "$enable_libwebpmux" = "yes"; then
+    build_gif2webp=yes
+  fi
+])
+AM_CONDITIONAL([BUILD_ANIMDIFF], [test "${build_animdiff}" = "yes"])
+AM_CONDITIONAL([BUILD_GIF2WEBP], [test "${build_gif2webp}" = "yes"])
+
+if test "$enable_libwebpmux" = "yes"; then
+  build_img2webp=yes
+fi
+AM_CONDITIONAL([BUILD_IMG2WEBP], [test "${build_img2webp}" = "yes"])
+
+dnl === check for WIC support ===
+
+AC_ARG_ENABLE([wic],
+              AS_HELP_STRING([--disable-wic],
+                             [Disable Windows Imaging Component (WIC) detection.
+                              @<:@default=auto@:>@]),,
+              [enable_wic=yes])
+
+case $host_os in
+mingw*)
+if test "$enable_wic" = "yes"; then
+  AC_CHECK_HEADERS([wincodec.h shlwapi.h windows.h])
+  if test "$ac_cv_header_wincodec_h" = "yes"; then
+    AC_MSG_CHECKING(for Windows Imaging Component support)
+    SAVED_LIBS=$LIBS
+    LIBS="-lshlwapi -lole32 $LIBS"
+    # match include structure from [cd]webp.c
+    wic_headers="
+      #define INITGUID
+      #define CINTERFACE
+      #define COBJMACROS
+      #define _WIN32_IE 0x500
+
+      #include <shlwapi.h>
+      #include <windows.h>
+      #include <wincodec.h>
+      "
+    # test for functions from each lib and the GUID is created properly
+    wic_main="
+      int main(void) {
+        CLSID_WICImagingFactory;
+        CoInitialize(NULL);
+        SHCreateStreamOnFile(NULL, 0, NULL);
+        return 0;
+      }
+      "
+    AC_LANG_PUSH(C)
+    AC_LINK_IFELSE(
+      [AC_LANG_SOURCE([
+         $wic_headers
+         $wic_main])],
+      [wic_support=yes],
+      [wic_support=no]
+    )
+    AC_LANG_POP
+
+    test "$wic_support" = "yes" || LIBS=$SAVED_LIBS
+    AC_MSG_RESULT(${wic_support-no})
+  fi
+fi
+esac
+
+dnl === If --enable-swap-16bit-csp is defined, add -DWEBP_SWAP_16BIT_CSP
+
+USE_SWAP_16BIT_CSP=""
+AC_MSG_CHECKING(if --enable-swap-16bit-csp option is specified)
+AC_ARG_ENABLE([swap-16bit-csp],
+              AS_HELP_STRING([--enable-swap-16bit-csp],
+                             [Enable byte swap for 16 bit colorspaces]))
+if test "$enable_swap_16bit_csp" = "yes"; then
+  USE_SWAP_16BIT_CSP="-DWEBP_SWAP_16BIT_CSP"
+fi
+AC_MSG_RESULT(${enable_swap_16bit_csp-no})
+AC_SUBST(USE_SWAP_16BIT_CSP)
+
+dnl === If --enable-experimental is defined, add -DWEBP_EXPERIMENTAL_FEATURES
+
+USE_EXPERIMENTAL_CODE=""
+AC_MSG_CHECKING(if --enable-experimental option is specified)
+AC_ARG_ENABLE([experimental], AS_HELP_STRING([--enable-experimental],
+                                             [Activate experimental features]))
+if test "$enable_experimental" = "yes"; then
+  AC_DEFINE(WEBP_EXPERIMENTAL_FEATURES, [1], [Enable experimental code])
+  USE_EXPERIMENTAL_CODE="-DWEBP_EXPERIMENTAL_FEATURES"
+fi
+AC_MSG_RESULT(${enable_experimental-no})
+AC_SUBST(USE_EXPERIMENTAL_CODE)
+
+dnl === Check whether libwebpmux should be built
+AC_MSG_CHECKING(whether libwebpmux is to be built)
+AC_ARG_ENABLE([libwebpmux],
+              AS_HELP_STRING([--enable-libwebpmux],
+                             [Build libwebpmux @<:@default=no@:>@]))
+AC_MSG_RESULT(${enable_libwebpmux-no})
+AM_CONDITIONAL([WANT_MUX], [test "$enable_libwebpmux" = "yes"])
+
+dnl === Check whether libwebpdemux should be built
+AC_MSG_CHECKING(whether libwebpdemux is to be built)
+AC_ARG_ENABLE([libwebpdemux],
+              AS_HELP_STRING([--enable-libwebpdemux],
+                             [Build libwebpdemux @<:@default=no@:>@]))
+AC_MSG_RESULT(${enable_libwebpdemux-no})
+AM_CONDITIONAL([WANT_DEMUX], [test "$enable_libwebpdemux" = "yes"])
+
+dnl === Check whether decoder library should be built.
+AC_MSG_CHECKING(whether decoder library is to be built)
+AC_ARG_ENABLE([libwebpdecoder],
+              AS_HELP_STRING([--enable-libwebpdecoder],
+                             [Build libwebpdecoder @<:@default=no@:>@]))
+AC_MSG_RESULT(${enable_libwebpdecoder-no})
+AM_CONDITIONAL([BUILD_LIBWEBPDECODER], [test "$enable_libwebpdecoder" = "yes"])
+
+dnl === Check whether libwebpextras should be built
+AC_MSG_CHECKING(whether libwebpextras is to be built)
+AC_ARG_ENABLE([libwebpextras],
+              AS_HELP_STRING([--enable-libwebpextras],
+                             [Build libwebpextras @<:@default=no@:>@]))
+AC_MSG_RESULT(${enable_libwebpextras-no})
+AM_CONDITIONAL([WANT_EXTRAS], [test "$enable_libwebpextras" = "yes"])
+
+dnl =========================
 
 AC_CONFIG_MACRO_DIR([m4])
-AC_CONFIG_HEADERS([config.h])
-AC_CONFIG_FILES([Makefile src/Makefile man/Makefile examples/Makefile src/dec/Makefile src/enc/Makefile src/libwebp.pc])
+AC_CONFIG_HEADERS([src/webp/config.h])
+AC_CONFIG_FILES([Makefile src/Makefile man/Makefile \
+                 examples/Makefile extras/Makefile imageio/Makefile \
+                 src/dec/Makefile src/enc/Makefile src/dsp/Makefile \
+                 src/demux/Makefile src/mux/Makefile \
+                 src/utils/Makefile \
+                 src/libwebp.pc src/libwebpdecoder.pc \
+                 src/demux/libwebpdemux.pc src/mux/libwebpmux.pc])
 
 
 AC_OUTPUT
+
+AC_MSG_NOTICE([
+WebP Configuration Summary
+--------------------------
+
+Shared libraries: ${enable_shared}
+Static libraries: ${enable_static}
+Threading support: ${enable_threading-no}
+libwebp: yes
+libwebpdecoder: ${enable_libwebpdecoder-no}
+libwebpdemux: ${enable_libwebpdemux-no}
+libwebpmux: ${enable_libwebpmux-no}
+libwebpextras: ${enable_libwebpextras-no}
+
+Tools:
+cwebp : yes
+  Input format support
+  ====================
+  JPEG : ${jpeg_support-no}
+  PNG  : ${png_support-no}
+  TIFF : ${tiff_support-no}
+  WIC  : ${wic_support-no}
+dwebp : yes
+  Output format support
+  =====================
+  PNG  : ${png_support-no}
+  WIC  : ${wic_support-no}
+GIF support : ${gif_support-no}
+anim_diff   : ${build_animdiff-no}
+gif2webp    : ${build_gif2webp-no}
+img2webp    : ${build_img2webp-no}
+webpmux     : ${enable_libwebpmux-no}
+vwebp       : ${build_vwebp-no}
+])

doc/README

@@ -0,0 +1,29 @@
+
+Generate libwebp Container Spec Docs from Text Source
+=====================================================
+
+HTML generation requires kramdown [1], easily installed as a
+rubygem [2].  Rubygems installation should satisfy dependencies
+automatically.
+
+[1]: http://kramdown.rubyforge.org/
+[2]: http://rubygems.org/
+
+HTML generation can then be done from the project root:
+
+$ kramdown doc/webp-container-spec.txt --template doc/template.html > \
+  doc/output/webp-container-spec.html
+
+kramdown can optionally syntax highlight code blocks, using CodeRay [3],
+a dependency of kramdown that rubygems will install automatically.  The
+following will apply inline CSS styling; an external stylesheet is not
+needed.
+
+$ kramdown doc/webp-lossless-bitstream-spec.txt --template \
+  doc/template.html --coderay-css style --coderay-line-numbers ' ' \
+  --coderay-default-lang c > \
+  doc/output/webp-lossless-bitstream-spec.html
+
+Optimally, use kramdown 0.13.7 or newer if syntax highlighting desired.
+
+[3]: http://coderay.rubychan.de/

doc/TODO

@@ -0,0 +1,13 @@
+<louquillio@google.com>, 20111004
+
+* Determine that normative RFC 2119 terms (MUST, SHOULD, MAY, etc.) are
+  truly intended in all cases where capitalized.
+
+* Several passages could be made clearer.
+
+  * Overall edit for scope.  Portions are phrased as an introduction to
+    the 0.1.3 RIFF container additions, rather than a holistic guide to
+    WebP.
+
+  * To wit, suggest s/[spec|specification]/guide/g .  "Spec" can imply a
+    standards track; in any case it's too formal for a work in progress.

doc/template.html

@@ -0,0 +1,94 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <title>WebP Container Specification</title>
+  <meta name="generator" content="kramdown <%= ::Kramdown::VERSION %>" />
+  <style type="text/css">
+  body {
+    color: #000;
+    background-color: #fff;
+    margin: 10%;
+    font-family: "Liberation Sans", "DejaVu Sans", "Bitstream Vera Sans", Arial, sans-serif;
+    line-height: 1.4;
+  }
+  h2 {
+    border-bottom: 1px solid #ccc;
+    padding-bottom: 0;
+  }
+  table {
+    border-collapse: collapse;
+  }
+  th, td {
+    border: 1px solid #999;
+    padding: .5em .7em;;
+  }
+  th {
+    color: #fff;
+    background-color: #000;
+  }
+  td {
+  }
+  hr {
+  }
+  code {
+    color: #000;
+    background-color: #f7f7f7;
+    padding: 0 3px;
+    font-family: "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", Consolata, monospace;
+  }
+  pre {
+    background-color: #f7f7f7;
+    padding: 1em;
+    border: 1px solid #ccc;
+    width: 42em;
+    overflow: auto;
+    font-family: "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", Consolata, monospace;
+  }
+  pre code {
+    background-color: #f7f7f7;
+    padding: 0; /* Only want padding on inline code, not blocks */
+  }
+  pre.terminal {
+    color: #fff;
+    background-color: #000;
+    border: 1px solid #ccc;
+    max-height: 30em;
+  }
+  pre.terminal code {
+    color: #fff;
+    background-color: #000;
+    font-size: smaller;
+  }
+  #markdown-toc ul {
+    list-style-type: disc;
+  }
+  ul#markdown-toc {
+    margin-top: -1em;
+    visibility: hidden;
+    -webkit-padding-start: 0;
+  }
+  ul#markdown-toc ul {
+    visibility: visible;
+  }
+  ul#markdown-toc ul ul{
+    visibility: visible;
+  }
+  ul#markdown-toc + hr {
+    margin-bottom: 4em;
+  }
+  ol ol { /* Format nested ordered lists */
+    list-style-type: lower-alpha;
+  }
+  dt {
+    font-style: italic;
+    font-weight: bold;
+  }
+  .caption {
+  }
+  </style>
+</head>
+<body>
+<%= @body %>
+</body>
+</html>

doc/webp-container-spec.txt

@@ -0,0 +1,822 @@
+<!--
+
+Although you may be viewing an alternate representation, this document
+is sourced in Markdown, a light-duty markup scheme, and is optimized for
+the [kramdown](http://kramdown.rubyforge.org/) transformer.
+
+See the accompanying README. External link targets are referenced at the
+end of this file.
+
+-->
+
+
+WebP Container Specification
+============================
+
+* TOC placeholder
+{:toc}
+
+
+Introduction
+------------
+
+WebP is an image format that uses either (i) the VP8 key frame encoding
+to compress image data in a lossy way, or (ii) the WebP lossless encoding
+(and possibly other encodings in the future). These encoding schemes should
+make it more efficient than currently used formats. It is optimized for fast
+image transfer over the network (e.g., for websites). The WebP format has
+feature parity (color profile, metadata, animation etc) with other formats as
+well. This document describes the structure of a WebP file.
+
+The WebP container (i.e., RIFF container for WebP) allows feature support over
+and above the basic use case of WebP (i.e., a file containing a single image
+encoded as a VP8 key frame). The WebP container provides additional support
+for:
+
+  * **Lossless compression.** An image can be losslessly compressed, using the
+    WebP Lossless Format.
+
+  * **Metadata.** An image may have metadata stored in EXIF or XMP formats.
+
+  * **Transparency.** An image may have transparency, i.e., an alpha channel.
+
+  * **Color Profile.** An image may have an embedded ICC profile as described
+    by the [International Color Consortium][iccspec].
+
+  * **Animation.** An image may have multiple frames with pauses between them,
+    making it an animation.
+
+The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
+"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
+document are to be interpreted as described in [RFC 2119][].
+
+Bit numbering in chunk diagrams starts at `0` for the most significant bit
+('MSB 0') as described in [RFC 1166][].
+
+**Note:** Out of the features mentioned above, lossy compression, lossless
+compression, transparency, metadata, color profile and animation are finalized
+and are to be considered stable.
+
+Terminology &amp; Basics
+------------------------
+
+A WebP file contains either a still image (i.e., an encoded matrix of pixels)
+or an [animation](#animation). Optionally, it can also contain transparency
+information, color profile and metadata. In case we need to refer only to the
+matrix of pixels, we will call it the _canvas_ of the image.
+
+Below are additional terms used throughout this document:
+
+_Reader/Writer_
+
+: Code that reads WebP files is referred to as a _reader_, while code that
+  writes them is referred to as a _writer_.
+
+_uint16_
+
+: A 16-bit, little-endian, unsigned integer.
+
+_uint24_
+
+: A 24-bit, little-endian, unsigned integer.
+
+_uint32_
+
+: A 32-bit, little-endian, unsigned integer.
+
+_FourCC_
+
+: A _FourCC_ (four-character code) is a _uint32_ created by concatenating four
+  ASCII characters in little-endian order.
+
+_1-based_
+
+: An unsigned integer field storing values offset by `-1`. e.g., Such a field
+  would store value _25_ as _24_.
+
+
+RIFF File Format
+----------------
+
+The WebP file format is based on the RIFF (resource interchange file format)
+document format.
+
+The basic element of a RIFF file is a _chunk_. It consists of:
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                         Chunk FourCC                          |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                          Chunk Size                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                         Chunk Payload                         |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Chunk FourCC: 32 bits
+
+: ASCII four-character code used for chunk identification.
+
+Chunk Size: 32 bits (_uint32_)
+
+: The size of the chunk not including this field, the chunk identifier or
+  padding.
+
+Chunk Payload: _Chunk Size_ bytes
+
+: The data payload. If _Chunk Size_ is odd, a single padding byte -- that
+  SHOULD be `0` -- is added.
+
+_ChunkHeader('ABCD')_
+
+: This is used to describe the _FourCC_ and _Chunk Size_ header of individual
+  chunks, where 'ABCD' is the FourCC for the chunk. This element's
+  size is 8 bytes.
+
+**Note:** RIFF has a convention that all-uppercase chunk FourCCs are standard
+chunks that apply to any RIFF file format, while FourCCs specific to a file
+format are all lowercase. WebP does not follow this convention.
+
+
+WebP File Header
+----------------
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |      'R'      |      'I'      |      'F'      |      'F'      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                           File Size                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |      'W'      |      'E'      |      'B'      |      'P'      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+'RIFF': 32 bits
+
+: The ASCII characters 'R' 'I' 'F' 'F'.
+
+File Size: 32 bits (_uint32_)
+
+: The size of the file in bytes starting at offset 8. The maximum value of
+  this field is 2^32 minus 10 bytes and thus the size of the whole file is at
+  most 4GiB minus 2 bytes.
+
+'WEBP': 32 bits
+
+: The ASCII characters 'W' 'E' 'B' 'P'.
+
+A WebP file MUST begin with a RIFF header with the FourCC 'WEBP'. The file size
+in the header is the total size of the chunks that follow plus `4` bytes for
+the 'WEBP' FourCC. The file SHOULD NOT contain anything after it. As the size
+of any chunk is even, the size given by the RIFF header is also even. The
+contents of individual chunks will be described in the following sections.
+
+
+Simple File Format (Lossy)
+--------------------------
+
+This layout SHOULD be used if the image requires _lossy_ encoding and does not
+require transparency or other advanced features provided by the extended format.
+Files with this layout are smaller and supported by older software.
+
+Simple WebP (lossy) file format:
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                    WebP file header (12 bytes)                |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                          VP8 chunk                            |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+VP8 chunk:
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                      ChunkHeader('VP8 ')                      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                           VP8 data                            |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+VP8 data: _Chunk Size_ bytes
+
+: VP8 bitstream data.
+
+The VP8 bitstream format specification can be found at [VP8 Data Format and
+Decoding Guide][vp8spec]. Note that the VP8 frame header contains the VP8 frame
+width and height. That is assumed to be the width and height of the canvas.
+
+The VP8 specification describes how to decode the image into Y'CbCr
+format. To convert to RGB, Rec. 601 SHOULD be used.
+
+
+Simple File Format (Lossless)
+-----------------------------
+
+**Note:** Older readers may not support files using the lossless format.
+
+This layout SHOULD be used if the image requires _lossless_ encoding (with an
+optional transparency channel) and does not require advanced features provided
+by the extended format.
+
+Simple WebP (lossless) file format:
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                    WebP file header (12 bytes)                |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                          VP8L chunk                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+VP8L chunk:
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                      ChunkHeader('VP8L')                      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                           VP8L data                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+VP8L data: _Chunk Size_ bytes
+
+: VP8L bitstream data.
+
+The current specification of the VP8L bitstream can be found at
+[WebP Lossless Bitstream Format][webpllspec]. Note that the VP8L header
+contains the VP8L image width and height. That is assumed to be the width
+and height of the canvas.
+
+
+Extended File Format
+--------------------
+
+**Note:** Older readers may not support files using the extended format.
+
+An extended format file consists of:
+
+  * A 'VP8X' chunk with information about features used in the file.
+
+  * An optional 'ICCP' chunk with color profile.
+
+  * An optional 'ANIM' chunk with animation control data.
+
+  * Image data.
+
+  * An optional 'EXIF' chunk with EXIF metadata.
+
+  * An optional 'XMP ' chunk with XMP metadata.
+
+  * An optional list of [unknown chunks](#unknown-chunks). _\[status: experimental\]_
+
+For a _still image_, the _image data_ consists of a single frame, which is made
+up of:
+
+  * An optional [alpha subchunk](#alpha).
+
+  * A [bitstream subchunk](#bitstream-vp8vp8l).
+
+For an _animated image_, the _image data_ consists of multiple frames. More
+details about frames can be found in the [Animation](#animation) section.
+
+All chunks SHOULD be placed in the same order as listed above. If a chunk
+appears in the wrong place, the file is invalid, but readers MAY parse the
+file, ignoring the chunks that come too late.
+
+**Rationale:** Setting the order of chunks should allow quicker file
+parsing. For example, if an 'ALPH' chunk does not appear in its required
+position, a decoder can choose to stop searching for it. The rule of
+ignoring late chunks should make programs that need to do a full search
+give the same results as the ones stopping early.
+
+Extended WebP file header:
+{:#extended_header}
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                   WebP file header (12 bytes)                 |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                      ChunkHeader('VP8X')                      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |Rsv|I|L|E|X|A|R|                   Reserved                    |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |          Canvas Width Minus One               |             ...
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    ...  Canvas Height Minus One    |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Reserved (Rsv): 2 bits
+
+: SHOULD be `0`.
+
+ICC profile (I): 1 bit
+
+: Set if the file contains an ICC profile.
+
+Alpha (L): 1 bit
+
+: Set if any of the frames of the image contain transparency information
+  ("alpha").
+
+EXIF metadata (E): 1 bit
+
+: Set if the file contains EXIF metadata.
+
+XMP metadata (X): 1 bit
+
+: Set if the file contains XMP metadata.
+
+Animation (A): 1 bit
+
+: Set if this is an animated image. Data in 'ANIM' and 'ANMF' chunks should be
+  used to control the animation.
+
+Reserved (R): 1 bit
+
+: SHOULD be `0`.
+
+Reserved: 24 bits
+
+: SHOULD be `0`.
+
+Canvas Width Minus One: 24 bits
+
+: _1-based_ width of the canvas in pixels.
+  The actual canvas width is '1 + Canvas Width Minus One'
+
+Canvas Height Minus One: 24 bits
+
+: _1-based_ height of the canvas in pixels.
+  The actual canvas height is '1 + Canvas Height Minus One'
+
+The product of _Canvas Width_ and _Canvas Height_ MUST be at most `2^32 - 1`.
+
+Future specifications MAY add more fields.
+
+### Chunks
+
+#### Animation
+
+An animation is controlled by ANIM and ANMF chunks.
+
+ANIM Chunk:
+{:#anim_chunk}
+
+For an animated image, this chunk contains the _global parameters_ of the
+animation.
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                      ChunkHeader('ANIM')                      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                       Background Color                        |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |          Loop Count           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Background Color: 32 bits (_uint32_)
+
+: The default background color of the canvas in \[Blue, Green, Red, Alpha\]
+  byte order. This color MAY be used to fill the unused space on the canvas
+  around the frames, as well as the transparent pixels of the first frame.
+  Background color is also used when disposal method is `1`.
+
+**Note**:
+
+  * Background color MAY contain a transparency value (alpha), even if the
+    _Alpha_ flag in [VP8X chunk](#extended_header) is unset.
+
+  * Viewer applications SHOULD treat the background color value as a hint, and
+    are not required to use it.
+
+  * The canvas is cleared at the start of each loop. The background color MAY be
+    used to achieve this.
+
+Loop Count: 16 bits (_uint16_)
+
+: The number of times to loop the animation. `0` means infinitely.
+
+This chunk MUST appear if the _Animation_ flag in the VP8X chunk is set.
+If the _Animation_ flag is not set and this chunk is present, it
+SHOULD be ignored.
+
+ANMF chunk:
+
+For animated images, this chunk contains information about a _single_ frame.
+If the _Animation flag_ is not set, then this chunk SHOULD NOT be present.
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                      ChunkHeader('ANMF')                      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                        Frame X                |             ...
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    ...          Frame Y            |   Frame Width Minus One     ...
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    ...             |           Frame Height Minus One              |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                 Frame Duration                |  Reserved |B|D|
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                         Frame Data                            |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Frame X: 24 bits (_uint24_)
+
+: The X coordinate of the upper left corner of the frame is `Frame X * 2`
+
+Frame Y: 24 bits (_uint24_)
+
+: The Y coordinate of the upper left corner of the frame is `Frame Y * 2`
+
+Frame Width Minus One: 24 bits (_uint24_)
+
+: The _1-based_ width of the frame.
+  The frame width is `1 + Frame Width Minus One`
+
+Frame Height Minus One: 24 bits (_uint24_)
+
+: The _1-based_ height of the frame.
+  The frame height is `1 + Frame Height Minus One`
+
+Frame Duration: 24 bits (_uint24_)
+
+: The time to wait before displaying the next frame, in 1 millisecond units.
+  In particular, frame duration of 0 is useful when one wants to update
+  multiple areas of the canvas at once during the animation.
+
+Reserved: 6 bits
+
+: SHOULD be 0.
+
+Blending method (B): 1 bit
+
+: Indicates how transparent pixels of _the current frame_ are to be blended
+  with corresponding pixels of the previous canvas:
+
+    * `0`: Use alpha blending. After disposing of the previous frame, render the
+      current frame on the canvas using [alpha-blending](#alpha-blending). If
+      the current frame does not have an alpha channel, assume alpha value of
+      255, effectively replacing the rectangle.
+
+    * `1`: Do not blend. After disposing of the previous frame, render the
+      current frame on the canvas by overwriting the rectangle covered by the
+      current frame.
+
+Disposal method (D): 1 bit
+
+: Indicates how _the current frame_ is to be treated after it has been
+  displayed (before rendering the next frame) on the canvas:
+
+    * `0`: Do not dispose. Leave the canvas as is.
+
+    * `1`: Dispose to background color. Fill the _rectangle_ on the canvas
+      covered by the _current frame_ with background color specified in the
+      [ANIM chunk](#anim_chunk).
+
+**Notes**:
+
+  * The frame disposal only applies to the _frame rectangle_, that is, the
+    rectangle defined by _Frame X_, _Frame Y_, _frame width_ and _frame height_.
+    It may or may not cover the whole canvas.
+
+{:#alpha-blending}
+  * **Alpha-blending**:
+
+    Given that each of the R, G, B and A channels is 8-bit, and the RGB
+    channels are _not premultiplied_ by alpha, the formula for blending
+    'dst' onto 'src' is:
+
+~~~~~
+    blend.A = src.A + dst.A * (1 - src.A / 255)
+    if blend.A = 0 then
+      blend.RGB = 0
+    else
+      blend.RGB = (src.RGB * src.A +
+                   dst.RGB * dst.A * (1 - src.A / 255)) / blend.A
+~~~~~
+
+  * Alpha-blending SHOULD be done in linear color space, by taking into account
+    the [color profile](#color-profile) of the image. If the color profile is
+    not present, sRGB is to be assumed. (Note that sRGB also needs to be
+    linearized due to a gamma of ~2.2).
+
+Frame Data: _Chunk Size_ - `16` bytes
+
+: Consists of:
+
+  * An optional [alpha subchunk](#alpha) for the frame.
+
+  * A [bitstream subchunk](#bitstream-vp8vp8l) for the frame.
+
+  * An optional list of [unknown chunks](#unknown-chunks).
+
+**Note**: The 'ANMF' payload, _Frame Data_ above, consists of individual
+_padded_ chunks as described by the [RIFF file format](#riff-file-format).
+
+#### Alpha
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                      ChunkHeader('ALPH')                      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |Rsv| P | F | C |     Alpha Bitstream...                        |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Reserved (Rsv): 2 bits
+
+: SHOULD be `0`.
+
+Pre-processing (P): 2 bits
+
+: These INFORMATIVE bits are used to signal the pre-processing that has
+  been performed during compression. The decoder can use this information to
+  e.g. dither the values or smooth the gradients prior to display.
+
+    * `0`: no pre-processing
+    * `1`: level reduction
+
+Filtering method (F): 2 bits
+
+: The filtering method used:
+
+    * `0`: None.
+    * `1`: Horizontal filter.
+    * `2`: Vertical filter.
+    * `3`: Gradient filter.
+
+For each pixel, filtering is performed using the following calculations.
+Assume the alpha values surrounding the current `X` position are labeled as:
+
+     C | B |
+    ---+---+
+     A | X |
+
+We seek to compute the alpha value at position `X`. First, a prediction is
+made depending on the filtering method:
+
+  * Method `0`: predictor = 0
+  * Method `1`: predictor = A
+  * Method `2`: predictor = B
+  * Method `3`: predictor = clip(A + B - C)
+
+where `clip(v)` is equal to:
+
+  * 0    if v < 0
+  * 255  if v > 255
+  * v    otherwise
+
+The final value is derived by adding the decompressed value `X` to the
+predictor and using modulo-256 arithmetic to wrap the \[256-511\] range
+into the \[0-255\] one:
+
+`alpha = (predictor + X) % 256`
+
+There are special cases for left-most and top-most pixel positions:
+
+  * Top-left value at location (0,0) uses 0 as predictor value. Otherwise,
+  * For horizontal or gradient filtering methods, the left-most pixels at
+    location (0, y) are predicted using the location (0, y-1) just above.
+  * For vertical or gradient filtering methods, the top-most pixels at
+    location (x, 0) are predicted using the location (x-1, 0) on the left.
+
+
+Decoders are not required to use this information in any specified way.
+
+Compression method (C): 2 bits
+
+: The compression method used:
+
+    * `0`: No compression.
+    * `1`: Compressed using the WebP lossless format.
+
+Alpha bitstream: _Chunk Size_ - `1` bytes
+
+: Encoded alpha bitstream.
+
+This optional chunk contains encoded alpha data for this frame. A frame
+containing a 'VP8L' chunk SHOULD NOT contain this chunk.
+
+**Rationale**: The transparency information is already part of the 'VP8L'
+chunk.
+
+The alpha channel data is stored as uncompressed raw data (when
+compression method is '0') or compressed using the lossless format
+(when the compression method is '1').
+
+  * Raw data: consists of a byte sequence of length width * height,
+    containing all the 8-bit transparency values in scan order.
+
+  * Lossless format compression: the byte sequence is a compressed
+    image-stream (as described in the [WebP Lossless Bitstream Format]
+    [webpllspec]) of implicit dimension width x height. That is, this
+    image-stream does NOT contain any headers describing the image dimension.
+
+    **Rationale**: the dimension is already known from other sources,
+    so storing it again would be redundant and error-prone.
+
+    Once the image-stream is decoded into ARGB color values, following
+    the process described in the lossless format specification, the
+    transparency information must be extracted from the *green* channel
+    of the ARGB quadruplet.
+
+    **Rationale**: the green channel is allowed extra transformation
+    steps in the specification -- unlike the other channels -- that can
+    improve compression.
+
+#### Bitstream (VP8/VP8L)
+
+This chunk contains compressed bitstream data for a single frame.
+
+A bitstream chunk may be either (i) a VP8 chunk, using "VP8 " (note the
+significant fourth-character space) as its tag _or_ (ii) a VP8L chunk, using
+"VP8L" as its tag.
+
+The formats of VP8 and VP8L chunks are as described in sections
+[Simple File Format (Lossy)](#simple-file-format-lossy)
+and [Simple File Format (Lossless)](#simple-file-format-lossless) respectively.
+
+#### Color profile
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                      ChunkHeader('ICCP')                      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                       Color Profile                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Color Profile: _Chunk Size_ bytes
+
+: ICC profile.
+
+This chunk MUST appear before the image data.
+
+There SHOULD be at most one such chunk. If there are more such chunks, readers
+MAY ignore all except the first one.
+See the [ICC Specification][iccspec] for details.
+
+If this chunk is not present, sRGB SHOULD be assumed.
+
+#### Metadata
+
+Metadata can be stored in 'EXIF' or 'XMP ' chunks.
+
+There SHOULD be at most one chunk of each type ('EXIF' and 'XMP '). If there
+are more such chunks, readers MAY ignore all except the first one. Also, a file
+may possibly contain both 'EXIF' and 'XMP ' chunks.
+
+The chunks are defined as follows:
+
+EXIF chunk:
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                      ChunkHeader('EXIF')                      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                        EXIF Metadata                          |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+EXIF Metadata: _Chunk Size_ bytes
+
+: image metadata in EXIF format.
+
+XMP chunk:
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                      ChunkHeader('XMP ')                      |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                        XMP Metadata                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+XMP Metadata: _Chunk Size_ bytes
+
+: image metadata in XMP format.
+
+Additional guidance about handling metadata can be found in the
+Metadata Working Group's [Guidelines for Handling Metadata][metadata].
+
+#### Unknown Chunks _\[status: experimental\]_
+
+A RIFF chunk (described in [this](#terminology-amp-basics) section) whose _chunk
+tag_ is different from any of the chunks described in this document, is
+considered an _unknown chunk_.
+
+**Rationale**: Allowing unknown chunks gives a provision for future extension
+of the format, and also allows storage of any application-specific data.
+
+A file MAY contain unknown chunks:
+
+  * At the end of the file as described in [Extended WebP file
+    header](#extended_header) section.
+  * At the end of ANMF chunks as described in the
+    [Animation](#animation) section.
+
+Readers SHOULD ignore these chunks. Writers SHOULD preserve them in their
+original order (unless they specifically intend to modify these chunks).
+
+### Assembling the Canvas from frames
+
+Here we provide an overview of how a reader should assemble a canvas in the
+case of an animated image. The notation _VP8X.field_ means the field in the
+'VP8X' chunk with the same description.
+
+Displaying an _animated image_ canvas MUST be equivalent to the following
+pseudocode:
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+assert VP8X.flags.hasAnimation
+canvas ← new image of size VP8X.canvasWidth x VP8X.canvasHeight with
+         background color ANIM.background_color.
+loop_count ← ANIM.loopCount
+dispose_method ← ANIM.disposeMethod
+if loop_count == 0:
+    loop_count = ∞
+frame_params ← nil
+assert next chunk in image_data is ANMF
+for loop = 0..loop_count - 1
+    clear canvas to ANIM.background_color or application defined color
+    until eof or non-ANMF chunk
+        frame_params.frameX = Frame X
+        frame_params.frameY = Frame Y
+        frame_params.frameWidth = Frame Width Minus One + 1
+        frame_params.frameHeight = Frame Height Minus One + 1
+        frame_params.frameDuration = Frame Duration
+        frame_right = frame_params.frameX + frame_params.frameWidth
+        frame_bottom = frame_params.frameY + frame_params.frameHeight
+        assert VP8X.canvasWidth >= frame_right
+        assert VP8X.canvasHeight >= frame_bottom
+        for subchunk in 'Frame Data':
+            if subchunk.tag == "ALPH":
+                assert alpha subchunks not found in 'Frame Data' earlier
+                frame_params.alpha = alpha_data
+            else if subchunk.tag == "VP8 " OR subchunk.tag == "VP8L":
+                assert bitstream subchunks not found in 'Frame Data' earlier
+                frame_params.bitstream = bitstream_data
+        render frame with frame_params.alpha and frame_params.bitstream on
+            canvas with top-left corner at (frame_params.frameX,
+            frame_params.frameY), using dispose method dispose_method.
+        canvas contains the decoded image.
+        Show the contents of the canvas for frame_params.frameDuration * 1ms.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+
+Example File Layouts
+--------------------
+
+A lossy encoded image with alpha may look as follows:
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+RIFF/WEBP
++- VP8X (descriptions of features used)
++- ALPH (alpha bitstream)
++- VP8 (bitstream)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+A losslessly encoded image may look as follows:
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+RIFF/WEBP
++- VP8X (descriptions of features used)
++- XYZW (unknown chunk)
++- VP8L (lossless bitstream)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+A lossless image with ICC profile and XMP metadata may
+look as follows:
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+RIFF/WEBP
++- VP8X (descriptions of features used)
++- ICCP (color profile)
++- VP8L (lossless bitstream)
++- XMP  (metadata)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+An animated image with EXIF metadata may look as follows:
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+RIFF/WEBP
++- VP8X (descriptions of features used)
++- ANIM (global animation parameters)
++- ANMF (frame1 parameters + data)
++- ANMF (frame2 parameters + data)
++- ANMF (frame3 parameters + data)
++- ANMF (frame4 parameters + data)
++- EXIF (metadata)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+[vp8spec]:  http://tools.ietf.org/html/rfc6386
+[webpllspec]: https://chromium.googlesource.com/webm/libwebp/+/master/doc/webp-lossless-bitstream-spec.txt
+[iccspec]: http://www.color.org/icc_specs2.xalter
+[metadata]: http://www.metadataworkinggroup.org/pdf/mwg_guidance.pdf
+[rfc 1166]: http://tools.ietf.org/html/rfc1166
+[rfc 2119]: http://tools.ietf.org/html/rfc2119

examples/Android.mk

@@ -0,0 +1,82 @@
+LOCAL_PATH := $(call my-dir)
+
+################################################################################
+# libexample_util
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    example_util.c \
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../src
+
+LOCAL_MODULE := example_util
+
+include $(BUILD_STATIC_LIBRARY)
+
+################################################################################
+# cwebp
+
+include $(CLEAR_VARS)
+
+# Note: to enable jpeg/png encoding the sources from AOSP can be used with
+# minor modification to their Android.mk files.
+LOCAL_SRC_FILES := \
+    cwebp.c \
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../src
+LOCAL_STATIC_LIBRARIES := example_util imageio_util imagedec webp
+
+LOCAL_MODULE := cwebp
+
+include $(BUILD_EXECUTABLE)
+
+################################################################################
+# dwebp
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    dwebp.c \
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../src
+LOCAL_STATIC_LIBRARIES := example_util imagedec imageenc webp
+
+LOCAL_MODULE := dwebp
+
+include $(BUILD_EXECUTABLE)
+
+################################################################################
+# webpmux
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    webpmux.c \
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../src
+LOCAL_STATIC_LIBRARIES := example_util imageio_util webpmux webp
+
+LOCAL_MODULE := webpmux_example
+
+include $(BUILD_EXECUTABLE)
+
+################################################################################
+# img2webp
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    img2webp.c \
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../src
+LOCAL_STATIC_LIBRARIES := example_util imageio_util imagedec webpmux webp
+
+LOCAL_MODULE := img2webp_example
+
+include $(BUILD_EXECUTABLE)

examples/Makefile.am

@@ -1,11 +1,75 @@
-AM_CPPFLAGS = -I$(top_srcdir)/src
+AM_CPPFLAGS += -I$(top_builddir)/src -I$(top_srcdir)/src
 
 bin_PROGRAMS = dwebp cwebp
+if BUILD_ANIMDIFF
+  noinst_PROGRAMS = anim_diff
+endif
+if BUILD_GIF2WEBP
+  bin_PROGRAMS += gif2webp
+endif
+if BUILD_IMG2WEBP
+  bin_PROGRAMS += img2webp
+endif
+if WANT_MUX
+  bin_PROGRAMS += webpmux
+endif
+if BUILD_VWEBP
+  bin_PROGRAMS += vwebp
+endif
+
+noinst_LTLIBRARIES = libexample_util.la
+
+libexample_util_la_SOURCES = example_util.c example_util.h
+libexample_util_la_LIBADD = ../src/libwebp.la
+
+anim_diff_SOURCES = anim_diff.c anim_util.c anim_util.h
+anim_diff_CPPFLAGS = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE) $(GIF_INCLUDES)
+anim_diff_LDADD  = ../src/demux/libwebpdemux.la
+anim_diff_LDADD += libexample_util.la ../imageio/libimageio_util.la
+anim_diff_LDADD += $(GIF_LIBS) -lm
+
+cwebp_SOURCES  = cwebp.c stopwatch.h
+cwebp_CPPFLAGS  = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE)
+cwebp_LDADD  = libexample_util.la ../imageio/libimageio_util.la
+cwebp_LDADD += ../imageio/libimagedec.la ../src/libwebp.la
+cwebp_LDADD += $(JPEG_LIBS) $(PNG_LIBS) $(TIFF_LIBS)
 
 dwebp_SOURCES = dwebp.c stopwatch.h
-dwebp_CPPFLAGS = $(AM_CPPFLAGS) $(PNG_INCLUDES) $(JPEG_INCLUDES)
-dwebp_LDADD = ../src/libwebp.la $(PNG_LIBS) $(JPEG_LIBS)
+dwebp_CPPFLAGS  = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE)
+dwebp_CPPFLAGS += $(JPEG_INCLUDES) $(PNG_INCLUDES)
+dwebp_LDADD  = libexample_util.la
+dwebp_LDADD += ../imageio/libimagedec.la
+dwebp_LDADD += ../imageio/libimageenc.la
+dwebp_LDADD += ../imageio/libimageio_util.la
+dwebp_LDADD += ../src/libwebp.la
+dwebp_LDADD +=$(PNG_LIBS) $(JPEG_LIBS)
 
-cwebp_SOURCES = cwebp.c stopwatch.h
-cwebp_CPPFLAGS = $(AM_CPPFLAGS) $(PNG_INCLUDES) $(JPEG_INCLUDES)
-cwebp_LDADD = ../src/libwebp.la $(PNG_LIBS) $(JPEG_LIBS)
+gif2webp_SOURCES = gif2webp.c gifdec.c gifdec.h
+gif2webp_CPPFLAGS = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE) $(GIF_INCLUDES)
+gif2webp_LDADD  = libexample_util.la ../imageio/libimageio_util.la
+gif2webp_LDADD += ../src/mux/libwebpmux.la ../src/libwebp.la $(GIF_LIBS)
+
+vwebp_SOURCES = vwebp.c
+vwebp_CPPFLAGS = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE) $(GL_INCLUDES)
+vwebp_LDADD  = libexample_util.la ../imageio/libimageio_util.la
+vwebp_LDADD += ../src/demux/libwebpdemux.la $(GL_LIBS)
+
+webpmux_SOURCES = webpmux.c
+webpmux_CPPFLAGS = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE)
+webpmux_LDADD  = libexample_util.la ../imageio/libimageio_util.la
+webpmux_LDADD += ../src/mux/libwebpmux.la ../src/libwebp.la
+
+img2webp_SOURCES = img2webp.c
+img2webp_CPPFLAGS = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE)
+img2webp_LDADD  = libexample_util.la ../imageio/libimageio_util.la
+img2webp_LDADD += ../imageio/libimagedec.la
+img2webp_LDADD += ../src/mux/libwebpmux.la ../src/libwebp.la
+img2webp_LDADD += $(PNG_LIBS) $(JPEG_LIBS) $(TIFF_LIBS)
+
+if BUILD_LIBWEBPDECODER
+  anim_diff_LDADD += ../src/libwebpdecoder.la
+  vwebp_LDADD += ../src/libwebpdecoder.la
+else
+  anim_diff_LDADD += ../src/libwebp.la
+  vwebp_LDADD += ../src/libwebp.la
+endif

examples/anim_diff.c

@@ -0,0 +1,303 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Checks if given pair of animated GIF/WebP images are identical:
+// That is: their reconstructed canvases match pixel-by-pixel and their other
+// animation properties (loop count etc) also match.
+//
+// example: anim_diff foo.gif bar.webp
+
+#include <assert.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>  // for 'strtod'.
+#include <string.h>  // for 'strcmp'.
+
+#include "./anim_util.h"
+
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#define snprintf _snprintf
+#endif
+
+// Returns true if 'a + b' will overflow.
+static int AdditionWillOverflow(int a, int b) {
+  return (b > 0) && (a > INT_MAX - b);
+}
+
+static int FramesAreEqual(const uint8_t* const rgba1,
+                          const uint8_t* const rgba2, int width, int height) {
+  const int stride = width * 4;  // Always true for 'DecodedFrame.rgba'.
+  return !memcmp(rgba1, rgba2, stride * height);
+}
+
+static WEBP_INLINE int PixelsAreSimilar(uint32_t src, uint32_t dst,
+                                        int max_allowed_diff) {
+  const int src_a = (src >> 24) & 0xff;
+  const int src_r = (src >> 16) & 0xff;
+  const int src_g = (src >> 8) & 0xff;
+  const int src_b = (src >> 0) & 0xff;
+  const int dst_a = (dst >> 24) & 0xff;
+  const int dst_r = (dst >> 16) & 0xff;
+  const int dst_g = (dst >> 8) & 0xff;
+  const int dst_b = (dst >> 0) & 0xff;
+
+  return (abs(src_r * src_a - dst_r * dst_a) <= (max_allowed_diff * 255)) &&
+         (abs(src_g * src_a - dst_g * dst_a) <= (max_allowed_diff * 255)) &&
+         (abs(src_b * src_a - dst_b * dst_a) <= (max_allowed_diff * 255)) &&
+         (abs(src_a - dst_a) <= max_allowed_diff);
+}
+
+static int FramesAreSimilar(const uint8_t* const rgba1,
+                            const uint8_t* const rgba2,
+                            int width, int height, int max_allowed_diff) {
+  int i, j;
+  assert(max_allowed_diff > 0);
+  for (j = 0; j < height; ++j) {
+    for (i = 0; i < width; ++i) {
+      const int stride = width * 4;
+      const size_t offset = j * stride + i;
+      if (!PixelsAreSimilar(rgba1[offset], rgba2[offset], max_allowed_diff)) {
+        return 0;
+      }
+    }
+  }
+  return 1;
+}
+
+// Minimize number of frames by combining successive frames that have at max
+// 'max_diff' difference per channel between corresponding pixels.
+static void MinimizeAnimationFrames(AnimatedImage* const img, int max_diff) {
+  uint32_t i;
+  for (i = 1; i < img->num_frames; ++i) {
+    DecodedFrame* const frame1 = &img->frames[i - 1];
+    DecodedFrame* const frame2 = &img->frames[i];
+    const uint8_t* const rgba1 = frame1->rgba;
+    const uint8_t* const rgba2 = frame2->rgba;
+    int should_merge_frames = 0;
+    // If merging frames will result in integer overflow for 'duration',
+    // skip merging.
+    if (AdditionWillOverflow(frame1->duration, frame2->duration)) continue;
+    if (max_diff > 0) {
+      should_merge_frames = FramesAreSimilar(rgba1, rgba2, img->canvas_width,
+                                             img->canvas_height, max_diff);
+    } else {
+      should_merge_frames =
+          FramesAreEqual(rgba1, rgba2, img->canvas_width, img->canvas_height);
+    }
+    if (should_merge_frames) {  // Merge 'i+1'th frame into 'i'th frame.
+      frame1->duration += frame2->duration;
+      if (i + 1 < img->num_frames) {
+        memmove(&img->frames[i], &img->frames[i + 1],
+                (img->num_frames - i - 1) * sizeof(*img->frames));
+      }
+      --img->num_frames;
+      --i;
+    }
+  }
+}
+
+static int CompareValues(uint32_t a, uint32_t b, const char* output_str) {
+  if (a != b) {
+    fprintf(stderr, "%s: %d vs %d\n", output_str, a, b);
+    return 0;
+  }
+  return 1;
+}
+
+static int CompareBackgroundColor(uint32_t bg1, uint32_t bg2, int premultiply) {
+  if (premultiply) {
+    const int alpha1 = (bg1 >> 24) & 0xff;
+    const int alpha2 = (bg2 >> 24) & 0xff;
+    if (alpha1 == 0 && alpha2 == 0) return 1;
+  }
+  if (bg1 != bg2) {
+    fprintf(stderr, "Background color mismatch: 0x%08x vs 0x%08x\n",
+            bg1, bg2);
+    return 0;
+  }
+  return 1;
+}
+
+// Note: As long as frame durations and reconstructed frames are identical, it
+// is OK for other aspects like offsets, dispose/blend method to vary.
+static int CompareAnimatedImagePair(const AnimatedImage* const img1,
+                                    const AnimatedImage* const img2,
+                                    int premultiply,
+                                    double min_psnr) {
+  int ok = 1;
+  const int is_multi_frame_image = (img1->num_frames > 1);
+  uint32_t i;
+
+  ok = CompareValues(img1->canvas_width, img2->canvas_width,
+                     "Canvas width mismatch") && ok;
+  ok = CompareValues(img1->canvas_height, img2->canvas_height,
+                     "Canvas height mismatch") && ok;
+  ok = CompareValues(img1->num_frames, img2->num_frames,
+                     "Frame count mismatch") && ok;
+  if (!ok) return 0;  // These are fatal failures, can't proceed.
+
+  if (is_multi_frame_image) {  // Checks relevant for multi-frame images only.
+    ok = CompareValues(img1->loop_count, img2->loop_count,
+                       "Loop count mismatch") && ok;
+    ok = CompareBackgroundColor(img1->bgcolor, img2->bgcolor,
+                                premultiply) && ok;
+  }
+
+  for (i = 0; i < img1->num_frames; ++i) {
+    // Pixel-by-pixel comparison.
+    const uint8_t* const rgba1 = img1->frames[i].rgba;
+    const uint8_t* const rgba2 = img2->frames[i].rgba;
+    int max_diff;
+    double psnr;
+    if (is_multi_frame_image) {  // Check relevant for multi-frame images only.
+      const char format[] = "Frame #%d, duration mismatch";
+      char tmp[sizeof(format) + 8];
+      ok = ok && (snprintf(tmp, sizeof(tmp), format, i) >= 0);
+      ok = ok && CompareValues(img1->frames[i].duration,
+                               img2->frames[i].duration, tmp);
+    }
+    GetDiffAndPSNR(rgba1, rgba2, img1->canvas_width, img1->canvas_height,
+                   premultiply, &max_diff, &psnr);
+    if (min_psnr > 0.) {
+      if (psnr < min_psnr) {
+        fprintf(stderr, "Frame #%d, psnr = %.2lf (min_psnr = %f)\n", i,
+                psnr, min_psnr);
+        ok = 0;
+      }
+    } else {
+      if (max_diff != 0) {
+        fprintf(stderr, "Frame #%d, max pixel diff: %d\n", i, max_diff);
+        ok = 0;
+      }
+    }
+  }
+  return ok;
+}
+
+static void Help(void) {
+  printf("Usage: anim_diff <image1> <image2> [options]\n");
+  printf("\nOptions:\n");
+  printf("  -dump_frames <folder> dump decoded frames in PAM format\n");
+  printf("  -min_psnr <float> ... minimum per-frame PSNR\n");
+  printf("  -raw_comparison ..... if this flag is not used, RGB is\n");
+  printf("                        premultiplied before comparison\n");
+#ifdef WEBP_EXPERIMENTAL_FEATURES
+  printf("  -max_diff <int> ..... maximum allowed difference per channel "
+         "                        between corresponding pixels in subsequent"
+         "                        frames\n");
+#endif
+}
+
+int main(int argc, const char* argv[]) {
+  int return_code = -1;
+  int dump_frames = 0;
+  const char* dump_folder = NULL;
+  double min_psnr = 0.;
+  int got_input1 = 0;
+  int got_input2 = 0;
+  int premultiply = 1;
+  int max_diff = 0;
+  int i, c;
+  const char* files[2] = { NULL, NULL };
+  AnimatedImage images[2];
+
+  if (argc < 3) {
+    Help();
+    return -1;
+  }
+
+  for (c = 1; c < argc; ++c) {
+    int parse_error = 0;
+    if (!strcmp(argv[c], "-dump_frames")) {
+      if (c < argc - 1) {
+        dump_frames = 1;
+        dump_folder = argv[++c];
+      } else {
+        parse_error = 1;
+      }
+    } else if (!strcmp(argv[c], "-min_psnr")) {
+      if (c < argc - 1) {
+        const char* const v = argv[++c];
+        char* end = NULL;
+        const double d = strtod(v, &end);
+        if (end == v) {
+          parse_error = 1;
+          fprintf(stderr, "Error! '%s' is not a floating point number.\n", v);
+        }
+        min_psnr = d;
+      } else {
+        parse_error = 1;
+      }
+    } else if (!strcmp(argv[c], "-raw_comparison")) {
+      premultiply = 0;
+#ifdef WEBP_EXPERIMENTAL_FEATURES
+    } else if (!strcmp(argv[c], "-max_diff")) {
+      if (c < argc - 1) {
+        const char* const v = argv[++c];
+        char* end = NULL;
+        const int n = (int)strtol(v, &end, 10);
+        if (end == v) {
+          parse_error = 1;
+          fprintf(stderr, "Error! '%s' is not an integer.\n", v);
+        }
+        max_diff = n;
+      } else {
+        parse_error = 1;
+      }
+#endif
+    } else {
+      if (!got_input1) {
+        files[0] = argv[c];
+        got_input1 = 1;
+      } else if (!got_input2) {
+        files[1] = argv[c];
+        got_input2 = 1;
+      } else {
+        parse_error = 1;
+      }
+    }
+    if (parse_error) {
+      Help();
+      return -1;
+    }
+  }
+  if (!got_input2) {
+    Help();
+    return -1;
+  }
+
+  if (dump_frames) {
+    printf("Dumping decoded frames in: %s\n", dump_folder);
+  }
+
+  memset(images, 0, sizeof(images));
+  for (i = 0; i < 2; ++i) {
+    printf("Decoding file: %s\n", files[i]);
+    if (!ReadAnimatedImage(files[i], &images[i], dump_frames, dump_folder)) {
+      fprintf(stderr, "Error decoding file: %s\n Aborting.\n", files[i]);
+      return_code = -2;
+      goto End;
+    } else {
+      MinimizeAnimationFrames(&images[i], max_diff);
+    }
+  }
+
+  if (!CompareAnimatedImagePair(&images[0], &images[1],
+                                premultiply, min_psnr)) {
+    fprintf(stderr, "\nFiles %s and %s differ.\n", files[0], files[1]);
+    return_code = -3;
+  } else {
+    printf("\nFiles %s and %s are identical.\n", files[0], files[1]);
+    return_code = 0;
+  }
+ End:
+  ClearAnimatedImage(&images[0]);
+  ClearAnimatedImage(&images[1]);
+  return return_code;
+}

examples/anim_util.c

@@ -0,0 +1,773 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Utilities for animated images
+
+#include "./anim_util.h"
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifdef WEBP_HAVE_GIF
+#include <gif_lib.h>
+#endif
+#include "webp/format_constants.h"
+#include "webp/decode.h"
+#include "webp/demux.h"
+#include "../imageio/imageio_util.h"
+
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#define snprintf _snprintf
+#endif
+
+static const int kNumChannels = 4;
+
+// -----------------------------------------------------------------------------
+// Common utilities.
+
+// Returns true if the frame covers the full canvas.
+static int IsFullFrame(int width, int height,
+                       int canvas_width, int canvas_height) {
+  return (width == canvas_width && height == canvas_height);
+}
+
+static int CheckSizeForOverflow(uint64_t size) {
+  return (size == (size_t)size);
+}
+
+static int AllocateFrames(AnimatedImage* const image, uint32_t num_frames) {
+  uint32_t i;
+  uint8_t* mem = NULL;
+  DecodedFrame* frames = NULL;
+  const uint64_t rgba_size =
+      (uint64_t)image->canvas_width * kNumChannels * image->canvas_height;
+  const uint64_t total_size = (uint64_t)num_frames * rgba_size * sizeof(*mem);
+  const uint64_t total_frame_size = (uint64_t)num_frames * sizeof(*frames);
+  if (!CheckSizeForOverflow(total_size) ||
+      !CheckSizeForOverflow(total_frame_size)) {
+    return 0;
+  }
+  mem = (uint8_t*)malloc((size_t)total_size);
+  frames = (DecodedFrame*)malloc((size_t)total_frame_size);
+
+  if (mem == NULL || frames == NULL) {
+    free(mem);
+    free(frames);
+    return 0;
+  }
+  free(image->raw_mem);
+  image->num_frames = num_frames;
+  image->frames = frames;
+  for (i = 0; i < num_frames; ++i) {
+    frames[i].rgba = mem + i * rgba_size;
+    frames[i].duration = 0;
+    frames[i].is_key_frame = 0;
+  }
+  image->raw_mem = mem;
+  return 1;
+}
+
+void ClearAnimatedImage(AnimatedImage* const image) {
+  if (image != NULL) {
+    free(image->raw_mem);
+    free(image->frames);
+    image->num_frames = 0;
+    image->frames = NULL;
+    image->raw_mem = NULL;
+  }
+}
+
+// Clear the canvas to transparent.
+static void ZeroFillCanvas(uint8_t* rgba,
+                           uint32_t canvas_width, uint32_t canvas_height) {
+  memset(rgba, 0, canvas_width * kNumChannels * canvas_height);
+}
+
+// Clear given frame rectangle to transparent.
+static void ZeroFillFrameRect(uint8_t* rgba, int rgba_stride, int x_offset,
+                              int y_offset, int width, int height) {
+  int j;
+  assert(width * kNumChannels <= rgba_stride);
+  rgba += y_offset * rgba_stride + x_offset * kNumChannels;
+  for (j = 0; j < height; ++j) {
+    memset(rgba, 0, width * kNumChannels);
+    rgba += rgba_stride;
+  }
+}
+
+// Copy width * height pixels from 'src' to 'dst'.
+static void CopyCanvas(const uint8_t* src, uint8_t* dst,
+                       uint32_t width, uint32_t height) {
+  assert(src != NULL && dst != NULL);
+  memcpy(dst, src, width * kNumChannels * height);
+}
+
+// Copy pixels in the given rectangle from 'src' to 'dst' honoring the 'stride'.
+static void CopyFrameRectangle(const uint8_t* src, uint8_t* dst, int stride,
+                               int x_offset, int y_offset,
+                               int width, int height) {
+  int j;
+  const int width_in_bytes = width * kNumChannels;
+  const size_t offset = y_offset * stride + x_offset * kNumChannels;
+  assert(width_in_bytes <= stride);
+  src += offset;
+  dst += offset;
+  for (j = 0; j < height; ++j) {
+    memcpy(dst, src, width_in_bytes);
+    src += stride;
+    dst += stride;
+  }
+}
+
+// Canonicalize all transparent pixels to transparent black to aid comparison.
+static void CleanupTransparentPixels(uint32_t* rgba,
+                                     uint32_t width, uint32_t height) {
+  const uint32_t* const rgba_end = rgba + width * height;
+  while (rgba < rgba_end) {
+    const uint8_t alpha = (*rgba >> 24) & 0xff;
+    if (alpha == 0) {
+      *rgba = 0;
+    }
+    ++rgba;
+  }
+}
+
+// Dump frame to a PAM file. Returns true on success.
+static int DumpFrame(const char filename[], const char dump_folder[],
+                     uint32_t frame_num, const uint8_t rgba[],
+                     int canvas_width, int canvas_height) {
+  int ok = 0;
+  size_t max_len;
+  int y;
+  const char* base_name = NULL;
+  char* file_name = NULL;
+  FILE* f = NULL;
+  const char* row;
+
+  base_name = strrchr(filename, '/');
+  base_name = (base_name == NULL) ? filename : base_name + 1;
+  max_len = strlen(dump_folder) + 1 + strlen(base_name)
+          + strlen("_frame_") + strlen(".pam") + 8;
+  file_name = (char*)malloc(max_len * sizeof(*file_name));
+  if (file_name == NULL) goto End;
+
+  if (snprintf(file_name, max_len, "%s/%s_frame_%d.pam",
+               dump_folder, base_name, frame_num) < 0) {
+    fprintf(stderr, "Error while generating file name\n");
+    goto End;
+  }
+
+  f = fopen(file_name, "wb");
+  if (f == NULL) {
+    fprintf(stderr, "Error opening file for writing: %s\n", file_name);
+    ok = 0;
+    goto End;
+  }
+  if (fprintf(f, "P7\nWIDTH %d\nHEIGHT %d\n"
+              "DEPTH 4\nMAXVAL 255\nTUPLTYPE RGB_ALPHA\nENDHDR\n",
+              canvas_width, canvas_height) < 0) {
+    fprintf(stderr, "Write error for file %s\n", file_name);
+    goto End;
+  }
+  row = (const char*)rgba;
+  for (y = 0; y < canvas_height; ++y) {
+    if (fwrite(row, canvas_width * kNumChannels, 1, f) != 1) {
+      fprintf(stderr, "Error writing to file: %s\n", file_name);
+      goto End;
+    }
+    row += canvas_width * kNumChannels;
+  }
+  ok = 1;
+ End:
+  if (f != NULL) fclose(f);
+  free(file_name);
+  return ok;
+}
+
+// -----------------------------------------------------------------------------
+// WebP Decoding.
+
+// Returns true if this is a valid WebP bitstream.
+static int IsWebP(const WebPData* const webp_data) {
+  return (WebPGetInfo(webp_data->bytes, webp_data->size, NULL, NULL) != 0);
+}
+
+// Read animated WebP bitstream 'file_str' into 'AnimatedImage' struct.
+static int ReadAnimatedWebP(const char filename[],
+                            const WebPData* const webp_data,
+                            AnimatedImage* const image, int dump_frames,
+                            const char dump_folder[]) {
+  int ok = 0;
+  int dump_ok = 1;
+  uint32_t frame_index = 0;
+  int prev_frame_timestamp = 0;
+  WebPAnimDecoder* dec;
+  WebPAnimInfo anim_info;
+
+  memset(image, 0, sizeof(*image));
+
+  dec = WebPAnimDecoderNew(webp_data, NULL);
+  if (dec == NULL) {
+    fprintf(stderr, "Error parsing image: %s\n", filename);
+    goto End;
+  }
+
+  if (!WebPAnimDecoderGetInfo(dec, &anim_info)) {
+    fprintf(stderr, "Error getting global info about the animation\n");
+    goto End;
+  }
+
+  // Animation properties.
+  image->canvas_width = anim_info.canvas_width;
+  image->canvas_height = anim_info.canvas_height;
+  image->loop_count = anim_info.loop_count;
+  image->bgcolor = anim_info.bgcolor;
+
+  // Allocate frames.
+  if (!AllocateFrames(image, anim_info.frame_count)) return 0;
+
+  // Decode frames.
+  while (WebPAnimDecoderHasMoreFrames(dec)) {
+    DecodedFrame* curr_frame;
+    uint8_t* curr_rgba;
+    uint8_t* frame_rgba;
+    int timestamp;
+
+    if (!WebPAnimDecoderGetNext(dec, &frame_rgba, &timestamp)) {
+      fprintf(stderr, "Error decoding frame #%u\n", frame_index);
+      goto End;
+    }
+    assert(frame_index < anim_info.frame_count);
+    curr_frame = &image->frames[frame_index];
+    curr_rgba = curr_frame->rgba;
+    curr_frame->duration = timestamp - prev_frame_timestamp;
+    curr_frame->is_key_frame = 0;  // Unused.
+    memcpy(curr_rgba, frame_rgba,
+           image->canvas_width * kNumChannels * image->canvas_height);
+
+    // Needed only because we may want to compare with GIF later.
+    CleanupTransparentPixels((uint32_t*)curr_rgba,
+                             image->canvas_width, image->canvas_height);
+
+    if (dump_frames && dump_ok) {
+      dump_ok = DumpFrame(filename, dump_folder, frame_index, curr_rgba,
+                          image->canvas_width, image->canvas_height);
+      if (!dump_ok) {  // Print error once, but continue decode loop.
+        fprintf(stderr, "Error dumping frames to %s\n", dump_folder);
+      }
+    }
+
+    ++frame_index;
+    prev_frame_timestamp = timestamp;
+  }
+  ok = dump_ok;
+
+ End:
+  WebPAnimDecoderDelete(dec);
+  return ok;
+}
+
+// -----------------------------------------------------------------------------
+// GIF Decoding.
+
+#ifdef WEBP_HAVE_GIF
+
+// Returns true if this is a valid GIF bitstream.
+static int IsGIF(const WebPData* const data) {
+  return data->size > GIF_STAMP_LEN &&
+         (!memcmp(GIF_STAMP, data->bytes, GIF_STAMP_LEN) ||
+          !memcmp(GIF87_STAMP, data->bytes, GIF_STAMP_LEN) ||
+          !memcmp(GIF89_STAMP, data->bytes, GIF_STAMP_LEN));
+}
+
+// GIFLIB_MAJOR is only defined in libgif >= 4.2.0.
+#if defined(GIFLIB_MAJOR) && defined(GIFLIB_MINOR)
+# define LOCAL_GIF_VERSION ((GIFLIB_MAJOR << 8) | GIFLIB_MINOR)
+# define LOCAL_GIF_PREREQ(maj, min) \
+    (LOCAL_GIF_VERSION >= (((maj) << 8) | (min)))
+#else
+# define LOCAL_GIF_VERSION 0
+# define LOCAL_GIF_PREREQ(maj, min) 0
+#endif
+
+#if !LOCAL_GIF_PREREQ(5, 0)
+
+// Added in v5.0
+typedef struct {
+  int DisposalMode;
+#define DISPOSAL_UNSPECIFIED      0       // No disposal specified
+#define DISPOSE_DO_NOT            1       // Leave image in place
+#define DISPOSE_BACKGROUND        2       // Set area to background color
+#define DISPOSE_PREVIOUS          3       // Restore to previous content
+  int UserInputFlag;       // User confirmation required before disposal
+  int DelayTime;           // Pre-display delay in 0.01sec units
+  int TransparentColor;    // Palette index for transparency, -1 if none
+#define NO_TRANSPARENT_COLOR     -1
+} GraphicsControlBlock;
+
+static int DGifExtensionToGCB(const size_t GifExtensionLength,
+                              const GifByteType* GifExtension,
+                              GraphicsControlBlock* gcb) {
+  if (GifExtensionLength != 4) {
+    return GIF_ERROR;
+  }
+  gcb->DisposalMode = (GifExtension[0] >> 2) & 0x07;
+  gcb->UserInputFlag = (GifExtension[0] & 0x02) != 0;
+  gcb->DelayTime = GifExtension[1] | (GifExtension[2] << 8);
+  if (GifExtension[0] & 0x01) {
+    gcb->TransparentColor = (int)GifExtension[3];
+  } else {
+    gcb->TransparentColor = NO_TRANSPARENT_COLOR;
+  }
+  return GIF_OK;
+}
+
+static int DGifSavedExtensionToGCB(GifFileType* GifFile, int ImageIndex,
+                                   GraphicsControlBlock* gcb) {
+  int i;
+  if (ImageIndex < 0 || ImageIndex > GifFile->ImageCount - 1) {
+    return GIF_ERROR;
+  }
+  gcb->DisposalMode = DISPOSAL_UNSPECIFIED;
+  gcb->UserInputFlag = 0;
+  gcb->DelayTime = 0;
+  gcb->TransparentColor = NO_TRANSPARENT_COLOR;
+
+  for (i = 0; i < GifFile->SavedImages[ImageIndex].ExtensionBlockCount; i++) {
+    ExtensionBlock* ep = &GifFile->SavedImages[ImageIndex].ExtensionBlocks[i];
+    if (ep->Function == GRAPHICS_EXT_FUNC_CODE) {
+      return DGifExtensionToGCB(
+          ep->ByteCount, (const GifByteType*)ep->Bytes, gcb);
+    }
+  }
+  return GIF_ERROR;
+}
+
+#define CONTINUE_EXT_FUNC_CODE 0x00
+
+// Signature was changed in v5.0
+#define DGifOpenFileName(a, b) DGifOpenFileName(a)
+
+#endif  // !LOCAL_GIF_PREREQ(5, 0)
+
+// Signature changed in v5.1
+#if !LOCAL_GIF_PREREQ(5, 1)
+#define DGifCloseFile(a, b) DGifCloseFile(a)
+#endif
+
+static void GIFDisplayError(const GifFileType* const gif, int gif_error) {
+  // libgif 4.2.0 has retired PrintGifError() and added GifErrorString().
+#if LOCAL_GIF_PREREQ(4, 2)
+#if LOCAL_GIF_PREREQ(5, 0)
+  const char* error_str =
+      GifErrorString((gif == NULL) ? gif_error : gif->Error);
+#else
+  const char* error_str = GifErrorString();
+  (void)gif;
+#endif
+  if (error_str == NULL) error_str = "Unknown error";
+  fprintf(stderr, "GIFLib Error %d: %s\n", gif_error, error_str);
+#else
+  (void)gif;
+  fprintf(stderr, "GIFLib Error %d: ", gif_error);
+  PrintGifError();
+  fprintf(stderr, "\n");
+#endif
+}
+
+static int IsKeyFrameGIF(const GifImageDesc* prev_desc, int prev_dispose,
+                         const DecodedFrame* const prev_frame,
+                         int canvas_width, int canvas_height) {
+  if (prev_frame == NULL) return 1;
+  if (prev_dispose == DISPOSE_BACKGROUND) {
+    if (IsFullFrame(prev_desc->Width, prev_desc->Height,
+                    canvas_width, canvas_height)) {
+      return 1;
+    }
+    if (prev_frame->is_key_frame) return 1;
+  }
+  return 0;
+}
+
+static int GetTransparentIndexGIF(GifFileType* gif) {
+  GraphicsControlBlock first_gcb;
+  memset(&first_gcb, 0, sizeof(first_gcb));
+  DGifSavedExtensionToGCB(gif, 0, &first_gcb);
+  return first_gcb.TransparentColor;
+}
+
+static uint32_t GetBackgroundColorGIF(GifFileType* gif) {
+  const int transparent_index = GetTransparentIndexGIF(gif);
+  const ColorMapObject* const color_map = gif->SColorMap;
+  if (transparent_index != NO_TRANSPARENT_COLOR &&
+      gif->SBackGroundColor == transparent_index) {
+    return 0x00000000;  // Special case: transparent black.
+  } else if (color_map == NULL || color_map->Colors == NULL
+             || gif->SBackGroundColor >= color_map->ColorCount) {
+    return 0xffffffff;  // Invalid: assume white.
+  } else {
+    const GifColorType color = color_map->Colors[gif->SBackGroundColor];
+    return (0xff << 24) |
+           (color.Red << 16) |
+           (color.Green << 8) |
+           (color.Blue << 0);
+  }
+}
+
+// Find appropriate app extension and get loop count from the next extension.
+static uint32_t GetLoopCountGIF(const GifFileType* const gif) {
+  int i;
+  for (i = 0; i < gif->ImageCount; ++i) {
+    const SavedImage* const image = &gif->SavedImages[i];
+    int j;
+    for (j = 0; (j + 1) < image->ExtensionBlockCount; ++j) {
+      const ExtensionBlock* const eb1 = image->ExtensionBlocks + j;
+      const ExtensionBlock* const eb2 = image->ExtensionBlocks + j + 1;
+      const char* const signature = (const char*)eb1->Bytes;
+      const int signature_is_ok =
+          (eb1->Function == APPLICATION_EXT_FUNC_CODE) &&
+          (eb1->ByteCount == 11) &&
+          (!memcmp(signature, "NETSCAPE2.0", 11) ||
+           !memcmp(signature, "ANIMEXTS1.0", 11));
+      if (signature_is_ok &&
+          eb2->Function == CONTINUE_EXT_FUNC_CODE && eb2->ByteCount >= 3 &&
+          eb2->Bytes[0] == 1) {
+        return ((uint32_t)(eb2->Bytes[2]) << 8) +
+               ((uint32_t)(eb2->Bytes[1]) << 0);
+      }
+    }
+  }
+  return 0;  // Default.
+}
+
+// Get duration of 'n'th frame in milliseconds.
+static int GetFrameDurationGIF(GifFileType* gif, int n) {
+  GraphicsControlBlock gcb;
+  memset(&gcb, 0, sizeof(gcb));
+  DGifSavedExtensionToGCB(gif, n, &gcb);
+  return gcb.DelayTime * 10;
+}
+
+// Returns true if frame 'target' completely covers 'covered'.
+static int CoversFrameGIF(const GifImageDesc* const target,
+                          const GifImageDesc* const covered) {
+  return target->Left <= covered->Left &&
+         covered->Left + covered->Width <= target->Left + target->Width &&
+         target->Top <= covered->Top &&
+         covered->Top + covered->Height <= target->Top + target->Height;
+}
+
+static void RemapPixelsGIF(const uint8_t* const src,
+                           const ColorMapObject* const cmap,
+                           int transparent_color, int len, uint8_t* dst) {
+  int i;
+  for (i = 0; i < len; ++i) {
+    if (src[i] != transparent_color) {
+      // If a pixel in the current frame is transparent, we don't modify it, so
+      // that we can see-through the corresponding pixel from an earlier frame.
+      const GifColorType c = cmap->Colors[src[i]];
+      dst[4 * i + 0] = c.Red;
+      dst[4 * i + 1] = c.Green;
+      dst[4 * i + 2] = c.Blue;
+      dst[4 * i + 3] = 0xff;
+    }
+  }
+}
+
+static int ReadFrameGIF(const SavedImage* const gif_image,
+                        const ColorMapObject* cmap, int transparent_color,
+                        int out_stride, uint8_t* const dst) {
+  const GifImageDesc* image_desc = &gif_image->ImageDesc;
+  const uint8_t* in;
+  uint8_t* out;
+  int j;
+
+  if (image_desc->ColorMap) cmap = image_desc->ColorMap;
+
+  if (cmap == NULL || cmap->ColorCount != (1 << cmap->BitsPerPixel)) {
+    fprintf(stderr, "Potentially corrupt color map.\n");
+    return 0;
+  }
+
+  in = (const uint8_t*)gif_image->RasterBits;
+  out = dst + image_desc->Top * out_stride + image_desc->Left * kNumChannels;
+
+  for (j = 0; j < image_desc->Height; ++j) {
+    RemapPixelsGIF(in, cmap, transparent_color, image_desc->Width, out);
+    in += image_desc->Width;
+    out += out_stride;
+  }
+  return 1;
+}
+
+// Read animated GIF bitstream from 'filename' into 'AnimatedImage' struct.
+static int ReadAnimatedGIF(const char filename[], AnimatedImage* const image,
+                           int dump_frames, const char dump_folder[]) {
+  uint32_t frame_count;
+  uint32_t canvas_width, canvas_height;
+  uint32_t i;
+  int gif_error;
+  GifFileType* gif;
+
+  gif = DGifOpenFileName(filename, NULL);
+  if (gif == NULL) {
+    fprintf(stderr, "Could not read file: %s.\n", filename);
+    return 0;
+  }
+
+  gif_error = DGifSlurp(gif);
+  if (gif_error != GIF_OK) {
+    fprintf(stderr, "Could not parse image: %s.\n", filename);
+    GIFDisplayError(gif, gif_error);
+    DGifCloseFile(gif, NULL);
+    return 0;
+  }
+
+  // Animation properties.
+  image->canvas_width = (uint32_t)gif->SWidth;
+  image->canvas_height = (uint32_t)gif->SHeight;
+  if (image->canvas_width > MAX_CANVAS_SIZE ||
+      image->canvas_height > MAX_CANVAS_SIZE) {
+    fprintf(stderr, "Invalid canvas dimension: %d x %d\n",
+            image->canvas_width, image->canvas_height);
+    DGifCloseFile(gif, NULL);
+    return 0;
+  }
+  image->loop_count = GetLoopCountGIF(gif);
+  image->bgcolor = GetBackgroundColorGIF(gif);
+
+  frame_count = (uint32_t)gif->ImageCount;
+  if (frame_count == 0) {
+    DGifCloseFile(gif, NULL);
+    return 0;
+  }
+
+  if (image->canvas_width == 0 || image->canvas_height == 0) {
+    image->canvas_width = gif->SavedImages[0].ImageDesc.Width;
+    image->canvas_height = gif->SavedImages[0].ImageDesc.Height;
+    gif->SavedImages[0].ImageDesc.Left = 0;
+    gif->SavedImages[0].ImageDesc.Top = 0;
+    if (image->canvas_width == 0 || image->canvas_height == 0) {
+      fprintf(stderr, "Invalid canvas size in GIF.\n");
+      DGifCloseFile(gif, NULL);
+      return 0;
+    }
+  }
+  // Allocate frames.
+  AllocateFrames(image, frame_count);
+
+  canvas_width = image->canvas_width;
+  canvas_height = image->canvas_height;
+
+  // Decode and reconstruct frames.
+  for (i = 0; i < frame_count; ++i) {
+    const int canvas_width_in_bytes = canvas_width * kNumChannels;
+    const SavedImage* const curr_gif_image = &gif->SavedImages[i];
+    GraphicsControlBlock curr_gcb;
+    DecodedFrame* curr_frame;
+    uint8_t* curr_rgba;
+
+    memset(&curr_gcb, 0, sizeof(curr_gcb));
+    DGifSavedExtensionToGCB(gif, i, &curr_gcb);
+
+    curr_frame = &image->frames[i];
+    curr_rgba = curr_frame->rgba;
+    curr_frame->duration = GetFrameDurationGIF(gif, i);
+
+    if (i == 0) {  // Initialize as transparent.
+      curr_frame->is_key_frame = 1;
+      ZeroFillCanvas(curr_rgba, canvas_width, canvas_height);
+    } else {
+      DecodedFrame* const prev_frame = &image->frames[i - 1];
+      const GifImageDesc* const prev_desc = &gif->SavedImages[i - 1].ImageDesc;
+      GraphicsControlBlock prev_gcb;
+      memset(&prev_gcb, 0, sizeof(prev_gcb));
+      DGifSavedExtensionToGCB(gif, i - 1, &prev_gcb);
+
+      curr_frame->is_key_frame =
+          IsKeyFrameGIF(prev_desc, prev_gcb.DisposalMode, prev_frame,
+                        canvas_width, canvas_height);
+
+      if (curr_frame->is_key_frame) {  // Initialize as transparent.
+        ZeroFillCanvas(curr_rgba, canvas_width, canvas_height);
+      } else {
+        int prev_frame_disposed, curr_frame_opaque;
+        int prev_frame_completely_covered;
+        // Initialize with previous canvas.
+        uint8_t* const prev_rgba = image->frames[i - 1].rgba;
+        CopyCanvas(prev_rgba, curr_rgba, canvas_width, canvas_height);
+
+        // Dispose previous frame rectangle.
+        prev_frame_disposed =
+            (prev_gcb.DisposalMode == DISPOSE_BACKGROUND ||
+             prev_gcb.DisposalMode == DISPOSE_PREVIOUS);
+        curr_frame_opaque =
+            (curr_gcb.TransparentColor == NO_TRANSPARENT_COLOR);
+        prev_frame_completely_covered =
+            curr_frame_opaque &&
+            CoversFrameGIF(&curr_gif_image->ImageDesc, prev_desc);
+
+        if (prev_frame_disposed && !prev_frame_completely_covered) {
+          switch (prev_gcb.DisposalMode) {
+            case DISPOSE_BACKGROUND: {
+              ZeroFillFrameRect(curr_rgba, canvas_width_in_bytes,
+                                prev_desc->Left, prev_desc->Top,
+                                prev_desc->Width, prev_desc->Height);
+              break;
+            }
+            case DISPOSE_PREVIOUS: {
+              int src_frame_num = i - 2;
+              while (src_frame_num >= 0) {
+                GraphicsControlBlock src_frame_gcb;
+                memset(&src_frame_gcb, 0, sizeof(src_frame_gcb));
+                DGifSavedExtensionToGCB(gif, src_frame_num, &src_frame_gcb);
+                if (src_frame_gcb.DisposalMode != DISPOSE_PREVIOUS) break;
+                --src_frame_num;
+              }
+              if (src_frame_num >= 0) {
+                // Restore pixels inside previous frame rectangle to
+                // corresponding pixels in source canvas.
+                uint8_t* const src_frame_rgba =
+                    image->frames[src_frame_num].rgba;
+                CopyFrameRectangle(src_frame_rgba, curr_rgba,
+                                   canvas_width_in_bytes,
+                                   prev_desc->Left, prev_desc->Top,
+                                   prev_desc->Width, prev_desc->Height);
+              } else {
+                // Source canvas doesn't exist. So clear previous frame
+                // rectangle to background.
+                ZeroFillFrameRect(curr_rgba, canvas_width_in_bytes,
+                                  prev_desc->Left, prev_desc->Top,
+                                  prev_desc->Width, prev_desc->Height);
+              }
+              break;
+            }
+            default:
+              break;  // Nothing to do.
+          }
+        }
+      }
+    }
+
+    // Decode current frame.
+    if (!ReadFrameGIF(curr_gif_image, gif->SColorMap, curr_gcb.TransparentColor,
+                      canvas_width_in_bytes, curr_rgba)) {
+      DGifCloseFile(gif, NULL);
+      return 0;
+    }
+
+    if (dump_frames) {
+      if (!DumpFrame(filename, dump_folder, i, curr_rgba,
+                     canvas_width, canvas_height)) {
+        DGifCloseFile(gif, NULL);
+        return 0;
+      }
+    }
+  }
+  DGifCloseFile(gif, NULL);
+  return 1;
+}
+
+#else
+
+static int IsGIF(const WebPData* const data) {
+  (void)data;
+  return 0;
+}
+
+static int ReadAnimatedGIF(const char filename[], AnimatedImage* const image,
+                           int dump_frames, const char dump_folder[]) {
+  (void)filename;
+  (void)image;
+  (void)dump_frames;
+  (void)dump_folder;
+  fprintf(stderr, "GIF support not compiled. Please install the libgif-dev "
+          "package before building.\n");
+  return 0;
+}
+
+#endif  // WEBP_HAVE_GIF
+
+// -----------------------------------------------------------------------------
+
+int ReadAnimatedImage(const char filename[], AnimatedImage* const image,
+                      int dump_frames, const char dump_folder[]) {
+  int ok = 0;
+  WebPData webp_data;
+
+  WebPDataInit(&webp_data);
+  memset(image, 0, sizeof(*image));
+
+  if (!ImgIoUtilReadFile(filename, &webp_data.bytes, &webp_data.size)) {
+    fprintf(stderr, "Error reading file: %s\n", filename);
+    return 0;
+  }
+
+  if (IsWebP(&webp_data)) {
+    ok = ReadAnimatedWebP(filename, &webp_data, image, dump_frames,
+                          dump_folder);
+  } else if (IsGIF(&webp_data)) {
+    ok = ReadAnimatedGIF(filename, image, dump_frames, dump_folder);
+  } else {
+    fprintf(stderr,
+            "Unknown file type: %s. Supported file types are WebP and GIF\n",
+            filename);
+    ok = 0;
+  }
+  if (!ok) ClearAnimatedImage(image);
+  WebPDataClear(&webp_data);
+  return ok;
+}
+
+static void Accumulate(double v1, double v2, double* const max_diff,
+                       double* const sse) {
+  const double diff = fabs(v1 - v2);
+  if (diff > *max_diff) *max_diff = diff;
+  *sse += diff * diff;
+}
+
+void GetDiffAndPSNR(const uint8_t rgba1[], const uint8_t rgba2[],
+                    uint32_t width, uint32_t height, int premultiply,
+                    int* const max_diff, double* const psnr) {
+  const uint32_t stride = width * kNumChannels;
+  const int kAlphaChannel = kNumChannels - 1;
+  double f_max_diff = 0.;
+  double sse = 0.;
+  uint32_t x, y;
+  for (y = 0; y < height; ++y) {
+    for (x = 0; x < stride; x += kNumChannels) {
+      int k;
+      const size_t offset = (size_t)y * stride + x;
+      const int alpha1 = rgba1[offset + kAlphaChannel];
+      const int alpha2 = rgba2[offset + kAlphaChannel];
+      Accumulate(alpha1, alpha2, &f_max_diff, &sse);
+      if (!premultiply) {
+        for (k = 0; k < kAlphaChannel; ++k) {
+          Accumulate(rgba1[offset + k], rgba2[offset + k], &f_max_diff, &sse);
+        }
+      } else {
+        // premultiply R/G/B channels with alpha value
+        for (k = 0; k < kAlphaChannel; ++k) {
+          Accumulate(rgba1[offset + k] * alpha1 / 255.,
+                     rgba2[offset + k] * alpha2 / 255.,
+                     &f_max_diff, &sse);
+        }
+      }
+    }
+  }
+  *max_diff = (int)f_max_diff;
+  if (*max_diff == 0) {
+    *psnr = 99.;  // PSNR when images are identical.
+  } else {
+    sse /= stride * height;
+    *psnr = 4.3429448 * log(255. * 255. / sse);
+  }
+}

examples/anim_util.h

@@ -0,0 +1,63 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Utilities for animated images
+
+#ifndef WEBP_EXAMPLES_ANIM_UTIL_H_
+#define WEBP_EXAMPLES_ANIM_UTIL_H_
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#include "webp/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+  uint8_t* rgba;         // Decoded and reconstructed full frame.
+  int duration;          // Frame duration in milliseconds.
+  int is_key_frame;      // True if this frame is a key-frame.
+} DecodedFrame;
+
+typedef struct {
+  uint32_t canvas_width;
+  uint32_t canvas_height;
+  uint32_t bgcolor;
+  uint32_t loop_count;
+  DecodedFrame* frames;
+  uint32_t num_frames;
+  void* raw_mem;
+} AnimatedImage;
+
+// Deallocate everything in 'image' (but not the object itself).
+void ClearAnimatedImage(AnimatedImage* const image);
+
+// Read animated image file into 'AnimatedImage' struct.
+// If 'dump_frames' is true, dump frames to 'dump_folder'.
+// Previous content of 'image' is obliterated.
+// Upon successful return, content of 'image' must be deleted by
+// calling 'ClearAnimatedImage'.
+int ReadAnimatedImage(const char filename[], AnimatedImage* const image,
+                      int dump_frames, const char dump_folder[]);
+
+// Given two RGBA buffers, calculate max pixel difference and PSNR.
+// If 'premultiply' is true, R/G/B values will be pre-multiplied by the
+// transparency before comparison.
+void GetDiffAndPSNR(const uint8_t rgba1[], const uint8_t rgba2[],
+                    uint32_t width, uint32_t height, int premultiply,
+                    int* const max_diff, double* const psnr);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_EXAMPLES_ANIM_UTIL_H_

examples/dwebp.c

@@ -1,14 +1,13 @@
-// Copyright 2010 Google Inc.
+// Copyright 2010 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
-//  simple command-line example calling libwebpdecode to
-//  decode a WebP image into a PPM image.
-//
-//  Compile with:     gcc -o dwebp dwebp.c -lwebpdecode
+//  Command-line tool for decoding a WebP image.
 //
 // Author: Skal (pascal.massimino@gmail.com)
 
@@ -17,355 +16,403 @@
 #include <stdlib.h>
 #include <string.h>
 
-#ifdef WEBP_HAVE_PNG
-#include <png.h>
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
 #endif
 
-#ifdef _WIN32
-#define CINTERFACE
-#define COBJMACROS
-#define _WIN32_IE 0x500  // Workaround bug in shlwapi.h when compiling C++
-                         // code with COBJMACROS.
-#include <shlwapi.h>
-#include <windows.h>
-#include <wincodec.h>
-#endif
+#include "../examples/example_util.h"
+#include "../imageio/image_enc.h"
+#include "../imageio/webpdec.h"
+#include "./stopwatch.h"
 
-#include "webp/decode.h"
-#include "stopwatch.h"
-
-#if defined(__cplusplus) || defined(c_plusplus)
+static int verbose = 0;
+static int quiet = 0;
+#ifndef WEBP_DLL
+#ifdef __cplusplus
 extern "C" {
 #endif
 
-//-----------------------------------------------------------------------------
-
-static int verbose = 0;
-
-#ifdef _WIN32
-
-#define IFS(fn)                \
-  do {                         \
-     if (SUCCEEDED(hr))        \
-     {                         \
-        hr = (fn);             \
-        if (FAILED(hr) && verbose)           \
-          printf(#fn " failed %08x\n", hr);  \
-     }                         \
-  } while (0)
+extern void* VP8GetCPUInfo;   // opaque forward declaration.
 
 #ifdef __cplusplus
-#define MAKE_REFGUID(x) (x)
-#else
-#define MAKE_REFGUID(x) &(x)
+}    // extern "C"
 #endif
+#endif  // WEBP_DLL
 
-static HRESULT CreateOutputStream(const char* out_file_name, IStream** ppStream) {
-  HRESULT hr = S_OK;
-  IFS(SHCreateStreamOnFileA(out_file_name, STGM_WRITE | STGM_CREATE, ppStream));
-  if (FAILED(hr))
-    printf("Error opening output file %s (%08x)\n", out_file_name, hr);
-  return hr;
-}
 
-static HRESULT WriteUsingWIC(const char* out_file_name, REFGUID container_guid,
-                             unsigned char* rgb, int stride,
-                             uint32_t width, uint32_t height) {
-  HRESULT hr = S_OK;
-  IWICImagingFactory* pFactory = NULL;
-  IWICBitmapFrameEncode* pFrame = NULL;
-  IWICBitmapEncoder* pEncoder = NULL;
-  IStream* pStream = NULL;
-  GUID pixel_format = GUID_WICPixelFormat24bppBGR;
-
-  IFS(CoInitialize(NULL));
-  IFS(CoCreateInstance(MAKE_REFGUID(CLSID_WICImagingFactory), NULL,
-          CLSCTX_INPROC_SERVER, MAKE_REFGUID(IID_IWICImagingFactory),
-          (LPVOID*)&pFactory));
-  if (hr == REGDB_E_CLASSNOTREG) {
-    printf("Couldn't access Windows Imaging Component (are you running \n");
-    printf("Windows XP SP3 or newer?). PNG support not available.\n");
-    printf("Use -ppm or -pgm for available PPM and PGM formats.\n");
-  }
-  IFS(CreateOutputStream(out_file_name, &pStream));
-  IFS(IWICImagingFactory_CreateEncoder(pFactory, container_guid, NULL,
-          &pEncoder));
-  IFS(IWICBitmapEncoder_Initialize(pEncoder, pStream,
-                                   WICBitmapEncoderNoCache));
-  IFS(IWICBitmapEncoder_CreateNewFrame(pEncoder, &pFrame, NULL));
-  IFS(IWICBitmapFrameEncode_Initialize(pFrame, NULL));
-  IFS(IWICBitmapFrameEncode_SetSize(pFrame, width, height));
-  IFS(IWICBitmapFrameEncode_SetPixelFormat(pFrame, &pixel_format));
-  IFS(IWICBitmapFrameEncode_WritePixels(pFrame, height, stride,
-          height * stride, rgb));
-  IFS(IWICBitmapFrameEncode_Commit(pFrame));
-  IFS(IWICBitmapEncoder_Commit(pEncoder));
-
-  if (pFrame != NULL) IUnknown_Release(pFrame);
-  if (pEncoder != NULL) IUnknown_Release(pEncoder);
-  if (pFactory != NULL) IUnknown_Release(pFactory);
-  if (pStream != NULL) IUnknown_Release(pStream);
-  return hr;
-}
-
-static int WritePNG(const char* out_file_name, unsigned char* rgb, int stride,
-                    uint32_t width, uint32_t height) {
-  return SUCCEEDED(WriteUsingWIC(out_file_name,
-             MAKE_REFGUID(GUID_ContainerFormatPng), rgb, stride, width,
-             height));
-}
-
-#elif defined(WEBP_HAVE_PNG)    // !WIN32
-static void PNGAPI error_function(png_structp png, png_const_charp dummy) {
-  (void)dummy;  // remove variable-unused warning
-  longjmp(png_jmpbuf(png), 1);
-}
-
-static int WritePNG(FILE* out_file, unsigned char* rgb, int stride,
-                    png_uint_32 width, png_uint_32 height) {
-  png_structp png;
-  png_infop info;
-  png_uint_32 y;
-
-  png = png_create_write_struct(PNG_LIBPNG_VER_STRING,
-                                NULL, error_function, NULL);
-  if (png == NULL) {
-    return 0;
-  }
-  info = png_create_info_struct(png);
-  if (info == NULL) {
-    png_destroy_write_struct(&png, NULL);
-    return 0;
-  }
-  if (setjmp(png_jmpbuf(png))) {
-    png_destroy_write_struct(&png, &info);
-    return 0;
-  }
-  png_init_io(png, out_file);
-  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_RGB,
-               PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
-               PNG_FILTER_TYPE_DEFAULT);
-  png_write_info(png, info);
-  for (y = 0; y < height; ++y) {
-    png_bytep row = rgb + y * stride;
-    png_write_rows(png, &row, 1);
-  }
-  png_write_end(png, info);
-  png_destroy_write_struct(&png, &info);
-  return 1;
-}
-#else    // !WIN32 && !WEBP_HAVE_PNG
-
-typedef uint32_t png_uint_32;
-
-static int WritePNG(FILE* out_file, unsigned char* rgb, int stride,
-                    png_uint_32 width, png_uint_32 height) {
-  printf("PNG support not compiled. Please install the libpng development "
-         "package before building.\n");
-  printf("You can run with -ppm flag to decode in PPM format.\n");
-  return 0;
-}
-#endif
-
-static int WritePPM(FILE* fout, unsigned char* rgb,
-                    uint32_t width, uint32_t height) {
-  fprintf(fout, "P6\n%d %d\n255\n", width, height);
-  return (fwrite(rgb, width * height, 3, fout) == 3);
-}
-
-static int WritePGM(FILE* fout,
-                    unsigned char* y_plane, unsigned char *u, unsigned char* v,
-                    int y_stride, int uv_stride,
-                    uint32_t width, uint32_t height) {
-  // Save a grayscale PGM file using the IMC4 layout
-  // (http://www.fourcc.org/yuv.php#IMC4). This is a very
-  // convenient format for viewing the samples, esp. for
-  // odd dimensions.
+static int SaveOutput(const WebPDecBuffer* const buffer,
+                      WebPOutputFileFormat format, const char* const out_file) {
+  const int use_stdout = (out_file != NULL) && !strcmp(out_file, "-");
   int ok = 1;
-  unsigned int y;
-  const unsigned int uv_width = (width + 1) / 2;
-  const unsigned int uv_height = (height + 1) / 2;
-  const unsigned int out_stride = (width + 1) & ~1;
-  fprintf(fout, "P5\n%d %d\n255\n", out_stride, height + uv_height);
-  for (y = 0; ok && y < height; ++y) {
-    ok &= (fwrite(y_plane + y * y_stride, width, 1, fout) == 1);
-    if (width & 1) fputc(0, fout);    // padding byte
+  Stopwatch stop_watch;
+
+  if (verbose) {
+    StopwatchReset(&stop_watch);
   }
-  for (y = 0; ok && y < uv_height; ++y) {
-    ok &= (fwrite(u + y * uv_stride, uv_width, 1, fout) == 1);
-    ok &= (fwrite(v + y * uv_stride, uv_width, 1, fout) == 1);
+  ok = WebPSaveImage(buffer, format, out_file);
+
+  if (ok) {
+    if (!quiet) {
+      if (use_stdout) {
+        fprintf(stderr, "Saved to stdout\n");
+      } else {
+        fprintf(stderr, "Saved file %s\n", out_file);
+      }
+    }
+    if (verbose) {
+      const double write_time = StopwatchReadAndReset(&stop_watch);
+      fprintf(stderr, "Time to write output: %.3fs\n", write_time);
+    }
+  } else {
+    if (use_stdout) {
+      fprintf(stderr, "Error writing to stdout !!\n");
+    } else {
+      fprintf(stderr, "Error writing file %s !!\n", out_file);
+    }
   }
   return ok;
 }
 
-typedef enum {
-  PNG = 0,
-  PPM,
-  PGM,
-} OutputFileFormat;
-
 static void Help(void) {
-  printf("Usage: dwebp "
-         "[in_file] [-h] [-v] [-ppm] [-pgm] [-version] [-o out_file]\n\n"
+  printf("Usage: dwebp in_file [options] [-o out_file]\n\n"
          "Decodes the WebP image file to PNG format [Default]\n"
          "Use following options to convert into alternate image formats:\n"
-         " -ppm:  save the raw RGB samples as color PPM\n"
-         " -pgm:  save the raw YUV samples as a grayscale PGM\n"
-         "        file with IMC4 layout.\n"
-         " -version: print version number and exit.\n"
-         "Use -v for verbose (e.g. print encoding/decoding times)\n"
+         "  -pam ......... save the raw RGBA samples as a color PAM\n"
+         "  -ppm ......... save the raw RGB samples as a color PPM\n"
+         "  -bmp ......... save as uncompressed BMP format\n"
+         "  -tiff ........ save as uncompressed TIFF format\n"
+         "  -pgm ......... save the raw YUV samples as a grayscale PGM\n"
+         "                 file with IMC4 layout\n"
+         "  -yuv ......... save the raw YUV samples in flat layout\n"
+         "\n"
+         " Other options are:\n"
+         "  -version ..... print version number and exit\n"
+         "  -nofancy ..... don't use the fancy YUV420 upscaler\n"
+         "  -nofilter .... disable in-loop filtering\n"
+         "  -nodither .... disable dithering\n"
+         "  -dither <d> .. dithering strength (in 0..100)\n"
+         "  -alpha_dither  use alpha-plane dithering if needed\n"
+         "  -mt .......... use multi-threading\n"
+         "  -crop <x> <y> <w> <h> ... crop output with the given rectangle\n"
+         "  -resize <w> <h> ......... scale the output (*after* any cropping)\n"
+         "  -flip ........ flip the output vertically\n"
+         "  -alpha ....... only save the alpha plane\n"
+         "  -incremental . use incremental decoding (useful for tests)\n"
+         "  -h ........... this help message\n"
+         "  -v ........... verbose (e.g. print encoding/decoding times)\n"
+         "  -quiet ....... quiet mode, don't print anything\n"
+#ifndef WEBP_DLL
+         "  -noasm ....... disable all assembly optimizations\n"
+#endif
         );
 }
 
+static const char* const kFormatType[] = {
+  "unspecified", "lossy", "lossless"
+};
+
+static uint8_t* AllocateExternalBuffer(WebPDecoderConfig* config,
+                                       WebPOutputFileFormat format,
+                                       int use_external_memory) {
+  uint8_t* external_buffer = NULL;
+  WebPDecBuffer* const output_buffer = &config->output;
+  int w = config->input.width;
+  int h = config->input.height;
+  if (config->options.use_scaling) {
+    w = config->options.scaled_width;
+    h = config->options.scaled_height;
+  } else if (config->options.use_cropping) {
+    w = config->options.crop_width;
+    h = config->options.crop_height;
+  }
+  if (format >= RGB && format <= rgbA_4444) {
+    const int bpp = (format == RGB || format == BGR) ? 3
+                  : (format == RGBA_4444 || format == rgbA_4444 ||
+                     format == RGB_565) ? 2
+                  : 4;
+    uint32_t stride = bpp * w + 7;   // <- just for exercising
+    external_buffer = (uint8_t*)malloc(stride * h);
+    if (external_buffer == NULL) return NULL;
+    output_buffer->u.RGBA.stride = stride;
+    output_buffer->u.RGBA.size = stride * h;
+    output_buffer->u.RGBA.rgba = external_buffer;
+  } else {    // YUV and YUVA
+    const int has_alpha = WebPIsAlphaMode(output_buffer->colorspace);
+    uint8_t* tmp;
+    uint32_t stride = w + 3;
+    uint32_t uv_stride = (w + 1) / 2 + 13;
+    uint32_t total_size = stride * h * (has_alpha ? 2 : 1)
+                        + 2 * uv_stride * (h + 1) / 2;
+    assert(format >= YUV && format <= YUVA);
+    external_buffer = (uint8_t*)malloc(total_size);
+    if (external_buffer == NULL) return NULL;
+    tmp = external_buffer;
+    output_buffer->u.YUVA.y = tmp;
+    output_buffer->u.YUVA.y_stride = stride;
+    output_buffer->u.YUVA.y_size = stride * h;
+    tmp += output_buffer->u.YUVA.y_size;
+    if (has_alpha) {
+      output_buffer->u.YUVA.a = tmp;
+      output_buffer->u.YUVA.a_stride = stride;
+      output_buffer->u.YUVA.a_size = stride * h;
+      tmp += output_buffer->u.YUVA.a_size;
+    } else {
+      output_buffer->u.YUVA.a = NULL;
+      output_buffer->u.YUVA.a_stride = 0;
+    }
+    output_buffer->u.YUVA.u = tmp;
+    output_buffer->u.YUVA.u_stride = uv_stride;
+    output_buffer->u.YUVA.u_size = uv_stride * (h + 1) / 2;
+    tmp += output_buffer->u.YUVA.u_size;
+
+    output_buffer->u.YUVA.v = tmp;
+    output_buffer->u.YUVA.v_stride = uv_stride;
+    output_buffer->u.YUVA.v_size = uv_stride * (h + 1) / 2;
+    tmp += output_buffer->u.YUVA.v_size;
+    assert(tmp <= external_buffer + total_size);
+  }
+  output_buffer->is_external_memory = use_external_memory;
+  return external_buffer;
+}
+
 int main(int argc, const char *argv[]) {
+  int ok = 0;
   const char *in_file = NULL;
   const char *out_file = NULL;
 
-  int width, height, stride, uv_stride;
-  uint8_t* out = NULL, *u = NULL, *v = NULL;
-  OutputFileFormat format = PNG;
-  Stopwatch stop_watch;
+  WebPDecoderConfig config;
+  WebPDecBuffer* const output_buffer = &config.output;
+  WebPBitstreamFeatures* const bitstream = &config.input;
+  WebPOutputFileFormat format = PNG;
+  uint8_t* external_buffer = NULL;
+  int use_external_memory = 0;
+  const uint8_t* data = NULL;
+
+  int incremental = 0;
   int c;
+
+  if (!WebPInitDecoderConfig(&config)) {
+    fprintf(stderr, "Library version mismatch!\n");
+    return -1;
+  }
+
   for (c = 1; c < argc; ++c) {
+    int parse_error = 0;
     if (!strcmp(argv[c], "-h") || !strcmp(argv[c], "-help")) {
       Help();
       return 0;
     } else if (!strcmp(argv[c], "-o") && c < argc - 1) {
       out_file = argv[++c];
+    } else if (!strcmp(argv[c], "-alpha")) {
+      format = ALPHA_PLANE_ONLY;
+    } else if (!strcmp(argv[c], "-nofancy")) {
+      config.options.no_fancy_upsampling = 1;
+    } else if (!strcmp(argv[c], "-nofilter")) {
+      config.options.bypass_filtering = 1;
+    } else if (!strcmp(argv[c], "-pam")) {
+      format = PAM;
     } else if (!strcmp(argv[c], "-ppm")) {
       format = PPM;
+    } else if (!strcmp(argv[c], "-bmp")) {
+      format = BMP;
+    } else if (!strcmp(argv[c], "-tiff")) {
+      format = TIFF;
+    } else if (!strcmp(argv[c], "-quiet")) {
+      quiet = 1;
     } else if (!strcmp(argv[c], "-version")) {
       const int version = WebPGetDecoderVersion();
       printf("%d.%d.%d\n",
-        (version >> 16) & 0xff, (version >> 8) & 0xff, version & 0xff);
+             (version >> 16) & 0xff, (version >> 8) & 0xff, version & 0xff);
       return 0;
     } else if (!strcmp(argv[c], "-pgm")) {
       format = PGM;
+    } else if (!strcmp(argv[c], "-yuv")) {
+      format = RAW_YUV;
+    } else if (!strcmp(argv[c], "-pixel_format") && c < argc - 1) {
+      const char* const fmt = argv[++c];
+      if      (!strcmp(fmt, "RGB"))  format = RGB;
+      else if (!strcmp(fmt, "RGBA")) format = RGBA;
+      else if (!strcmp(fmt, "BGR"))  format = BGR;
+      else if (!strcmp(fmt, "BGRA")) format = BGRA;
+      else if (!strcmp(fmt, "ARGB")) format = ARGB;
+      else if (!strcmp(fmt, "RGBA_4444")) format = RGBA_4444;
+      else if (!strcmp(fmt, "RGB_565")) format = RGB_565;
+      else if (!strcmp(fmt, "rgbA")) format = rgbA;
+      else if (!strcmp(fmt, "bgrA")) format = bgrA;
+      else if (!strcmp(fmt, "Argb")) format = Argb;
+      else if (!strcmp(fmt, "rgbA_4444")) format = rgbA_4444;
+      else if (!strcmp(fmt, "YUV"))  format = YUV;
+      else if (!strcmp(fmt, "YUVA")) format = YUVA;
+      else {
+        fprintf(stderr, "Can't parse pixel_format %s\n", fmt);
+        parse_error = 1;
+      }
+    } else if (!strcmp(argv[c], "-external_memory") && c < argc - 1) {
+      use_external_memory = ExUtilGetInt(argv[++c], 0, &parse_error);
+      parse_error |= (use_external_memory > 2 || use_external_memory < 0);
+      if (parse_error) {
+        fprintf(stderr, "Can't parse 'external_memory' value %s\n", argv[c]);
+      }
+    } else if (!strcmp(argv[c], "-mt")) {
+      config.options.use_threads = 1;
+    } else if (!strcmp(argv[c], "-alpha_dither")) {
+      config.options.alpha_dithering_strength = 100;
+    } else if (!strcmp(argv[c], "-nodither")) {
+      config.options.dithering_strength = 0;
+    } else if (!strcmp(argv[c], "-dither") && c < argc - 1) {
+      config.options.dithering_strength =
+          ExUtilGetInt(argv[++c], 0, &parse_error);
+    } else if (!strcmp(argv[c], "-crop") && c < argc - 4) {
+      config.options.use_cropping = 1;
+      config.options.crop_left   = ExUtilGetInt(argv[++c], 0, &parse_error);
+      config.options.crop_top    = ExUtilGetInt(argv[++c], 0, &parse_error);
+      config.options.crop_width  = ExUtilGetInt(argv[++c], 0, &parse_error);
+      config.options.crop_height = ExUtilGetInt(argv[++c], 0, &parse_error);
+    } else if ((!strcmp(argv[c], "-scale") || !strcmp(argv[c], "-resize")) &&
+               c < argc - 2) {  // '-scale' is left for compatibility
+      config.options.use_scaling = 1;
+      config.options.scaled_width  = ExUtilGetInt(argv[++c], 0, &parse_error);
+      config.options.scaled_height = ExUtilGetInt(argv[++c], 0, &parse_error);
+    } else if (!strcmp(argv[c], "-flip")) {
+      config.options.flip = 1;
     } else if (!strcmp(argv[c], "-v")) {
       verbose = 1;
+#ifndef WEBP_DLL
+    } else if (!strcmp(argv[c], "-noasm")) {
+      VP8GetCPUInfo = NULL;
+#endif
+    } else if (!strcmp(argv[c], "-incremental")) {
+      incremental = 1;
+    } else if (!strcmp(argv[c], "--")) {
+      if (c < argc - 1) in_file = argv[++c];
+      break;
     } else if (argv[c][0] == '-') {
-      printf("Unknown option '%s'\n", argv[c]);
+      fprintf(stderr, "Unknown option '%s'\n", argv[c]);
       Help();
       return -1;
     } else {
       in_file = argv[c];
     }
+
+    if (parse_error) {
+      Help();
+      return -1;
+    }
   }
 
   if (in_file == NULL) {
-    printf("missing input file!!\n");
+    fprintf(stderr, "missing input file!!\n");
     Help();
     return -1;
   }
 
+  if (quiet) verbose = 0;
+
   {
-    uint32_t data_size = 0;
-    void* data = NULL;
-    int ok;
-    FILE* const in = fopen(in_file, "rb");
-    if (!in) {
-      fprintf(stderr, "cannot open input file '%s'\n", in_file);
-      return 1;
-    }
-    fseek(in, 0, SEEK_END);
-    data_size = ftell(in);
-    fseek(in, 0, SEEK_SET);
-    data = malloc(data_size);
-    ok = (fread(data, data_size, 1, in) == 1);
-    fclose(in);
-    if (!ok) {
-      free(data);
+    VP8StatusCode status = VP8_STATUS_OK;
+    size_t data_size = 0;
+    if (!LoadWebP(in_file, &data, &data_size, bitstream)) {
       return -1;
     }
 
-    if (verbose)
-      StopwatchReadAndReset(&stop_watch);
     switch (format) {
       case PNG:
-#ifdef _WIN32
-        out = WebPDecodeBGR((const uint8_t*)data, data_size, &width, &height);
+#ifdef HAVE_WINCODEC_H
+        output_buffer->colorspace = bitstream->has_alpha ? MODE_BGRA : MODE_BGR;
 #else
-        out = WebPDecodeRGB((const uint8_t*)data, data_size, &width, &height);
+        output_buffer->colorspace = bitstream->has_alpha ? MODE_RGBA : MODE_RGB;
 #endif
         break;
+      case PAM:
+        output_buffer->colorspace = MODE_RGBA;
+        break;
       case PPM:
-        out = WebPDecodeRGB((const uint8_t*)data, data_size, &width, &height);
+        output_buffer->colorspace = MODE_RGB;  // drops alpha for PPM
+        break;
+      case BMP:
+        output_buffer->colorspace = bitstream->has_alpha ? MODE_BGRA : MODE_BGR;
+        break;
+      case TIFF:    // note: force pre-multiplied alpha
+        output_buffer->colorspace =
+            bitstream->has_alpha ? MODE_rgbA : MODE_RGB;
         break;
       case PGM:
-        out = WebPDecodeYUV((const uint8_t*)data, data_size, &width, &height,
-                            &u, &v, &stride, &uv_stride);
+      case RAW_YUV:
+        output_buffer->colorspace = bitstream->has_alpha ? MODE_YUVA : MODE_YUV;
         break;
-      default:
-        free(data);
-        return -1;
+      case ALPHA_PLANE_ONLY:
+        output_buffer->colorspace = MODE_YUVA;
+        break;
+      // forced modes:
+      case RGB: output_buffer->colorspace = MODE_RGB; break;
+      case RGBA: output_buffer->colorspace = MODE_RGBA; break;
+      case BGR: output_buffer->colorspace = MODE_BGR; break;
+      case BGRA: output_buffer->colorspace = MODE_BGRA; break;
+      case ARGB: output_buffer->colorspace = MODE_ARGB; break;
+      case RGBA_4444: output_buffer->colorspace = MODE_RGBA_4444; break;
+      case RGB_565: output_buffer->colorspace = MODE_RGB_565; break;
+      case rgbA: output_buffer->colorspace = MODE_rgbA; break;
+      case bgrA: output_buffer->colorspace = MODE_bgrA; break;
+      case Argb: output_buffer->colorspace = MODE_Argb; break;
+      case rgbA_4444: output_buffer->colorspace = MODE_rgbA_4444; break;
+      case YUV: output_buffer->colorspace = MODE_YUV; break;
+      case YUVA: output_buffer->colorspace = MODE_YUVA; break;
+      default: goto Exit;
     }
 
-    if (verbose) {
-      const double time = StopwatchReadAndReset(&stop_watch);
-      printf("Time to decode picture: %.3fs\n", time);
+    if (use_external_memory > 0 && format >= RGB) {
+      external_buffer = AllocateExternalBuffer(&config, format,
+                                               use_external_memory);
+      if (external_buffer == NULL) goto Exit;
     }
 
-    free(data);
-  }
+    {
+      Stopwatch stop_watch;
+      if (verbose) StopwatchReset(&stop_watch);
 
-  if (!out) {
-    fprintf(stderr, "Decoding of %s failed.\n", in_file);
-    return -1;
-  }
-
-  if (out_file) {
-    FILE* fout = NULL;
-    int needs_open_file = 0;
-
-    printf("Decoded %s. Dimensions: %d x %d. Now saving...\n", in_file, width, height);
-    StopwatchReadAndReset(&stop_watch);
-#ifdef _WIN32
-    if (format != PNG) {
-      needs_open_file = 1;
-    }
-#else
-    needs_open_file = 1;
-#endif
-    if (needs_open_file) fout = fopen(out_file, "wb");
-    if (!needs_open_file || fout) {
-      int ok = 1;
-      if (format == PNG) {
-#ifdef _WIN32
-        ok &= WritePNG(out_file, out, 3 * width, width, height);
-#else
-        ok &= WritePNG(fout, out, 3 * width, width, height);
-#endif
-      } else if (format == PPM) {
-        ok &= WritePPM(fout, out, width, height);
-      } else if (format == PGM) {
-        ok &= WritePGM(fout, out, u, v, stride, uv_stride, width, height);
-      }
-      if (fout)
-        fclose(fout);
-      if (ok) {
-        printf("Saved file %s\n", out_file);
-        if (verbose) {
-          const double time = StopwatchReadAndReset(&stop_watch);
-          printf("Time to write output: %.3fs\n", time);
-        }
+      if (incremental) {
+        status = DecodeWebPIncremental(data, data_size, &config);
       } else {
-        fprintf(stderr, "Error writing file %s !!\n", out_file);
+        status = DecodeWebP(data, data_size, &config);
+      }
+      if (verbose) {
+        const double decode_time = StopwatchReadAndReset(&stop_watch);
+        fprintf(stderr, "Time to decode picture: %.3fs\n", decode_time);
       }
-    } else {
-      fprintf(stderr, "Error opening output file %s\n", out_file);
     }
-  } else {
-    printf("File %s can be decoded (dimensions: %d x %d).\n",
-           in_file, width, height);
-    printf("Nothing written; use -o flag to save the result as e.g. PNG.\n");
-  }
-  free(out);
 
-  return 0;
+    ok = (status == VP8_STATUS_OK);
+    if (!ok) {
+      PrintWebPError(in_file, status);
+      goto Exit;
+    }
+  }
+
+  if (out_file != NULL) {
+    if (!quiet) {
+      fprintf(stderr, "Decoded %s. Dimensions: %d x %d %s. Format: %s. "
+                      "Now saving...\n",
+              in_file, output_buffer->width, output_buffer->height,
+              bitstream->has_alpha ? " (with alpha)" : "",
+              kFormatType[bitstream->format]);
+    }
+    ok = SaveOutput(output_buffer, format, out_file);
+  } else {
+    if (!quiet) {
+      fprintf(stderr, "File %s can be decoded "
+                      "(dimensions: %d x %d %s. Format: %s).\n",
+              in_file, output_buffer->width, output_buffer->height,
+              bitstream->has_alpha ? " (with alpha)" : "",
+              kFormatType[bitstream->format]);
+      fprintf(stderr, "Nothing written; "
+                      "use -o flag to save the result as e.g. PNG.\n");
+    }
+  }
+ Exit:
+  WebPFreeDecBuffer(output_buffer);
+  free((void*)external_buffer);
+  free((void*)data);
+  return ok ? 0 : -1;
 }
 
-//-----------------------------------------------------------------------------
-
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif
+//------------------------------------------------------------------------------

examples/example_util.c

@@ -0,0 +1,58 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  Utility functions used by the example programs.
+//
+
+#include "./example_util.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+//------------------------------------------------------------------------------
+// String parsing
+
+uint32_t ExUtilGetUInt(const char* const v, int base, int* const error) {
+  char* end = NULL;
+  const uint32_t n = (v != NULL) ? (uint32_t)strtoul(v, &end, base) : 0u;
+  if (end == v && error != NULL && !*error) {
+    *error = 1;
+    fprintf(stderr, "Error! '%s' is not an integer.\n",
+            (v != NULL) ? v : "(null)");
+  }
+  return n;
+}
+
+int ExUtilGetInt(const char* const v, int base, int* const error) {
+  return (int)ExUtilGetUInt(v, base, error);
+}
+
+int ExUtilGetInts(const char* v, int base, int max_output, int output[]) {
+  int n, error = 0;
+  for (n = 0; v != NULL && n < max_output; ++n) {
+    const int value = ExUtilGetInt(v, base, &error);
+    if (error) return -1;
+    output[n] = value;
+    v = strchr(v, ',');
+    if (v != NULL) ++v;   // skip over the trailing ','
+  }
+  return n;
+}
+
+float ExUtilGetFloat(const char* const v, int* const error) {
+  char* end = NULL;
+  const float f = (v != NULL) ? (float)strtod(v, &end) : 0.f;
+  if (end == v && error != NULL && !*error) {
+    *error = 1;
+    fprintf(stderr, "Error! '%s' is not a floating point number.\n",
+            (v != NULL) ? v : "(null)");
+  }
+  return f;
+}

examples/example_util.h

@@ -0,0 +1,42 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  Utility functions used by the example programs.
+//
+
+#ifndef WEBP_EXAMPLES_EXAMPLE_UTIL_H_
+#define WEBP_EXAMPLES_EXAMPLE_UTIL_H_
+
+#include "webp/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//------------------------------------------------------------------------------
+// String parsing
+
+// Parses 'v' using strto(ul|l|d)(). If error is non-NULL, '*error' is set to
+// true on failure while on success it is left unmodified to allow chaining of
+// calls. An error is only printed on the first occurrence.
+uint32_t ExUtilGetUInt(const char* const v, int base, int* const error);
+int ExUtilGetInt(const char* const v, int base, int* const error);
+float ExUtilGetFloat(const char* const v, int* const error);
+
+// This variant of ExUtilGetInt() will parse multiple integers from a
+// comma-separated list. Up to 'max_output' integers are parsed.
+// The result is placed in the output[] array, and the number of integers
+// actually parsed is returned, or -1 if an error occurred.
+int ExUtilGetInts(const char* v, int base, int max_output, int output[]);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_EXAMPLES_EXAMPLE_UTIL_H_

examples/gif2webp.c

@@ -0,0 +1,559 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  simple tool to convert animated GIFs to WebP
+//
+// Authors: Skal (pascal.massimino@gmail.com)
+//          Urvang (urvang@google.com)
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#ifdef WEBP_HAVE_GIF
+
+#include <gif_lib.h>
+#include "webp/encode.h"
+#include "webp/mux.h"
+#include "../examples/example_util.h"
+#include "../imageio/imageio_util.h"
+#include "./gifdec.h"
+
+//------------------------------------------------------------------------------
+
+static int transparent_index = GIF_INDEX_INVALID;  // Opaque by default.
+
+static const char* const kErrorMessages[-WEBP_MUX_NOT_ENOUGH_DATA + 1] = {
+  "WEBP_MUX_NOT_FOUND", "WEBP_MUX_INVALID_ARGUMENT", "WEBP_MUX_BAD_DATA",
+  "WEBP_MUX_MEMORY_ERROR", "WEBP_MUX_NOT_ENOUGH_DATA"
+};
+
+static const char* ErrorString(WebPMuxError err) {
+  assert(err <= WEBP_MUX_NOT_FOUND && err >= WEBP_MUX_NOT_ENOUGH_DATA);
+  return kErrorMessages[-err];
+}
+
+enum {
+  METADATA_ICC  = (1 << 0),
+  METADATA_XMP  = (1 << 1),
+  METADATA_ALL  = METADATA_ICC | METADATA_XMP
+};
+
+//------------------------------------------------------------------------------
+
+static void Help(void) {
+  printf("Usage:\n");
+  printf(" gif2webp [options] gif_file -o webp_file\n");
+  printf("Options:\n");
+  printf("  -h / -help ............. this help\n");
+  printf("  -lossy ................. encode image using lossy compression\n");
+  printf("  -mixed ................. for each frame in the image, pick lossy\n"
+         "                           or lossless compression heuristically\n");
+  printf("  -q <float> ............. quality factor (0:small..100:big)\n");
+  printf("  -m <int> ............... compression method (0=fast, 6=slowest)\n");
+  printf("  -min_size .............. minimize output size (default:off)\n"
+         "                           lossless compression by default; can be\n"
+         "                           combined with -q, -m, -lossy or -mixed\n"
+         "                           options\n");
+  printf("  -kmin <int> ............ min distance between key frames\n");
+  printf("  -kmax <int> ............ max distance between key frames\n");
+  printf("  -f <int> ............... filter strength (0=off..100)\n");
+  printf("  -metadata <string> ..... comma separated list of metadata to\n");
+  printf("                           ");
+  printf("copy from the input to the output if present\n");
+  printf("                           "
+         "Valid values: all, none, icc, xmp (default)\n");
+  printf("  -mt .................... use multi-threading if available\n");
+  printf("\n");
+  printf("  -version ............... print version number and exit\n");
+  printf("  -v ..................... verbose\n");
+  printf("  -quiet ................. don't print anything\n");
+  printf("\n");
+}
+
+//------------------------------------------------------------------------------
+
+int main(int argc, const char *argv[]) {
+  int verbose = 0;
+  int gif_error = GIF_ERROR;
+  WebPMuxError err = WEBP_MUX_OK;
+  int ok = 0;
+  const char *in_file = NULL, *out_file = NULL;
+  FILE* out = NULL;
+  GifFileType* gif = NULL;
+  int frame_duration = 0;
+  int frame_timestamp = 0;
+  GIFDisposeMethod orig_dispose = GIF_DISPOSE_NONE;
+
+  WebPPicture frame;                // Frame rectangle only (not disposed).
+  WebPPicture curr_canvas;          // Not disposed.
+  WebPPicture prev_canvas;          // Disposed.
+
+  WebPAnimEncoder* enc = NULL;
+  WebPAnimEncoderOptions enc_options;
+  WebPConfig config;
+
+  int is_first_frame = 1;     // Whether we are processing the first frame.
+  int done;
+  int c;
+  int quiet = 0;
+  WebPData webp_data;
+
+  int keep_metadata = METADATA_XMP;  // ICC not output by default.
+  WebPData icc_data;
+  int stored_icc = 0;         // Whether we have already stored an ICC profile.
+  WebPData xmp_data;
+  int stored_xmp = 0;         // Whether we have already stored an XMP profile.
+  int loop_count = 0;
+  int stored_loop_count = 0;  // Whether we have found an explicit loop count.
+  WebPMux* mux = NULL;
+
+  int default_kmin = 1;  // Whether to use default kmin value.
+  int default_kmax = 1;
+
+  if (!WebPConfigInit(&config) || !WebPAnimEncoderOptionsInit(&enc_options) ||
+      !WebPPictureInit(&frame) || !WebPPictureInit(&curr_canvas) ||
+      !WebPPictureInit(&prev_canvas)) {
+    fprintf(stderr, "Error! Version mismatch!\n");
+    return -1;
+  }
+  config.lossless = 1;  // Use lossless compression by default.
+
+  WebPDataInit(&webp_data);
+  WebPDataInit(&icc_data);
+  WebPDataInit(&xmp_data);
+
+  if (argc == 1) {
+    Help();
+    return 0;
+  }
+
+  for (c = 1; c < argc; ++c) {
+    int parse_error = 0;
+    if (!strcmp(argv[c], "-h") || !strcmp(argv[c], "-help")) {
+      Help();
+      return 0;
+    } else if (!strcmp(argv[c], "-o") && c < argc - 1) {
+      out_file = argv[++c];
+    } else if (!strcmp(argv[c], "-lossy")) {
+      config.lossless = 0;
+    } else if (!strcmp(argv[c], "-mixed")) {
+      enc_options.allow_mixed = 1;
+      config.lossless = 0;
+    } else if (!strcmp(argv[c], "-q") && c < argc - 1) {
+      config.quality = ExUtilGetFloat(argv[++c], &parse_error);
+    } else if (!strcmp(argv[c], "-m") && c < argc - 1) {
+      config.method = ExUtilGetInt(argv[++c], 0, &parse_error);
+    } else if (!strcmp(argv[c], "-min_size")) {
+      enc_options.minimize_size = 1;
+    } else if (!strcmp(argv[c], "-kmax") && c < argc - 1) {
+      enc_options.kmax = ExUtilGetInt(argv[++c], 0, &parse_error);
+      default_kmax = 0;
+    } else if (!strcmp(argv[c], "-kmin") && c < argc - 1) {
+      enc_options.kmin = ExUtilGetInt(argv[++c], 0, &parse_error);
+      default_kmin = 0;
+    } else if (!strcmp(argv[c], "-f") && c < argc - 1) {
+      config.filter_strength = ExUtilGetInt(argv[++c], 0, &parse_error);
+    } else if (!strcmp(argv[c], "-metadata") && c < argc - 1) {
+      static const struct {
+        const char* option;
+        int flag;
+      } kTokens[] = {
+        { "all",  METADATA_ALL },
+        { "none", 0 },
+        { "icc",  METADATA_ICC },
+        { "xmp",  METADATA_XMP },
+      };
+      const size_t kNumTokens = sizeof(kTokens) / sizeof(*kTokens);
+      const char* start = argv[++c];
+      const char* const end = start + strlen(start);
+
+      keep_metadata = 0;
+      while (start < end) {
+        size_t i;
+        const char* token = strchr(start, ',');
+        if (token == NULL) token = end;
+
+        for (i = 0; i < kNumTokens; ++i) {
+          if ((size_t)(token - start) == strlen(kTokens[i].option) &&
+              !strncmp(start, kTokens[i].option, strlen(kTokens[i].option))) {
+            if (kTokens[i].flag != 0) {
+              keep_metadata |= kTokens[i].flag;
+            } else {
+              keep_metadata = 0;
+            }
+            break;
+          }
+        }
+        if (i == kNumTokens) {
+          fprintf(stderr, "Error! Unknown metadata type '%.*s'\n",
+                  (int)(token - start), start);
+          Help();
+          return -1;
+        }
+        start = token + 1;
+      }
+    } else if (!strcmp(argv[c], "-mt")) {
+      ++config.thread_level;
+    } else if (!strcmp(argv[c], "-version")) {
+      const int enc_version = WebPGetEncoderVersion();
+      const int mux_version = WebPGetMuxVersion();
+      printf("WebP Encoder version: %d.%d.%d\nWebP Mux version: %d.%d.%d\n",
+             (enc_version >> 16) & 0xff, (enc_version >> 8) & 0xff,
+             enc_version & 0xff, (mux_version >> 16) & 0xff,
+             (mux_version >> 8) & 0xff, mux_version & 0xff);
+      return 0;
+    } else if (!strcmp(argv[c], "-quiet")) {
+      quiet = 1;
+      enc_options.verbose = 0;
+    } else if (!strcmp(argv[c], "-v")) {
+      verbose = 1;
+      enc_options.verbose = 1;
+    } else if (!strcmp(argv[c], "--")) {
+      if (c < argc - 1) in_file = argv[++c];
+      break;
+    } else if (argv[c][0] == '-') {
+      fprintf(stderr, "Error! Unknown option '%s'\n", argv[c]);
+      Help();
+      return -1;
+    } else {
+      in_file = argv[c];
+    }
+
+    if (parse_error) {
+      Help();
+      return -1;
+    }
+  }
+
+  // Appropriate default kmin, kmax values for lossy and lossless.
+  if (default_kmin) {
+    enc_options.kmin = config.lossless ? 9 : 3;
+  }
+  if (default_kmax) {
+    enc_options.kmax = config.lossless ? 17 : 5;
+  }
+
+  if (!WebPValidateConfig(&config)) {
+    fprintf(stderr, "Error! Invalid configuration.\n");
+    goto End;
+  }
+
+  if (in_file == NULL) {
+    fprintf(stderr, "No input file specified!\n");
+    Help();
+    goto End;
+  }
+
+  // Start the decoder object
+#if LOCAL_GIF_PREREQ(5,0)
+  gif = DGifOpenFileName(in_file, &gif_error);
+#else
+  gif = DGifOpenFileName(in_file);
+#endif
+  if (gif == NULL) goto End;
+
+  // Loop over GIF images
+  done = 0;
+  do {
+    GifRecordType type;
+    if (DGifGetRecordType(gif, &type) == GIF_ERROR) goto End;
+
+    switch (type) {
+      case IMAGE_DESC_RECORD_TYPE: {
+        GIFFrameRect gif_rect;
+        GifImageDesc* const image_desc = &gif->Image;
+
+        if (!DGifGetImageDesc(gif)) goto End;
+
+        if (is_first_frame) {
+          if (verbose) {
+            printf("Canvas screen: %d x %d\n", gif->SWidth, gif->SHeight);
+          }
+          // Fix some broken GIF global headers that report
+          // 0 x 0 screen dimension.
+          if (gif->SWidth == 0 || gif->SHeight == 0) {
+            image_desc->Left = 0;
+            image_desc->Top = 0;
+            gif->SWidth = image_desc->Width;
+            gif->SHeight = image_desc->Height;
+            if (gif->SWidth <= 0 || gif->SHeight <= 0) {
+              goto End;
+            }
+            if (verbose) {
+              printf("Fixed canvas screen dimension to: %d x %d\n",
+                     gif->SWidth, gif->SHeight);
+            }
+          }
+          // Allocate current buffer.
+          frame.width = gif->SWidth;
+          frame.height = gif->SHeight;
+          frame.use_argb = 1;
+          if (!WebPPictureAlloc(&frame)) goto End;
+          GIFClearPic(&frame, NULL);
+          WebPPictureCopy(&frame, &curr_canvas);
+          WebPPictureCopy(&frame, &prev_canvas);
+
+          // Background color.
+          GIFGetBackgroundColor(gif->SColorMap, gif->SBackGroundColor,
+                                transparent_index,
+                                &enc_options.anim_params.bgcolor);
+
+          // Initialize encoder.
+          enc = WebPAnimEncoderNew(curr_canvas.width, curr_canvas.height,
+                                   &enc_options);
+          if (enc == NULL) {
+            fprintf(stderr,
+                    "Error! Could not create encoder object. Possibly due to "
+                    "a memory error.\n");
+            goto End;
+          }
+          is_first_frame = 0;
+        }
+
+        // Some even more broken GIF can have sub-rect with zero width/height.
+        if (image_desc->Width == 0 || image_desc->Height == 0) {
+          image_desc->Width = gif->SWidth;
+          image_desc->Height = gif->SHeight;
+        }
+
+        if (!GIFReadFrame(gif, transparent_index, &gif_rect, &frame)) {
+          goto End;
+        }
+        // Blend frame rectangle with previous canvas to compose full canvas.
+        // Note that 'curr_canvas' is same as 'prev_canvas' at this point.
+        GIFBlendFrames(&frame, &gif_rect, &curr_canvas);
+
+        if (!WebPAnimEncoderAdd(enc, &curr_canvas, frame_timestamp, &config)) {
+          fprintf(stderr, "%s\n", WebPAnimEncoderGetError(enc));
+        }
+
+        // Update canvases.
+        GIFDisposeFrame(orig_dispose, &gif_rect, &prev_canvas, &curr_canvas);
+        GIFCopyPixels(&curr_canvas, &prev_canvas);
+
+        // Update timestamp (for next frame).
+        frame_timestamp += frame_duration;
+
+        // In GIF, graphic control extensions are optional for a frame, so we
+        // may not get one before reading the next frame. To handle this case,
+        // we reset frame properties to reasonable defaults for the next frame.
+        orig_dispose = GIF_DISPOSE_NONE;
+        frame_duration = 0;
+        transparent_index = GIF_INDEX_INVALID;
+        break;
+      }
+      case EXTENSION_RECORD_TYPE: {
+        int extension;
+        GifByteType *data = NULL;
+        if (DGifGetExtension(gif, &extension, &data) == GIF_ERROR) {
+          goto End;
+        }
+        if (data == NULL) continue;
+
+        switch (extension) {
+          case COMMENT_EXT_FUNC_CODE: {
+            break;  // Do nothing for now.
+          }
+          case GRAPHICS_EXT_FUNC_CODE: {
+            if (!GIFReadGraphicsExtension(data, &frame_duration, &orig_dispose,
+                                          &transparent_index)) {
+              goto End;
+            }
+            break;
+          }
+          case PLAINTEXT_EXT_FUNC_CODE: {
+            break;
+          }
+          case APPLICATION_EXT_FUNC_CODE: {
+            if (data[0] != 11) break;    // Chunk is too short
+            if (!memcmp(data + 1, "NETSCAPE2.0", 11) ||
+                !memcmp(data + 1, "ANIMEXTS1.0", 11)) {
+              if (!GIFReadLoopCount(gif, &data, &loop_count)) {
+                goto End;
+              }
+              if (verbose) {
+                fprintf(stderr, "Loop count: %d\n", loop_count);
+              }
+              stored_loop_count = (loop_count != 0);
+            } else {  // An extension containing metadata.
+              // We only store the first encountered chunk of each type, and
+              // only if requested by the user.
+              const int is_xmp = (keep_metadata & METADATA_XMP) &&
+                                 !stored_xmp &&
+                                 !memcmp(data + 1, "XMP DataXMP", 11);
+              const int is_icc = (keep_metadata & METADATA_ICC) &&
+                                 !stored_icc &&
+                                 !memcmp(data + 1, "ICCRGBG1012", 11);
+              if (is_xmp || is_icc) {
+                if (!GIFReadMetadata(gif, &data,
+                                     is_xmp ? &xmp_data : &icc_data)) {
+                  goto End;
+                }
+                if (is_icc) {
+                  stored_icc = 1;
+                } else if (is_xmp) {
+                  stored_xmp = 1;
+                }
+              }
+            }
+            break;
+          }
+          default: {
+            break;  // skip
+          }
+        }
+        while (data != NULL) {
+          if (DGifGetExtensionNext(gif, &data) == GIF_ERROR) goto End;
+        }
+        break;
+      }
+      case TERMINATE_RECORD_TYPE: {
+        done = 1;
+        break;
+      }
+      default: {
+        if (verbose) {
+          fprintf(stderr, "Skipping over unknown record type %d\n", type);
+        }
+        break;
+      }
+    }
+  } while (!done);
+
+  // Last NULL frame.
+  if (!WebPAnimEncoderAdd(enc, NULL, frame_timestamp, NULL)) {
+    fprintf(stderr, "Error flushing WebP muxer.\n");
+    fprintf(stderr, "%s\n", WebPAnimEncoderGetError(enc));
+  }
+
+  if (!WebPAnimEncoderAssemble(enc, &webp_data)) {
+    fprintf(stderr, "%s\n", WebPAnimEncoderGetError(enc));
+    goto End;
+  }
+
+  if (stored_loop_count || stored_icc || stored_xmp) {
+    // Re-mux to add loop count and/or metadata as needed.
+    mux = WebPMuxCreate(&webp_data, 1);
+    if (mux == NULL) {
+      fprintf(stderr, "ERROR: Could not re-mux to add loop count/metadata.\n");
+      goto End;
+    }
+    WebPDataClear(&webp_data);
+
+    if (stored_loop_count) {  // Update loop count.
+      WebPMuxAnimParams new_params;
+      err = WebPMuxGetAnimationParams(mux, &new_params);
+      if (err != WEBP_MUX_OK) {
+        fprintf(stderr, "ERROR (%s): Could not fetch loop count.\n",
+                ErrorString(err));
+        goto End;
+      }
+      new_params.loop_count = loop_count;
+      err = WebPMuxSetAnimationParams(mux, &new_params);
+      if (err != WEBP_MUX_OK) {
+        fprintf(stderr, "ERROR (%s): Could not update loop count.\n",
+                ErrorString(err));
+        goto End;
+      }
+    }
+
+    if (stored_icc) {   // Add ICCP chunk.
+      err = WebPMuxSetChunk(mux, "ICCP", &icc_data, 1);
+      if (verbose) {
+        fprintf(stderr, "ICC size: %d\n", (int)icc_data.size);
+      }
+      if (err != WEBP_MUX_OK) {
+        fprintf(stderr, "ERROR (%s): Could not set ICC chunk.\n",
+                ErrorString(err));
+        goto End;
+      }
+    }
+
+    if (stored_xmp) {   // Add XMP chunk.
+      err = WebPMuxSetChunk(mux, "XMP ", &xmp_data, 1);
+      if (verbose) {
+        fprintf(stderr, "XMP size: %d\n", (int)xmp_data.size);
+      }
+      if (err != WEBP_MUX_OK) {
+        fprintf(stderr, "ERROR (%s): Could not set XMP chunk.\n",
+                ErrorString(err));
+        goto End;
+      }
+    }
+
+    err = WebPMuxAssemble(mux, &webp_data);
+    if (err != WEBP_MUX_OK) {
+      fprintf(stderr, "ERROR (%s): Could not assemble when re-muxing to add "
+              "loop count/metadata.\n", ErrorString(err));
+      goto End;
+    }
+  }
+
+  if (out_file != NULL) {
+    if (!ImgIoUtilWriteFile(out_file, webp_data.bytes, webp_data.size)) {
+      fprintf(stderr, "Error writing output file: %s\n", out_file);
+      goto End;
+    }
+    if (!quiet) {
+      fprintf(stderr, "Saved output file (%d bytes): %s\n",
+              (int)webp_data.size, out_file);
+    }
+  } else {
+    if (!quiet) {
+      fprintf(stderr, "Nothing written; use -o flag to save the result "
+                      "(%d bytes).\n", (int)webp_data.size);
+    }
+  }
+
+  // All OK.
+  ok = 1;
+  gif_error = GIF_OK;
+
+ End:
+  WebPDataClear(&icc_data);
+  WebPDataClear(&xmp_data);
+  WebPMuxDelete(mux);
+  WebPDataClear(&webp_data);
+  WebPPictureFree(&frame);
+  WebPPictureFree(&curr_canvas);
+  WebPPictureFree(&prev_canvas);
+  WebPAnimEncoderDelete(enc);
+  if (out != NULL && out_file != NULL) fclose(out);
+
+  if (gif_error != GIF_OK) {
+    GIFDisplayError(gif, gif_error);
+  }
+  if (gif != NULL) {
+#if LOCAL_GIF_PREREQ(5,1)
+    DGifCloseFile(gif, &gif_error);
+#else
+    DGifCloseFile(gif);
+#endif
+  }
+
+  return !ok;
+}
+
+#else  // !WEBP_HAVE_GIF
+
+int main(int argc, const char *argv[]) {
+  fprintf(stderr, "GIF support not enabled in %s.\n", argv[0]);
+  (void)argc;
+  return 0;
+}
+
+#endif
+
+//------------------------------------------------------------------------------

examples/gifdec.c

@@ -0,0 +1,410 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// GIF decode.
+
+#include "./gifdec.h"
+
+#include <stdio.h>
+
+#ifdef WEBP_HAVE_GIF
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "webp/encode.h"
+#include "webp/mux_types.h"
+
+#define GIF_TRANSPARENT_COLOR 0x00000000u
+#define GIF_WHITE_COLOR       0xffffffffu
+#define GIF_TRANSPARENT_MASK  0x01
+#define GIF_DISPOSE_MASK      0x07
+#define GIF_DISPOSE_SHIFT     2
+
+// from utils/utils.h
+extern void WebPCopyPlane(const uint8_t* src, int src_stride,
+                          uint8_t* dst, int dst_stride,
+                          int width, int height);
+extern void WebPCopyPixels(const WebPPicture* const src,
+                           WebPPicture* const dst);
+
+void GIFGetBackgroundColor(const ColorMapObject* const color_map,
+                           int bgcolor_index, int transparent_index,
+                           uint32_t* const bgcolor) {
+  if (transparent_index != GIF_INDEX_INVALID &&
+      bgcolor_index == transparent_index) {
+    *bgcolor = GIF_TRANSPARENT_COLOR;  // Special case.
+  } else if (color_map == NULL || color_map->Colors == NULL
+             || bgcolor_index >= color_map->ColorCount) {
+    *bgcolor = GIF_WHITE_COLOR;
+    fprintf(stderr,
+            "GIF decode warning: invalid background color index. Assuming "
+            "white background.\n");
+  } else {
+    const GifColorType color = color_map->Colors[bgcolor_index];
+    *bgcolor = (0xffu       << 24)
+             | (color.Red   << 16)
+             | (color.Green <<  8)
+             | (color.Blue  <<  0);
+  }
+}
+
+int GIFReadGraphicsExtension(const GifByteType* const buf, int* const duration,
+                             GIFDisposeMethod* const dispose,
+                             int* const transparent_index) {
+  const int flags = buf[1];
+  const int dispose_raw = (flags >> GIF_DISPOSE_SHIFT) & GIF_DISPOSE_MASK;
+  const int duration_raw = buf[2] | (buf[3] << 8);  // In 10 ms units.
+  if (buf[0] != 4) return 0;
+  *duration = duration_raw * 10;  // Duration is in 1 ms units.
+  switch (dispose_raw) {
+    case 3:
+      *dispose = GIF_DISPOSE_RESTORE_PREVIOUS;
+      break;
+    case 2:
+      *dispose = GIF_DISPOSE_BACKGROUND;
+      break;
+    case 1:
+    case 0:
+    default:
+      *dispose = GIF_DISPOSE_NONE;
+      break;
+  }
+  *transparent_index =
+      (flags & GIF_TRANSPARENT_MASK) ? buf[4] : GIF_INDEX_INVALID;
+  return 1;
+}
+
+static int Remap(const GifFileType* const gif, const uint8_t* const src,
+                 int len, int transparent_index, uint32_t* dst) {
+  int i;
+  const GifColorType* colors;
+  const ColorMapObject* const cmap =
+      gif->Image.ColorMap ? gif->Image.ColorMap : gif->SColorMap;
+  if (cmap == NULL) return 1;
+  if (cmap->Colors == NULL || cmap->ColorCount <= 0) return 0;
+  colors = cmap->Colors;
+
+  for (i = 0; i < len; ++i) {
+    if (src[i] == transparent_index) {
+      dst[i] = GIF_TRANSPARENT_COLOR;
+    } else if (src[i] < cmap->ColorCount) {
+      const GifColorType c = colors[src[i]];
+      dst[i] = c.Blue | (c.Green << 8) | (c.Red << 16) | (0xffu << 24);
+    } else {
+      return 0;
+    }
+  }
+  return 1;
+}
+
+int GIFReadFrame(GifFileType* const gif, int transparent_index,
+                 GIFFrameRect* const gif_rect, WebPPicture* const picture) {
+  WebPPicture sub_image;
+  const GifImageDesc* const image_desc = &gif->Image;
+  uint32_t* dst = NULL;
+  uint8_t* tmp = NULL;
+  const GIFFrameRect rect = {
+      image_desc->Left, image_desc->Top, image_desc->Width, image_desc->Height
+  };
+  const uint64_t memory_needed = 4 * rect.width * (uint64_t)rect.height;
+  int ok = 0;
+  *gif_rect = rect;
+
+  if (memory_needed != (size_t)memory_needed || memory_needed > (4ULL << 32)) {
+    fprintf(stderr, "Image is too large (%d x %d).", rect.width, rect.height);
+    return 0;
+  }
+
+  // Use a view for the sub-picture:
+  if (!WebPPictureView(picture, rect.x_offset, rect.y_offset,
+                       rect.width, rect.height, &sub_image)) {
+    fprintf(stderr, "Sub-image %dx%d at position %d,%d is invalid!\n",
+            rect.width, rect.height, rect.x_offset, rect.y_offset);
+    return 0;
+  }
+  dst = sub_image.argb;
+
+  tmp = (uint8_t*)malloc(rect.width * sizeof(*tmp));
+  if (tmp == NULL) goto End;
+
+  if (image_desc->Interlace) {  // Interlaced image.
+    // We need 4 passes, with the following offsets and jumps.
+    const int interlace_offsets[] = { 0, 4, 2, 1 };
+    const int interlace_jumps[]   = { 8, 8, 4, 2 };
+    int pass;
+    for (pass = 0; pass < 4; ++pass) {
+      const size_t stride = (size_t)sub_image.argb_stride;
+      int y = interlace_offsets[pass];
+      uint32_t* row = dst + y * stride;
+      const size_t jump = interlace_jumps[pass] * stride;
+      for (; y < rect.height; y += interlace_jumps[pass], row += jump) {
+        if (DGifGetLine(gif, tmp, rect.width) == GIF_ERROR) goto End;
+        if (!Remap(gif, tmp, rect.width, transparent_index, row)) goto End;
+      }
+    }
+  } else {  // Non-interlaced image.
+    int y;
+    uint32_t* ptr = dst;
+    for (y = 0; y < rect.height; ++y, ptr += sub_image.argb_stride) {
+      if (DGifGetLine(gif, tmp, rect.width) == GIF_ERROR) goto End;
+      if (!Remap(gif, tmp, rect.width, transparent_index, ptr)) goto End;
+    }
+  }
+  ok = 1;
+
+ End:
+  if (!ok) picture->error_code = sub_image.error_code;
+  WebPPictureFree(&sub_image);
+  free(tmp);
+  return ok;
+}
+
+int GIFReadLoopCount(GifFileType* const gif, GifByteType** const buf,
+                     int* const loop_count) {
+  assert(!memcmp(*buf + 1, "NETSCAPE2.0", 11) ||
+         !memcmp(*buf + 1, "ANIMEXTS1.0", 11));
+  if (DGifGetExtensionNext(gif, buf) == GIF_ERROR) {
+    return 0;
+  }
+  if (*buf == NULL) {
+    return 0;  // Loop count sub-block missing.
+  }
+  if ((*buf)[0] < 3 || (*buf)[1] != 1) {
+    return 0;   // wrong size/marker
+  }
+  *loop_count = (*buf)[2] | ((*buf)[3] << 8);
+  return 1;
+}
+
+int GIFReadMetadata(GifFileType* const gif, GifByteType** const buf,
+                    WebPData* const metadata) {
+  const int is_xmp = !memcmp(*buf + 1, "XMP DataXMP", 11);
+  const int is_icc = !memcmp(*buf + 1, "ICCRGBG1012", 11);
+  assert(is_xmp || is_icc);
+  (void)is_icc;  // silence unused warning.
+  // Construct metadata from sub-blocks.
+  // Usual case (including ICC profile): In each sub-block, the
+  // first byte specifies its size in bytes (0 to 255) and the
+  // rest of the bytes contain the data.
+  // Special case for XMP data: In each sub-block, the first byte
+  // is also part of the XMP payload. XMP in GIF also has a 257
+  // byte padding data. See the XMP specification for details.
+  while (1) {
+    WebPData subblock;
+    const uint8_t* tmp;
+    if (DGifGetExtensionNext(gif, buf) == GIF_ERROR) {
+      return 0;
+    }
+    if (*buf == NULL) break;  // Finished.
+    subblock.size = is_xmp ? (*buf)[0] + 1 : (*buf)[0];
+    assert(subblock.size > 0);
+    subblock.bytes = is_xmp ? *buf : *buf + 1;
+    // Note: We store returned value in 'tmp' first, to avoid
+    // leaking old memory in metadata->bytes on error.
+    tmp = (uint8_t*)realloc((void*)metadata->bytes,
+                            metadata->size + subblock.size);
+    if (tmp == NULL) {
+      return 0;
+    }
+    memcpy((void*)(tmp + metadata->size),
+           subblock.bytes, subblock.size);
+    metadata->bytes = tmp;
+    metadata->size += subblock.size;
+  }
+  if (is_xmp) {
+    // XMP padding data is 0x01, 0xff, 0xfe ... 0x01, 0x00.
+    const size_t xmp_pading_size = 257;
+    if (metadata->size > xmp_pading_size) {
+      metadata->size -= xmp_pading_size;
+    }
+  }
+  return 1;
+}
+
+static void ClearRectangle(WebPPicture* const picture,
+                           int left, int top, int width, int height) {
+  int i, j;
+  const size_t stride = picture->argb_stride;
+  uint32_t* dst = picture->argb + top * stride + left;
+  for (j = 0; j < height; ++j, dst += stride) {
+    for (i = 0; i < width; ++i) dst[i] = GIF_TRANSPARENT_COLOR;
+  }
+}
+
+void GIFClearPic(WebPPicture* const pic, const GIFFrameRect* const rect) {
+  if (rect != NULL) {
+    ClearRectangle(pic, rect->x_offset, rect->y_offset,
+                   rect->width, rect->height);
+  } else {
+    ClearRectangle(pic, 0, 0, pic->width, pic->height);
+  }
+}
+
+void GIFCopyPixels(const WebPPicture* const src, WebPPicture* const dst) {
+  WebPCopyPixels(src, dst);
+}
+
+void GIFDisposeFrame(GIFDisposeMethod dispose, const GIFFrameRect* const rect,
+                     const WebPPicture* const prev_canvas,
+                     WebPPicture* const curr_canvas) {
+  assert(rect != NULL);
+  if (dispose == GIF_DISPOSE_BACKGROUND) {
+    GIFClearPic(curr_canvas, rect);
+  } else if (dispose == GIF_DISPOSE_RESTORE_PREVIOUS) {
+    const size_t src_stride = prev_canvas->argb_stride;
+    const uint32_t* const src = prev_canvas->argb + rect->x_offset
+                              + rect->y_offset * src_stride;
+    const size_t dst_stride = curr_canvas->argb_stride;
+    uint32_t* const dst = curr_canvas->argb + rect->x_offset
+                        + rect->y_offset * dst_stride;
+    assert(prev_canvas != NULL);
+    WebPCopyPlane((uint8_t*)src, (int)(4 * src_stride),
+                  (uint8_t*)dst, (int)(4 * dst_stride),
+                  4 * rect->width, rect->height);
+  }
+}
+
+void GIFBlendFrames(const WebPPicture* const src,
+                    const GIFFrameRect* const rect, WebPPicture* const dst) {
+  int i, j;
+  const size_t src_stride = src->argb_stride;
+  const size_t dst_stride = dst->argb_stride;
+  assert(src->width == dst->width && src->height == dst->height);
+  for (j = rect->y_offset; j < rect->y_offset + rect->height; ++j) {
+    for (i = rect->x_offset; i < rect->x_offset + rect->width; ++i) {
+      const uint32_t src_pixel = src->argb[j * src_stride + i];
+      const int src_alpha = src_pixel >> 24;
+      if (src_alpha != 0) {
+        dst->argb[j * dst_stride + i] = src_pixel;
+      }
+    }
+  }
+}
+
+void GIFDisplayError(const GifFileType* const gif, int gif_error) {
+  // libgif 4.2.0 has retired PrintGifError() and added GifErrorString().
+#if LOCAL_GIF_PREREQ(4,2)
+#if LOCAL_GIF_PREREQ(5,0)
+  // Static string actually, hence the const char* cast.
+  const char* error_str = (const char*)GifErrorString(
+      (gif == NULL) ? gif_error : gif->Error);
+#else
+  const char* error_str = (const char*)GifErrorString();
+  (void)gif;
+#endif
+  if (error_str == NULL) error_str = "Unknown error";
+  fprintf(stderr, "GIFLib Error %d: %s\n", gif_error, error_str);
+#else
+  (void)gif;
+  fprintf(stderr, "GIFLib Error %d: ", gif_error);
+  PrintGifError();
+  fprintf(stderr, "\n");
+#endif
+}
+
+#else  // !WEBP_HAVE_GIF
+
+static void ErrorGIFNotAvailable() {
+  fprintf(stderr, "GIF support not compiled. Please install the libgif-dev "
+          "package before building.\n");
+}
+
+void GIFGetBackgroundColor(const struct ColorMapObject* const color_map,
+                           int bgcolor_index, int transparent_index,
+                           uint32_t* const bgcolor) {
+  (void)color_map;
+  (void)bgcolor_index;
+  (void)transparent_index;
+  (void)bgcolor;
+  ErrorGIFNotAvailable();
+}
+
+int GIFReadGraphicsExtension(const GifByteType* const data, int* const duration,
+                             GIFDisposeMethod* const dispose,
+                             int* const transparent_index) {
+  (void)data;
+  (void)duration;
+  (void)dispose;
+  (void)transparent_index;
+  ErrorGIFNotAvailable();
+  return 0;
+}
+
+int GIFReadFrame(struct GifFileType* const gif, int transparent_index,
+                 GIFFrameRect* const gif_rect,
+                 struct WebPPicture* const picture) {
+  (void)gif;
+  (void)transparent_index;
+  (void)gif_rect;
+  (void)picture;
+  ErrorGIFNotAvailable();
+  return 0;
+}
+
+int GIFReadLoopCount(struct GifFileType* const gif, GifByteType** const buf,
+                     int* const loop_count) {
+  (void)gif;
+  (void)buf;
+  (void)loop_count;
+  ErrorGIFNotAvailable();
+  return 0;
+}
+
+int GIFReadMetadata(struct GifFileType* const gif, GifByteType** const buf,
+                    struct WebPData* const metadata) {
+  (void)gif;
+  (void)buf;
+  (void)metadata;
+  ErrorGIFNotAvailable();
+  return 0;
+}
+
+void GIFDisposeFrame(GIFDisposeMethod dispose, const GIFFrameRect* const rect,
+                     const struct WebPPicture* const prev_canvas,
+                     struct WebPPicture* const curr_canvas) {
+  (void)dispose;
+  (void)rect;
+  (void)prev_canvas;
+  (void)curr_canvas;
+  ErrorGIFNotAvailable();
+}
+
+void GIFBlendFrames(const struct WebPPicture* const src,
+                    const GIFFrameRect* const rect,
+                    struct WebPPicture* const dst) {
+  (void)src;
+  (void)rect;
+  (void)dst;
+  ErrorGIFNotAvailable();
+}
+
+void GIFDisplayError(const struct GifFileType* const gif, int gif_error) {
+  (void)gif;
+  (void)gif_error;
+  ErrorGIFNotAvailable();
+}
+
+void GIFClearPic(struct WebPPicture* const pic,
+                 const GIFFrameRect* const rect) {
+  (void)pic;
+  (void)rect;
+  ErrorGIFNotAvailable();
+}
+
+void GIFCopyPixels(const struct WebPPicture* const src,
+                   struct WebPPicture* const dst) {
+  (void)src;
+  (void)dst;
+  ErrorGIFNotAvailable();
+}
+
+#endif  // WEBP_HAVE_GIF
+
+// -----------------------------------------------------------------------------

examples/gifdec.h

@@ -0,0 +1,116 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// GIF decode.
+
+#ifndef WEBP_EXAMPLES_GIFDEC_H_
+#define WEBP_EXAMPLES_GIFDEC_H_
+
+#include <stdio.h>
+#include "webp/types.h"
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#ifdef WEBP_HAVE_GIF
+#include <gif_lib.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// GIFLIB_MAJOR is only defined in libgif >= 4.2.0.
+#if defined(GIFLIB_MAJOR) && defined(GIFLIB_MINOR)
+# define LOCAL_GIF_VERSION ((GIFLIB_MAJOR << 8) | GIFLIB_MINOR)
+# define LOCAL_GIF_PREREQ(maj, min) \
+    (LOCAL_GIF_VERSION >= (((maj) << 8) | (min)))
+#else
+# define LOCAL_GIF_VERSION 0
+# define LOCAL_GIF_PREREQ(maj, min) 0
+#endif
+
+#define GIF_INDEX_INVALID (-1)
+
+typedef enum GIFDisposeMethod {
+  GIF_DISPOSE_NONE,
+  GIF_DISPOSE_BACKGROUND,
+  GIF_DISPOSE_RESTORE_PREVIOUS
+} GIFDisposeMethod;
+
+typedef struct {
+  int x_offset, y_offset, width, height;
+} GIFFrameRect;
+
+struct WebPData;
+struct WebPPicture;
+
+#ifndef WEBP_HAVE_GIF
+struct ColorMapObject;
+struct GifFileType;
+typedef unsigned char GifByteType;
+#endif
+
+// Given the index of background color and transparent color, returns the
+// corresponding background color (in BGRA format) in 'bgcolor'.
+void GIFGetBackgroundColor(const struct ColorMapObject* const color_map,
+                           int bgcolor_index, int transparent_index,
+                           uint32_t* const bgcolor);
+
+// Parses the given graphics extension data to get frame duration (in 1ms
+// units), dispose method and transparent color index.
+// Returns true on success.
+int GIFReadGraphicsExtension(const GifByteType* const buf, int* const duration,
+                             GIFDisposeMethod* const dispose,
+                             int* const transparent_index);
+
+// Reads the next GIF frame from 'gif' into 'picture'. Also, returns the GIF
+// frame dimensions and offsets in 'rect'.
+// Returns true on success.
+int GIFReadFrame(struct GifFileType* const gif, int transparent_index,
+                 GIFFrameRect* const gif_rect,
+                 struct WebPPicture* const picture);
+
+// Parses loop count from the given Netscape extension data.
+int GIFReadLoopCount(struct GifFileType* const gif, GifByteType** const buf,
+                     int* const loop_count);
+
+// Parses the given ICC or XMP extension data and stores it into 'metadata'.
+// Returns true on success.
+int GIFReadMetadata(struct GifFileType* const gif, GifByteType** const buf,
+                    struct WebPData* const metadata);
+
+// Dispose the pixels within 'rect' of 'curr_canvas' based on 'dispose' method
+// and 'prev_canvas'.
+void GIFDisposeFrame(GIFDisposeMethod dispose, const GIFFrameRect* const rect,
+                     const struct WebPPicture* const prev_canvas,
+                     struct WebPPicture* const curr_canvas);
+
+// Given 'src' picture and its frame rectangle 'rect', blend it into 'dst'.
+void GIFBlendFrames(const struct WebPPicture* const src,
+                    const GIFFrameRect* const rect,
+                    struct WebPPicture* const dst);
+
+// Prints an error string based on 'gif_error'.
+void GIFDisplayError(const struct GifFileType* const gif, int gif_error);
+
+// In the given 'pic', clear the pixels in 'rect' to transparent color.
+void GIFClearPic(struct WebPPicture* const pic, const GIFFrameRect* const rect);
+
+// Copy pixels from 'src' to 'dst' honoring strides. 'src' and 'dst' are assumed
+// to be already allocated.
+void GIFCopyPixels(const struct WebPPicture* const src,
+                   struct WebPPicture* const dst);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_EXAMPLES_GIFDEC_H_

examples/img2webp.c

@@ -0,0 +1,300 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  generate an animated WebP out of a sequence of images
+//  (PNG, JPEG, ...)
+//
+//  Example usage:
+//     img2webp -o out.webp -q 40 -mixed -duration 40 input??.png
+//
+// Author: skal@google.com (Pascal Massimino)
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#include "../examples/example_util.h"
+#include "../imageio/image_dec.h"
+#include "../imageio/imageio_util.h"
+#include "./stopwatch.h"
+#include "webp/encode.h"
+#include "webp/mux.h"
+
+//------------------------------------------------------------------------------
+
+static void Help(void) {
+  printf("Usage:\n\n");
+  printf("  img2webp [file-level options] [image files...] "
+         "[per-frame options...]\n");
+  printf("\n");
+
+  printf("File-level options (only used at the start of compression):\n");
+  printf(" -min_size ............ minimize size\n");
+  printf(" -loop <int> .......... loop count (default: 0, = infinite loop)\n");
+  printf(" -kmax <int> .......... maximum number of frame between key-frames\n"
+         "                        (0=only keyframes)\n");
+  printf(" -kmin <int> .......... minimum number of frame between key-frames\n"
+         "                        (0=disable key-frames altogether)\n");
+  printf(" -mixed ............... use mixed lossy/lossless automatic mode\n");
+  printf(" -v ................... verbose mode\n");
+  printf(" -h ................... this help\n");
+  printf("\n");
+
+  printf("Per-frame options (only used for subsequent images input):\n");
+  printf(" -d <int> ............. frame duration in ms (default: 100)\n");
+  printf(" -lossless  ........... use lossless mode (default)\n");
+  printf(" -lossy ... ........... use lossy mode\n");
+  printf(" -q <float> ........... quality\n");
+  printf(" -m <int> ............. method to use\n");
+
+  printf("\n");
+  printf("example: img2webp -loop 2 in0.png -lossy in1.jpg\n"
+         "                  -d 80 in2.tiff -o out.webp\n");
+}
+
+//------------------------------------------------------------------------------
+
+static int ReadImage(const char filename[], WebPPicture* const pic) {
+  const uint8_t* data = NULL;
+  size_t data_size = 0;
+  WebPImageReader reader;
+  int ok;
+#ifdef HAVE_WINCODEC_H
+  // Try to decode the file using WIC falling back to the other readers for
+  // e.g., WebP.
+  ok = ReadPictureWithWIC(filename, pic, 1, NULL);
+  if (ok) return 1;
+#endif
+  if (!ImgIoUtilReadFile(filename, &data, &data_size)) return 0;
+  reader = WebPGuessImageReader(data, data_size);
+  ok = reader(data, data_size, pic, 1, NULL);
+  free((void*)data);
+  return ok;
+}
+
+static int SetLoopCount(int loop_count, WebPData* const webp_data) {
+  int ok = 1;
+  WebPMuxError err;
+  uint32_t features;
+  WebPMuxAnimParams new_params;
+  WebPMux* const mux = WebPMuxCreate(webp_data, 1);
+  if (mux == NULL) return 0;
+
+  err = WebPMuxGetFeatures(mux, &features);
+  ok = (err == WEBP_MUX_OK);
+  if (!ok || !(features & ANIMATION_FLAG)) goto End;
+
+  err = WebPMuxGetAnimationParams(mux, &new_params);
+  ok = (err == WEBP_MUX_OK);
+  if (ok) {
+    new_params.loop_count = loop_count;
+    err = WebPMuxSetAnimationParams(mux, &new_params);
+    ok = (err == WEBP_MUX_OK);
+  }
+  if (ok) {
+    WebPDataClear(webp_data);
+    err = WebPMuxAssemble(mux, webp_data);
+    ok = (err == WEBP_MUX_OK);
+  }
+
+ End:
+  WebPMuxDelete(mux);
+  if (!ok) {
+    fprintf(stderr, "Error during loop-count setting\n");
+  }
+  return ok;
+}
+
+//------------------------------------------------------------------------------
+
+int main(int argc, char* argv[]) {
+  const char* output = NULL;
+  WebPAnimEncoder* enc = NULL;
+  int verbose = 0;
+  int pic_num = 0;
+  int duration = 100;
+  int timestamp_ms = 0;
+  int ok = 1;
+  int loop_count = 0;
+  int width = 0, height = 0;
+  WebPAnimEncoderOptions anim_config;
+  WebPConfig config;
+  WebPPicture pic;
+  WebPData webp_data;
+  int c;
+  int have_input = 0;
+
+  WebPDataInit(&webp_data);
+  if (!WebPAnimEncoderOptionsInit(&anim_config) ||
+      !WebPConfigInit(&config) ||
+      !WebPPictureInit(&pic)) {
+    fprintf(stderr, "Library version mismatch!\n");
+    return 1;
+  }
+
+  // 1st pass of option parsing
+  for (c = 1; ok && c < argc; ++c) {
+    if (argv[c][0] == '-') {
+      int parse_error = 0;
+      if (!strcmp(argv[c], "-o") && c + 1 < argc) {
+        argv[c] = NULL;
+        output = argv[++c];
+      } else if (!strcmp(argv[c], "-kmin") && c + 1 < argc) {
+        argv[c] = NULL;
+        anim_config.kmin = ExUtilGetInt(argv[++c], 0, &parse_error);
+      } else if (!strcmp(argv[c], "-kmax") && c + 1 < argc) {
+        argv[c] = NULL;
+        anim_config.kmax = ExUtilGetInt(argv[++c], 0, &parse_error);
+      } else if (!strcmp(argv[c], "-loop") && c + 1 < argc) {
+        argv[c] = NULL;
+        loop_count = ExUtilGetInt(argv[++c], 0, &parse_error);
+        if (loop_count < 0) {
+          fprintf(stderr, "Invalid non-positive loop-count (%d)\n", loop_count);
+          parse_error = 1;
+        }
+      } else if (!strcmp(argv[c], "-min_size")) {
+        anim_config.minimize_size = 1;
+      } else if (!strcmp(argv[c], "-mixed")) {
+        anim_config.allow_mixed = 1;
+        config.lossless = 0;
+      } else if (!strcmp(argv[c], "-v")) {
+        verbose = 1;
+      } else if (!strcmp(argv[c], "-h") || !strcmp(argv[c], "-help")) {
+        Help();
+        return 0;
+      } else {
+        continue;
+      }
+      ok = !parse_error;
+      if (!ok) goto End;
+      argv[c] = NULL;   // mark option as 'parsed' during 1st pass
+    } else {
+      have_input |= 1;
+    }
+  }
+  if (!have_input) {
+    fprintf(stderr, "No input file(s) for generating animation!\n");
+    return 0;
+  }
+
+  // image-reading pass
+  pic_num = 0;
+  config.lossless = 1;
+  for (c = 1; ok && c < argc; ++c) {
+    if (argv[c] == NULL) continue;
+    if (argv[c][0] == '-') {    // parse local options
+      int parse_error = 0;
+      if (!strcmp(argv[c], "-lossy")) {
+        if (!anim_config.allow_mixed) config.lossless = 0;
+      } else if (!strcmp(argv[c], "-lossless")) {
+        if (!anim_config.allow_mixed) config.lossless = 1;
+      } else if (!strcmp(argv[c], "-q") && c + 1 < argc) {
+        config.quality = ExUtilGetFloat(argv[++c], &parse_error);
+      } else if (!strcmp(argv[c], "-m") && c + 1 < argc) {
+        config.method = ExUtilGetInt(argv[++c], 0, &parse_error);
+      } else if (!strcmp(argv[c], "-d") && c + 1 < argc) {
+        duration = ExUtilGetInt(argv[++c], 0, &parse_error);
+        if (duration <= 0) {
+          fprintf(stderr, "Invalid negative duration (%d)\n", duration);
+          parse_error = 1;
+        }
+      } else {
+        parse_error = 1;   // shouldn't be here.
+        fprintf(stderr, "Unknown option [%s]\n", argv[c]);
+      }
+      ok = !parse_error;
+      if (!ok) goto End;
+      continue;
+    }
+
+    if (ok) {
+      ok = WebPValidateConfig(&config);
+      if (!ok) {
+        fprintf(stderr, "Invalid configuration.\n");
+        goto End;
+      }
+    }
+
+    // read next input image
+    pic.use_argb = 1;
+    ok = ReadImage(argv[c], &pic);
+    if (!ok) goto End;
+
+    if (enc == NULL) {
+      width  = pic.width;
+      height = pic.height;
+      enc = WebPAnimEncoderNew(width, height, &anim_config);
+      ok = (enc != NULL);
+      if (!ok) {
+        fprintf(stderr, "Could not create WebPAnimEncoder object.\n");
+      }
+    }
+
+    if (ok) {
+      ok = (width == pic.width && height == pic.height);
+      if (!ok) {
+        fprintf(stderr, "Frame #%d dimension mismatched! "
+                        "Got %d x %d. Was expecting %d x %d.\n",
+                pic_num, pic.width, pic.height, width, height);
+      }
+    }
+
+    if (ok) {
+      ok = WebPAnimEncoderAdd(enc, &pic, timestamp_ms, &config);
+      if (!ok) {
+        fprintf(stderr, "Error while adding frame #%d\n", pic_num);
+      }
+    }
+    WebPPictureFree(&pic);
+    if (!ok) goto End;
+
+    if (verbose) {
+      fprintf(stderr, "Added frame #%3d at time %4d (file: %s)\n",
+              pic_num, timestamp_ms, argv[c]);
+    }
+    timestamp_ms += duration;
+    ++pic_num;
+  }
+
+  // add a last fake frame to signal the last duration
+  ok = ok && WebPAnimEncoderAdd(enc, NULL, timestamp_ms, NULL);
+  ok = ok && WebPAnimEncoderAssemble(enc, &webp_data);
+  if (!ok) {
+    fprintf(stderr, "Error during final animation assembly.\n");
+  }
+
+ End:
+  // free resources
+  WebPAnimEncoderDelete(enc);
+
+  if (ok && loop_count > 0) {  // Re-mux to add loop count.
+    ok = SetLoopCount(loop_count, &webp_data);
+  }
+
+  if (ok) {
+    if (output != NULL) {
+      ok = ImgIoUtilWriteFile(output, webp_data.bytes, webp_data.size);
+      if (ok) fprintf(stderr, "output file: %s     ", output);
+    } else {
+      fprintf(stderr, "[no output file specified]   ");
+    }
+  }
+
+  if (ok) {
+    fprintf(stderr, "[%d frames, %u bytes].\n",
+            pic_num, (unsigned int)webp_data.size);
+  }
+
+  WebPDataClear(&webp_data);
+  return ok ? 0 : 1;
+}

examples/stopwatch.h

@@ -1,8 +1,10 @@
-// Copyright 2011 Google Inc.
+// Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
 //  Helper functions to measure elapsed time.
@@ -12,12 +14,18 @@
 #ifndef WEBP_EXAMPLES_STOPWATCH_H_
 #define WEBP_EXAMPLES_STOPWATCH_H_
 
-#ifdef _WIN32
+#include "webp/types.h"
+
+#if defined _WIN32 && !defined __GNUC__
 #include <windows.h>
 
 typedef LARGE_INTEGER Stopwatch;
 
-static inline double StopwatchReadAndReset(Stopwatch* watch) {
+static WEBP_INLINE void StopwatchReset(Stopwatch* watch) {
+  QueryPerformanceCounter(watch);
+}
+
+static WEBP_INLINE double StopwatchReadAndReset(Stopwatch* watch) {
   const LARGE_INTEGER old_value = *watch;
   LARGE_INTEGER freq;
   if (!QueryPerformanceCounter(watch))
@@ -30,18 +38,26 @@ static inline double StopwatchReadAndReset(Stopwatch* watch) {
 }
 
 
-#else    // !_WIN32
+#else    /* !_WIN32 */
+#include <string.h>  // memcpy
 #include <sys/time.h>
 
 typedef struct timeval Stopwatch;
 
-static inline double StopwatchReadAndReset(Stopwatch* watch) {
-  const struct timeval old_value = *watch;
+static WEBP_INLINE void StopwatchReset(Stopwatch* watch) {
   gettimeofday(watch, NULL);
-  return watch->tv_sec - old_value.tv_sec +
-      (watch->tv_usec - old_value.tv_usec) / 1000000.0;
 }
 
-#endif   // !_WIN32
+static WEBP_INLINE double StopwatchReadAndReset(Stopwatch* watch) {
+  struct timeval old_value;
+  double delta_sec, delta_usec;
+  memcpy(&old_value, watch, sizeof(old_value));
+  gettimeofday(watch, NULL);
+  delta_sec = (double)watch->tv_sec - old_value.tv_sec;
+  delta_usec = (double)watch->tv_usec - old_value.tv_usec;
+  return delta_sec + delta_usec / 1000000.0;
+}
 
-#endif  // WEBP_EXAMPLES_STOPWATCH_H_
+#endif   /* _WIN32 */
+
+#endif  /* WEBP_EXAMPLES_STOPWATCH_H_ */

examples/vwebp.c

@@ -0,0 +1,582 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  Simple OpenGL-based WebP file viewer.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#if defined(__unix__) || defined(__CYGWIN__)
+#define _POSIX_C_SOURCE 200112L  // for setenv
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if defined(WEBP_HAVE_GL)
+
+#if defined(HAVE_GLUT_GLUT_H)
+#include <GLUT/glut.h>
+#else
+#include <GL/glut.h>
+#ifdef FREEGLUT
+#include <GL/freeglut.h>
+#endif
+#endif
+
+#ifdef WEBP_HAVE_QCMS
+#include <qcms.h>
+#endif
+
+#include "webp/decode.h"
+#include "webp/demux.h"
+
+#include "../examples/example_util.h"
+#include "../imageio/imageio_util.h"
+
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#define snprintf _snprintf
+#endif
+
+// Unfortunate global variables. Gathered into a struct for comfort.
+static struct {
+  int has_animation;
+  int has_color_profile;
+  int done;
+  int decoding_error;
+  int print_info;
+  int only_deltas;
+  int use_color_profile;
+
+  int canvas_width, canvas_height;
+  int loop_count;
+  uint32_t bg_color;
+
+  const char* file_name;
+  WebPData data;
+  WebPDecoderConfig config;
+  const WebPDecBuffer* pic;
+  WebPDemuxer* dmux;
+  WebPIterator curr_frame;
+  WebPIterator prev_frame;
+  WebPChunkIterator iccp;
+  int viewport_width, viewport_height;
+} kParams;
+
+static void ClearPreviousPic(void) {
+  WebPFreeDecBuffer((WebPDecBuffer*)kParams.pic);
+  kParams.pic = NULL;
+}
+
+static void ClearParams(void) {
+  ClearPreviousPic();
+  WebPDataClear(&kParams.data);
+  WebPDemuxReleaseIterator(&kParams.curr_frame);
+  WebPDemuxReleaseIterator(&kParams.prev_frame);
+  WebPDemuxReleaseChunkIterator(&kParams.iccp);
+  WebPDemuxDelete(kParams.dmux);
+  kParams.dmux = NULL;
+}
+
+// Sets the previous frame to the dimensions of the canvas and has it dispose
+// to background to cause the canvas to be cleared.
+static void ClearPreviousFrame(void) {
+  WebPIterator* const prev = &kParams.prev_frame;
+  prev->width = kParams.canvas_width;
+  prev->height = kParams.canvas_height;
+  prev->x_offset = prev->y_offset = 0;
+  prev->dispose_method = WEBP_MUX_DISPOSE_BACKGROUND;
+}
+
+// -----------------------------------------------------------------------------
+// Color profile handling
+static int ApplyColorProfile(const WebPData* const profile,
+                             WebPDecBuffer* const rgba) {
+#ifdef WEBP_HAVE_QCMS
+  int i, ok = 0;
+  uint8_t* line;
+  uint8_t major_revision;
+  qcms_profile* input_profile = NULL;
+  qcms_profile* output_profile = NULL;
+  qcms_transform* transform = NULL;
+  const qcms_data_type input_type = QCMS_DATA_RGBA_8;
+  const qcms_data_type output_type = QCMS_DATA_RGBA_8;
+  const qcms_intent intent = QCMS_INTENT_DEFAULT;
+
+  if (profile == NULL || rgba == NULL) return 0;
+  if (profile->bytes == NULL || profile->size < 10) return 1;
+  major_revision = profile->bytes[8];
+
+  qcms_enable_iccv4();
+  input_profile = qcms_profile_from_memory(profile->bytes, profile->size);
+  // qcms_profile_is_bogus() is broken with ICCv4.
+  if (input_profile == NULL ||
+      (major_revision < 4 && qcms_profile_is_bogus(input_profile))) {
+    fprintf(stderr, "Color profile is bogus!\n");
+    goto Error;
+  }
+
+  output_profile = qcms_profile_sRGB();
+  if (output_profile == NULL) {
+    fprintf(stderr, "Error creating output color profile!\n");
+    goto Error;
+  }
+
+  qcms_profile_precache_output_transform(output_profile);
+  transform = qcms_transform_create(input_profile, input_type,
+                                    output_profile, output_type,
+                                    intent);
+  if (transform == NULL) {
+    fprintf(stderr, "Error creating color transform!\n");
+    goto Error;
+  }
+
+  line = rgba->u.RGBA.rgba;
+  for (i = 0; i < rgba->height; ++i, line += rgba->u.RGBA.stride) {
+    qcms_transform_data(transform, line, line, rgba->width);
+  }
+  ok = 1;
+
+ Error:
+  if (input_profile != NULL) qcms_profile_release(input_profile);
+  if (output_profile != NULL) qcms_profile_release(output_profile);
+  if (transform != NULL) qcms_transform_release(transform);
+  return ok;
+#else
+  (void)profile;
+  (void)rgba;
+  return 1;
+#endif  // WEBP_HAVE_QCMS
+}
+
+//------------------------------------------------------------------------------
+// File decoding
+
+static int Decode(void) {   // Fills kParams.curr_frame
+  const WebPIterator* const curr = &kParams.curr_frame;
+  WebPDecoderConfig* const config = &kParams.config;
+  WebPDecBuffer* const output_buffer = &config->output;
+  int ok = 0;
+
+  ClearPreviousPic();
+  output_buffer->colorspace = MODE_RGBA;
+  ok = (WebPDecode(curr->fragment.bytes, curr->fragment.size,
+                   config) == VP8_STATUS_OK);
+  if (!ok) {
+    fprintf(stderr, "Decoding of frame #%d failed!\n", curr->frame_num);
+  } else {
+    kParams.pic = output_buffer;
+    if (kParams.use_color_profile) {
+      ok = ApplyColorProfile(&kParams.iccp.chunk, output_buffer);
+      if (!ok) {
+        fprintf(stderr, "Applying color profile to frame #%d failed!\n",
+                curr->frame_num);
+      }
+    }
+  }
+  return ok;
+}
+
+static void decode_callback(int what) {
+  if (what == 0 && !kParams.done) {
+    int duration = 0;
+    if (kParams.dmux != NULL) {
+      WebPIterator* const curr = &kParams.curr_frame;
+      if (!WebPDemuxNextFrame(curr)) {
+        WebPDemuxReleaseIterator(curr);
+        if (WebPDemuxGetFrame(kParams.dmux, 1, curr)) {
+          --kParams.loop_count;
+          kParams.done = (kParams.loop_count == 0);
+          if (kParams.done) return;
+          ClearPreviousFrame();
+        } else {
+          kParams.decoding_error = 1;
+          kParams.done = 1;
+          return;
+        }
+      }
+      duration = curr->duration;
+    }
+    if (!Decode()) {
+      kParams.decoding_error = 1;
+      kParams.done = 1;
+    } else {
+      glutPostRedisplay();
+      glutTimerFunc(duration, decode_callback, what);
+    }
+  }
+}
+
+//------------------------------------------------------------------------------
+// Callbacks
+
+static void HandleKey(unsigned char key, int pos_x, int pos_y) {
+  (void)pos_x;
+  (void)pos_y;
+  if (key == 'q' || key == 'Q' || key == 27 /* Esc */) {
+#ifdef FREEGLUT
+    glutLeaveMainLoop();
+#else
+    ClearParams();
+    exit(0);
+#endif
+  } else if (key == 'c') {
+    if (kParams.has_color_profile && !kParams.decoding_error) {
+      kParams.use_color_profile = 1 - kParams.use_color_profile;
+
+      if (kParams.has_animation) {
+        // Restart the completed animation to pickup the color profile change.
+        if (kParams.done && kParams.loop_count == 0) {
+          kParams.loop_count =
+              (int)WebPDemuxGetI(kParams.dmux, WEBP_FF_LOOP_COUNT) + 1;
+          kParams.done = 0;
+          // Start the decode loop immediately.
+          glutTimerFunc(0, decode_callback, 0);
+        }
+      } else {
+        Decode();
+        glutPostRedisplay();
+      }
+    }
+  } else if (key == 'i') {
+    kParams.print_info = 1 - kParams.print_info;
+    // TODO(skal): handle refresh of animation's last-frame too. It's quite
+    // more involved though (need to save the previous frame).
+    if (!kParams.has_animation) ClearPreviousFrame();
+    glutPostRedisplay();
+  } else if (key == 'd') {
+    kParams.only_deltas = 1 - kParams.only_deltas;
+    glutPostRedisplay();
+  }
+}
+
+static void HandleReshape(int width, int height) {
+  // TODO(skal): should we preserve aspect ratio?
+  // Also: handle larger-than-screen pictures correctly.
+  glViewport(0, 0, width, height);
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity();
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
+  kParams.viewport_width = width;
+  kParams.viewport_height = height;
+  if (!kParams.has_animation) ClearPreviousFrame();
+}
+
+static void PrintString(const char* const text) {
+  void* const font = GLUT_BITMAP_9_BY_15;
+  int i;
+  for (i = 0; text[i]; ++i) {
+    glutBitmapCharacter(font, text[i]);
+  }
+}
+
+static float GetColorf(uint32_t color, int shift) {
+  return (color >> shift) / 255.f;
+}
+
+static void DrawCheckerBoard(void) {
+  const int square_size = 8;  // must be a power of 2
+  int x, y;
+  GLint viewport[4];  // x, y, width, height
+
+  glPushMatrix();
+
+  glGetIntegerv(GL_VIEWPORT, viewport);
+  // shift to integer coordinates with (0,0) being top-left.
+  glOrtho(0, viewport[2], viewport[3], 0, -1, 1);
+  for (y = 0; y < viewport[3]; y += square_size) {
+    for (x = 0; x < viewport[2]; x += square_size) {
+      const GLubyte color = 128 + 64 * (!((x + y) & square_size));
+      glColor3ub(color, color, color);
+      glRecti(x, y, x + square_size, y + square_size);
+    }
+  }
+  glPopMatrix();
+}
+
+static void HandleDisplay(void) {
+  const WebPDecBuffer* const pic = kParams.pic;
+  const WebPIterator* const curr = &kParams.curr_frame;
+  WebPIterator* const prev = &kParams.prev_frame;
+  GLfloat xoff, yoff;
+  if (pic == NULL) return;
+  glPushMatrix();
+  glPixelZoom((GLfloat)(+1. / kParams.canvas_width * kParams.viewport_width),
+              (GLfloat)(-1. / kParams.canvas_height * kParams.viewport_height));
+  xoff = (GLfloat)(2. * curr->x_offset / kParams.canvas_width);
+  yoff = (GLfloat)(2. * curr->y_offset / kParams.canvas_height);
+  glRasterPos2f(-1.f + xoff, 1.f - yoff);
+  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+  glPixelStorei(GL_UNPACK_ROW_LENGTH, pic->u.RGBA.stride / 4);
+
+  if (kParams.only_deltas) {
+    DrawCheckerBoard();
+  } else if (prev->dispose_method == WEBP_MUX_DISPOSE_BACKGROUND ||
+      curr->blend_method == WEBP_MUX_NO_BLEND) {
+    // glScissor() takes window coordinates (0,0 at bottom left).
+    int window_x, window_y;
+    int frame_w, frame_h;
+    if (prev->dispose_method == WEBP_MUX_DISPOSE_BACKGROUND) {
+      // Clear the previous frame rectangle.
+      window_x = prev->x_offset;
+      window_y = kParams.canvas_height - prev->y_offset - prev->height;
+      frame_w = prev->width;
+      frame_h = prev->height;
+    } else {  // curr->blend_method == WEBP_MUX_NO_BLEND.
+      // We simulate no-blending behavior by first clearing the current frame
+      // rectangle (to a checker-board) and then alpha-blending against it.
+      window_x = curr->x_offset;
+      window_y = kParams.canvas_height - curr->y_offset - curr->height;
+      frame_w = curr->width;
+      frame_h = curr->height;
+    }
+    glEnable(GL_SCISSOR_TEST);
+    // Only update the requested area, not the whole canvas.
+    window_x = window_x * kParams.viewport_width / kParams.canvas_width;
+    window_y = window_y * kParams.viewport_height / kParams.canvas_height;
+    frame_w = frame_w * kParams.viewport_width / kParams.canvas_width;
+    frame_h = frame_h * kParams.viewport_height / kParams.canvas_height;
+    glScissor(window_x, window_y, frame_w, frame_h);
+
+    glClear(GL_COLOR_BUFFER_BIT);  // use clear color
+    DrawCheckerBoard();
+
+    glDisable(GL_SCISSOR_TEST);
+  }
+
+  *prev = *curr;
+
+  glDrawPixels(pic->width, pic->height,
+               GL_RGBA, GL_UNSIGNED_BYTE,
+               (GLvoid*)pic->u.RGBA.rgba);
+  if (kParams.print_info) {
+    char tmp[32];
+
+    glColor4f(0.90f, 0.0f, 0.90f, 1.0f);
+    glRasterPos2f(-0.95f, 0.90f);
+    PrintString(kParams.file_name);
+
+    snprintf(tmp, sizeof(tmp), "Dimension:%d x %d", pic->width, pic->height);
+    glColor4f(0.90f, 0.0f, 0.90f, 1.0f);
+    glRasterPos2f(-0.95f, 0.80f);
+    PrintString(tmp);
+    if (curr->x_offset != 0 || curr->y_offset != 0) {
+      snprintf(tmp, sizeof(tmp), " (offset:%d,%d)",
+               curr->x_offset, curr->y_offset);
+      glRasterPos2f(-0.95f, 0.70f);
+      PrintString(tmp);
+    }
+  }
+  glPopMatrix();
+  glFlush();
+}
+
+static void StartDisplay(void) {
+  const int width = kParams.canvas_width;
+  const int height = kParams.canvas_height;
+  glutInitDisplayMode(GLUT_RGBA);
+  glutInitWindowSize(width, height);
+  glutCreateWindow("WebP viewer");
+  glutDisplayFunc(HandleDisplay);
+  glutReshapeFunc(HandleReshape);
+  glutIdleFunc(NULL);
+  glutKeyboardFunc(HandleKey);
+  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+  glEnable(GL_BLEND);
+  glClearColor(GetColorf(kParams.bg_color, 0),
+               GetColorf(kParams.bg_color, 8),
+               GetColorf(kParams.bg_color, 16),
+               GetColorf(kParams.bg_color, 24));
+  glClear(GL_COLOR_BUFFER_BIT);
+  DrawCheckerBoard();
+}
+
+//------------------------------------------------------------------------------
+// Main
+
+static void Help(void) {
+  printf("Usage: vwebp in_file [options]\n\n"
+         "Decodes the WebP image file and visualize it using OpenGL\n"
+         "Options are:\n"
+         "  -version ..... print version number and exit\n"
+         "  -noicc ....... don't use the icc profile if present\n"
+         "  -nofancy ..... don't use the fancy YUV420 upscaler\n"
+         "  -nofilter .... disable in-loop filtering\n"
+         "  -dither <int>  dithering strength (0..100), default=50\n"
+         "  -noalphadither disable alpha plane dithering\n"
+         "  -mt .......... use multi-threading\n"
+         "  -info ........ print info\n"
+         "  -h ........... this help message\n"
+         "\n"
+         "Keyboard shortcuts:\n"
+         "  'c' ................ toggle use of color profile\n"
+         "  'i' ................ overlay file information\n"
+         "  'd' ................ disable blending & disposal (debug)\n"
+         "  'q' / 'Q' / ESC .... quit\n"
+        );
+}
+
+int main(int argc, char *argv[]) {
+  int c;
+  WebPDecoderConfig* const config = &kParams.config;
+  WebPIterator* const curr = &kParams.curr_frame;
+
+  if (!WebPInitDecoderConfig(config)) {
+    fprintf(stderr, "Library version mismatch!\n");
+    return -1;
+  }
+  config->options.dithering_strength = 50;
+  config->options.alpha_dithering_strength = 100;
+  kParams.use_color_profile = 1;
+
+  for (c = 1; c < argc; ++c) {
+    int parse_error = 0;
+    if (!strcmp(argv[c], "-h") || !strcmp(argv[c], "-help")) {
+      Help();
+      return 0;
+    } else if (!strcmp(argv[c], "-noicc")) {
+      kParams.use_color_profile = 0;
+    } else if (!strcmp(argv[c], "-nofancy")) {
+      config->options.no_fancy_upsampling = 1;
+    } else if (!strcmp(argv[c], "-nofilter")) {
+      config->options.bypass_filtering = 1;
+    } else if (!strcmp(argv[c], "-noalphadither")) {
+      config->options.alpha_dithering_strength = 0;
+    } else if (!strcmp(argv[c], "-dither") && c + 1 < argc) {
+      config->options.dithering_strength =
+          ExUtilGetInt(argv[++c], 0, &parse_error);
+    } else if (!strcmp(argv[c], "-info")) {
+      kParams.print_info = 1;
+    } else if (!strcmp(argv[c], "-version")) {
+      const int dec_version = WebPGetDecoderVersion();
+      const int dmux_version = WebPGetDemuxVersion();
+      printf("WebP Decoder version: %d.%d.%d\nWebP Demux version: %d.%d.%d\n",
+             (dec_version >> 16) & 0xff, (dec_version >> 8) & 0xff,
+             dec_version & 0xff, (dmux_version >> 16) & 0xff,
+             (dmux_version >> 8) & 0xff, dmux_version & 0xff);
+      return 0;
+    } else if (!strcmp(argv[c], "-mt")) {
+      config->options.use_threads = 1;
+    } else if (!strcmp(argv[c], "--")) {
+      if (c < argc - 1) kParams.file_name = argv[++c];
+      break;
+    } else if (argv[c][0] == '-') {
+      printf("Unknown option '%s'\n", argv[c]);
+      Help();
+      return -1;
+    } else {
+      kParams.file_name = argv[c];
+    }
+
+    if (parse_error) {
+      Help();
+      return -1;
+    }
+  }
+
+  if (kParams.file_name == NULL) {
+    printf("missing input file!!\n");
+    Help();
+    return 0;
+  }
+
+  if (!ImgIoUtilReadFile(kParams.file_name,
+                         &kParams.data.bytes, &kParams.data.size)) {
+    goto Error;
+  }
+
+  if (!WebPGetInfo(kParams.data.bytes, kParams.data.size, NULL, NULL)) {
+    fprintf(stderr, "Input file doesn't appear to be WebP format.\n");
+    goto Error;
+  }
+
+  kParams.dmux = WebPDemux(&kParams.data);
+  if (kParams.dmux == NULL) {
+    fprintf(stderr, "Could not create demuxing object!\n");
+    goto Error;
+  }
+
+  kParams.canvas_width = WebPDemuxGetI(kParams.dmux, WEBP_FF_CANVAS_WIDTH);
+  kParams.canvas_height = WebPDemuxGetI(kParams.dmux, WEBP_FF_CANVAS_HEIGHT);
+  if (kParams.print_info) {
+    printf("Canvas: %d x %d\n", kParams.canvas_width, kParams.canvas_height);
+  }
+
+  ClearPreviousFrame();
+
+  memset(&kParams.iccp, 0, sizeof(kParams.iccp));
+  kParams.has_color_profile =
+      !!(WebPDemuxGetI(kParams.dmux, WEBP_FF_FORMAT_FLAGS) & ICCP_FLAG);
+  if (kParams.has_color_profile) {
+#ifdef WEBP_HAVE_QCMS
+    if (!WebPDemuxGetChunk(kParams.dmux, "ICCP", 1, &kParams.iccp)) goto Error;
+    printf("VP8X: Found color profile\n");
+#else
+    fprintf(stderr, "Warning: color profile present, but qcms is unavailable!\n"
+            "Build libqcms from Mozilla or Chromium and define WEBP_HAVE_QCMS "
+            "before building.\n");
+#endif
+  }
+
+  if (!WebPDemuxGetFrame(kParams.dmux, 1, curr)) goto Error;
+
+  kParams.has_animation = (curr->num_frames > 1);
+  kParams.loop_count = (int)WebPDemuxGetI(kParams.dmux, WEBP_FF_LOOP_COUNT);
+  kParams.bg_color = WebPDemuxGetI(kParams.dmux, WEBP_FF_BACKGROUND_COLOR);
+  printf("VP8X: Found %d images in file (loop count = %d)\n",
+         curr->num_frames, kParams.loop_count);
+
+  // Decode first frame
+  if (!Decode()) goto Error;
+
+  // Position iterator to last frame. Next call to HandleDisplay will wrap over.
+  // We take this into account by bumping up loop_count.
+  WebPDemuxGetFrame(kParams.dmux, 0, curr);
+  if (kParams.loop_count) ++kParams.loop_count;
+
+#if defined(__unix__) || defined(__CYGWIN__)
+  // Work around GLUT compositor bug.
+  // https://bugs.launchpad.net/ubuntu/+source/freeglut/+bug/369891
+  setenv("XLIB_SKIP_ARGB_VISUALS", "1", 1);
+#endif
+
+  // Start display (and timer)
+  glutInit(&argc, argv);
+#ifdef FREEGLUT
+  glutSetOption(GLUT_ACTION_ON_WINDOW_CLOSE, GLUT_ACTION_CONTINUE_EXECUTION);
+#endif
+  StartDisplay();
+
+  if (kParams.has_animation) glutTimerFunc(0, decode_callback, 0);
+  glutMainLoop();
+
+  // Should only be reached when using FREEGLUT:
+  ClearParams();
+  return 0;
+
+ Error:
+  ClearParams();
+  return -1;
+}
+
+#else   // !WEBP_HAVE_GL
+
+int main(int argc, const char *argv[]) {
+  fprintf(stderr, "OpenGL support not enabled in %s.\n", argv[0]);
+  (void)argc;
+  return 0;
+}
+
+#endif
+
+//------------------------------------------------------------------------------

extras/Makefile.am

@@ -0,0 +1,26 @@
+AM_CPPFLAGS += -I$(top_builddir)/src -I$(top_srcdir)/src
+noinst_LTLIBRARIES = libwebpextras.la
+
+noinst_HEADERS =
+noinst_HEADERS += ../src/webp/types.h
+
+libwebpextras_la_SOURCES =
+libwebpextras_la_SOURCES += extras.c extras.h quality_estimate.c
+
+libwebpextras_la_CPPFLAGS = $(AM_CPPFLAGS)
+libwebpextras_la_LDFLAGS = -lm
+libwebpextras_la_LIBADD = ../src/libwebp.la
+
+noinst_PROGRAMS = get_disto webp_quality
+
+get_disto_SOURCES = get_disto.c
+get_disto_CPPFLAGS  = $(AM_CPPFLAGS)
+get_disto_LDADD = ../imageio/libimageio_util.la ../imageio/libimagedec.la
+get_disto_LDADD += ../src/libwebp.la
+get_disto_LDADD += $(PNG_LIBS) $(JPEG_LIBS) $(TIFF_LIBS)
+
+webp_quality_SOURCES  = webp_quality.c
+webp_quality_CPPFLAGS = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE)
+webp_quality_LDADD  = ../imageio/libimageio_util.la
+webp_quality_LDADD += libwebpextras.la
+webp_quality_LDADD += ../src/libwebp.la

extras/extras.c

@@ -0,0 +1,142 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  Additional WebP utilities.
+//
+
+#include "./extras.h"
+#include "webp/format_constants.h"
+
+#include <assert.h>
+#include <string.h>
+
+#define XTRA_MAJ_VERSION 0
+#define XTRA_MIN_VERSION 1
+#define XTRA_REV_VERSION 0
+
+//------------------------------------------------------------------------------
+
+int WebPGetExtrasVersion(void) {
+  return (XTRA_MAJ_VERSION << 16) | (XTRA_MIN_VERSION << 8) | XTRA_REV_VERSION;
+}
+
+//------------------------------------------------------------------------------
+
+int WebPImportGray(const uint8_t* gray_data, WebPPicture* pic) {
+  int y, width, uv_width;
+  if (pic == NULL || gray_data == NULL) return 0;
+  pic->colorspace = WEBP_YUV420;
+  if (!WebPPictureAlloc(pic)) return 0;
+  width = pic->width;
+  uv_width = (width + 1) >> 1;
+  for (y = 0; y < pic->height; ++y) {
+    memcpy(pic->y + y * pic->y_stride, gray_data, width);
+    gray_data += width;    // <- we could use some 'data_stride' here if needed
+    if ((y & 1) == 0) {
+      memset(pic->u + (y >> 1) * pic->uv_stride, 128, uv_width);
+      memset(pic->v + (y >> 1) * pic->uv_stride, 128, uv_width);
+    }
+  }
+  return 1;
+}
+
+int WebPImportRGB565(const uint8_t* rgb565, WebPPicture* pic) {
+  int x, y;
+  if (pic == NULL || rgb565 == NULL) return 0;
+  pic->colorspace = WEBP_YUV420;
+  pic->use_argb = 1;
+  if (!WebPPictureAlloc(pic)) return 0;
+  for (y = 0; y < pic->height; ++y) {
+    const int width = pic->width;
+    uint32_t* dst = pic->argb + y * pic->argb_stride;
+    for (x = 0; x < width; ++x) {
+#ifdef WEBP_SWAP_16BIT_CSP
+      const uint32_t rg = rgb565[2 * x + 1];
+      const uint32_t gb = rgb565[2 * x + 0];
+#else
+      const uint32_t rg = rgb565[2 * x + 0];
+      const uint32_t gb = rgb565[2 * x + 1];
+#endif
+      uint32_t r = rg & 0xf8;
+      uint32_t g = ((rg << 5) | (gb >> 3)) & 0xfc;
+      uint32_t b = (gb << 5);
+      // dithering
+      r = r | (r >> 5);
+      g = g | (g >> 6);
+      b = b | (b >> 5);
+      dst[x] = (r << 16) | (g << 8) | b;
+    }
+    rgb565 += 2 * width;
+  }
+  return 1;
+}
+
+int WebPImportRGB4444(const uint8_t* rgb4444, WebPPicture* pic) {
+  int x, y;
+  if (pic == NULL || rgb4444 == NULL) return 0;
+  pic->colorspace = WEBP_YUV420;
+  pic->use_argb = 1;
+  if (!WebPPictureAlloc(pic)) return 0;
+  for (y = 0; y < pic->height; ++y) {
+    const int width = pic->width;
+    uint32_t* dst = pic->argb + y * pic->argb_stride;
+    for (x = 0; x < width; ++x) {
+#ifdef WEBP_SWAP_16BIT_CSP
+      const uint32_t rg = rgb4444[2 * x + 1];
+      const uint32_t ba = rgb4444[2 * x + 0];
+#else
+      const uint32_t rg = rgb4444[2 * x + 0];
+      const uint32_t ba = rgb4444[2 * x + 1];
+#endif
+      uint32_t r = rg & 0xf0;
+      uint32_t g = (rg << 4);
+      uint32_t b = (ba & 0xf0);
+      uint32_t a = (ba << 4);
+      // dithering
+      r = r | (r >> 4);
+      g = g | (g >> 4);
+      b = b | (b >> 4);
+      a = a | (a >> 4);
+      dst[x] = (a << 24) | (r << 16) | (g << 8) | b;
+    }
+    rgb4444 += 2 * width;
+  }
+  return 1;
+}
+
+int WebPImportColorMappedARGB(const uint8_t* indexed, int indexed_stride,
+                              const uint32_t palette[], int palette_size,
+                              WebPPicture* pic) {
+  int x, y;
+  uint32_t* dst;
+  // 256 as the input buffer is uint8_t.
+  assert(MAX_PALETTE_SIZE <= 256);
+  if (pic == NULL || indexed == NULL || indexed_stride < pic->width ||
+      palette == NULL || palette_size > MAX_PALETTE_SIZE || palette_size <= 0) {
+    return 0;
+  }
+  pic->use_argb = 1;
+  if (!WebPPictureAlloc(pic)) return 0;
+  dst = pic->argb;
+  for (y = 0; y < pic->height; ++y) {
+    for (x = 0; x < pic->width; ++x) {
+      // Make sure we are within the palette.
+      if (indexed[x] >= palette_size) {
+        WebPPictureFree(pic);
+        return 0;
+      }
+      dst[x] = palette[indexed[x]];
+    }
+    indexed += indexed_stride;
+    dst += pic->argb_stride;
+  }
+  return 1;
+}
+
+//------------------------------------------------------------------------------

extras/extras.h

@@ -0,0 +1,70 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+
+#ifndef WEBP_EXTRAS_EXTRAS_H_
+#define WEBP_EXTRAS_EXTRAS_H_
+
+#include "webp/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "webp/encode.h"
+
+#define WEBP_EXTRAS_ABI_VERSION 0x0001    // MAJOR(8b) + MINOR(8b)
+
+//------------------------------------------------------------------------------
+
+// Returns the version number of the extras library, packed in hexadecimal using
+// 8bits for each of major/minor/revision. E.g: v2.5.7 is 0x020507.
+WEBP_EXTERN(int) WebPGetExtrasVersion(void);
+
+//------------------------------------------------------------------------------
+// Ad-hoc colorspace importers.
+
+// Import luma sample (gray scale image) into 'picture'. The 'picture'
+// width and height must be set prior to calling this function.
+WEBP_EXTERN(int) WebPImportGray(const uint8_t* gray, WebPPicture* picture);
+
+// Import rgb sample in RGB565 packed format into 'picture'. The 'picture'
+// width and height must be set prior to calling this function.
+WEBP_EXTERN(int) WebPImportRGB565(const uint8_t* rgb565, WebPPicture* pic);
+
+// Import rgb sample in RGB4444 packed format into 'picture'. The 'picture'
+// width and height must be set prior to calling this function.
+WEBP_EXTERN(int) WebPImportRGB4444(const uint8_t* rgb4444, WebPPicture* pic);
+
+// Import a color mapped image. The number of colors is less or equal to
+// MAX_PALETTE_SIZE. 'pic' must have been initialized. Its content, if any,
+// will be discarded. Returns 'false' in case of error, or if indexed[] contains
+// invalid indices.
+WEBP_EXTERN(int)
+WebPImportColorMappedARGB(const uint8_t* indexed, int indexed_stride,
+                          const uint32_t palette[], int palette_size,
+                          WebPPicture* pic);
+
+//------------------------------------------------------------------------------
+
+// Parse a bitstream, search for VP8 (lossy) header and report a
+// rough estimation of the quality factor used for compressing the bitstream.
+// If the bitstream is in lossless format, the special value '101' is returned.
+// Otherwise (lossy bitstream), the returned value is in the range [0..100].
+// Any error (invalid bitstream, animated WebP, incomplete header, etc.)
+// will return a value of -1.
+WEBP_EXTERN(int) VP8EstimateQuality(const uint8_t* const data, size_t size);
+
+//------------------------------------------------------------------------------
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  /* WEBP_EXTRAS_EXTRAS_H_ */

extras/get_disto.c

@@ -0,0 +1,343 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Simple tool to load two webp/png/jpg/tiff files and compute PSNR/SSIM.
+// This is mostly a wrapper around WebPPictureDistortion().
+//
+/*
+ gcc -o get_disto get_disto.c -O3 -I../ -L../examples -L../imageio \
+    -lexample_util -limageio_util -limagedec -lwebp -L/opt/local/lib \
+    -lpng -lz -ljpeg -ltiff -lm -lpthread
+*/
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "webp/encode.h"
+#include "../imageio/image_dec.h"
+#include "../imageio/imageio_util.h"
+
+static size_t ReadPicture(const char* const filename, WebPPicture* const pic,
+                          int keep_alpha) {
+  const uint8_t* data = NULL;
+  size_t data_size = 0;
+  WebPImageReader reader = NULL;
+  int ok = ImgIoUtilReadFile(filename, &data, &data_size);
+  if (!ok) goto End;
+
+  pic->use_argb = 1;  // force ARGB
+
+#ifdef HAVE_WINCODEC_H
+  // Try to decode the file using WIC falling back to the other readers for
+  // e.g., WebP.
+  ok = ReadPictureWithWIC(filename, pic, keep_alpha, NULL);
+  if (ok) goto End;
+#endif
+  reader = WebPGuessImageReader(data, data_size);
+  ok = reader(data, data_size, pic, keep_alpha, NULL);
+
+ End:
+  if (!ok) {
+    fprintf(stderr, "Error! Could not process file %s\n", filename);
+  }
+  free((void*)data);
+  return ok ? data_size : 0;
+}
+
+static void RescalePlane(uint8_t* plane, int width, int height,
+                         int x_stride, int y_stride, int max) {
+  const uint32_t factor = (max > 0) ? (255u << 16) / max : 0;
+  int x, y;
+  for (y = 0; y < height; ++y) {
+    uint8_t* const ptr = plane + y * y_stride;
+    for (x = 0; x < width * x_stride; x += x_stride) {
+      const uint32_t diff = (ptr[x] * factor + (1 << 15)) >> 16;
+      ptr[x] = diff;
+    }
+  }
+}
+
+// Return the max absolute difference.
+static int DiffScaleChannel(uint8_t* src1, int stride1,
+                            const uint8_t* src2, int stride2,
+                            int x_stride, int w, int h, int do_scaling) {
+  int x, y;
+  int max = 0;
+  for (y = 0; y < h; ++y) {
+    uint8_t* const ptr1 = src1 + y * stride1;
+    const uint8_t* const ptr2 = src2 + y * stride2;
+    for (x = 0; x < w * x_stride; x += x_stride) {
+      const int diff = abs(ptr1[x] - ptr2[x]);
+      if (diff > max) max = diff;
+      ptr1[x] = diff;
+    }
+  }
+
+  if (do_scaling) RescalePlane(src1, w, h, x_stride, stride1, max);
+  return max;
+}
+
+//------------------------------------------------------------------------------
+// SSIM calculation. We re-implement these functions here, out of dsp/, to avoid
+// breaking the library's hidden visibility. This code duplication avoids the
+// bigger annoyance of having to open up internal details of libdsp...
+
+#define SSIM_KERNEL 3   // total size of the kernel: 2 * SSIM_KERNEL + 1
+
+// struct for accumulating statistical moments
+typedef struct {
+  uint32_t w;              // sum(w_i) : sum of weights
+  uint32_t xm, ym;         // sum(w_i * x_i), sum(w_i * y_i)
+  uint32_t xxm, xym, yym;  // sum(w_i * x_i * x_i), etc.
+} DistoStats;
+
+// hat-shaped filter. Sum of coefficients is equal to 16.
+static const uint32_t kWeight[2 * SSIM_KERNEL + 1] = { 1, 2, 3, 4, 3, 2, 1 };
+
+static WEBP_INLINE double SSIMCalculation(const DistoStats* const stats) {
+  const uint32_t N = stats->w;
+  const uint32_t w2 =  N * N;
+  const uint32_t C1 = 20 * w2;
+  const uint32_t C2 = 60 * w2;
+  const uint32_t C3 = 8 * 8 * w2;   // 'dark' limit ~= 6
+  const uint64_t xmxm = (uint64_t)stats->xm * stats->xm;
+  const uint64_t ymym = (uint64_t)stats->ym * stats->ym;
+  if (xmxm + ymym >= C3) {
+    const int64_t xmym = (int64_t)stats->xm * stats->ym;
+    const int64_t sxy = (int64_t)stats->xym * N - xmym;    // can be negative
+    const uint64_t sxx = (uint64_t)stats->xxm * N - xmxm;
+    const uint64_t syy = (uint64_t)stats->yym * N - ymym;
+    // we descale by 8 to prevent overflow during the fnum/fden multiply.
+    const uint64_t num_S = (2 * (uint64_t)(sxy < 0 ? 0 : sxy) + C2) >> 8;
+    const uint64_t den_S = (sxx + syy + C2) >> 8;
+    const uint64_t fnum = (2 * xmym + C1) * num_S;
+    const uint64_t fden = (xmxm + ymym + C1) * den_S;
+    const double r = (double)fnum / fden;
+    assert(r >= 0. && r <= 1.0);
+    return r;
+  }
+  return 1.;   // area is too dark to contribute meaningfully
+}
+
+static double SSIMGetClipped(const uint8_t* src1, int stride1,
+                             const uint8_t* src2, int stride2,
+                             int xo, int yo, int W, int H) {
+  DistoStats stats = { 0, 0, 0, 0, 0, 0 };
+  const int ymin = (yo - SSIM_KERNEL < 0) ? 0 : yo - SSIM_KERNEL;
+  const int ymax = (yo + SSIM_KERNEL > H - 1) ? H - 1 : yo + SSIM_KERNEL;
+  const int xmin = (xo - SSIM_KERNEL < 0) ? 0 : xo - SSIM_KERNEL;
+  const int xmax = (xo + SSIM_KERNEL > W - 1) ? W - 1 : xo + SSIM_KERNEL;
+  int x, y;
+  src1 += ymin * stride1;
+  src2 += ymin * stride2;
+  for (y = ymin; y <= ymax; ++y, src1 += stride1, src2 += stride2) {
+    for (x = xmin; x <= xmax; ++x) {
+      const uint32_t w = kWeight[SSIM_KERNEL + x - xo]
+                       * kWeight[SSIM_KERNEL + y - yo];
+      const uint32_t s1 = src1[x];
+      const uint32_t s2 = src2[x];
+      stats.w   += w;
+      stats.xm  += w * s1;
+      stats.ym  += w * s2;
+      stats.xxm += w * s1 * s1;
+      stats.xym += w * s1 * s2;
+      stats.yym += w * s2 * s2;
+    }
+  }
+  return SSIMCalculation(&stats);
+}
+
+// Compute SSIM-score map. Return -1 in case of error, max diff otherwise.
+static int SSIMScaleChannel(uint8_t* src1, int stride1,
+                            const uint8_t* src2, int stride2,
+                            int x_stride, int w, int h, int do_scaling) {
+  int x, y;
+  int max = 0;
+  uint8_t* const plane1 = (uint8_t*)malloc(2 * w * h * sizeof(*plane1));
+  uint8_t* const plane2 = plane1 + w * h;
+  if (plane1 == NULL) return -1;
+
+  // extract plane
+  for (y = 0; y < h; ++y) {
+    for (x = 0; x < w; ++x) {
+      plane1[x + y * w] = src1[x * x_stride + y * stride1];
+      plane2[x + y * w] = src2[x * x_stride + y * stride2];
+    }
+  }
+  for (y = 0; y < h; ++y) {
+    for (x = 0; x < w; ++x) {
+      const double ssim = SSIMGetClipped(plane1, w, plane2, w, x, y, w, h);
+      int diff = (int)(255 * (1. - ssim));
+      if (diff < 0) {
+        diff = 0;
+      } else if (diff > max) {
+        max = diff;
+      }
+      src1[x * x_stride + y * stride1] = (diff > 255) ? 255u : (uint8_t)diff;
+    }
+  }
+  free(plane1);
+
+  if (do_scaling) RescalePlane(src1, w, h, x_stride, stride1, max);
+  return max;
+}
+
+// Convert an argb picture to luminance.
+static void ConvertToGray(WebPPicture* const pic) {
+  int x, y;
+  assert(pic != NULL);
+  assert(pic->use_argb);
+  for (y = 0; y < pic->height; ++y) {
+    uint32_t* const row = &pic->argb[y * pic->argb_stride];
+    for (x = 0; x < pic->width; ++x) {
+      const uint32_t argb = row[x];
+      const uint32_t r = (argb >> 16) & 0xff;
+      const uint32_t g = (argb >>  8) & 0xff;
+      const uint32_t b = (argb >>  0) & 0xff;
+      // We use BT.709 for converting to luminance.
+      const uint32_t Y = (uint32_t)(0.2126 * r + 0.7152 * g + 0.0722 * b + .5);
+      row[x] = (argb & 0xff000000u) | (Y * 0x010101u);
+    }
+  }
+}
+
+static void Help(void) {
+  fprintf(stderr,
+          "Usage: get_disto [-ssim][-psnr][-alpha] compressed.webp orig.webp\n"
+          "  -ssim ..... print SSIM distortion\n"
+          "  -psnr ..... print PSNR distortion (default)\n"
+          "  -alpha .... preserve alpha plane\n"
+          "  -h ........ this message\n"
+          "  -o <file> . save the diff map as a WebP lossless file\n"
+          "  -scale .... scale the difference map to fit [0..255] range\n"
+          "  -gray ..... use grayscale for difference map (-scale)\n"
+          " Also handles PNG, JPG and TIFF files, in addition to WebP.\n");
+}
+
+int main(int argc, const char *argv[]) {
+  WebPPicture pic1, pic2;
+  size_t size1 = 0, size2 = 0;
+  int ret = 1;
+  float disto[5];
+  int type = 0;
+  int c;
+  int help = 0;
+  int keep_alpha = 0;
+  int scale = 0;
+  int use_gray = 0;
+  const char* name1 = NULL;
+  const char* name2 = NULL;
+  const char* output = NULL;
+
+  if (!WebPPictureInit(&pic1) || !WebPPictureInit(&pic2)) {
+    fprintf(stderr, "Can't init pictures\n");
+    return 1;
+  }
+
+  for (c = 1; c < argc; ++c) {
+    if (!strcmp(argv[c], "-ssim")) {
+      type = 1;
+    } else if (!strcmp(argv[c], "-psnr")) {
+      type = 0;
+    } else if (!strcmp(argv[c], "-alpha")) {
+      keep_alpha = 1;
+    } else if (!strcmp(argv[c], "-scale")) {
+      scale = 1;
+    } else if (!strcmp(argv[c], "-gray")) {
+      use_gray = 1;
+    } else if (!strcmp(argv[c], "-h")) {
+      help = 1;
+      ret = 0;
+    } else if (!strcmp(argv[c], "-o")) {
+      if (++c == argc) {
+        fprintf(stderr, "missing file name after %s option.\n", argv[c - 1]);
+        goto End;
+      }
+      output = argv[c];
+    } else if (name1 == NULL) {
+      name1 = argv[c];
+    } else {
+      name2 = argv[c];
+    }
+  }
+  if (help || name1 == NULL || name2 == NULL) {
+    if (!help) {
+      fprintf(stderr, "Error: missing arguments.\n");
+    }
+    Help();
+    goto End;
+  }
+  size1 = ReadPicture(name1, &pic1, 1);
+  size2 = ReadPicture(name1, &pic2, 1);
+  if (size1 == 0 || size2 == 0) goto End;
+
+  if (!keep_alpha) {
+    WebPBlendAlpha(&pic1, 0x00000000);
+    WebPBlendAlpha(&pic2, 0x00000000);
+  }
+
+  if (!WebPPictureDistortion(&pic1, &pic2, type, disto)) {
+    fprintf(stderr, "Error while computing the distortion.\n");
+    goto End;
+  }
+  printf("%u %.2f    %.2f %.2f %.2f %.2f\n",
+         (unsigned int)size1,
+         disto[4], disto[0], disto[1], disto[2], disto[3]);
+
+  if (output != NULL) {
+    uint8_t* data = NULL;
+    size_t data_size = 0;
+    if (pic1.use_argb != pic2.use_argb) {
+      fprintf(stderr, "Pictures are not in the same argb format. "
+                      "Can't save the difference map.\n");
+      goto End;
+    }
+    if (pic1.use_argb) {
+      int n;
+      fprintf(stderr, "max differences per channel: ");
+      for (n = 0; n < 3; ++n) {    // skip the alpha channel
+        const int range = (type == 1) ?
+          SSIMScaleChannel((uint8_t*)pic1.argb + n, pic1.argb_stride * 4,
+                           (const uint8_t*)pic2.argb + n, pic2.argb_stride * 4,
+                           4, pic1.width, pic1.height, scale) :
+          DiffScaleChannel((uint8_t*)pic1.argb + n, pic1.argb_stride * 4,
+                           (const uint8_t*)pic2.argb + n, pic2.argb_stride * 4,
+                           4, pic1.width, pic1.height, scale);
+        if (range < 0) fprintf(stderr, "\nError computing diff map\n");
+        fprintf(stderr, "[%d]", range);
+      }
+      fprintf(stderr, "\n");
+      if (use_gray) ConvertToGray(&pic1);
+    } else {
+      fprintf(stderr, "Can only compute the difference map in ARGB format.\n");
+      goto End;
+    }
+    data_size = WebPEncodeLosslessBGRA((const uint8_t*)pic1.argb,
+                                       pic1.width, pic1.height,
+                                       pic1.argb_stride * 4,
+                                       &data);
+    if (data_size == 0) {
+      fprintf(stderr, "Error during lossless encoding.\n");
+      goto End;
+    }
+    ret = ImgIoUtilWriteFile(output, data, data_size) ? 0 : 1;
+    WebPFree(data);
+    if (ret) goto End;
+  }
+  ret = 0;
+
+ End:
+  WebPPictureFree(&pic1);
+  WebPPictureFree(&pic2);
+  return ret;
+}

extras/quality_estimate.c

@@ -0,0 +1,129 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  VP8EstimateQuality(): rough encoding quality estimate
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include "./extras.h"
+#include "webp/decode.h"
+
+#include <math.h>
+
+//------------------------------------------------------------------------------
+
+#define INVALID_BIT_POS (1ull << 63)
+
+// In most cases, we don't need to use a full arithmetic decoder, since
+// all the header's bits are written using a uniform probability of 128.
+// We can just parse the header as if it was bits (works in 99.999% cases).
+static WEBP_INLINE uint32_t GetBit(const uint8_t* const data, size_t nb,
+                                   uint64_t max_size, uint64_t* const bit_pos) {
+  uint32_t val = 0;
+  if (*bit_pos + nb <= 8 * max_size) {
+    while (nb-- > 0) {
+      const uint64_t p = (*bit_pos)++;
+      const int bit = !!(data[p >> 3] & (128 >> ((p & 7))));
+      val = (val << 1) | bit;
+    }
+  } else {
+    *bit_pos = INVALID_BIT_POS;
+  }
+  return val;
+}
+
+#define GET_BIT(n) GetBit(data, (n), size, &bit_pos)
+#define CONDITIONAL_SKIP(n) (GET_BIT(1) ? GET_BIT((n)) : 0)
+
+int VP8EstimateQuality(const uint8_t* const data, size_t size) {
+  size_t pos = 0;
+  uint64_t bit_pos;
+  uint64_t sig = 0x00;
+  int ok = 0;
+  int Q = -1;
+  WebPBitstreamFeatures features;
+
+  if (data == NULL) return -1;
+
+  if (WebPGetFeatures(data, size, &features) != VP8_STATUS_OK) {
+    return -1;   // invalid file
+  }
+  if (features.format == 2) return 101;  // lossless
+  if (features.format == 0 || features.has_animation) return -1;   // mixed
+
+  while (pos < size) {
+    sig = (sig >> 8) | ((uint64_t)data[pos++] << 40);
+    if ((sig >> 24) == 0x2a019dull) {
+      ok = 1;
+      break;
+    }
+  }
+  if (!ok) return -1;
+  if (pos + 4 > size) return -1;
+
+  // Skip main Header
+  // width  = (data[pos + 0] | (data[pos + 1] << 8)) & 0x3fff;
+  // height = (data[pos + 2] | (data[pos + 3] << 8)) & 0x3fff;
+  pos += 4;
+  bit_pos = pos * 8;
+
+  GET_BIT(2);  // color_space + clamp type
+
+  // Segment header
+  if (GET_BIT(1)) {       // use_segment_
+    int s;
+    const int update_map = GET_BIT(1);
+    if (GET_BIT(1)) {     // update data
+      const int absolute_delta = GET_BIT(1);
+      int q[4]  = { 0, 0, 0, 0 };
+      for (s = 0; s < 4; ++s) {
+        if (GET_BIT(1)) {
+          q[s] = GET_BIT(7);
+          if (GET_BIT(1)) q[s] = -q[s];   // sign
+        }
+      }
+      if (absolute_delta) Q = q[0];  // just use the first segment's quantizer
+      for (s = 0; s < 4; ++s) CONDITIONAL_SKIP(7);   //  filter strength
+    }
+    if (update_map) {
+      for (s = 0; s < 3; ++s) CONDITIONAL_SKIP(8);
+    }
+  }
+  // Filter header
+  GET_BIT(1 + 6 + 3);     // simple + level + sharpness
+  if (GET_BIT(1)) {       // use_lf_delta
+    if (GET_BIT(1)) {     // update lf_delta?
+      int n;
+      for (n = 0; n < 4 + 4; ++n) CONDITIONAL_SKIP(6);
+    }
+  }
+  // num partitions
+  GET_BIT(2);
+
+  // ParseQuant
+  {
+    const int base_q = GET_BIT(7);
+    /* dqy1_dc = */ CONDITIONAL_SKIP(5);
+    /* dqy2_dc = */ CONDITIONAL_SKIP(5);
+    /* dqy2_ac = */ CONDITIONAL_SKIP(5);
+    /* dquv_dc = */ CONDITIONAL_SKIP(5);
+    /* dquv_ac = */ CONDITIONAL_SKIP(5);
+
+    if (Q < 0) Q = base_q;
+  }
+  if (bit_pos == INVALID_BIT_POS) return -1;
+
+  // base mapping
+  Q = (127 - Q) * 100 / 127;
+  // correction for power-law behavior in low range
+  if (Q < 80) {
+    Q = (int)(pow(Q / 80., 1. / 0.38) * 80);
+  }
+  return Q;
+}

extras/webp_quality.c

@@ -0,0 +1,50 @@
+// Simple tool to roughly evaluate the quality encoding of a webp bitstream
+//
+// Result is a *rough* estimation of the quality. You should just consider
+// the bucket it's in (q > 80? > 50? > 20?) and not take it for face value.
+/*
+ gcc -o webp_quality webp_quality.c -O3 -I../ -L. -L../imageio \
+    -limageio_util -lwebpextras -lwebp -lm -lpthread
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "./extras.h"
+#include "../imageio/imageio_util.h"
+
+int main(int argc, const char *argv[]) {
+  int c;
+  int quiet = 0;
+  int ok = 1;
+  for (c = 1; ok && c < argc; ++c) {
+    if (!strcmp(argv[c], "-quiet")) {
+      quiet = 1;
+    } else if (!strcmp(argv[c], "-help") || !strcmp(argv[c], "-h")) {
+      printf("webp_quality [-h][-quiet] webp_files...\n");
+      return 0;
+    } else {
+      const char* const filename = argv[c];
+      const uint8_t* data = NULL;
+      size_t data_size = 0;
+      int q;
+      ok = ImgIoUtilReadFile(filename, &data, &data_size);
+      if (!ok) break;
+      q = VP8EstimateQuality(data, data_size);
+      if (!quiet) printf("[%s] ", filename);
+      if (q < 0) {
+        fprintf(stderr, "Not a WebP file, or not a lossy WebP file.\n");
+        ok = 0;
+      } else {
+        if (!quiet) {
+          printf("Estimated quality factor: %d\n", q);
+        } else {
+          printf("%d\n", q);   // just print the number
+        }
+      }
+      free((void*)data);
+    }
+  }
+  return ok ? 0 : 1;
+}

gradle.properties

@@ -0,0 +1,14 @@
+# Project-wide Gradle settings.
+
+# IDE (e.g. Android Studio) users:
+# Gradle settings configured through the IDE *will override*
+# any settings specified in this file.
+
+# For more details on how to configure your build environment visit
+# http://www.gradle.org/docs/current/userguide/build_environment.html
+
+# Versions for gradle
+BUILD_TOOLS_VERSION=23.0.3
+COMPILE_SDK_VERSION=23
+ANDROID_GRADLE_PLUGIN_VERSION=1.5.0
+GRADLE_DOWNLOAD_TASK_VERSION=2.1.0

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Thu May 12 17:06:25 CEST 2016
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.13-bin.zip

gradlew

@@ -0,0 +1,164 @@
+#!/usr/bin/env bash
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn ( ) {
+    echo "$*"
+}
+
+die ( ) {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules
+function splitJvmOpts() {
+    JVM_OPTS=("$@")
+}
+eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS
+JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME"
+
+exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"

gradlew.bat

@@ -0,0 +1,90 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+if "%@eval[2+2]" == "4" goto 4NT_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+goto execute
+
+:4NT_args
+@rem Get arguments from the 4NT Shell from JP Software
+set CMD_LINE_ARGS=%$
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

imageio/Android.mk

@@ -0,0 +1,53 @@
+LOCAL_PATH := $(call my-dir)
+
+################################################################################
+# libimageio_util
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    imageio_util.c \
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../src
+
+LOCAL_MODULE := imageio_util
+
+include $(BUILD_STATIC_LIBRARY)
+
+################################################################################
+# libimagedec
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    image_dec.c \
+    jpegdec.c \
+    metadata.c \
+    pngdec.c \
+    tiffdec.c \
+    webpdec.c \
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../src
+LOCAL_STATIC_LIBRARIES := imageio_util
+
+LOCAL_MODULE := imagedec
+
+include $(BUILD_STATIC_LIBRARY)
+
+################################################################################
+# libimageenc
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    image_enc.c \
+
+LOCAL_CFLAGS := $(WEBP_CFLAGS)
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../src
+LOCAL_STATIC_LIBRARIES := imageio_util
+
+LOCAL_MODULE := imageenc
+
+include $(BUILD_STATIC_LIBRARY)

imageio/Makefile.am

@@ -0,0 +1,22 @@
+AM_CPPFLAGS += -I$(top_builddir)/src -I$(top_srcdir)/src
+noinst_LTLIBRARIES = libimageio_util.la libimagedec.la libimageenc.la
+
+noinst_HEADERS =
+noinst_HEADERS += ../src/webp/decode.h
+noinst_HEADERS += ../src/webp/types.h
+
+libimageio_util_la_SOURCES = imageio_util.c imageio_util.h
+
+libimagedec_la_SOURCES  = image_dec.c image_dec.h
+libimagedec_la_SOURCES += jpegdec.c jpegdec.h
+libimagedec_la_SOURCES += metadata.c metadata.h
+libimagedec_la_SOURCES += pngdec.c pngdec.h
+libimagedec_la_SOURCES += tiffdec.c tiffdec.h
+libimagedec_la_SOURCES += webpdec.c webpdec.h
+libimagedec_la_SOURCES += wicdec.c wicdec.h
+libimagedec_la_CPPFLAGS = $(JPEG_INCLUDES) $(PNG_INCLUDES) $(TIFF_INCLUDES)
+libimagedec_la_CPPFLAGS += $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE)
+
+libimageenc_la_SOURCES  = image_enc.c image_enc.h
+libimageenc_la_CPPFLAGS = $(JPEG_INCLUDES) $(PNG_INCLUDES) $(TIFF_INCLUDES)
+libimageenc_la_CPPFLAGS += $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE)

imageio/image_dec.c

@@ -0,0 +1,61 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Generic image-type guessing.
+
+#include "./image_dec.h"
+
+static WEBP_INLINE uint32_t GetBE32(const uint8_t buf[]) {
+  return ((uint32_t)buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
+}
+
+WebPInputFileFormat WebPGuessImageType(const uint8_t* const data,
+                                       size_t data_size) {
+  WebPInputFileFormat format = WEBP_UNSUPPORTED_FORMAT;
+  if (data != NULL && data_size >= 12) {
+    const uint32_t magic1 = GetBE32(data + 0);
+    const uint32_t magic2 = GetBE32(data + 8);
+    if (magic1 == 0x89504E47U) {
+      format = WEBP_PNG_FORMAT;
+    } else if (magic1 >= 0xFFD8FF00U && magic1 <= 0xFFD8FFFFU) {
+      format = WEBP_JPEG_FORMAT;
+    } else if (magic1 == 0x49492A00 || magic1 == 0x4D4D002A) {
+      format = WEBP_TIFF_FORMAT;
+    } else if (magic1 == 0x52494646 && magic2 == 0x57454250) {
+      format = WEBP_WEBP_FORMAT;
+    }
+  }
+  return format;
+}
+
+static int FailReader(const uint8_t* const data, size_t data_size,
+                      struct WebPPicture* const pic,
+                      int keep_alpha, struct Metadata* const metadata) {
+  (void)data;
+  (void)data_size;
+  (void)pic;
+  (void)keep_alpha;
+  (void)metadata;
+  return 0;
+}
+
+WebPImageReader WebPGetImageReader(WebPInputFileFormat format) {
+  switch (format) {
+    case WEBP_PNG_FORMAT: return ReadPNG;
+    case WEBP_JPEG_FORMAT: return ReadJPEG;
+    case WEBP_TIFF_FORMAT: return ReadTIFF;
+    case WEBP_WEBP_FORMAT: return ReadWebP;
+    default: return FailReader;
+  }
+}
+
+WebPImageReader WebPGuessImageReader(const uint8_t* const data,
+                                     size_t data_size) {
+  return WebPGetImageReader(WebPGuessImageType(data, data_size));
+}

imageio/image_dec.h

@@ -0,0 +1,65 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  All-in-one library to decode PNG/JPEG/WebP/TIFF/WIC input images.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#ifndef WEBP_IMAGEIO_IMAGE_DEC_H_
+#define WEBP_IMAGEIO_IMAGE_DEC_H_
+
+#include "webp/types.h"
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#include "./metadata.h"
+#include "./jpegdec.h"
+#include "./pngdec.h"
+#include "./tiffdec.h"
+#include "./webpdec.h"
+#include "./wicdec.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum {
+  WEBP_PNG_FORMAT = 0,
+  WEBP_JPEG_FORMAT,
+  WEBP_TIFF_FORMAT,
+  WEBP_WEBP_FORMAT,
+  WEBP_UNSUPPORTED_FORMAT
+} WebPInputFileFormat;
+
+// Try to infer the image format. 'data_size' should be larger than 12.
+// Returns WEBP_UNSUPPORTED_FORMAT if format can't be guess safely.
+WebPInputFileFormat WebPGuessImageType(const uint8_t* const data,
+                                       size_t data_size);
+
+// Signature for common image-reading functions (ReadPNG, ReadJPEG, ...)
+typedef int (*WebPImageReader)(const uint8_t* const data, size_t data_size,
+                               struct WebPPicture* const pic,
+                               int keep_alpha, struct Metadata* const metadata);
+
+// Return the reader associated to a given file format.
+WebPImageReader WebPGetImageReader(WebPInputFileFormat format);
+
+// This function is similar to WebPGuessImageType(), but returns a
+// suitable reader function. The returned reader is never NULL, but
+// unknown formats will return an always-failing valid reader.
+WebPImageReader WebPGuessImageReader(const uint8_t* const data,
+                                     size_t data_size);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_IMAGEIO_IMAGE_DEC_H_

imageio/image_enc.c

@@ -0,0 +1,591 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Save image
+
+#include "./image_enc.h"
+
+#include <assert.h>
+#include <string.h>
+
+#ifdef WEBP_HAVE_PNG
+#include <png.h>
+#include <setjmp.h>   // note: this must be included *after* png.h
+#endif
+
+#ifdef HAVE_WINCODEC_H
+#ifdef __MINGW32__
+#define INITGUID  // Without this GUIDs are declared extern and fail to link
+#endif
+#define CINTERFACE
+#define COBJMACROS
+#define _WIN32_IE 0x500  // Workaround bug in shlwapi.h when compiling C++
+                         // code with COBJMACROS.
+#include <ole2.h>  // CreateStreamOnHGlobal()
+#include <shlwapi.h>
+#include <windows.h>
+#include <wincodec.h>
+#endif
+
+#include "./imageio_util.h"
+
+//------------------------------------------------------------------------------
+// PNG
+
+#ifdef HAVE_WINCODEC_H
+
+#define IFS(fn)                                                     \
+  do {                                                              \
+    if (SUCCEEDED(hr)) {                                            \
+      hr = (fn);                                                    \
+      if (FAILED(hr)) fprintf(stderr, #fn " failed %08lx\n", hr);   \
+    }                                                               \
+  } while (0)
+
+#ifdef __cplusplus
+#define MAKE_REFGUID(x) (x)
+#else
+#define MAKE_REFGUID(x) &(x)
+#endif
+
+static HRESULT CreateOutputStream(const char* out_file_name,
+                                  int write_to_mem, IStream** stream) {
+  HRESULT hr = S_OK;
+  if (write_to_mem) {
+    // Output to a memory buffer. This is freed when 'stream' is released.
+    IFS(CreateStreamOnHGlobal(NULL, TRUE, stream));
+  } else {
+    IFS(SHCreateStreamOnFileA(out_file_name, STGM_WRITE | STGM_CREATE, stream));
+  }
+  if (FAILED(hr)) {
+    fprintf(stderr, "Error opening output file %s (%08lx)\n",
+            out_file_name, hr);
+  }
+  return hr;
+}
+
+static HRESULT WriteUsingWIC(const char* out_file_name, int use_stdout,
+                             REFGUID container_guid,
+                             uint8_t* rgb, int stride,
+                             uint32_t width, uint32_t height, int has_alpha) {
+  HRESULT hr = S_OK;
+  IWICImagingFactory* factory = NULL;
+  IWICBitmapFrameEncode* frame = NULL;
+  IWICBitmapEncoder* encoder = NULL;
+  IStream* stream = NULL;
+  WICPixelFormatGUID pixel_format = has_alpha ? GUID_WICPixelFormat32bppBGRA
+                                              : GUID_WICPixelFormat24bppBGR;
+
+  if (out_file_name == NULL || rgb == NULL) return E_INVALIDARG;
+
+  IFS(CoInitialize(NULL));
+  IFS(CoCreateInstance(MAKE_REFGUID(CLSID_WICImagingFactory), NULL,
+                       CLSCTX_INPROC_SERVER,
+                       MAKE_REFGUID(IID_IWICImagingFactory),
+                       (LPVOID*)&factory));
+  if (hr == REGDB_E_CLASSNOTREG) {
+    fprintf(stderr,
+            "Couldn't access Windows Imaging Component (are you running "
+            "Windows XP SP3 or newer?). PNG support not available. "
+            "Use -ppm or -pgm for available PPM and PGM formats.\n");
+  }
+  IFS(CreateOutputStream(out_file_name, use_stdout, &stream));
+  IFS(IWICImagingFactory_CreateEncoder(factory, container_guid, NULL,
+                                       &encoder));
+  IFS(IWICBitmapEncoder_Initialize(encoder, stream,
+                                   WICBitmapEncoderNoCache));
+  IFS(IWICBitmapEncoder_CreateNewFrame(encoder, &frame, NULL));
+  IFS(IWICBitmapFrameEncode_Initialize(frame, NULL));
+  IFS(IWICBitmapFrameEncode_SetSize(frame, width, height));
+  IFS(IWICBitmapFrameEncode_SetPixelFormat(frame, &pixel_format));
+  IFS(IWICBitmapFrameEncode_WritePixels(frame, height, stride,
+                                        height * stride, rgb));
+  IFS(IWICBitmapFrameEncode_Commit(frame));
+  IFS(IWICBitmapEncoder_Commit(encoder));
+
+  if (SUCCEEDED(hr) && use_stdout) {
+    HGLOBAL image;
+    IFS(GetHGlobalFromStream(stream, &image));
+    if (SUCCEEDED(hr)) {
+      HANDLE std_output = GetStdHandle(STD_OUTPUT_HANDLE);
+      DWORD mode;
+      const BOOL update_mode = GetConsoleMode(std_output, &mode);
+      const void* const image_mem = GlobalLock(image);
+      DWORD bytes_written = 0;
+
+      // Clear output processing if necessary, then output the image.
+      if (update_mode) SetConsoleMode(std_output, 0);
+      if (!WriteFile(std_output, image_mem, (DWORD)GlobalSize(image),
+                     &bytes_written, NULL) ||
+          bytes_written != GlobalSize(image)) {
+        hr = E_FAIL;
+      }
+      if (update_mode) SetConsoleMode(std_output, mode);
+      GlobalUnlock(image);
+    }
+  }
+
+  if (frame != NULL) IUnknown_Release(frame);
+  if (encoder != NULL) IUnknown_Release(encoder);
+  if (factory != NULL) IUnknown_Release(factory);
+  if (stream != NULL) IUnknown_Release(stream);
+  return hr;
+}
+
+int WebPWritePNG(const char* out_file_name, int use_stdout,
+                 const WebPDecBuffer* const buffer) {
+  const uint32_t width = buffer->width;
+  const uint32_t height = buffer->height;
+  uint8_t* const rgb = buffer->u.RGBA.rgba;
+  const int stride = buffer->u.RGBA.stride;
+  const int has_alpha = WebPIsAlphaMode(buffer->colorspace);
+
+  return SUCCEEDED(WriteUsingWIC(out_file_name, use_stdout,
+                                 MAKE_REFGUID(GUID_ContainerFormatPng),
+                                 rgb, stride, width, height, has_alpha));
+}
+
+#elif defined(WEBP_HAVE_PNG)    // !HAVE_WINCODEC_H
+static void PNGAPI PNGErrorFunction(png_structp png, png_const_charp dummy) {
+  (void)dummy;  // remove variable-unused warning
+  longjmp(png_jmpbuf(png), 1);
+}
+
+int WebPWritePNG(FILE* out_file, const WebPDecBuffer* const buffer) {
+  const uint32_t width = buffer->width;
+  const uint32_t height = buffer->height;
+  png_bytep row = buffer->u.RGBA.rgba;
+  const int stride = buffer->u.RGBA.stride;
+  const int has_alpha = WebPIsAlphaMode(buffer->colorspace);
+  volatile png_structp png;
+  volatile png_infop info;
+  png_uint_32 y;
+
+  if (out_file == NULL || buffer == NULL) return 0;
+
+  png = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+                                NULL, PNGErrorFunction, NULL);
+  if (png == NULL) {
+    return 0;
+  }
+  info = png_create_info_struct(png);
+  if (info == NULL) {
+    png_destroy_write_struct((png_structpp)&png, NULL);
+    return 0;
+  }
+  if (setjmp(png_jmpbuf(png))) {
+    png_destroy_write_struct((png_structpp)&png, (png_infopp)&info);
+    return 0;
+  }
+  png_init_io(png, out_file);
+  png_set_IHDR(png, info, width, height, 8,
+               has_alpha ? PNG_COLOR_TYPE_RGBA : PNG_COLOR_TYPE_RGB,
+               PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
+               PNG_FILTER_TYPE_DEFAULT);
+  png_write_info(png, info);
+  for (y = 0; y < height; ++y) {
+    png_write_rows(png, &row, 1);
+    row += stride;
+  }
+  png_write_end(png, info);
+  png_destroy_write_struct((png_structpp)&png, (png_infopp)&info);
+  return 1;
+}
+#else    // !HAVE_WINCODEC_H && !WEBP_HAVE_PNG
+int WebPWritePNG(FILE* fout, const WebPDecBuffer* const buffer) {
+  if (fout == NULL || buffer == NULL) return 0;
+
+  fprintf(stderr, "PNG support not compiled. Please install the libpng "
+          "development package before building.\n");
+  fprintf(stderr, "You can run with -ppm flag to decode in PPM format.\n");
+  return 0;
+}
+#endif
+
+//------------------------------------------------------------------------------
+// PPM / PAM
+
+static int WritePPMPAM(FILE* fout, const WebPDecBuffer* const buffer,
+                       int alpha) {
+  if (fout == NULL || buffer == NULL) {
+    return 0;
+  } else {
+    const uint32_t width = buffer->width;
+    const uint32_t height = buffer->height;
+    const uint8_t* row = buffer->u.RGBA.rgba;
+    const int stride = buffer->u.RGBA.stride;
+    const size_t bytes_per_px = alpha ? 4 : 3;
+    uint32_t y;
+
+    if (row == NULL) return 0;
+
+    if (alpha) {
+      fprintf(fout, "P7\nWIDTH %u\nHEIGHT %u\nDEPTH 4\nMAXVAL 255\n"
+                    "TUPLTYPE RGB_ALPHA\nENDHDR\n", width, height);
+    } else {
+      fprintf(fout, "P6\n%u %u\n255\n", width, height);
+    }
+    for (y = 0; y < height; ++y) {
+      if (fwrite(row, width, bytes_per_px, fout) != bytes_per_px) {
+        return 0;
+      }
+      row += stride;
+    }
+  }
+  return 1;
+}
+
+int WebPWritePPM(FILE* fout, const WebPDecBuffer* const buffer) {
+  return WritePPMPAM(fout, buffer, 0);
+}
+
+int WebPWritePAM(FILE* fout, const WebPDecBuffer* const buffer) {
+  return WritePPMPAM(fout, buffer, 1);
+}
+
+//------------------------------------------------------------------------------
+// Raw PGM
+
+// Save 16b mode (RGBA4444, RGB565, ...) for debugging purpose.
+int WebPWrite16bAsPGM(FILE* fout, const WebPDecBuffer* const buffer) {
+  const uint32_t width = buffer->width;
+  const uint32_t height = buffer->height;
+  const uint8_t* rgba = buffer->u.RGBA.rgba;
+  const int stride = buffer->u.RGBA.stride;
+  const uint32_t bytes_per_px = 2;
+  uint32_t y;
+
+  if (fout == NULL || buffer == NULL || rgba == NULL) return 0;
+
+  fprintf(fout, "P5\n%u %u\n255\n", width * bytes_per_px, height);
+  for (y = 0; y < height; ++y) {
+    if (fwrite(rgba, width, bytes_per_px, fout) != bytes_per_px) {
+      return 0;
+    }
+    rgba += stride;
+  }
+  return 1;
+}
+
+//------------------------------------------------------------------------------
+// BMP
+
+static void PutLE16(uint8_t* const dst, uint32_t value) {
+  dst[0] = (value >> 0) & 0xff;
+  dst[1] = (value >> 8) & 0xff;
+}
+
+static void PutLE32(uint8_t* const dst, uint32_t value) {
+  PutLE16(dst + 0, (value >>  0) & 0xffff);
+  PutLE16(dst + 2, (value >> 16) & 0xffff);
+}
+
+#define BMP_HEADER_SIZE 54
+int WebPWriteBMP(FILE* fout, const WebPDecBuffer* const buffer) {
+  const int has_alpha = WebPIsAlphaMode(buffer->colorspace);
+  const uint32_t width = buffer->width;
+  const uint32_t height = buffer->height;
+  const uint8_t* rgba = buffer->u.RGBA.rgba;
+  const int stride = buffer->u.RGBA.stride;
+  const uint32_t bytes_per_px = has_alpha ? 4 : 3;
+  uint32_t y;
+  const uint32_t line_size = bytes_per_px * width;
+  const uint32_t bmp_stride = (line_size + 3) & ~3;   // pad to 4
+  const uint32_t total_size = bmp_stride * height + BMP_HEADER_SIZE;
+  uint8_t bmp_header[BMP_HEADER_SIZE] = { 0 };
+
+  if (fout == NULL || buffer == NULL || rgba == NULL) return 0;
+
+  // bitmap file header
+  PutLE16(bmp_header + 0, 0x4d42);                // signature 'BM'
+  PutLE32(bmp_header + 2, total_size);            // size including header
+  PutLE32(bmp_header + 6, 0);                     // reserved
+  PutLE32(bmp_header + 10, BMP_HEADER_SIZE);      // offset to pixel array
+  // bitmap info header
+  PutLE32(bmp_header + 14, 40);                   // DIB header size
+  PutLE32(bmp_header + 18, width);                // dimensions
+  PutLE32(bmp_header + 22, -(int)height);         // vertical flip!
+  PutLE16(bmp_header + 26, 1);                    // number of planes
+  PutLE16(bmp_header + 28, bytes_per_px * 8);     // bits per pixel
+  PutLE32(bmp_header + 30, 0);                    // no compression (BI_RGB)
+  PutLE32(bmp_header + 34, 0);                    // image size (dummy)
+  PutLE32(bmp_header + 38, 2400);                 // x pixels/meter
+  PutLE32(bmp_header + 42, 2400);                 // y pixels/meter
+  PutLE32(bmp_header + 46, 0);                    // number of palette colors
+  PutLE32(bmp_header + 50, 0);                    // important color count
+
+  // TODO(skal): color profile
+
+  // write header
+  if (fwrite(bmp_header, sizeof(bmp_header), 1, fout) != 1) {
+    return 0;
+  }
+
+  // write pixel array
+  for (y = 0; y < height; ++y) {
+    if (fwrite(rgba, line_size, 1, fout) != 1) {
+      return 0;
+    }
+    // write padding zeroes
+    if (bmp_stride != line_size) {
+      const uint8_t zeroes[3] = { 0 };
+      if (fwrite(zeroes, bmp_stride - line_size, 1, fout) != 1) {
+        return 0;
+      }
+    }
+    rgba += stride;
+  }
+  return 1;
+}
+#undef BMP_HEADER_SIZE
+
+//------------------------------------------------------------------------------
+// TIFF
+
+#define NUM_IFD_ENTRIES 15
+#define EXTRA_DATA_SIZE 16
+// 10b for signature/header + n * 12b entries + 4b for IFD terminator:
+#define EXTRA_DATA_OFFSET (10 + 12 * NUM_IFD_ENTRIES + 4)
+#define TIFF_HEADER_SIZE (EXTRA_DATA_OFFSET + EXTRA_DATA_SIZE)
+
+int WebPWriteTIFF(FILE* fout, const WebPDecBuffer* const buffer) {
+  const int has_alpha = WebPIsAlphaMode(buffer->colorspace);
+  const uint32_t width = buffer->width;
+  const uint32_t height = buffer->height;
+  const uint8_t* rgba = buffer->u.RGBA.rgba;
+  const int stride = buffer->u.RGBA.stride;
+  const uint8_t bytes_per_px = has_alpha ? 4 : 3;
+  // For non-alpha case, we omit tag 0x152 (ExtraSamples).
+  const uint8_t num_ifd_entries = has_alpha ? NUM_IFD_ENTRIES
+                                            : NUM_IFD_ENTRIES - 1;
+  uint8_t tiff_header[TIFF_HEADER_SIZE] = {
+    0x49, 0x49, 0x2a, 0x00,   // little endian signature
+    8, 0, 0, 0,               // offset to the unique IFD that follows
+    // IFD (offset = 8). Entries must be written in increasing tag order.
+    num_ifd_entries, 0,       // Number of entries in the IFD (12 bytes each).
+    0x00, 0x01, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0,    //  10: Width  (TBD)
+    0x01, 0x01, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0,    //  22: Height (TBD)
+    0x02, 0x01, 3, 0, bytes_per_px, 0, 0, 0,     //  34: BitsPerSample: 8888
+        EXTRA_DATA_OFFSET + 0, 0, 0, 0,
+    0x03, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0,    //  46: Compression: none
+    0x06, 0x01, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0,    //  58: Photometric: RGB
+    0x11, 0x01, 4, 0, 1, 0, 0, 0,                //  70: Strips offset:
+        TIFF_HEADER_SIZE, 0, 0, 0,               //      data follows header
+    0x12, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0,    //  82: Orientation: topleft
+    0x15, 0x01, 3, 0, 1, 0, 0, 0,                //  94: SamplesPerPixels
+        bytes_per_px, 0, 0, 0,
+    0x16, 0x01, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0,    // 106: Rows per strip (TBD)
+    0x17, 0x01, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0,    // 118: StripByteCount (TBD)
+    0x1a, 0x01, 5, 0, 1, 0, 0, 0,                // 130: X-resolution
+        EXTRA_DATA_OFFSET + 8, 0, 0, 0,
+    0x1b, 0x01, 5, 0, 1, 0, 0, 0,                // 142: Y-resolution
+        EXTRA_DATA_OFFSET + 8, 0, 0, 0,
+    0x1c, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0,    // 154: PlanarConfiguration
+    0x28, 0x01, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0,    // 166: ResolutionUnit (inch)
+    0x52, 0x01, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0,    // 178: ExtraSamples: rgbA
+    0, 0, 0, 0,                                  // 190: IFD terminator
+    // EXTRA_DATA_OFFSET:
+    8, 0, 8, 0, 8, 0, 8, 0,      // BitsPerSample
+    72, 0, 0, 0, 1, 0, 0, 0      // 72 pixels/inch, for X/Y-resolution
+  };
+  uint32_t y;
+
+  if (fout == NULL || buffer == NULL || rgba == NULL) return 0;
+
+  // Fill placeholders in IFD:
+  PutLE32(tiff_header + 10 + 8, width);
+  PutLE32(tiff_header + 22 + 8, height);
+  PutLE32(tiff_header + 106 + 8, height);
+  PutLE32(tiff_header + 118 + 8, width * bytes_per_px * height);
+  if (!has_alpha) PutLE32(tiff_header + 178, 0);  // IFD terminator
+
+  // write header
+  if (fwrite(tiff_header, sizeof(tiff_header), 1, fout) != 1) {
+    return 0;
+  }
+  // write pixel values
+  for (y = 0; y < height; ++y) {
+    if (fwrite(rgba, bytes_per_px, width, fout) != width) {
+      return 0;
+    }
+    rgba += stride;
+  }
+
+  return 1;
+}
+
+#undef TIFF_HEADER_SIZE
+#undef EXTRA_DATA_OFFSET
+#undef EXTRA_DATA_SIZE
+#undef NUM_IFD_ENTRIES
+
+//------------------------------------------------------------------------------
+// Raw Alpha
+
+int WebPWriteAlphaPlane(FILE* fout, const WebPDecBuffer* const buffer) {
+  if (fout == NULL || buffer == NULL) {
+    return 0;
+  } else {
+    const uint32_t width = buffer->width;
+    const uint32_t height = buffer->height;
+    const uint8_t* a = buffer->u.YUVA.a;
+    const int a_stride = buffer->u.YUVA.a_stride;
+    uint32_t y;
+
+    if (a == NULL) return 0;
+
+    fprintf(fout, "P5\n%u %u\n255\n", width, height);
+    for (y = 0; y < height; ++y) {
+      if (fwrite(a, width, 1, fout) != 1) return 0;
+      a += a_stride;
+    }
+    return 1;
+  }
+}
+
+//------------------------------------------------------------------------------
+// PGM with IMC4 layout
+
+int WebPWritePGM(FILE* fout, const WebPDecBuffer* const buffer) {
+  if (fout == NULL || buffer == NULL) {
+    return 0;
+  } else {
+    const int width = buffer->width;
+    const int height = buffer->height;
+    const WebPYUVABuffer* const yuv = &buffer->u.YUVA;
+    const uint8_t* src_y = yuv->y;
+    const uint8_t* src_u = yuv->u;
+    const uint8_t* src_v = yuv->v;
+    const uint8_t* src_a = yuv->a;
+    const int uv_width = (width + 1) / 2;
+    const int uv_height = (height + 1) / 2;
+    const int a_height = (src_a != NULL) ? height : 0;
+    int ok = 1;
+    int y;
+
+    if (src_y == NULL || src_u == NULL || src_v == NULL) return 0;
+
+    fprintf(fout, "P5\n%d %d\n255\n",
+            (width + 1) & ~1, height + uv_height + a_height);
+    for (y = 0; ok && y < height; ++y) {
+      ok &= (fwrite(src_y, width, 1, fout) == 1);
+      if (width & 1) fputc(0, fout);    // padding byte
+      src_y += yuv->y_stride;
+    }
+    for (y = 0; ok && y < uv_height; ++y) {
+      ok &= (fwrite(src_u, uv_width, 1, fout) == 1);
+      ok &= (fwrite(src_v, uv_width, 1, fout) == 1);
+      src_u += yuv->u_stride;
+      src_v += yuv->v_stride;
+    }
+    for (y = 0; ok && y < a_height; ++y) {
+      ok &= (fwrite(src_a, width, 1, fout) == 1);
+      if (width & 1) fputc(0, fout);    // padding byte
+      src_a += yuv->a_stride;
+    }
+    return ok;
+  }
+}
+
+//------------------------------------------------------------------------------
+// Raw YUV(A) planes
+
+int WebPWriteYUV(FILE* fout, const WebPDecBuffer* const buffer) {
+  if (fout == NULL || buffer == NULL) {
+    return 0;
+  } else {
+    const int width = buffer->width;
+    const int height = buffer->height;
+    const WebPYUVABuffer* const yuv = &buffer->u.YUVA;
+    const uint8_t* src_y = yuv->y;
+    const uint8_t* src_u = yuv->u;
+    const uint8_t* src_v = yuv->v;
+    const uint8_t* src_a = yuv->a;
+    const int uv_width = (width + 1) / 2;
+    const int uv_height = (height + 1) / 2;
+    const int a_height = (src_a != NULL) ? height : 0;
+    int ok = 1;
+    int y;
+
+    if (src_y == NULL || src_u == NULL || src_v == NULL) return 0;
+
+    for (y = 0; ok && y < height; ++y) {
+      ok &= (fwrite(src_y, width, 1, fout) == 1);
+      src_y += yuv->y_stride;
+    }
+    for (y = 0; ok && y < uv_height; ++y) {
+      ok &= (fwrite(src_u, uv_width, 1, fout) == 1);
+      src_u += yuv->u_stride;
+    }
+    for (y = 0; ok && y < uv_height; ++y) {
+      ok &= (fwrite(src_v, uv_width, 1, fout) == 1);
+      src_v += yuv->v_stride;
+    }
+    for (y = 0; ok && y < a_height; ++y) {
+      ok &= (fwrite(src_a, width, 1, fout) == 1);
+      src_a += yuv->a_stride;
+    }
+    return ok;
+  }
+}
+
+//------------------------------------------------------------------------------
+// Generic top-level call
+
+int WebPSaveImage(const WebPDecBuffer* const buffer,
+                  WebPOutputFileFormat format, const char* const out_file) {
+  FILE* fout = NULL;
+  int needs_open_file = 1;
+  const int use_stdout = (out_file != NULL) && !strcmp(out_file, "-");
+  int ok = 1;
+
+  if (buffer == NULL || out_file == NULL) return 0;
+
+#ifdef HAVE_WINCODEC_H
+  needs_open_file = (format != PNG);
+#endif
+
+  if (needs_open_file) {
+    fout = use_stdout ? ImgIoUtilSetBinaryMode(stdout) : fopen(out_file, "wb");
+    if (fout == NULL) {
+      fprintf(stderr, "Error opening output file %s\n", out_file);
+      return 0;
+    }
+  }
+
+  if (format == PNG ||
+      format == RGBA || format == BGRA || format == ARGB ||
+      format == rgbA || format == bgrA || format == Argb) {
+#ifdef HAVE_WINCODEC_H
+    ok &= WebPWritePNG(out_file, use_stdout, buffer);
+#else
+    ok &= WebPWritePNG(fout, buffer);
+#endif
+  } else if (format == PAM) {
+    ok &= WebPWritePAM(fout, buffer);
+  } else if (format == PPM || format == RGB || format == BGR) {
+    ok &= WebPWritePPM(fout, buffer);
+  } else if (format == RGBA_4444 || format == RGB_565 || format == rgbA_4444) {
+    ok &= WebPWrite16bAsPGM(fout, buffer);
+  } else if (format == BMP) {
+    ok &= WebPWriteBMP(fout, buffer);
+  } else if (format == TIFF) {
+    ok &= WebPWriteTIFF(fout, buffer);
+  } else if (format == RAW_YUV) {
+    ok &= WebPWriteYUV(fout, buffer);
+  } else if (format == PGM || format == YUV || format == YUVA) {
+    ok &= WebPWritePGM(fout, buffer);
+  } else if (format == ALPHA_PLANE_ONLY) {
+    ok &= WebPWriteAlphaPlane(fout, buffer);
+  }
+  if (fout != NULL && fout != stdout) {
+    fclose(fout);
+  }
+  return ok;
+}

imageio/image_enc.h

@@ -0,0 +1,96 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  All-in-one library to save PNG/JPEG/WebP/TIFF/WIC images.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#ifndef WEBP_IMAGEIO_IMAGE_ENC_H_
+#define WEBP_IMAGEIO_IMAGE_ENC_H_
+
+#include <stdio.h>
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#include "webp/types.h"
+#include "webp/decode.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Output types
+typedef enum {
+  PNG = 0,
+  PAM,
+  PPM,
+  PGM,
+  BMP,
+  TIFF,
+  RAW_YUV,
+  ALPHA_PLANE_ONLY,  // this is for experimenting only
+  // forced colorspace output (for testing, mostly)
+  RGB, RGBA, BGR, BGRA, ARGB,
+  RGBA_4444, RGB_565,
+  rgbA, bgrA, Argb, rgbA_4444,
+  YUV, YUVA
+} WebPOutputFileFormat;
+
+// General all-purpose call.
+// Most formats expect a 'buffer' containing RGBA-like samples, except
+// RAW_YUV, YUV and YUVA formats.
+// If 'out_file_name' is "-", data is saved to stdout.
+// Returns false if an error occurred, true otherwise.
+int WebPSaveImage(const WebPDecBuffer* const buffer,
+                  WebPOutputFileFormat format, const char* const out_file_name);
+
+// Save to PNG.
+#ifdef HAVE_WINCODEC_H
+int WebPWritePNG(const char* out_file_name, int use_stdout,
+                 const struct WebPDecBuffer* const buffer);
+#else
+int WebPWritePNG(FILE* out_file, const WebPDecBuffer* const buffer);
+#endif
+
+// Save to PPM format (RGB, no alpha)
+int WebPWritePPM(FILE* fout, const struct WebPDecBuffer* const buffer);
+
+// Save to PAM format (= PPM + alpha)
+int WebPWritePAM(FILE* fout, const struct WebPDecBuffer* const buffer);
+
+// Save 16b mode (RGBA4444, RGB565, ...) for debugging purposes.
+int WebPWrite16bAsPGM(FILE* fout, const struct WebPDecBuffer* const buffer);
+
+// Save as BMP
+int WebPWriteBMP(FILE* fout, const struct WebPDecBuffer* const buffer);
+
+// Save as TIFF
+int WebPWriteTIFF(FILE* fout, const struct WebPDecBuffer* const buffer);
+
+// Save the ALPHA plane (only) as a PGM
+int WebPWriteAlphaPlane(FILE* fout, const struct WebPDecBuffer* const buffer);
+
+// Save as YUV samples as PGM format (using IMC4 layout).
+// See: http://www.fourcc.org/yuv.php#IMC4.
+// (very convenient format for viewing the samples, esp. for odd dimensions).
+int WebPWritePGM(FILE* fout, const struct WebPDecBuffer* const buffer);
+
+// Save YUV(A) planes sequentially (raw dump)
+int WebPWriteYUV(FILE* fout, const struct WebPDecBuffer* const buffer);
+
+// Save 16b mode (RGBA4444, RGB565, ...) as PGM format, for debugging purposes.
+int WebPWrite16bAsPGM(FILE* fout, const struct WebPDecBuffer* const buffer);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_IMAGEIO_IMAGE_ENC_H_

imageio/imageio_util.c

@@ -0,0 +1,143 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  Utility functions used by the image decoders.
+//
+
+#include "./imageio_util.h"
+
+#if defined(_WIN32)
+#include <fcntl.h>   // for _O_BINARY
+#include <io.h>      // for _setmode()
+#endif
+#include <stdlib.h>
+#include <string.h>
+
+// -----------------------------------------------------------------------------
+// File I/O
+
+FILE* ImgIoUtilSetBinaryMode(FILE* file) {
+#if defined(_WIN32)
+  if (_setmode(_fileno(file), _O_BINARY) == -1) {
+    fprintf(stderr, "Failed to reopen file in O_BINARY mode.\n");
+    return NULL;
+  }
+#endif
+  return file;
+}
+
+int ImgIoUtilReadFromStdin(const uint8_t** data, size_t* data_size) {
+  static const size_t kBlockSize = 16384;  // default initial size
+  size_t max_size = 0;
+  size_t size = 0;
+  uint8_t* input = NULL;
+
+  if (data == NULL || data_size == NULL) return 0;
+  *data = NULL;
+  *data_size = 0;
+
+  if (!ImgIoUtilSetBinaryMode(stdin)) return 0;
+
+  while (!feof(stdin)) {
+    // We double the buffer size each time and read as much as possible.
+    const size_t extra_size = (max_size == 0) ? kBlockSize : max_size;
+    void* const new_data = realloc(input, max_size + extra_size);
+    if (new_data == NULL) goto Error;
+    input = (uint8_t*)new_data;
+    max_size += extra_size;
+    size += fread(input + size, 1, extra_size, stdin);
+    if (size < max_size) break;
+  }
+  if (ferror(stdin)) goto Error;
+  *data = input;
+  *data_size = size;
+  return 1;
+
+ Error:
+  free(input);
+  fprintf(stderr, "Could not read from stdin\n");
+  return 0;
+}
+
+int ImgIoUtilReadFile(const char* const file_name,
+                      const uint8_t** data, size_t* data_size) {
+  int ok;
+  void* file_data;
+  size_t file_size;
+  FILE* in;
+  const int from_stdin = (file_name == NULL) || !strcmp(file_name, "-");
+
+  if (from_stdin) return ImgIoUtilReadFromStdin(data, data_size);
+
+  if (data == NULL || data_size == NULL) return 0;
+  *data = NULL;
+  *data_size = 0;
+
+  in = fopen(file_name, "rb");
+  if (in == NULL) {
+    fprintf(stderr, "cannot open input file '%s'\n", file_name);
+    return 0;
+  }
+  fseek(in, 0, SEEK_END);
+  file_size = ftell(in);
+  fseek(in, 0, SEEK_SET);
+  file_data = malloc(file_size);
+  if (file_data == NULL) return 0;
+  ok = (fread(file_data, file_size, 1, in) == 1);
+  fclose(in);
+
+  if (!ok) {
+    fprintf(stderr, "Could not read %d bytes of data from file %s\n",
+            (int)file_size, file_name);
+    free(file_data);
+    return 0;
+  }
+  *data = (uint8_t*)file_data;
+  *data_size = file_size;
+  return 1;
+}
+
+int ImgIoUtilWriteFile(const char* const file_name,
+                       const uint8_t* data, size_t data_size) {
+  int ok;
+  FILE* out;
+  const int to_stdout = (file_name == NULL) || !strcmp(file_name, "-");
+
+  if (data == NULL) {
+    return 0;
+  }
+  out = to_stdout ? stdout : fopen(file_name, "wb");
+  if (out == NULL) {
+    fprintf(stderr, "Error! Cannot open output file '%s'\n", file_name);
+    return 0;
+  }
+  ok = (fwrite(data, data_size, 1, out) == 1);
+  if (out != stdout) fclose(out);
+  return ok;
+}
+
+// -----------------------------------------------------------------------------
+
+void ImgIoUtilCopyPlane(const uint8_t* src, int src_stride,
+                        uint8_t* dst, int dst_stride, int width, int height) {
+  while (height-- > 0) {
+    memcpy(dst, src, width * sizeof(*dst));
+    src += src_stride;
+    dst += dst_stride;
+  }
+}
+
+// -----------------------------------------------------------------------------
+
+int ImgIoUtilCheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
+  const uint64_t total_size = nmemb * size;
+  return (total_size == (size_t)total_size);
+}
+
+// -----------------------------------------------------------------------------

imageio/imageio_util.h

@@ -0,0 +1,61 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  Utility functions used by the image decoders.
+//
+
+#ifndef WEBP_IMAGEIO_IMAGEIO_UTIL_H_
+#define WEBP_IMAGEIO_IMAGEIO_UTIL_H_
+
+#include <stdio.h>
+#include "webp/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//------------------------------------------------------------------------------
+// File I/O
+
+// Reopen file in binary (O_BINARY) mode.
+// Returns 'file' on success, NULL otherwise.
+FILE* ImgIoUtilSetBinaryMode(FILE* file);
+
+// Allocates storage for entire file 'file_name' and returns contents and size
+// in 'data' and 'data_size'. Returns 1 on success, 0 otherwise. '*data' should
+// be deleted using free().
+// If 'file_name' is NULL or equal to "-", input is read from stdin by calling
+// the function ImgIoUtilReadFromStdin().
+int ImgIoUtilReadFile(const char* const file_name,
+                      const uint8_t** data, size_t* data_size);
+
+// Same as ImgIoUtilReadFile(), but reads until EOF from stdin instead.
+int ImgIoUtilReadFromStdin(const uint8_t** data, size_t* data_size);
+
+// Write a data segment into a file named 'file_name'. Returns true if ok.
+// If 'file_name' is NULL or equal to "-", output is written to stdout.
+int ImgIoUtilWriteFile(const char* const file_name,
+                       const uint8_t* data, size_t data_size);
+
+//------------------------------------------------------------------------------
+
+// Copy width x height pixels from 'src' to 'dst' honoring the strides.
+void ImgIoUtilCopyPlane(const uint8_t* src, int src_stride,
+                        uint8_t* dst, int dst_stride, int width, int height);
+
+//------------------------------------------------------------------------------
+
+// Returns 0 in case of overflow of nmemb * size.
+int ImgIoUtilCheckSizeArgumentsOverflow(uint64_t nmemb, size_t size);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_IMAGEIO_IMAGEIO_UTIL_H_

imageio/jpegdec.c

@@ -0,0 +1,359 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// JPEG decode.
+
+#include "./jpegdec.h"
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#include <stdio.h>
+
+#ifdef WEBP_HAVE_JPEG
+#include <jpeglib.h>
+#include <jerror.h>
+#include <setjmp.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "webp/encode.h"
+#include "./imageio_util.h"
+#include "./metadata.h"
+
+// -----------------------------------------------------------------------------
+// Metadata processing
+
+#ifndef JPEG_APP1
+# define JPEG_APP1 (JPEG_APP0 + 1)
+#endif
+#ifndef JPEG_APP2
+# define JPEG_APP2 (JPEG_APP0 + 2)
+#endif
+
+typedef struct {
+  const uint8_t* data;
+  size_t data_length;
+  int seq;  // this segment's sequence number [1, 255] for use in reassembly.
+} ICCPSegment;
+
+static void SaveMetadataMarkers(j_decompress_ptr dinfo) {
+  const unsigned int max_marker_length = 0xffff;
+  jpeg_save_markers(dinfo, JPEG_APP1, max_marker_length);  // Exif/XMP
+  jpeg_save_markers(dinfo, JPEG_APP2, max_marker_length);  // ICC profile
+}
+
+static int CompareICCPSegments(const void* a, const void* b) {
+  const ICCPSegment* s1 = (const ICCPSegment*)a;
+  const ICCPSegment* s2 = (const ICCPSegment*)b;
+  return s1->seq - s2->seq;
+}
+
+// Extract ICC profile segments from the marker list in 'dinfo', reassembling
+// and storing them in 'iccp'.
+// Returns true on success and false for memory errors and corrupt profiles.
+static int StoreICCP(j_decompress_ptr dinfo, MetadataPayload* const iccp) {
+  // ICC.1:2010-12 (4.3.0.0) Annex B.4 Embedding ICC Profiles in JPEG files
+  static const char kICCPSignature[] = "ICC_PROFILE";
+  static const size_t kICCPSignatureLength = 12;  // signature includes '\0'
+  static const size_t kICCPSkipLength = 14;  // signature + seq & count
+  int expected_count = 0;
+  int actual_count = 0;
+  int seq_max = 0;
+  size_t total_size = 0;
+  ICCPSegment iccp_segments[255];
+  jpeg_saved_marker_ptr marker;
+
+  memset(iccp_segments, 0, sizeof(iccp_segments));
+  for (marker = dinfo->marker_list; marker != NULL; marker = marker->next) {
+    if (marker->marker == JPEG_APP2 &&
+        marker->data_length > kICCPSkipLength &&
+        !memcmp(marker->data, kICCPSignature, kICCPSignatureLength)) {
+      // ICC_PROFILE\0<seq><count>; 'seq' starts at 1.
+      const int seq = marker->data[kICCPSignatureLength];
+      const int count = marker->data[kICCPSignatureLength + 1];
+      const size_t segment_size = marker->data_length - kICCPSkipLength;
+      ICCPSegment* segment;
+
+      if (segment_size == 0 || count == 0 || seq == 0) {
+        fprintf(stderr, "[ICCP] size (%d) / count (%d) / sequence number (%d)"
+                        " cannot be 0!\n",
+                (int)segment_size, seq, count);
+        return 0;
+      }
+
+      if (expected_count == 0) {
+        expected_count = count;
+      } else if (expected_count != count) {
+        fprintf(stderr, "[ICCP] Inconsistent segment count (%d / %d)!\n",
+                expected_count, count);
+        return 0;
+      }
+
+      segment = iccp_segments + seq - 1;
+      if (segment->data_length != 0) {
+        fprintf(stderr, "[ICCP] Duplicate segment number (%d)!\n" , seq);
+        return 0;
+      }
+
+      segment->data = marker->data + kICCPSkipLength;
+      segment->data_length = segment_size;
+      segment->seq = seq;
+      total_size += segment_size;
+      if (seq > seq_max) seq_max = seq;
+      ++actual_count;
+    }
+  }
+
+  if (actual_count == 0) return 1;
+  if (seq_max != actual_count) {
+    fprintf(stderr, "[ICCP] Discontinuous segments, expected: %d actual: %d!\n",
+            actual_count, seq_max);
+    return 0;
+  }
+  if (expected_count != actual_count) {
+    fprintf(stderr, "[ICCP] Segment count: %d does not match expected: %d!\n",
+            actual_count, expected_count);
+    return 0;
+  }
+
+  // The segments may appear out of order in the file, sort them based on
+  // sequence number before assembling the payload.
+  qsort(iccp_segments, actual_count, sizeof(*iccp_segments),
+        CompareICCPSegments);
+
+  iccp->bytes = (uint8_t*)malloc(total_size);
+  if (iccp->bytes == NULL) return 0;
+  iccp->size = total_size;
+
+  {
+    int i;
+    size_t offset = 0;
+    for (i = 0; i < seq_max; ++i) {
+      memcpy(iccp->bytes + offset,
+             iccp_segments[i].data, iccp_segments[i].data_length);
+      offset += iccp_segments[i].data_length;
+    }
+  }
+  return 1;
+}
+
+// Returns true on success and false for memory errors and corrupt profiles.
+// The caller must use MetadataFree() on 'metadata' in all cases.
+static int ExtractMetadataFromJPEG(j_decompress_ptr dinfo,
+                                   Metadata* const metadata) {
+  static const struct {
+    int marker;
+    const char* signature;
+    size_t signature_length;
+    size_t storage_offset;
+  } kJPEGMetadataMap[] = {
+    // Exif 2.2 Section 4.7.2 Interoperability Structure of APP1 ...
+    { JPEG_APP1, "Exif\0",                        6, METADATA_OFFSET(exif) },
+    // XMP Specification Part 3 Section 3 Embedding XMP Metadata ... #JPEG
+    // TODO(jzern) Add support for 'ExtendedXMP'
+    { JPEG_APP1, "http://ns.adobe.com/xap/1.0/", 29, METADATA_OFFSET(xmp) },
+    { 0, NULL, 0, 0 },
+  };
+  jpeg_saved_marker_ptr marker;
+  // Treat ICC profiles separately as they may be segmented and out of order.
+  if (!StoreICCP(dinfo, &metadata->iccp)) return 0;
+
+  for (marker = dinfo->marker_list; marker != NULL; marker = marker->next) {
+    int i;
+    for (i = 0; kJPEGMetadataMap[i].marker != 0; ++i) {
+      if (marker->marker == kJPEGMetadataMap[i].marker &&
+          marker->data_length > kJPEGMetadataMap[i].signature_length &&
+          !memcmp(marker->data, kJPEGMetadataMap[i].signature,
+                  kJPEGMetadataMap[i].signature_length)) {
+        MetadataPayload* const payload =
+            (MetadataPayload*)((uint8_t*)metadata +
+                               kJPEGMetadataMap[i].storage_offset);
+
+        if (payload->bytes == NULL) {
+          const char* marker_data = (const char*)marker->data +
+                                    kJPEGMetadataMap[i].signature_length;
+          const size_t marker_data_length =
+              marker->data_length - kJPEGMetadataMap[i].signature_length;
+          if (!MetadataCopy(marker_data, marker_data_length, payload)) return 0;
+        } else {
+          fprintf(stderr, "Ignoring additional '%s' marker\n",
+                  kJPEGMetadataMap[i].signature);
+        }
+      }
+    }
+  }
+  return 1;
+}
+
+#undef JPEG_APP1
+#undef JPEG_APP2
+
+// -----------------------------------------------------------------------------
+// JPEG decoding
+
+struct my_error_mgr {
+  struct jpeg_error_mgr pub;
+  jmp_buf setjmp_buffer;
+};
+
+static void my_error_exit(j_common_ptr dinfo) {
+  struct my_error_mgr* myerr = (struct my_error_mgr*)dinfo->err;
+  dinfo->err->output_message(dinfo);
+  longjmp(myerr->setjmp_buffer, 1);
+}
+
+typedef struct {
+  struct jpeg_source_mgr pub;
+  const uint8_t* data;
+  size_t data_size;
+} JPEGReadContext;
+
+static void ContextInit(j_decompress_ptr cinfo) {
+  JPEGReadContext* const ctx = (JPEGReadContext*)cinfo->src;
+  ctx->pub.next_input_byte = ctx->data;
+  ctx->pub.bytes_in_buffer = ctx->data_size;
+}
+
+static boolean ContextFill(j_decompress_ptr cinfo) {
+  // we shouldn't get here.
+  ERREXIT(cinfo, JERR_FILE_READ);
+  return FALSE;
+}
+
+static void ContextSkip(j_decompress_ptr cinfo, long jump_size) {
+  JPEGReadContext* const ctx = (JPEGReadContext*)cinfo->src;
+  size_t jump = (size_t)jump_size;
+  if (jump > ctx->pub.bytes_in_buffer) {  // Don't overflow the buffer.
+    jump = ctx->pub.bytes_in_buffer;
+  }
+  ctx->pub.bytes_in_buffer -= jump;
+  ctx->pub.next_input_byte += jump;
+}
+
+static void ContextTerm(j_decompress_ptr cinfo) {
+  (void)cinfo;
+}
+
+static void ContextSetup(volatile struct jpeg_decompress_struct* const cinfo,
+                         JPEGReadContext* const ctx) {
+  cinfo->src = (struct jpeg_source_mgr*)ctx;
+  ctx->pub.init_source = ContextInit;
+  ctx->pub.fill_input_buffer = ContextFill;
+  ctx->pub.skip_input_data = ContextSkip;
+  ctx->pub.resync_to_restart = jpeg_resync_to_restart;
+  ctx->pub.term_source = ContextTerm;
+  ctx->pub.bytes_in_buffer = 0;
+  ctx->pub.next_input_byte = NULL;
+}
+
+int ReadJPEG(const uint8_t* const data, size_t data_size,
+             WebPPicture* const pic, int keep_alpha,
+             Metadata* const metadata) {
+  volatile int ok = 0;
+  int width, height;
+  int64_t stride;
+  volatile struct jpeg_decompress_struct dinfo;
+  struct my_error_mgr jerr;
+  uint8_t* volatile rgb = NULL;
+  JSAMPROW buffer[1];
+  JPEGReadContext ctx;
+
+  if (data == NULL || data_size == 0 || pic == NULL) return 0;
+
+  (void)keep_alpha;
+  memset(&ctx, 0, sizeof(ctx));
+  ctx.data = data;
+  ctx.data_size = data_size;
+
+  memset((j_decompress_ptr)&dinfo, 0, sizeof(dinfo));   // for setjmp sanity
+  dinfo.err = jpeg_std_error(&jerr.pub);
+  jerr.pub.error_exit = my_error_exit;
+
+  if (setjmp(jerr.setjmp_buffer)) {
+ Error:
+    MetadataFree(metadata);
+    jpeg_destroy_decompress((j_decompress_ptr)&dinfo);
+    goto End;
+  }
+
+  jpeg_create_decompress((j_decompress_ptr)&dinfo);
+  ContextSetup(&dinfo, &ctx);
+  if (metadata != NULL) SaveMetadataMarkers((j_decompress_ptr)&dinfo);
+  jpeg_read_header((j_decompress_ptr)&dinfo, TRUE);
+
+  dinfo.out_color_space = JCS_RGB;
+  dinfo.do_fancy_upsampling = TRUE;
+
+  jpeg_start_decompress((j_decompress_ptr)&dinfo);
+
+  if (dinfo.output_components != 3) {
+    goto Error;
+  }
+
+  width = dinfo.output_width;
+  height = dinfo.output_height;
+  stride = (int64_t)dinfo.output_width * dinfo.output_components * sizeof(*rgb);
+
+  if (stride != (int)stride ||
+      !ImgIoUtilCheckSizeArgumentsOverflow(stride, height)) {
+    goto End;
+  }
+
+  rgb = (uint8_t*)malloc((size_t)stride * height);
+  if (rgb == NULL) {
+    goto End;
+  }
+  buffer[0] = (JSAMPLE*)rgb;
+
+  while (dinfo.output_scanline < dinfo.output_height) {
+    if (jpeg_read_scanlines((j_decompress_ptr)&dinfo, buffer, 1) != 1) {
+      goto End;
+    }
+    buffer[0] += stride;
+  }
+
+  if (metadata != NULL) {
+    ok = ExtractMetadataFromJPEG((j_decompress_ptr)&dinfo, metadata);
+    if (!ok) {
+      fprintf(stderr, "Error extracting JPEG metadata!\n");
+      goto Error;
+    }
+  }
+
+  jpeg_finish_decompress((j_decompress_ptr)&dinfo);
+  jpeg_destroy_decompress((j_decompress_ptr)&dinfo);
+
+  // WebP conversion.
+  pic->width = width;
+  pic->height = height;
+  ok = WebPPictureImportRGB(pic, rgb, (int)stride);
+  if (!ok) goto Error;
+
+ End:
+  free(rgb);
+  return ok;
+}
+#else  // !WEBP_HAVE_JPEG
+int ReadJPEG(const uint8_t* const data, size_t data_size,
+             struct WebPPicture* const pic, int keep_alpha,
+             struct Metadata* const metadata) {
+  (void)data;
+  (void)data_size;
+  (void)pic;
+  (void)keep_alpha;
+  (void)metadata;
+  fprintf(stderr, "JPEG support not compiled. Please install the libjpeg "
+          "development package before building.\n");
+  return 0;
+}
+#endif  // WEBP_HAVE_JPEG
+
+// -----------------------------------------------------------------------------

imageio/jpegdec.h

@@ -0,0 +1,37 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// JPEG decode.
+
+#ifndef WEBP_IMAGEIO_JPEGDEC_H_
+#define WEBP_IMAGEIO_JPEGDEC_H_
+
+#include "webp/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct Metadata;
+struct WebPPicture;
+
+// Reads a JPEG from 'data', returning the decoded output in 'pic'.
+// The output is RGB or YUV depending on pic->use_argb value.
+// Returns true on success.
+// 'keep_alpha' has no effect, but is kept for coherence with other signatures
+// for image readers.
+int ReadJPEG(const uint8_t* const data, size_t data_size,
+             struct WebPPicture* const pic, int keep_alpha,
+             struct Metadata* const metadata);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_IMAGEIO_JPEGDEC_H_

imageio/metadata.c

@@ -0,0 +1,49 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  Metadata types and functions.
+//
+
+#include "./metadata.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "webp/types.h"
+
+void MetadataInit(Metadata* const metadata) {
+  if (metadata == NULL) return;
+  memset(metadata, 0, sizeof(*metadata));
+}
+
+void MetadataPayloadDelete(MetadataPayload* const payload) {
+  if (payload == NULL) return;
+  free(payload->bytes);
+  payload->bytes = NULL;
+  payload->size = 0;
+}
+
+void MetadataFree(Metadata* const metadata) {
+  if (metadata == NULL) return;
+  MetadataPayloadDelete(&metadata->exif);
+  MetadataPayloadDelete(&metadata->iccp);
+  MetadataPayloadDelete(&metadata->xmp);
+}
+
+int MetadataCopy(const char* metadata, size_t metadata_len,
+                 MetadataPayload* const payload) {
+  if (metadata == NULL || metadata_len == 0 || payload == NULL) return 0;
+  payload->bytes = (uint8_t*)malloc(metadata_len);
+  if (payload->bytes == NULL) return 0;
+  payload->size = metadata_len;
+  memcpy(payload->bytes, metadata, metadata_len);
+  return 1;
+}
+
+// -----------------------------------------------------------------------------

imageio/metadata.h

@@ -0,0 +1,47 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//  Metadata types and functions.
+//
+
+#ifndef WEBP_IMAGEIO_METADATA_H_
+#define WEBP_IMAGEIO_METADATA_H_
+
+#include "webp/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct MetadataPayload {
+  uint8_t* bytes;
+  size_t size;
+} MetadataPayload;
+
+typedef struct Metadata {
+  MetadataPayload exif;
+  MetadataPayload iccp;
+  MetadataPayload xmp;
+} Metadata;
+
+#define METADATA_OFFSET(x) offsetof(Metadata, x)
+
+void MetadataInit(Metadata* const metadata);
+void MetadataPayloadDelete(MetadataPayload* const payload);
+void MetadataFree(Metadata* const metadata);
+
+// Stores 'metadata' to 'payload->bytes', returns false on allocation error.
+int MetadataCopy(const char* metadata, size_t metadata_len,
+                 MetadataPayload* const payload);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_IMAGEIO_METADATA_H_

imageio/pngdec.c

@@ -0,0 +1,331 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// PNG decode.
+
+#include "./pngdec.h"
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#include <stdio.h>
+
+#ifdef WEBP_HAVE_PNG
+#include <png.h>
+#include <setjmp.h>   // note: this must be included *after* png.h
+#include <stdlib.h>
+#include <string.h>
+
+#include "webp/encode.h"
+#include "./imageio_util.h"
+#include "./metadata.h"
+
+static void PNGAPI error_function(png_structp png, png_const_charp error) {
+  if (error != NULL) fprintf(stderr, "libpng error: %s\n", error);
+  longjmp(png_jmpbuf(png), 1);
+}
+
+// Converts the NULL terminated 'hexstring' which contains 2-byte character
+// representations of hex values to raw data.
+// 'hexstring' may contain values consisting of [A-F][a-f][0-9] in pairs,
+// e.g., 7af2..., separated by any number of newlines.
+// 'expected_length' is the anticipated processed size.
+// On success the raw buffer is returned with its length equivalent to
+// 'expected_length'. NULL is returned if the processed length is less than
+// 'expected_length' or any character aside from those above is encountered.
+// The returned buffer must be freed by the caller.
+static uint8_t* HexStringToBytes(const char* hexstring,
+                                 size_t expected_length) {
+  const char* src = hexstring;
+  size_t actual_length = 0;
+  uint8_t* const raw_data = (uint8_t*)malloc(expected_length);
+  uint8_t* dst;
+
+  if (raw_data == NULL) return NULL;
+
+  for (dst = raw_data; actual_length < expected_length && *src != '\0'; ++src) {
+    char* end;
+    char val[3];
+    if (*src == '\n') continue;
+    val[0] = *src++;
+    val[1] = *src;
+    val[2] = '\0';
+    *dst++ = (uint8_t)strtol(val, &end, 16);
+    if (end != val + 2) break;
+    ++actual_length;
+  }
+
+  if (actual_length != expected_length) {
+    free(raw_data);
+    return NULL;
+  }
+  return raw_data;
+}
+
+static int ProcessRawProfile(const char* profile, size_t profile_len,
+                             MetadataPayload* const payload) {
+  const char* src = profile;
+  char* end;
+  int expected_length;
+
+  if (profile == NULL || profile_len == 0) return 0;
+
+  // ImageMagick formats 'raw profiles' as
+  // '\n<name>\n<length>(%8lu)\n<hex payload>\n'.
+  if (*src != '\n') {
+    fprintf(stderr, "Malformed raw profile, expected '\\n' got '\\x%.2X'\n",
+            *src);
+    return 0;
+  }
+  ++src;
+  // skip the profile name and extract the length.
+  while (*src != '\0' && *src++ != '\n') {}
+  expected_length = (int)strtol(src, &end, 10);
+  if (*end != '\n') {
+    fprintf(stderr, "Malformed raw profile, expected '\\n' got '\\x%.2X'\n",
+            *end);
+    return 0;
+  }
+  ++end;
+
+  // 'end' now points to the profile payload.
+  payload->bytes = HexStringToBytes(end, expected_length);
+  if (payload->bytes == NULL) return 0;
+  payload->size = expected_length;
+  return 1;
+}
+
+static const struct {
+  const char* name;
+  int (*process)(const char* profile, size_t profile_len,
+                 MetadataPayload* const payload);
+  size_t storage_offset;
+} kPNGMetadataMap[] = {
+  // http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/PNG.html#TextualData
+  // See also: ExifTool on CPAN.
+  { "Raw profile type exif", ProcessRawProfile, METADATA_OFFSET(exif) },
+  { "Raw profile type xmp",  ProcessRawProfile, METADATA_OFFSET(xmp) },
+  // Exiftool puts exif data in APP1 chunk, too.
+  { "Raw profile type APP1", ProcessRawProfile, METADATA_OFFSET(exif) },
+  // XMP Specification Part 3, Section 3 #PNG
+  { "XML:com.adobe.xmp",     MetadataCopy,      METADATA_OFFSET(xmp) },
+  { NULL, NULL, 0 },
+};
+
+// Looks for metadata at both the beginning and end of the PNG file, giving
+// preference to the head.
+// Returns true on success. The caller must use MetadataFree() on 'metadata' in
+// all cases.
+static int ExtractMetadataFromPNG(png_structp png,
+                                  png_infop const head_info,
+                                  png_infop const end_info,
+                                  Metadata* const metadata) {
+  int p;
+
+  for (p = 0; p < 2; ++p)  {
+    png_infop const info = (p == 0) ? head_info : end_info;
+    png_textp text = NULL;
+    const png_uint_32 num = png_get_text(png, info, &text, NULL);
+    png_uint_32 i;
+    // Look for EXIF / XMP metadata.
+    for (i = 0; i < num; ++i, ++text) {
+      int j;
+      for (j = 0; kPNGMetadataMap[j].name != NULL; ++j) {
+        if (!strcmp(text->key, kPNGMetadataMap[j].name)) {
+          MetadataPayload* const payload =
+              (MetadataPayload*)((uint8_t*)metadata +
+                                 kPNGMetadataMap[j].storage_offset);
+          png_size_t text_length;
+          switch (text->compression) {
+#ifdef PNG_iTXt_SUPPORTED
+            case PNG_ITXT_COMPRESSION_NONE:
+            case PNG_ITXT_COMPRESSION_zTXt:
+              text_length = text->itxt_length;
+              break;
+#endif
+            case PNG_TEXT_COMPRESSION_NONE:
+            case PNG_TEXT_COMPRESSION_zTXt:
+            default:
+              text_length = text->text_length;
+              break;
+          }
+          if (payload->bytes != NULL) {
+            fprintf(stderr, "Ignoring additional '%s'\n", text->key);
+          } else if (!kPNGMetadataMap[j].process(text->text, text_length,
+                                                 payload)) {
+            fprintf(stderr, "Failed to process: '%s'\n", text->key);
+            return 0;
+          }
+          break;
+        }
+      }
+    }
+    // Look for an ICC profile.
+    {
+      png_charp name;
+      int comp_type;
+#if ((PNG_LIBPNG_VER_MAJOR << 8) | PNG_LIBPNG_VER_MINOR << 0) < \
+    ((1 << 8) | (5 << 0))
+      png_charp profile;
+#else  // >= libpng 1.5.0
+      png_bytep profile;
+#endif
+      png_uint_32 len;
+
+      if (png_get_iCCP(png, info,
+                       &name, &comp_type, &profile, &len) == PNG_INFO_iCCP) {
+        if (!MetadataCopy((const char*)profile, len, &metadata->iccp)) return 0;
+      }
+    }
+  }
+
+  return 1;
+}
+
+typedef struct {
+  const uint8_t* data;
+  size_t data_size;
+  png_size_t offset;
+} PNGReadContext;
+
+static void ReadFunc(png_structp png_ptr, png_bytep data, png_size_t length) {
+  PNGReadContext* const ctx = (PNGReadContext*)png_get_io_ptr(png_ptr);
+  if (ctx->data_size - ctx->offset < length) {
+    png_error(png_ptr, "ReadFunc: invalid read length (overflow)!");
+  }
+  memcpy(data, ctx->data + ctx->offset, length);
+  ctx->offset += length;
+}
+
+int ReadPNG(const uint8_t* const data, size_t data_size,
+            struct WebPPicture* const pic,
+            int keep_alpha, struct Metadata* const metadata) {
+  volatile png_structp png = NULL;
+  volatile png_infop info = NULL;
+  volatile png_infop end_info = NULL;
+  PNGReadContext context = { NULL, 0, 0 };
+  int color_type, bit_depth, interlaced;
+  int has_alpha;
+  int num_passes;
+  int p;
+  volatile int ok = 0;
+  png_uint_32 width, height, y;
+  int64_t stride;
+  uint8_t* volatile rgb = NULL;
+
+  if (data == NULL || data_size == 0 || pic == NULL) return 0;
+
+  context.data = data;
+  context.data_size = data_size;
+
+  png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
+  if (png == NULL) goto End;
+
+  png_set_error_fn(png, 0, error_function, NULL);
+  if (setjmp(png_jmpbuf(png))) {
+ Error:
+    MetadataFree(metadata);
+    goto End;
+  }
+
+  info = png_create_info_struct(png);
+  if (info == NULL) goto Error;
+  end_info = png_create_info_struct(png);
+  if (end_info == NULL) goto Error;
+
+  png_set_read_fn(png, &context, ReadFunc);
+  png_read_info(png, info);
+  if (!png_get_IHDR(png, info,
+                    &width, &height, &bit_depth, &color_type, &interlaced,
+                    NULL, NULL)) goto Error;
+
+  png_set_strip_16(png);
+  png_set_packing(png);
+  if (color_type == PNG_COLOR_TYPE_PALETTE) {
+    png_set_palette_to_rgb(png);
+  }
+  if (color_type == PNG_COLOR_TYPE_GRAY ||
+      color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
+    if (bit_depth < 8) {
+      png_set_expand_gray_1_2_4_to_8(png);
+    }
+    png_set_gray_to_rgb(png);
+  }
+  if (png_get_valid(png, info, PNG_INFO_tRNS)) {
+    png_set_tRNS_to_alpha(png);
+    has_alpha = 1;
+  } else {
+    has_alpha = !!(color_type & PNG_COLOR_MASK_ALPHA);
+  }
+
+  if (!keep_alpha) {
+    png_set_strip_alpha(png);
+    has_alpha = 0;
+  }
+
+  num_passes = png_set_interlace_handling(png);
+  png_read_update_info(png, info);
+
+  stride = (int64_t)(has_alpha ? 4 : 3) * width * sizeof(*rgb);
+  if (stride != (int)stride ||
+      !ImgIoUtilCheckSizeArgumentsOverflow(stride, height)) {
+    goto Error;
+  }
+
+  rgb = (uint8_t*)malloc((size_t)stride * height);
+  if (rgb == NULL) goto Error;
+  for (p = 0; p < num_passes; ++p) {
+    png_bytep row = rgb;
+    for (y = 0; y < height; ++y) {
+      png_read_rows(png, &row, NULL, 1);
+      row += stride;
+    }
+  }
+  png_read_end(png, end_info);
+
+  if (metadata != NULL &&
+      !ExtractMetadataFromPNG(png, info, end_info, metadata)) {
+    fprintf(stderr, "Error extracting PNG metadata!\n");
+    goto Error;
+  }
+
+  pic->width = (int)width;
+  pic->height = (int)height;
+  ok = has_alpha ? WebPPictureImportRGBA(pic, rgb, (int)stride)
+                 : WebPPictureImportRGB(pic, rgb, (int)stride);
+
+  if (!ok) {
+    goto Error;
+  }
+
+ End:
+  if (png != NULL) {
+    png_destroy_read_struct((png_structpp)&png,
+                            (png_infopp)&info, (png_infopp)&end_info);
+  }
+  free(rgb);
+  return ok;
+}
+#else  // !WEBP_HAVE_PNG
+int ReadPNG(const uint8_t* const data, size_t data_size,
+            struct WebPPicture* const pic,
+            int keep_alpha, struct Metadata* const metadata) {
+  (void)data;
+  (void)data_size;
+  (void)pic;
+  (void)keep_alpha;
+  (void)metadata;
+  fprintf(stderr, "PNG support not compiled. Please install the libpng "
+          "development package before building.\n");
+  return 0;
+}
+#endif  // WEBP_HAVE_PNG
+
+// -----------------------------------------------------------------------------

imageio/pngdec.h

@@ -0,0 +1,37 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// PNG decode.
+
+#ifndef WEBP_IMAGEIO_PNGDEC_H_
+#define WEBP_IMAGEIO_PNGDEC_H_
+
+#include "webp/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct Metadata;
+struct WebPPicture;
+
+// Reads a PNG from 'data', returning the decoded output in 'pic'.
+// Output is RGBA or YUVA, depending on pic->use_argb value.
+// If 'keep_alpha' is true and the PNG has an alpha channel, the output is RGBA
+// or YUVA. Otherwise, alpha channel is dropped and output is RGB or YUV.
+// Returns true on success.
+int ReadPNG(const uint8_t* const data, size_t data_size,
+            struct WebPPicture* const pic,
+            int keep_alpha, struct Metadata* const metadata);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_IMAGEIO_PNGDEC_H_

imageio/tiffdec.c

@@ -0,0 +1,210 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// TIFF decode.
+
+#include "./tiffdec.h"
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#include <stdio.h>
+#include <string.h>
+
+#ifdef WEBP_HAVE_TIFF
+#include <tiffio.h>
+
+#include "webp/encode.h"
+#include "./imageio_util.h"
+#include "./metadata.h"
+
+static const struct {
+  ttag_t tag;
+  size_t storage_offset;
+} kTIFFMetadataMap[] = {
+  { TIFFTAG_ICCPROFILE, METADATA_OFFSET(iccp) },
+  { TIFFTAG_XMLPACKET,  METADATA_OFFSET(xmp) },
+  { 0, 0 },
+};
+
+// Returns true on success. The caller must use MetadataFree() on 'metadata' in
+// all cases.
+static int ExtractMetadataFromTIFF(TIFF* const tif, Metadata* const metadata) {
+  int i;
+  toff_t exif_ifd_offset;
+
+  for (i = 0; kTIFFMetadataMap[i].tag != 0; ++i) {
+    MetadataPayload* const payload =
+        (MetadataPayload*)((uint8_t*)metadata +
+                           kTIFFMetadataMap[i].storage_offset);
+    void* tag_data;
+    uint32 tag_data_len;
+
+    if (TIFFGetField(tif, kTIFFMetadataMap[i].tag, &tag_data_len, &tag_data) &&
+        !MetadataCopy((const char*)tag_data, tag_data_len, payload)) {
+      return 0;
+    }
+  }
+
+  // TODO(jzern): To extract the raw EXIF directory some parsing of it would be
+  // necessary to determine the overall size. In addition, value offsets in
+  // individual directory entries may need to be updated as, depending on the
+  // type, they are file based.
+  // Exif 2.2 Section 4.6.2 Tag Structure
+  // TIFF Revision 6.0 Part 1 Section 2 TIFF Structure #Image File Directory
+  if (TIFFGetField(tif, TIFFTAG_EXIFIFD, &exif_ifd_offset)) {
+    fprintf(stderr, "Warning: EXIF extraction from TIFF is unsupported.\n");
+  }
+  return 1;
+}
+
+// Ad-hoc structure to supply read-from-memory functionalities.
+typedef struct {
+  const uint8_t* data;
+  toff_t size;
+  toff_t pos;
+} MyData;
+
+static int MyClose(thandle_t opaque) {
+  (void)opaque;
+  return 0;
+}
+
+static toff_t MySize(thandle_t opaque) {
+  const MyData* const my_data = (MyData*)opaque;
+  return my_data->size;
+}
+
+static toff_t MySeek(thandle_t opaque, toff_t offset, int whence) {
+  MyData* const my_data = (MyData*)opaque;
+  offset += (whence == SEEK_CUR) ? my_data->pos
+          : (whence == SEEK_SET) ? 0
+          : my_data->size;
+  if (offset > my_data->size) return (toff_t)-1;
+  my_data->pos = offset;
+  return offset;
+}
+
+static int MyMapFile(thandle_t opaque, void** base, toff_t* size) {
+  (void)opaque;
+  (void)base;
+  (void)size;
+  return 0;
+}
+static void MyUnmapFile(thandle_t opaque, void* base, toff_t size) {
+  (void)opaque;
+  (void)base;
+  (void)size;
+}
+
+static tsize_t MyRead(thandle_t opaque, void* dst, tsize_t size) {
+  MyData* const my_data = (MyData*)opaque;
+  if (my_data->pos + size > my_data->size) {
+    size = my_data->size - my_data->pos;
+  }
+  if (size > 0) {
+    memcpy(dst, my_data->data + my_data->pos, size);
+    my_data->pos += size;
+  }
+  return size;
+}
+
+int ReadTIFF(const uint8_t* const data, size_t data_size,
+             WebPPicture* const pic, int keep_alpha,
+             Metadata* const metadata) {
+  MyData my_data = { data, (toff_t)data_size, 0 };
+  TIFF* tif;
+  uint32 width, height;
+  uint32* raster;
+  int64_t alloc_size;
+  int ok = 0;
+  tdir_t dircount;
+
+  if (data == NULL || data_size == 0 || pic == NULL) return 0;
+
+  tif = TIFFClientOpen("Memory", "r", &my_data,
+                       MyRead, MyRead, MySeek, MyClose,
+                       MySize, MyMapFile, MyUnmapFile);
+  if (tif == NULL) {
+    fprintf(stderr, "Error! Cannot parse TIFF file\n");
+    return 0;
+  }
+
+  dircount = TIFFNumberOfDirectories(tif);
+  if (dircount > 1) {
+    fprintf(stderr, "Warning: multi-directory TIFF files are not supported.\n"
+                    "Only the first will be used, %d will be ignored.\n",
+                    dircount - 1);
+  }
+
+  if (!(TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &width) &&
+        TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &height))) {
+    fprintf(stderr, "Error! Cannot retrieve TIFF image dimensions.\n");
+    goto End;
+  }
+
+  if (!ImgIoUtilCheckSizeArgumentsOverflow((uint64_t)width * height,
+                                           sizeof(*raster))) {
+    goto End;
+  }
+  // _Tiffmalloc uses a signed type for size.
+  alloc_size = (int64_t)((uint64_t)width * height * sizeof(*raster));
+  if (alloc_size < 0 || alloc_size != (tsize_t)alloc_size) goto End;
+
+  raster = (uint32*)_TIFFmalloc((tsize_t)alloc_size);
+  if (raster != NULL) {
+    if (TIFFReadRGBAImageOriented(tif, width, height, raster,
+                                  ORIENTATION_TOPLEFT, 1)) {
+      const int stride = width * sizeof(*raster);
+      pic->width = width;
+      pic->height = height;
+      // TIFF data is ABGR
+#ifdef WORDS_BIGENDIAN
+      TIFFSwabArrayOfLong(raster, width * height);
+#endif
+      ok = keep_alpha
+         ? WebPPictureImportRGBA(pic, (const uint8_t*)raster, stride)
+         : WebPPictureImportRGBX(pic, (const uint8_t*)raster, stride);
+    }
+    _TIFFfree(raster);
+  } else {
+    fprintf(stderr, "Error allocating TIFF RGBA memory!\n");
+  }
+
+  if (ok) {
+    if (metadata != NULL) {
+      ok = ExtractMetadataFromTIFF(tif, metadata);
+      if (!ok) {
+        fprintf(stderr, "Error extracting TIFF metadata!\n");
+        MetadataFree(metadata);
+        WebPPictureFree(pic);
+      }
+    }
+  }
+ End:
+  TIFFClose(tif);
+  return ok;
+}
+#else  // !WEBP_HAVE_TIFF
+int ReadTIFF(const uint8_t* const data, size_t data_size,
+             struct WebPPicture* const pic, int keep_alpha,
+             struct Metadata* const metadata) {
+  (void)data;
+  (void)data_size;
+  (void)pic;
+  (void)keep_alpha;
+  (void)metadata;
+  fprintf(stderr, "TIFF support not compiled. Please install the libtiff "
+          "development package before building.\n");
+  return 0;
+}
+#endif  // WEBP_HAVE_TIFF
+
+// -----------------------------------------------------------------------------

imageio/tiffdec.h

@@ -0,0 +1,37 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// TIFF decode.
+
+#ifndef WEBP_IMAGEIO_TIFFDEC_H_
+#define WEBP_IMAGEIO_TIFFDEC_H_
+
+#include "webp/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct Metadata;
+struct WebPPicture;
+
+// Reads a TIFF from 'data', returning the decoded output in 'pic'.
+// Output is RGBA or YUVA, depending on pic->use_argb value.
+// If 'keep_alpha' is true and the TIFF has an alpha channel, the output is RGBA
+// or YUVA. Otherwise, alpha channel is dropped and output is RGB or YUV.
+// Returns true on success.
+int ReadTIFF(const uint8_t* const data, size_t data_size,
+             struct WebPPicture* const pic, int keep_alpha,
+             struct Metadata* const metadata);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_IMAGEIO_TIFFDEC_H_

imageio/webpdec.c

@@ -0,0 +1,190 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// WebP decode.
+
+#include "./webpdec.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "webp/decode.h"
+#include "webp/encode.h"
+#include "./imageio_util.h"
+#include "./metadata.h"
+
+//------------------------------------------------------------------------------
+// WebP decoding
+
+static const char* const kStatusMessages[VP8_STATUS_NOT_ENOUGH_DATA + 1] = {
+  "OK", "OUT_OF_MEMORY", "INVALID_PARAM", "BITSTREAM_ERROR",
+  "UNSUPPORTED_FEATURE", "SUSPENDED", "USER_ABORT", "NOT_ENOUGH_DATA"
+};
+
+static void PrintAnimationWarning(const WebPDecoderConfig* const config) {
+  if (config->input.has_animation) {
+    fprintf(stderr,
+            "Error! Decoding of an animated WebP file is not supported.\n"
+            "       Use webpmux to extract the individual frames or\n"
+            "       vwebp to view this image.\n");
+  }
+}
+
+void PrintWebPError(const char* const in_file, int status) {
+  fprintf(stderr, "Decoding of %s failed.\n", in_file);
+  fprintf(stderr, "Status: %d", status);
+  if (status >= VP8_STATUS_OK && status <= VP8_STATUS_NOT_ENOUGH_DATA) {
+    fprintf(stderr, "(%s)", kStatusMessages[status]);
+  }
+  fprintf(stderr, "\n");
+}
+
+int LoadWebP(const char* const in_file,
+             const uint8_t** data, size_t* data_size,
+             WebPBitstreamFeatures* bitstream) {
+  VP8StatusCode status;
+  WebPBitstreamFeatures local_features;
+  if (!ImgIoUtilReadFile(in_file, data, data_size)) return 0;
+
+  if (bitstream == NULL) {
+    bitstream = &local_features;
+  }
+
+  status = WebPGetFeatures(*data, *data_size, bitstream);
+  if (status != VP8_STATUS_OK) {
+    free((void*)*data);
+    *data = NULL;
+    *data_size = 0;
+    PrintWebPError(in_file, status);
+    return 0;
+  }
+  return 1;
+}
+
+//------------------------------------------------------------------------------
+
+VP8StatusCode DecodeWebP(const uint8_t* const data, size_t data_size,
+                         WebPDecoderConfig* const config) {
+  if (config == NULL) return VP8_STATUS_INVALID_PARAM;
+  PrintAnimationWarning(config);
+  return WebPDecode(data, data_size, config);
+}
+
+VP8StatusCode DecodeWebPIncremental(
+    const uint8_t* const data, size_t data_size,
+    WebPDecoderConfig* const config) {
+  VP8StatusCode status = VP8_STATUS_OK;
+  if (config == NULL) return VP8_STATUS_INVALID_PARAM;
+
+  PrintAnimationWarning(config);
+
+  // Decoding call.
+  {
+    WebPIDecoder* const idec = WebPIDecode(data, data_size, config);
+    if (idec == NULL) {
+      fprintf(stderr, "Failed during WebPINewDecoder().\n");
+      return VP8_STATUS_OUT_OF_MEMORY;
+    } else {
+#ifdef WEBP_EXPERIMENTAL_FEATURES
+      size_t size = 0;
+      const size_t incr = 2 + (data_size / 20);
+      while (size < data_size) {
+        size_t next_size = size + (rand() % incr);
+        if (next_size > data_size) next_size = data_size;
+        status = WebPIUpdate(idec, data, next_size);
+        if (status != VP8_STATUS_OK && status != VP8_STATUS_SUSPENDED) break;
+        size = next_size;
+      }
+#else
+      status = WebPIUpdate(idec, data, data_size);
+#endif
+      WebPIDelete(idec);
+    }
+  }
+  return status;
+}
+
+// -----------------------------------------------------------------------------
+
+int ReadWebP(const uint8_t* const data, size_t data_size,
+             WebPPicture* const pic,
+             int keep_alpha, Metadata* const metadata) {
+  int ok = 0;
+  VP8StatusCode status = VP8_STATUS_OK;
+  WebPDecoderConfig config;
+  WebPDecBuffer* const output_buffer = &config.output;
+  WebPBitstreamFeatures* const bitstream = &config.input;
+
+  if (data == NULL || data_size == 0 || pic == NULL) return 0;
+
+  // TODO(jzern): add Exif/XMP/ICC extraction.
+  if (metadata != NULL) {
+    fprintf(stderr, "Warning: metadata extraction from WebP is unsupported.\n");
+  }
+
+  if (!WebPInitDecoderConfig(&config)) {
+    fprintf(stderr, "Library version mismatch!\n");
+    return 0;
+  }
+
+  status = WebPGetFeatures(data, data_size, bitstream);
+  if (status != VP8_STATUS_OK) {
+    PrintWebPError("input data", status);
+    return 0;
+  }
+  {
+    const int has_alpha = keep_alpha && bitstream->has_alpha;
+    if (pic->use_argb) {
+      output_buffer->colorspace = has_alpha ? MODE_RGBA : MODE_RGB;
+    } else {
+      output_buffer->colorspace = has_alpha ? MODE_YUVA : MODE_YUV;
+    }
+
+    status = DecodeWebP(data, data_size, &config);
+    if (status == VP8_STATUS_OK) {
+      pic->width = output_buffer->width;
+      pic->height = output_buffer->height;
+      if (pic->use_argb) {
+        const uint8_t* const rgba = output_buffer->u.RGBA.rgba;
+        const int stride = output_buffer->u.RGBA.stride;
+        ok = has_alpha ? WebPPictureImportRGBA(pic, rgba, stride)
+                       : WebPPictureImportRGB(pic, rgba, stride);
+      } else {
+        pic->colorspace = has_alpha ? WEBP_YUV420A : WEBP_YUV420;
+        ok = WebPPictureAlloc(pic);
+        if (!ok) {
+          status = VP8_STATUS_OUT_OF_MEMORY;
+        } else {
+          const WebPYUVABuffer* const yuva = &output_buffer->u.YUVA;
+          const int uv_width = (pic->width + 1) >> 1;
+          const int uv_height = (pic->height + 1) >> 1;
+          ImgIoUtilCopyPlane(yuva->y, yuva->y_stride,
+                             pic->y, pic->y_stride, pic->width, pic->height);
+          ImgIoUtilCopyPlane(yuva->u, yuva->u_stride,
+                             pic->u, pic->uv_stride, uv_width, uv_height);
+          ImgIoUtilCopyPlane(yuva->v, yuva->v_stride,
+                             pic->v, pic->uv_stride, uv_width, uv_height);
+          if (has_alpha) {
+            ImgIoUtilCopyPlane(yuva->a, yuva->a_stride,
+                               pic->a, pic->a_stride, pic->width, pic->height);
+          }
+        }
+      }
+    }
+  }
+
+  if (status != VP8_STATUS_OK) {
+    PrintWebPError("input data", status);
+  }
+
+  WebPFreeDecBuffer(output_buffer);
+  return ok;
+}
+
+// -----------------------------------------------------------------------------

imageio/webpdec.h

@@ -0,0 +1,67 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// WebP decode.
+
+#ifndef WEBP_IMAGEIO_WEBPDEC_H_
+#define WEBP_IMAGEIO_WEBPDEC_H_
+
+#include "webp/decode.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct Metadata;
+struct WebPPicture;
+
+//------------------------------------------------------------------------------
+// WebP decoding
+
+// Prints an informative error message regarding decode failure of 'in_file'.
+// 'status' is treated as a VP8StatusCode and if valid will be printed as a
+// text string.
+void PrintWebPError(const char* const in_file, int status);
+
+// Reads a WebP from 'in_file', returning the contents and size in 'data' and
+// 'data_size'. If not NULL, 'bitstream' is populated using WebPGetFeatures().
+// Returns true on success.
+int LoadWebP(const char* const in_file,
+             const uint8_t** data, size_t* data_size,
+             WebPBitstreamFeatures* bitstream);
+
+// Decodes the WebP contained in 'data'.
+// 'config' is a structure previously initialized by WebPInitDecoderConfig().
+// 'config->output' should have the desired colorspace selected.
+// Returns the decoder status. On success 'config->output' will contain the
+// decoded picture.
+VP8StatusCode DecodeWebP(const uint8_t* const data, size_t data_size,
+                         WebPDecoderConfig* const config);
+
+// Same as DecodeWebP(), but using the incremental decoder.
+VP8StatusCode DecodeWebPIncremental(
+    const uint8_t* const data, size_t data_size,
+    WebPDecoderConfig* const config);
+
+//------------------------------------------------------------------------------
+
+// Reads a WebP from 'in_file', returning the decoded output in 'pic'.
+// Output is RGBA or YUVA, depending on pic->use_argb value.
+// If 'keep_alpha' is true and the WebP has an alpha channel, the output is RGBA
+// or YUVA. Otherwise, alpha channel is dropped and output is RGB or YUV.
+// Returns true on success.
+int ReadWebP(const uint8_t* const data, size_t data_size,
+             struct WebPPicture* const pic,
+             int keep_alpha, struct Metadata* const metadata);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_IMAGEIO_WEBPDEC_H_

imageio/wicdec.c

@@ -0,0 +1,396 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Windows Imaging Component (WIC) decode.
+
+#include "./wicdec.h"
+
+#ifdef HAVE_CONFIG_H
+#include "webp/config.h"
+#endif
+
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifdef HAVE_WINCODEC_H
+#ifdef __MINGW32__
+#define INITGUID  // Without this GUIDs are declared extern and fail to link
+#endif
+#define CINTERFACE
+#define COBJMACROS
+#define _WIN32_IE 0x500  // Workaround bug in shlwapi.h when compiling C++
+                         // code with COBJMACROS.
+#include <ole2.h>  // CreateStreamOnHGlobal()
+#include <shlwapi.h>
+#include <windows.h>
+#include <wincodec.h>
+
+#include "webp/encode.h"
+#include "./imageio_util.h"
+#include "./metadata.h"
+
+#define IFS(fn)                                                     \
+  do {                                                              \
+    if (SUCCEEDED(hr)) {                                            \
+      hr = (fn);                                                    \
+      if (FAILED(hr)) fprintf(stderr, #fn " failed %08lx\n", hr);   \
+    }                                                               \
+  } while (0)
+
+// modified version of DEFINE_GUID from guiddef.h.
+#define WEBP_DEFINE_GUID(name, l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8) \
+  static const GUID name = \
+      { l, w1, w2, { b1, b2,  b3,  b4,  b5,  b6,  b7,  b8 } }
+
+#ifdef __cplusplus
+#define MAKE_REFGUID(x) (x)
+#else
+#define MAKE_REFGUID(x) &(x)
+#endif
+
+typedef struct WICFormatImporter {
+  const GUID* pixel_format;
+  int bytes_per_pixel;
+  int (*import)(WebPPicture* const, const uint8_t* const, int);
+} WICFormatImporter;
+
+// From Microsoft SDK 7.0a -- wincodec.h
+// Create local copies for compatibility when building against earlier
+// versions of the SDK.
+WEBP_DEFINE_GUID(GUID_WICPixelFormat24bppBGR_,
+                 0x6fddc324, 0x4e03, 0x4bfe,
+                 0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0c);
+WEBP_DEFINE_GUID(GUID_WICPixelFormat24bppRGB_,
+                 0x6fddc324, 0x4e03, 0x4bfe,
+                 0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0d);
+WEBP_DEFINE_GUID(GUID_WICPixelFormat32bppBGRA_,
+                 0x6fddc324, 0x4e03, 0x4bfe,
+                 0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x0f);
+WEBP_DEFINE_GUID(GUID_WICPixelFormat32bppRGBA_,
+                 0xf5c7ad2d, 0x6a8d, 0x43dd,
+                 0xa7, 0xa8, 0xa2, 0x99, 0x35, 0x26, 0x1a, 0xe9);
+WEBP_DEFINE_GUID(GUID_WICPixelFormat64bppBGRA_,
+                 0x1562ff7c, 0xd352, 0x46f9,
+                 0x97, 0x9e, 0x42, 0x97, 0x6b, 0x79, 0x22, 0x46);
+WEBP_DEFINE_GUID(GUID_WICPixelFormat64bppRGBA_,
+                 0x6fddc324, 0x4e03, 0x4bfe,
+                 0xb1, 0x85, 0x3d, 0x77, 0x76, 0x8d, 0xc9, 0x16);
+
+static HRESULT OpenInputStream(const char* filename, IStream** stream) {
+  HRESULT hr = S_OK;
+  if (!strcmp(filename, "-")) {
+    const uint8_t* data = NULL;
+    size_t data_size = 0;
+    const int ok = ImgIoUtilReadFile(filename, &data, &data_size);
+    if (ok) {
+      HGLOBAL image = GlobalAlloc(GMEM_MOVEABLE, data_size);
+      if (image != NULL) {
+        void* const image_mem = GlobalLock(image);
+        if (image_mem != NULL) {
+          memcpy(image_mem, data, data_size);
+          GlobalUnlock(image);
+          IFS(CreateStreamOnHGlobal(image, TRUE, stream));
+        } else {
+          hr = E_FAIL;
+        }
+      } else {
+        hr = E_OUTOFMEMORY;
+      }
+      free((void*)data);
+    } else {
+      hr = E_FAIL;
+    }
+  } else {
+    IFS(SHCreateStreamOnFileA(filename, STGM_READ, stream));
+  }
+
+  if (FAILED(hr)) {
+    fprintf(stderr, "Error opening input file %s (%08lx)\n", filename, hr);
+  }
+  return hr;
+}
+
+// -----------------------------------------------------------------------------
+// Metadata processing
+
+// Stores the first non-zero sized color profile from 'frame' to 'iccp'.
+// Returns an HRESULT to indicate success or failure. The caller is responsible
+// for freeing 'iccp->bytes' in either case.
+static HRESULT ExtractICCP(IWICImagingFactory* const factory,
+                           IWICBitmapFrameDecode* const frame,
+                           MetadataPayload* const iccp) {
+  HRESULT hr = S_OK;
+  UINT i, count;
+  IWICColorContext** color_contexts;
+
+  IFS(IWICBitmapFrameDecode_GetColorContexts(frame, 0, NULL, &count));
+  if (FAILED(hr) || count == 0) return hr;
+
+  color_contexts = (IWICColorContext**)calloc(count, sizeof(*color_contexts));
+  if (color_contexts == NULL) return E_OUTOFMEMORY;
+  for (i = 0; SUCCEEDED(hr) && i < count; ++i) {
+    IFS(IWICImagingFactory_CreateColorContext(factory, &color_contexts[i]));
+  }
+
+  if (SUCCEEDED(hr)) {
+    UINT num_color_contexts;
+    IFS(IWICBitmapFrameDecode_GetColorContexts(frame,
+                                               count, color_contexts,
+                                               &num_color_contexts));
+    assert(FAILED(hr) || num_color_contexts <= count);
+    for (i = 0; SUCCEEDED(hr) && i < num_color_contexts; ++i) {
+      WICColorContextType type;
+      IFS(IWICColorContext_GetType(color_contexts[i], &type));
+      if (SUCCEEDED(hr) && type == WICColorContextProfile) {
+        UINT size;
+        IFS(IWICColorContext_GetProfileBytes(color_contexts[i],
+                                             0, NULL, &size));
+        if (SUCCEEDED(hr) && size > 0) {
+          iccp->bytes = (uint8_t*)malloc(size);
+          if (iccp->bytes == NULL) {
+            hr = E_OUTOFMEMORY;
+            break;
+          }
+          iccp->size = size;
+          IFS(IWICColorContext_GetProfileBytes(color_contexts[i],
+                                               (UINT)iccp->size, iccp->bytes,
+                                               &size));
+          if (SUCCEEDED(hr) && size != iccp->size) {
+            fprintf(stderr, "Warning! ICC profile size (%u) != expected (%u)\n",
+                    size, (uint32_t)iccp->size);
+            iccp->size = size;
+          }
+          break;
+        }
+      }
+    }
+  }
+  for (i = 0; i < count; ++i) {
+    if (color_contexts[i] != NULL) IUnknown_Release(color_contexts[i]);
+  }
+  free(color_contexts);
+  return hr;
+}
+
+static HRESULT ExtractMetadata(IWICImagingFactory* const factory,
+                               IWICBitmapFrameDecode* const frame,
+                               Metadata* const metadata) {
+  // TODO(jzern): add XMP/EXIF extraction.
+  const HRESULT hr = ExtractICCP(factory, frame, &metadata->iccp);
+  if (FAILED(hr)) MetadataFree(metadata);
+  return hr;
+}
+
+// -----------------------------------------------------------------------------
+
+static int HasPalette(GUID pixel_format) {
+  return (IsEqualGUID(MAKE_REFGUID(pixel_format),
+                      MAKE_REFGUID(GUID_WICPixelFormat1bppIndexed)) ||
+          IsEqualGUID(MAKE_REFGUID(pixel_format),
+                      MAKE_REFGUID(GUID_WICPixelFormat2bppIndexed)) ||
+          IsEqualGUID(MAKE_REFGUID(pixel_format),
+                      MAKE_REFGUID(GUID_WICPixelFormat4bppIndexed)) ||
+          IsEqualGUID(MAKE_REFGUID(pixel_format),
+                      MAKE_REFGUID(GUID_WICPixelFormat8bppIndexed)));
+}
+
+static int HasAlpha(IWICImagingFactory* const factory,
+                    IWICBitmapDecoder* const decoder,
+                    IWICBitmapFrameDecode* const frame,
+                    GUID pixel_format) {
+  int has_alpha;
+  if (HasPalette(pixel_format)) {
+    IWICPalette* frame_palette = NULL;
+    IWICPalette* global_palette = NULL;
+    BOOL frame_palette_has_alpha = FALSE;
+    BOOL global_palette_has_alpha = FALSE;
+
+    // A palette may exist at the frame or container level,
+    // check IWICPalette::HasAlpha() for both if present.
+    if (SUCCEEDED(IWICImagingFactory_CreatePalette(factory, &frame_palette)) &&
+        SUCCEEDED(IWICBitmapFrameDecode_CopyPalette(frame, frame_palette))) {
+      IWICPalette_HasAlpha(frame_palette, &frame_palette_has_alpha);
+    }
+    if (SUCCEEDED(IWICImagingFactory_CreatePalette(factory, &global_palette)) &&
+        SUCCEEDED(IWICBitmapDecoder_CopyPalette(decoder, global_palette))) {
+      IWICPalette_HasAlpha(global_palette, &global_palette_has_alpha);
+    }
+    has_alpha = frame_palette_has_alpha || global_palette_has_alpha;
+
+    if (frame_palette != NULL) IUnknown_Release(frame_palette);
+    if (global_palette != NULL) IUnknown_Release(global_palette);
+  } else {
+    has_alpha = IsEqualGUID(MAKE_REFGUID(pixel_format),
+                            MAKE_REFGUID(GUID_WICPixelFormat32bppRGBA_)) ||
+                IsEqualGUID(MAKE_REFGUID(pixel_format),
+                            MAKE_REFGUID(GUID_WICPixelFormat32bppBGRA_)) ||
+                IsEqualGUID(MAKE_REFGUID(pixel_format),
+                            MAKE_REFGUID(GUID_WICPixelFormat64bppRGBA_)) ||
+                IsEqualGUID(MAKE_REFGUID(pixel_format),
+                            MAKE_REFGUID(GUID_WICPixelFormat64bppBGRA_));
+  }
+  return has_alpha;
+}
+
+int ReadPictureWithWIC(const char* const filename,
+                       WebPPicture* const pic, int keep_alpha,
+                       Metadata* const metadata) {
+  // From Microsoft SDK 6.0a -- ks.h
+  // Define a local copy to avoid link errors under mingw.
+  WEBP_DEFINE_GUID(GUID_NULL_, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
+  static const WICFormatImporter kAlphaFormatImporters[] = {
+    { &GUID_WICPixelFormat32bppBGRA_, 4, WebPPictureImportBGRA },
+    { &GUID_WICPixelFormat32bppRGBA_, 4, WebPPictureImportRGBA },
+    { NULL, 0, NULL },
+  };
+  static const WICFormatImporter kNonAlphaFormatImporters[] = {
+    { &GUID_WICPixelFormat24bppBGR_, 3, WebPPictureImportBGR },
+    { &GUID_WICPixelFormat24bppRGB_, 3, WebPPictureImportRGB },
+    { NULL, 0, NULL },
+  };
+  HRESULT hr = S_OK;
+  IWICBitmapFrameDecode* frame = NULL;
+  IWICFormatConverter* converter = NULL;
+  IWICImagingFactory* factory = NULL;
+  IWICBitmapDecoder* decoder = NULL;
+  IStream* stream = NULL;
+  UINT frame_count = 0;
+  UINT width = 0, height = 0;
+  BYTE* rgb = NULL;
+  WICPixelFormatGUID src_pixel_format = GUID_WICPixelFormatUndefined;
+  const WICFormatImporter* importer = NULL;
+  GUID src_container_format = GUID_NULL_;
+  static const GUID* kAlphaContainers[] = {
+    &GUID_ContainerFormatBmp,
+    &GUID_ContainerFormatPng,
+    &GUID_ContainerFormatTiff,
+    NULL
+  };
+  int has_alpha = 0;
+  int64_t stride;
+
+  if (filename == NULL || pic == NULL) return 0;
+
+  IFS(CoInitialize(NULL));
+  IFS(CoCreateInstance(MAKE_REFGUID(CLSID_WICImagingFactory), NULL,
+                       CLSCTX_INPROC_SERVER,
+                       MAKE_REFGUID(IID_IWICImagingFactory),
+                       (LPVOID*)&factory));
+  if (hr == REGDB_E_CLASSNOTREG) {
+    fprintf(stderr,
+            "Couldn't access Windows Imaging Component (are you running "
+            "Windows XP SP3 or newer?). Most formats not available. "
+            "Use -s for the available YUV input.\n");
+  }
+  // Prepare for image decoding.
+  IFS(OpenInputStream(filename, &stream));
+  IFS(IWICImagingFactory_CreateDecoderFromStream(
+          factory, stream, NULL,
+          WICDecodeMetadataCacheOnDemand, &decoder));
+  IFS(IWICBitmapDecoder_GetFrameCount(decoder, &frame_count));
+  if (SUCCEEDED(hr) && frame_count == 0) {
+    fprintf(stderr, "No frame found in input file.\n");
+    hr = E_FAIL;
+  }
+  IFS(IWICBitmapDecoder_GetFrame(decoder, 0, &frame));
+  IFS(IWICBitmapFrameDecode_GetPixelFormat(frame, &src_pixel_format));
+  IFS(IWICBitmapDecoder_GetContainerFormat(decoder, &src_container_format));
+
+  if (SUCCEEDED(hr) && keep_alpha) {
+    const GUID** guid;
+    for (guid = kAlphaContainers; *guid != NULL; ++guid) {
+      if (IsEqualGUID(MAKE_REFGUID(src_container_format),
+                      MAKE_REFGUID(**guid))) {
+        has_alpha = HasAlpha(factory, decoder, frame, src_pixel_format);
+        break;
+      }
+    }
+  }
+
+  // Prepare for pixel format conversion (if necessary).
+  IFS(IWICImagingFactory_CreateFormatConverter(factory, &converter));
+
+  for (importer = has_alpha ? kAlphaFormatImporters : kNonAlphaFormatImporters;
+       hr == S_OK && importer->import != NULL; ++importer) {
+    BOOL can_convert;
+    const HRESULT cchr = IWICFormatConverter_CanConvert(
+        converter,
+        MAKE_REFGUID(src_pixel_format),
+        MAKE_REFGUID(*importer->pixel_format),
+        &can_convert);
+    if (SUCCEEDED(cchr) && can_convert) break;
+  }
+  if (importer->import == NULL) hr = E_FAIL;
+
+  IFS(IWICFormatConverter_Initialize(converter, (IWICBitmapSource*)frame,
+                                     importer->pixel_format,
+                                     WICBitmapDitherTypeNone,
+                                     NULL, 0.0, WICBitmapPaletteTypeCustom));
+
+  // Decode.
+  IFS(IWICFormatConverter_GetSize(converter, &width, &height));
+  stride = (int64_t)importer->bytes_per_pixel * width * sizeof(*rgb);
+  if (stride != (int)stride ||
+      !ImgIoUtilCheckSizeArgumentsOverflow(stride, height)) {
+    hr = E_FAIL;
+  }
+
+  if (SUCCEEDED(hr)) {
+    rgb = (BYTE*)malloc((size_t)stride * height);
+    if (rgb == NULL)
+      hr = E_OUTOFMEMORY;
+  }
+  IFS(IWICFormatConverter_CopyPixels(converter, NULL,
+                                     (UINT)stride, (UINT)stride * height, rgb));
+
+  // WebP conversion.
+  if (SUCCEEDED(hr)) {
+    int ok;
+    pic->width = width;
+    pic->height = height;
+    pic->use_argb = 1;    // For WIC, we always force to argb
+    ok = importer->import(pic, rgb, (int)stride);
+    if (!ok) hr = E_FAIL;
+  }
+  if (SUCCEEDED(hr)) {
+    if (metadata != NULL) {
+      hr = ExtractMetadata(factory, frame, metadata);
+      if (FAILED(hr)) {
+        fprintf(stderr, "Error extracting image metadata using WIC!\n");
+      }
+    }
+  }
+
+  // Cleanup.
+  if (converter != NULL) IUnknown_Release(converter);
+  if (frame != NULL) IUnknown_Release(frame);
+  if (decoder != NULL) IUnknown_Release(decoder);
+  if (factory != NULL) IUnknown_Release(factory);
+  if (stream != NULL) IUnknown_Release(stream);
+  free(rgb);
+  return SUCCEEDED(hr);
+}
+#else  // !HAVE_WINCODEC_H
+int ReadPictureWithWIC(const char* const filename,
+                       struct WebPPicture* const pic, int keep_alpha,
+                       struct Metadata* const metadata) {
+  (void)filename;
+  (void)pic;
+  (void)keep_alpha;
+  (void)metadata;
+  fprintf(stderr, "Windows Imaging Component (WIC) support not compiled. "
+                  "Visual Studio and mingw-w64 builds support WIC. Make sure "
+                  "wincodec.h detection is working correctly if using autoconf "
+                  "and HAVE_WINCODEC_H is defined before building.\n");
+  return 0;
+}
+#endif  // HAVE_WINCODEC_H
+
+// -----------------------------------------------------------------------------

imageio/wicdec.h

@@ -0,0 +1,34 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Windows Imaging Component (WIC) decode.
+
+#ifndef WEBP_IMAGEIO_WICDEC_H_
+#define WEBP_IMAGEIO_WICDEC_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct Metadata;
+struct WebPPicture;
+
+// Reads an image from 'filename', returning the decoded output in 'pic'.
+// If 'keep_alpha' is true and the image has an alpha channel, the output is
+// RGBA otherwise it will be RGB. pic->use_argb is always forced to true.
+// Returns true on success.
+int ReadPictureWithWIC(const char* const filename,
+                       struct WebPPicture* const pic, int keep_alpha,
+                       struct Metadata* const metadata);
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  // WEBP_IMAGEIO_WICDEC_H_

iosbuild.sh

@@ -0,0 +1,129 @@
+#!/bin/bash
+#
+# This script generates 'WebP.framework' and 'WebPDecoder.framework'. An iOS
+# app can decode WebP images by including 'WebPDecoder.framework' and both
+# encode and decode WebP images by including 'WebP.framework'.
+#
+# Run ./iosbuild.sh to generate the frameworks under the current directory
+# (the previous build will be erased if it exists).
+#
+# This script is inspired by the build script written by Carson McDonald.
+# (http://www.ioncannon.net/programming/1483/using-webp-to-reduce-native-ios-app-size/).
+
+set -e
+
+# Extract the latest SDK version from the final field of the form: iphoneosX.Y
+readonly SDK=$(xcodebuild -showsdks \
+  | grep iphoneos | sort | tail -n 1 | awk '{print substr($NF, 9)}'
+)
+# Extract Xcode version.
+readonly XCODE=$(xcodebuild -version | grep Xcode | cut -d " " -f2)
+if [[ -z "${XCODE}" ]]; then
+  echo "Xcode not available"
+  exit 1
+fi
+
+readonly OLDPATH=${PATH}
+
+# Add iPhoneOS-V6 to the list of platforms below if you need armv6 support.
+# Note that iPhoneOS-V6 support is not available with the iOS6 SDK.
+PLATFORMS="iPhoneSimulator iPhoneSimulator64"
+PLATFORMS+=" iPhoneOS-V7 iPhoneOS-V7s iPhoneOS-V7-arm64"
+readonly PLATFORMS
+readonly SRCDIR=$(dirname $0)
+readonly TOPDIR=$(pwd)
+readonly BUILDDIR="${TOPDIR}/iosbuild"
+readonly TARGETDIR="${TOPDIR}/WebP.framework"
+readonly DECTARGETDIR="${TOPDIR}/WebPDecoder.framework"
+readonly DEVELOPER=$(xcode-select --print-path)
+readonly PLATFORMSROOT="${DEVELOPER}/Platforms"
+readonly LIPO=$(xcrun -sdk iphoneos${SDK} -find lipo)
+LIBLIST=''
+DECLIBLIST=''
+
+if [[ -z "${SDK}" ]]; then
+  echo "iOS SDK not available"
+  exit 1
+elif [[ ${SDK%%.*} -gt 8 ]]; then
+  EXTRA_CFLAGS="-fembed-bitcode"
+elif [[ ${SDK} < 6.0 ]]; then
+  echo "You need iOS SDK version 6.0 or above"
+  exit 1
+else
+  echo "iOS SDK Version ${SDK}"
+fi
+
+rm -rf ${BUILDDIR} ${TARGETDIR} ${DECTARGETDIR}
+mkdir -p ${BUILDDIR} ${TARGETDIR}/Headers/ ${DECTARGETDIR}/Headers/
+
+if [[ ! -e ${SRCDIR}/configure ]]; then
+  if ! (cd ${SRCDIR} && sh autogen.sh); then
+    cat <<EOT
+Error creating configure script!
+This script requires the autoconf/automake and libtool to build. MacPorts can
+be used to obtain these:
+http://www.macports.org/install.php
+EOT
+    exit 1
+  fi
+fi
+
+for PLATFORM in ${PLATFORMS}; do
+  ARCH2=""
+  if [[ "${PLATFORM}" == "iPhoneOS-V7-arm64" ]]; then
+    PLATFORM="iPhoneOS"
+    ARCH="aarch64"
+    ARCH2="arm64"
+  elif [[ "${PLATFORM}" == "iPhoneOS-V7s" ]]; then
+    PLATFORM="iPhoneOS"
+    ARCH="armv7s"
+  elif [[ "${PLATFORM}" == "iPhoneOS-V7" ]]; then
+    PLATFORM="iPhoneOS"
+    ARCH="armv7"
+  elif [[ "${PLATFORM}" == "iPhoneOS-V6" ]]; then
+    PLATFORM="iPhoneOS"
+    ARCH="armv6"
+  elif [[ "${PLATFORM}" == "iPhoneSimulator64" ]]; then
+    PLATFORM="iPhoneSimulator"
+    ARCH="x86_64"
+  else
+    ARCH="i386"
+  fi
+
+  ROOTDIR="${BUILDDIR}/${PLATFORM}-${SDK}-${ARCH}"
+  mkdir -p "${ROOTDIR}"
+
+  DEVROOT="${DEVELOPER}/Toolchains/XcodeDefault.xctoolchain"
+  SDKROOT="${PLATFORMSROOT}/"
+  SDKROOT+="${PLATFORM}.platform/Developer/SDKs/${PLATFORM}${SDK}.sdk/"
+  CFLAGS="-arch ${ARCH2:-${ARCH}} -pipe -isysroot ${SDKROOT} -O3 -DNDEBUG"
+  CFLAGS+=" -miphoneos-version-min=6.0 ${EXTRA_CFLAGS}"
+
+  set -x
+  export PATH="${DEVROOT}/usr/bin:${OLDPATH}"
+  ${SRCDIR}/configure --host=${ARCH}-apple-darwin --prefix=${ROOTDIR} \
+    --build=$(${SRCDIR}/config.guess) \
+    --disable-shared --enable-static \
+    --enable-libwebpdecoder --enable-swap-16bit-csp \
+    CFLAGS="${CFLAGS}"
+  set +x
+
+  # run make only in the src/ directory to create libwebp.a/libwebpdecoder.a
+  cd src/
+  make V=0
+  make install
+
+  LIBLIST+=" ${ROOTDIR}/lib/libwebp.a"
+  DECLIBLIST+=" ${ROOTDIR}/lib/libwebpdecoder.a"
+
+  make clean
+  cd ..
+
+  export PATH=${OLDPATH}
+done
+
+cp -a ${SRCDIR}/src/webp/{decode,encode,types}.h ${TARGETDIR}/Headers/
+${LIPO} -create ${LIBLIST} -output ${TARGETDIR}/WebP
+
+cp -a ${SRCDIR}/src/webp/{decode,types}.h ${DECTARGETDIR}/Headers/
+${LIPO} -create ${DECLIBLIST} -output ${DECTARGETDIR}/WebPDecoder

m4/ax_pthread.m4

@@ -0,0 +1,332 @@
+# ===========================================================================
+#        http://www.gnu.org/software/autoconf-archive/ax_pthread.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
+#
+# DESCRIPTION
+#
+#   This macro figures out how to build C programs using POSIX threads. It
+#   sets the PTHREAD_LIBS output variable to the threads library and linker
+#   flags, and the PTHREAD_CFLAGS output variable to any special C compiler
+#   flags that are needed. (The user can also force certain compiler
+#   flags/libs to be tested by setting these environment variables.)
+#
+#   Also sets PTHREAD_CC to any special C compiler that is needed for
+#   multi-threaded programs (defaults to the value of CC otherwise). (This
+#   is necessary on AIX to use the special cc_r compiler alias.)
+#
+#   NOTE: You are assumed to not only compile your program with these flags,
+#   but also link it with them as well. e.g. you should link with
+#   $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS
+#
+#   If you are only building threads programs, you may wish to use these
+#   variables in your default LIBS, CFLAGS, and CC:
+#
+#     LIBS="$PTHREAD_LIBS $LIBS"
+#     CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+#     CC="$PTHREAD_CC"
+#
+#   In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant
+#   has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to that name
+#   (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
+#
+#   Also HAVE_PTHREAD_PRIO_INHERIT is defined if pthread is found and the
+#   PTHREAD_PRIO_INHERIT symbol is defined when compiling with
+#   PTHREAD_CFLAGS.
+#
+#   ACTION-IF-FOUND is a list of shell commands to run if a threads library
+#   is found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it
+#   is not found. If ACTION-IF-FOUND is not specified, the default action
+#   will define HAVE_PTHREAD.
+#
+#   Please let the authors know if this macro fails on any platform, or if
+#   you have any other suggestions or comments. This macro was based on work
+#   by SGJ on autoconf scripts for FFTW (http://www.fftw.org/) (with help
+#   from M. Frigo), as well as ac_pthread and hb_pthread macros posted by
+#   Alejandro Forero Cuervo to the autoconf macro repository. We are also
+#   grateful for the helpful feedback of numerous users.
+#
+#   Updated for Autoconf 2.68 by Daniel Richard G.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
+#   Copyright (c) 2011 Daniel Richard G. <skunk@iSKUNK.ORG>
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 21
+
+AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
+AC_DEFUN([AX_PTHREAD], [
+AC_REQUIRE([AC_CANONICAL_HOST])
+AC_LANG_PUSH([C])
+ax_pthread_ok=no
+
+# We used to check for pthread.h first, but this fails if pthread.h
+# requires special compiler flags (e.g. on True64 or Sequent).
+# It gets checked for in the link test anyway.
+
+# First of all, check if the user has set any of the PTHREAD_LIBS,
+# etcetera environment variables, and if threads linking works using
+# them:
+if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
+        AC_TRY_LINK_FUNC([pthread_join], [ax_pthread_ok=yes])
+        AC_MSG_RESULT([$ax_pthread_ok])
+        if test x"$ax_pthread_ok" = xno; then
+                PTHREAD_LIBS=""
+                PTHREAD_CFLAGS=""
+        fi
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+fi
+
+# We must check for the threads library under a number of different
+# names; the ordering is very important because some systems
+# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
+# libraries is broken (non-POSIX).
+
+# Create a list of thread flags to try.  Items starting with a "-" are
+# C compiler flags, and other items are library names, except for "none"
+# which indicates that we try without any flags at all, and "pthread-config"
+# which is a program returning the flags for the Pth emulation library.
+
+ax_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
+
+# The ordering *is* (sometimes) important.  Some notes on the
+# individual items follow:
+
+# pthreads: AIX (must check this before -lpthread)
+# none: in case threads are in libc; should be tried before -Kthread and
+#       other compiler flags to prevent continual compiler warnings
+# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
+# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
+# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
+# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
+# -pthreads: Solaris/gcc
+# -mthreads: Mingw32/gcc, Lynx/gcc
+# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
+#      doesn't hurt to check since this sometimes defines pthreads too;
+#      also defines -D_REENTRANT)
+#      ... -mt is also the pthreads flag for HP/aCC
+# pthread: Linux, etcetera
+# --thread-safe: KAI C++
+# pthread-config: use pthread-config program (for GNU Pth library)
+
+case ${host_os} in
+        solaris*)
+
+        # On Solaris (at least, for some versions), libc contains stubbed
+        # (non-functional) versions of the pthreads routines, so link-based
+        # tests will erroneously succeed.  (We need to link with -pthreads/-mt/
+        # -lpthread.)  (The stubs are missing pthread_cleanup_push, or rather
+        # a function called by this macro, so we could check for that, but
+        # who knows whether they'll stub that too in a future libc.)  So,
+        # we'll just look for -pthreads and -lpthread first:
+
+        ax_pthread_flags="-pthreads pthread -mt -pthread $ax_pthread_flags"
+        ;;
+
+        darwin*)
+        ax_pthread_flags="-pthread $ax_pthread_flags"
+        ;;
+esac
+
+# Clang doesn't consider unrecognized options an error unless we specify
+# -Werror. We throw in some extra Clang-specific options to ensure that
+# this doesn't happen for GCC, which also accepts -Werror.
+
+AC_MSG_CHECKING([if compiler needs -Werror to reject unknown flags])
+save_CFLAGS="$CFLAGS"
+ax_pthread_extra_flags="-Werror"
+CFLAGS="$CFLAGS $ax_pthread_extra_flags -Wunknown-warning-option -Wsizeof-array-argument"
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([int foo(void);],[foo()])],
+                  [AC_MSG_RESULT([yes])],
+                  [ax_pthread_extra_flags=
+                   AC_MSG_RESULT([no])])
+CFLAGS="$save_CFLAGS"
+
+if test x"$ax_pthread_ok" = xno; then
+for flag in $ax_pthread_flags; do
+
+        case $flag in
+                none)
+                AC_MSG_CHECKING([whether pthreads work without any flags])
+                ;;
+
+                -*)
+                AC_MSG_CHECKING([whether pthreads work with $flag])
+                PTHREAD_CFLAGS="$flag"
+                ;;
+
+                pthread-config)
+                AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no])
+                if test x"$ax_pthread_config" = xno; then continue; fi
+                PTHREAD_CFLAGS="`pthread-config --cflags`"
+                PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
+                ;;
+
+                *)
+                AC_MSG_CHECKING([for the pthreads library -l$flag])
+                PTHREAD_LIBS="-l$flag"
+                ;;
+        esac
+
+        save_LIBS="$LIBS"
+        save_CFLAGS="$CFLAGS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS $ax_pthread_extra_flags"
+
+        # Check for various functions.  We must include pthread.h,
+        # since some functions may be macros.  (On the Sequent, we
+        # need a special flag -Kthread to make this header compile.)
+        # We check for pthread_join because it is in -lpthread on IRIX
+        # while pthread_create is in libc.  We check for pthread_attr_init
+        # due to DEC craziness with -lpthreads.  We check for
+        # pthread_cleanup_push because it is one of the few pthread
+        # functions on Solaris that doesn't have a non-functional libc stub.
+        # We try pthread_create on general principles.
+        AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>
+                        static void routine(void *a) { a = 0; }
+                        static void *start_routine(void *a) { return a; }],
+                       [pthread_t th; pthread_attr_t attr;
+                        pthread_create(&th, 0, start_routine, 0);
+                        pthread_join(th, 0);
+                        pthread_attr_init(&attr);
+                        pthread_cleanup_push(routine, 0);
+                        pthread_cleanup_pop(0) /* ; */])],
+                [ax_pthread_ok=yes],
+                [])
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        AC_MSG_RESULT([$ax_pthread_ok])
+        if test "x$ax_pthread_ok" = xyes; then
+                break;
+        fi
+
+        PTHREAD_LIBS=""
+        PTHREAD_CFLAGS=""
+done
+fi
+
+# Various other checks:
+if test "x$ax_pthread_ok" = xyes; then
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+
+        # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
+        AC_MSG_CHECKING([for joinable pthread attribute])
+        attr_name=unknown
+        for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
+            AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>],
+                           [int attr = $attr; return attr /* ; */])],
+                [attr_name=$attr; break],
+                [])
+        done
+        AC_MSG_RESULT([$attr_name])
+        if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
+            AC_DEFINE_UNQUOTED([PTHREAD_CREATE_JOINABLE], [$attr_name],
+                               [Define to necessary symbol if this constant
+                                uses a non-standard name on your system.])
+        fi
+
+        AC_MSG_CHECKING([if more special flags are required for pthreads])
+        flag=no
+        case ${host_os} in
+            aix* | freebsd* | darwin*) flag="-D_THREAD_SAFE";;
+            osf* | hpux*) flag="-D_REENTRANT";;
+            solaris*)
+            if test "$GCC" = "yes"; then
+                flag="-D_REENTRANT"
+            else
+                # TODO: What about Clang on Solaris?
+                flag="-mt -D_REENTRANT"
+            fi
+            ;;
+        esac
+        AC_MSG_RESULT([$flag])
+        if test "x$flag" != xno; then
+            PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
+        fi
+
+        AC_CACHE_CHECK([for PTHREAD_PRIO_INHERIT],
+            [ax_cv_PTHREAD_PRIO_INHERIT], [
+                AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <pthread.h>]],
+                                                [[int i = PTHREAD_PRIO_INHERIT;]])],
+                    [ax_cv_PTHREAD_PRIO_INHERIT=yes],
+                    [ax_cv_PTHREAD_PRIO_INHERIT=no])
+            ])
+        AS_IF([test "x$ax_cv_PTHREAD_PRIO_INHERIT" = "xyes"],
+            [AC_DEFINE([HAVE_PTHREAD_PRIO_INHERIT], [1], [Have PTHREAD_PRIO_INHERIT.])])
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        # More AIX lossage: compile with *_r variant
+        if test "x$GCC" != xyes; then
+            case $host_os in
+                aix*)
+                AS_CASE(["x/$CC"],
+                  [x*/c89|x*/c89_128|x*/c99|x*/c99_128|x*/cc|x*/cc128|x*/xlc|x*/xlc_v6|x*/xlc128|x*/xlc128_v6],
+                  [#handle absolute path differently from PATH based program lookup
+                   AS_CASE(["x$CC"],
+                     [x/*],
+                     [AS_IF([AS_EXECUTABLE_P([${CC}_r])],[PTHREAD_CC="${CC}_r"])],
+                     [AC_CHECK_PROGS([PTHREAD_CC],[${CC}_r],[$CC])])])
+                ;;
+            esac
+        fi
+fi
+
+test -n "$PTHREAD_CC" || PTHREAD_CC="$CC"
+
+AC_SUBST([PTHREAD_LIBS])
+AC_SUBST([PTHREAD_CFLAGS])
+AC_SUBST([PTHREAD_CC])
+
+# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
+if test x"$ax_pthread_ok" = xyes; then
+        ifelse([$1],,[AC_DEFINE([HAVE_PTHREAD],[1],[Define if you have POSIX threads libraries and header files.])],[$1])
+        :
+else
+        ax_pthread_ok=no
+        $2
+fi
+AC_LANG_POP
+])dnl AX_PTHREAD

makefile.unix

@@ -2,7 +2,8 @@
 # system, for simple local building of the libraries and tools.
 # It will not install the libraries system-wide, but just create the 'cwebp'
 # and 'dwebp' tools in the examples/ directory, along with the static
-# library 'src/libwebp.a'.
+# libraries 'src/libwebp.a', 'src/libwebpdecoder.a', 'src/mux/libwebpmux.a',
+# 'src/demux/libwebpdemux.a' and 'extras/libwebpextras.a'.
 #
 # To build the library and examples, use:
 #    make -f makefile.unix
@@ -10,79 +11,450 @@
 
 #### Customizable part ####
 
-# These flag assume you have libpng and libjpeg installed. If not, either
-# follow below install instructions or just comment out the next lines.
-EXTRA_FLAGS= -DWEBP_HAVE_PNG -DWEBP_HAVE_JPEG
-EXTRA_LIBS= -lpng -ljpeg
-ifeq ("$(HOSTTYPE)", "intel-mac")
+# These flags assume you have libpng, libjpeg, libtiff and libgif installed. If
+# not, either follow the install instructions below or just comment out the next
+# four lines.
+EXTRA_FLAGS= -DWEBP_HAVE_PNG -DWEBP_HAVE_JPEG -DWEBP_HAVE_TIFF
+DWEBP_LIBS= -lpng -lz
+CWEBP_LIBS= $(DWEBP_LIBS) -ljpeg -ltiff
+GIF_LIBS = -lgif
+
+ifeq ($(strip $(shell uname)), Darwin)
+  # Work around a problem linking tables marked as common symbols,
+  # cf., src/enc/yuv.[hc]
+  # Failure observed with: gcc 4.2.1 and 4.0.1.
+  EXTRA_FLAGS += -fno-common
+  EXTRA_FLAGS += -DHAVE_GLUT_GLUT_H
   EXTRA_FLAGS += -I/opt/local/include
   EXTRA_LIBS  += -L/opt/local/lib
+  GL_LIBS = -framework GLUT -framework OpenGL
+else
+  GL_LIBS = -lglut -lGL
 endif
 
+
 # To install libraries on Mac OS X:
 # 1. Install MacPorts (http://www.macports.org/install.php)
 # 2. Run "sudo port install jpeg"
 # 3. Run "sudo port install libpng"
+# 4. Run "sudo port install tiff"
+# 5. Run "sudo port install giflib"
 
 # To install libraries on Linux:
 # 1. Run "sudo apt-get install libjpeg62-dev"
 # 2. Run "sudo apt-get install libpng12-dev"
+# 3. Run "sudo apt-get install libtiff4-dev"
+# 4. Run "sudo apt-get install libgif-dev"
 
 # Uncomment for build for 32bit platform
 # Alternatively, you can just use the command
 # 'make -f makefile.unix EXTRA_FLAGS=-m32' to that effect.
 # EXTRA_FLAGS += -m32
 
+# Extra flags to enable experimental features and code
+# EXTRA_FLAGS += -DWEBP_EXPERIMENTAL_FEATURES
+
+# Extra flags to enable byte swap for 16 bit colorspaces.
+# EXTRA_FLAGS += -DWEBP_SWAP_16BIT_CSP
+
+# Extra flags to enable multi-threading
+EXTRA_FLAGS += -DWEBP_USE_THREAD
+EXTRA_LIBS += -lpthread
+
+# Control symbol visibility. Comment out if your compiler doesn't support it.
+EXTRA_FLAGS += -fvisibility=hidden
+
 # Extra flags to emulate C89 strictness with the full ANSI
 EXTRA_FLAGS += -Wextra -Wold-style-definition
 EXTRA_FLAGS += -Wmissing-prototypes
 EXTRA_FLAGS += -Wmissing-declarations
 EXTRA_FLAGS += -Wdeclaration-after-statement
+EXTRA_FLAGS += -Wshadow
+EXTRA_FLAGS += -Wformat-security -Wformat-nonliteral
+# EXTRA_FLAGS += -Wvla
+
+# SSE4.1-specific flags:
+ifeq ($(HAVE_SSE41), 1)
+EXTRA_FLAGS += -DWEBP_HAVE_SSE41
+src/dsp/%_sse41.o: EXTRA_FLAGS += -msse4.1
+endif
+
+# AVX2-specific flags:
+ifeq ($(HAVE_AVX2), 1)
+EXTRA_FLAGS += -DWEBP_HAVE_AVX2
+src/dsp/%_avx2.o: EXTRA_FLAGS += -mavx2
+endif
+
+# NEON-specific flags:
+# EXTRA_FLAGS += -march=armv7-a -mfloat-abi=hard -mfpu=neon -mtune=cortex-a8
+# -> seems to make the overall lib slower: -fno-split-wide-types
+
+# MIPS (MSA) 32-bit build specific flags for mips32r5 (p5600):
+# EXTRA_FLAGS += -mips32r5 -mabi=32 -mtune=p5600 -mmsa -mfp64
+# EXTRA_FLAGS += -msched-weight -mload-store-pairs
+
+# MIPS (MSA) 64-bit build specific flags for mips64r6 (i6400):
+# EXTRA_FLAGS += -mips64r6 -mabi=64 -mtune=i6400 -mmsa -mfp64
+# EXTRA_FLAGS += -msched-weight -mload-store-pairs
 
 #### Nothing should normally be changed below this line ####
 
-CC = gcc -Isrc/ -Iexamples/ -Wall
+AR = ar
+ARFLAGS = r
+CPPFLAGS = -Isrc/ -Wall
 CFLAGS = -O3 -DNDEBUG $(EXTRA_FLAGS)
-LDFLAGS = src/libwebp.a $(EXTRA_LIBS) -lm
+CC = gcc
+INSTALL = install
+GROFF = /usr/bin/groff
+COL = /usr/bin/col
+LDFLAGS = $(EXTRA_LIBS) $(EXTRA_FLAGS) -lm
 
-OBJS = src/enc/webpenc.o src/enc/bit_writer.o src/enc/syntax.o \
-       src/enc/dsp.o src/enc/tree.o src/enc/config.o src/enc/frame.o \
-       src/enc/quant.o src/enc/iterator.o src/enc/analysis.o \
-       src/enc/cost.o src/enc/picture.o src/enc/filter.o \
-       src/dec/bits.o src/dec/dsp.o src/dec/frame.o src/dec/webp.o \
-       src/dec/quant.o src/dec/tree.o src/dec/vp8.o src/dec/yuv.o \
-       src/dec/idec.o
-HDRS = src/webp/encode.h src/enc/vp8enci.h src/enc/bit_writer.h \
-       src/enc/cost.h src/dec/bits.h  src/dec/vp8i.h src/dec/yuv.h
-OUTPUT = examples/cwebp examples/dwebp src/libwebp.a
+ANIM_UTIL_OBJS = \
+    examples/anim_util.o \
 
-all:ex
+DEC_OBJS = \
+    src/dec/alpha_dec.o \
+    src/dec/buffer_dec.o \
+    src/dec/frame_dec.o \
+    src/dec/idec_dec.o \
+    src/dec/io_dec.o \
+    src/dec/quant_dec.o \
+    src/dec/tree_dec.o \
+    src/dec/vp8_dec.o \
+    src/dec/vp8l_dec.o \
+    src/dec/webp_dec.o \
 
-.c.o:  $(HDRS)
-	$(CC) $(CFLAGS) -c $< -o $@
+DEMUX_OBJS = \
+    src/demux/anim_decode.o \
+    src/demux/demux.o \
 
-libwebp.a:  $(OBJS) $(HDRS)
-	ar r src/libwebp.a $(OBJS)
+DSP_DEC_OBJS = \
+    src/dsp/alpha_processing.o \
+    src/dsp/alpha_processing_mips_dsp_r2.o \
+    src/dsp/alpha_processing_neon.o \
+    src/dsp/alpha_processing_sse2.o \
+    src/dsp/alpha_processing_sse41.o \
+    src/dsp/cpu.o \
+    src/dsp/dec.o \
+    src/dsp/dec_clip_tables.o \
+    src/dsp/dec_mips32.o \
+    src/dsp/dec_mips_dsp_r2.o \
+    src/dsp/dec_msa.o \
+    src/dsp/dec_neon.o \
+    src/dsp/dec_sse2.o \
+    src/dsp/dec_sse41.o \
+    src/dsp/filters.o \
+    src/dsp/filters_mips_dsp_r2.o \
+    src/dsp/filters_msa.o \
+    src/dsp/filters_neon.o \
+    src/dsp/filters_sse2.o \
+    src/dsp/lossless.o \
+    src/dsp/lossless_mips_dsp_r2.o \
+    src/dsp/lossless_msa.o \
+    src/dsp/lossless_neon.o \
+    src/dsp/lossless_sse2.o \
+    src/dsp/rescaler.o \
+    src/dsp/rescaler_mips32.o \
+    src/dsp/rescaler_mips_dsp_r2.o \
+    src/dsp/rescaler_msa.o \
+    src/dsp/rescaler_neon.o \
+    src/dsp/rescaler_sse2.o \
+    src/dsp/upsampling.o \
+    src/dsp/upsampling_mips_dsp_r2.o \
+    src/dsp/upsampling_msa.o \
+    src/dsp/upsampling_neon.o \
+    src/dsp/upsampling_sse2.o \
+    src/dsp/yuv.o \
+    src/dsp/yuv_mips32.o \
+    src/dsp/yuv_mips_dsp_r2.o \
+    src/dsp/yuv_sse2.o \
 
-ex: examples/cwebp.o examples/dwebp.o libwebp.a
-	$(CC) -o examples/cwebp examples/cwebp.o $(LDFLAGS)
-	$(CC) -o examples/dwebp examples/dwebp.o $(LDFLAGS)
+DSP_ENC_OBJS = \
+    src/dsp/argb.o \
+    src/dsp/argb_mips_dsp_r2.o \
+    src/dsp/argb_sse2.o \
+    src/dsp/cost.o \
+    src/dsp/cost_mips32.o \
+    src/dsp/cost_mips_dsp_r2.o \
+    src/dsp/cost_sse2.o \
+    src/dsp/enc.o \
+    src/dsp/enc_avx2.o \
+    src/dsp/enc_mips32.o \
+    src/dsp/enc_mips_dsp_r2.o \
+    src/dsp/enc_msa.o \
+    src/dsp/enc_neon.o \
+    src/dsp/enc_sse2.o \
+    src/dsp/enc_sse41.o \
+    src/dsp/lossless_enc.o \
+    src/dsp/lossless_enc_mips32.o \
+    src/dsp/lossless_enc_mips_dsp_r2.o \
+    src/dsp/lossless_enc_msa.o \
+    src/dsp/lossless_enc_neon.o \
+    src/dsp/lossless_enc_sse2.o \
+    src/dsp/lossless_enc_sse41.o \
+
+ENC_OBJS = \
+    src/enc/alpha_enc.o \
+    src/enc/analysis_enc.o \
+    src/enc/backward_references_enc.o \
+    src/enc/config_enc.o \
+    src/enc/cost_enc.o \
+    src/enc/delta_palettization_enc.o \
+    src/enc/filter_enc.o \
+    src/enc/frame_enc.o \
+    src/enc/histogram_enc.o \
+    src/enc/iterator_enc.o \
+    src/enc/near_lossless_enc.o \
+    src/enc/picture_enc.o \
+    src/enc/picture_csp_enc.o \
+    src/enc/picture_psnr_enc.o \
+    src/enc/picture_rescale_enc.o \
+    src/enc/picture_tools_enc.o \
+    src/enc/predictor_enc.o \
+    src/enc/quant_enc.o \
+    src/enc/syntax_enc.o \
+    src/enc/token_enc.o \
+    src/enc/tree_enc.o \
+    src/enc/vp8l_enc.o \
+    src/enc/webp_enc.o \
+
+EX_FORMAT_DEC_OBJS = \
+    imageio/image_dec.o \
+    imageio/jpegdec.o \
+    imageio/metadata.o \
+    imageio/pngdec.o \
+    imageio/tiffdec.o \
+    imageio/webpdec.o \
+
+EX_FORMAT_ENC_OBJS = \
+    imageio/image_enc.o \
+
+EX_UTIL_OBJS = \
+    examples/example_util.o \
+
+GIFDEC_OBJS = \
+    examples/gifdec.o \
+
+IMAGE_UTIL_OBJS = \
+    imageio/imageio_util.o \
+
+MUX_OBJS = \
+    src/mux/anim_encode.o \
+    src/mux/muxedit.o \
+    src/mux/muxinternal.o \
+    src/mux/muxread.o \
+
+UTILS_DEC_OBJS = \
+    src/utils/bit_reader_utils.o \
+    src/utils/color_cache_utils.o \
+    src/utils/filters_utils.o \
+    src/utils/huffman_utils.o \
+    src/utils/quant_levels_dec_utils.o \
+    src/utils/random_utils.o \
+    src/utils/rescaler_utils.o \
+    src/utils/thread_utils.o \
+    src/utils/utils.o \
+
+UTILS_ENC_OBJS = \
+    src/utils/bit_writer_utils.o \
+    src/utils/huffman_encode_utils.o \
+    src/utils/quant_levels_utils.o \
+
+EXTRA_OBJS = \
+    extras/extras.o \
+    extras/quality_estimate.o \
+
+LIBWEBPDECODER_OBJS = $(DEC_OBJS) $(DSP_DEC_OBJS) $(UTILS_DEC_OBJS)
+LIBWEBP_OBJS = $(LIBWEBPDECODER_OBJS) $(ENC_OBJS) $(DSP_ENC_OBJS) \
+               $(UTILS_ENC_OBJS)
+LIBWEBPMUX_OBJS = $(MUX_OBJS)
+LIBWEBPDEMUX_OBJS = $(DEMUX_OBJS)
+LIBWEBPEXTRA_OBJS = $(EXTRA_OBJS)
+
+HDRS_INSTALLED = \
+    src/webp/decode.h \
+    src/webp/demux.h \
+    src/webp/encode.h \
+    src/webp/mux.h \
+    src/webp/mux_types.h \
+    src/webp/types.h \
+
+HDRS = \
+    src/dec/alphai_dec.h \
+    src/dec/common_dec.h \
+    src/dec/vp8_dec.h \
+    src/dec/vp8i_dec.h \
+    src/dec/vp8li_dec.h \
+    src/dec/webpi_dec.h \
+    src/dsp/common_sse2.h \
+    src/dsp/dsp.h \
+    src/dsp/lossless.h \
+    src/dsp/lossless_common.h \
+    src/dsp/mips_macro.h \
+    src/dsp/msa_macro.h \
+    src/dsp/neon.h \
+    src/dsp/yuv.h \
+    src/enc/backward_references_enc.h \
+    src/enc/cost_enc.h \
+    src/enc/delta_palettization_enc.h \
+    src/enc/histogram_enc.h \
+    src/enc/vp8i_enc.h \
+    src/enc/vp8li_enc.h \
+    src/mux/animi.h \
+    src/mux/muxi.h \
+    src/utils/bit_reader_utils.h \
+    src/utils/bit_reader_inl_utils.h \
+    src/utils/bit_writer_utils.h \
+    src/utils/color_cache_utils.h \
+    src/utils/endian_inl_utils.h \
+    src/utils/filters_utils.h \
+    src/utils/huffman_utils.h \
+    src/utils/huffman_encode_utils.h \
+    src/utils/quant_levels_utils.h \
+    src/utils/quant_levels_dec_utils.h \
+    src/utils/random_utils.h \
+    src/utils/rescaler_utils.h \
+    src/utils/thread_utils.h \
+    src/utils/utils.h \
+    src/webp/format_constants.h \
+    $(HDRS_INSTALLED) \
+
+OUT_LIBS = examples/libexample_util.a
+OUT_LIBS += imageio/libimageio_util.a
+OUT_LIBS += imageio/libimagedec.a
+OUT_LIBS += imageio/libimageenc.a
+OUT_LIBS += src/libwebpdecoder.a
+OUT_LIBS += src/libwebp.a
+EXTRA_LIB = extras/libwebpextras.a
+OUT_EXAMPLES = examples/cwebp examples/dwebp
+EXTRA_EXAMPLES = examples/gif2webp examples/vwebp examples/webpmux \
+                 examples/anim_diff examples/img2webp
+OTHER_EXAMPLES = extras/get_disto extras/webp_quality
+
+OUTPUT = $(OUT_LIBS) $(OUT_EXAMPLES)
+ifeq ($(MAKECMDGOALS),clean)
+  OUTPUT += $(EXTRA_EXAMPLES) $(OTHER_EXAMPLES)
+  OUTPUT += src/demux/libwebpdemux.a src/mux/libwebpmux.a $(EXTRA_LIB)
+  OUTPUT += examples/libgifdec.a examples/libanim_util.a
+endif
+
+ex: $(OUT_EXAMPLES)
+all: ex $(EXTRA_EXAMPLES) $(OTHER_EXAMPLES)
+extras: $(EXTRA_LIB)
+
+$(EX_FORMAT_DEC_OBJS): %.o: %.h
+
+# special dependencies:
+#   tree_dec.c/vp8_dec.c/bit_reader_utils.c <->
+#     bit_reader_inl_utils.h, endian_inl_utils.h
+#   bit_writer_utils.c <-> endian_inl_utils.h
+src/dec/tree_dec.o: src/utils/bit_reader_inl_utils.h
+src/dec/tree_dec.o: src/utils/endian_inl_utils.h
+src/dec/vp8_dec.o: src/utils/bit_reader_inl_utils.h src/utils/endian_inl_utils.h
+src/utils/bit_reader_utils.o: src/utils/bit_reader_inl_utils.h
+src/utils/bit_reader_utils.o: src/utils/endian_inl_utils.h
+src/utils/bit_writer_utils.o: src/utils/endian_inl_utils.h
+
+%.o: %.c $(HDRS)
+	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@
+
+examples/libanim_util.a: $(ANIM_UTIL_OBJS)
+examples/libexample_util.a: $(EX_UTIL_OBJS)
+examples/libgifdec.a: $(GIFDEC_OBJS)
+extras/libwebpextras.a: $(LIBWEBPEXTRA_OBJS)
+imageio/libimagedec.a: $(EX_FORMAT_DEC_OBJS)
+imageio/libimageenc.a: $(EX_FORMAT_ENC_OBJS)
+imageio/libimageio_util.a: $(IMAGE_UTIL_OBJS)
+src/libwebpdecoder.a: $(LIBWEBPDECODER_OBJS)
+src/libwebp.a: $(LIBWEBP_OBJS)
+src/mux/libwebpmux.a: $(LIBWEBPMUX_OBJS)
+src/demux/libwebpdemux.a: $(LIBWEBPDEMUX_OBJS)
+
+%.a:
+	$(AR) $(ARFLAGS) $@ $^
+
+examples/anim_diff: examples/anim_diff.o $(ANIM_UTIL_OBJS) $(GIFDEC_OBJS)
+examples/cwebp: examples/cwebp.o
+examples/dwebp: examples/dwebp.o
+examples/gif2webp: examples/gif2webp.o $(GIFDEC_OBJS)
+examples/vwebp: examples/vwebp.o
+examples/webpmux: examples/webpmux.o
+examples/img2webp: examples/img2webp.o
+
+examples/anim_diff: examples/libanim_util.a examples/libgifdec.a
+examples/anim_diff: src/demux/libwebpdemux.a examples/libexample_util.a
+examples/anim_diff: imageio/libimageio_util.a src/libwebp.a
+examples/anim_diff: EXTRA_LIBS += $(GIF_LIBS)
+examples/anim_diff: EXTRA_FLAGS += -DWEBP_HAVE_GIF
+examples/cwebp: examples/libexample_util.a
+examples/cwebp: imageio/libimagedec.a
+examples/cwebp: imageio/libimageio_util.a
+examples/cwebp: src/libwebp.a
+examples/cwebp: EXTRA_LIBS += $(CWEBP_LIBS)
+examples/dwebp: examples/libexample_util.a
+examples/dwebp: imageio/libimagedec.a
+examples/dwebp: imageio/libimageenc.a
+examples/dwebp: imageio/libimageio_util.a
+examples/dwebp: src/libwebp.a
+examples/dwebp: EXTRA_LIBS += $(DWEBP_LIBS)
+examples/gif2webp: examples/libexample_util.a imageio/libimageio_util.a
+examples/gif2webp: examples/libgifdec.a src/mux/libwebpmux.a src/libwebp.a
+examples/gif2webp: EXTRA_LIBS += $(GIF_LIBS)
+examples/gif2webp: EXTRA_FLAGS += -DWEBP_HAVE_GIF
+examples/vwebp: examples/libexample_util.a src/demux/libwebpdemux.a
+examples/vwebp: imageio/libimageio_util.a src/libwebp.a
+examples/vwebp: EXTRA_LIBS += $(GL_LIBS)
+examples/vwebp: EXTRA_FLAGS += -DWEBP_HAVE_GL
+examples/webpmux: examples/libexample_util.a imageio/libimageio_util.a
+examples/webpmux: src/mux/libwebpmux.a src/libwebpdecoder.a
+examples/img2webp: examples/libexample_util.a imageio/libimageio_util.a
+examples/img2webp: imageio/libimagedec.a
+examples/img2webp: src/mux/libwebpmux.a src/libwebp.a
+examples/img2webp: EXTRA_LIBS += $(CWEBP_LIBS)
+
+extras/get_disto: extras/get_disto.o
+extras/get_disto: imageio/libimagedec.a imageio/libimageio_util.a src/libwebp.a
+extras/get_disto: EXTRA_LIBS += $(CWEBP_LIBS)
+
+extras/webp_quality: extras/webp_quality.o
+extras/webp_quality: imageio/libimageio_util.a
+extras/webp_quality: $(EXTRA_LIB) src/libwebp.a
+
+$(OUT_EXAMPLES) $(EXTRA_EXAMPLES) $(OTHER_EXAMPLES):
+	$(CC) -o $@ $^ $(LDFLAGS)
+
+dist: DESTDIR := dist
+dist: OUT_EXAMPLES += $(EXTRA_EXAMPLES)
+dist: all
+	$(INSTALL) -m755 -d $(DESTDIR)/include/webp \
+	           $(DESTDIR)/bin $(DESTDIR)/doc $(DESTDIR)/lib
+	$(INSTALL) -m755 -s $(OUT_EXAMPLES) $(DESTDIR)/bin
+	$(INSTALL) -m644 $(HDRS_INSTALLED) $(DESTDIR)/include/webp
+	$(INSTALL) -m644 src/libwebp.a $(DESTDIR)/lib
+	$(INSTALL) -m644 src/demux/libwebpdemux.a $(DESTDIR)/lib
+	$(INSTALL) -m644 src/mux/libwebpmux.a $(DESTDIR)/lib
+	umask 022; \
+	for m in man/[cdv]webp.1 man/gif2webp.1 man/webpmux.1 \
+                 man/img2webp.1; do \
+	  basenam=$$(basename $$m .1); \
+	  $(GROFF) -t -e -man -T utf8 $$m \
+	    | $(COL) -bx >$(DESTDIR)/doc/$${basenam}.txt; \
+	  $(GROFF) -t -e -man -T html $$m \
+	    | $(COL) -bx >$(DESTDIR)/doc/$${basenam}.html; \
+	done
 
 clean:
-	rm -f ${OUTPUT} *~ \
-              src/enc/*.o src/enc/*~ \
+	$(RM) $(OUTPUT) *~ \
+              examples/*.o examples/*~ \
+              extras/*.o extras/*~ \
+              imageio/*.o imageio/*~ \
               src/dec/*.o src/dec/*~ \
-              examples/*.o examples/*~
+              src/demux/*.o src/demux/*~ \
+              src/dsp/*.o src/dsp/*~ \
+              src/enc/*.o src/enc/*~ \
+              src/mux/*.o src/mux/*~ \
+              src/utils/*.o src/utils/*~ \
+              src/webp/*~ man/*~ doc/*~ swig/*~ \
 
-superclean: clean
-	rm -rf .git *.log *.cache *~
-	rm -rf .deps */.deps */*/.deps
-	rm -rf .libs */.libs */*/.libs
-	rm -f */*.lo */*/*.lo
-	rm -f */*.la */*/*.la
-	rm -f Makefile */Makefile */*/Makefile
-	rm -f Makefile.in */Makefile.in */*/Makefile.in
-	rm -f config.log autom4te.cache libtool config.h stamp-h1
-	rm -f aclocal.m4 compile config.guess config.h.in config.sub config.status
-	rm -f configure depcomp install-sh ltmain.sh missing src/libwebp.pc
-	rm -f m4/*
+.PHONY: all clean dist ex
+.SUFFIXES:

man/Makefile.am

@@ -1,2 +1,11 @@
 man_MANS = cwebp.1 dwebp.1
+if WANT_MUX
+  man_MANS += webpmux.1
+endif
+if BUILD_GIF2WEBP
+  man_MANS += gif2webp.1
+endif
+if BUILD_VWEBP
+  man_MANS += vwebp.1
+endif
 EXTRA_DIST = $(man_MANS)

man/cwebp.1

@@ -1,26 +1,30 @@
 .\"                                      Hey, EMACS: -*- nroff -*-
-.TH CWEBP 1 "March  28, 2011"
+.TH CWEBP 1 "January 20, 2017"
 .SH NAME
 cwebp \- compress an image file to a WebP file
 .SH SYNOPSIS
 .B cwebp
-.RI [ options ] " input_file -o output_file.webp
+.RI [ options ] " input_file \-o output_file.webp
 .br
 .SH DESCRIPTION
 This manual page documents the
 .B cwebp
 command.
 .PP
-\fBcwebp\fP compresses image using the WebP format.
-Input format can be either PNG, JPEG, or raw Y'CbCr samples.
-When using PNG, the transparency information (alpha channel) is currently
-discarded.
+\fBcwebp\fP compresses an image using the WebP format.
+Input format can be either PNG, JPEG, TIFF, WebP or raw Y'CbCr samples.
 .SH OPTIONS
 The basic options are:
 .TP
-.B \-o string
+.BI \-o " string
 Specify the name of the output WebP file. If omitted, \fBcwebp\fP will
 perform compression but only report statistics.
+Using "\-" as output name will direct output to 'stdout'.
+.TP
+.BI \-\- " string
+Explicitly specify the input file. This option is useful if the input
+file starts with a '\-' for instance. This option must appear \fBlast\fP.
+Any other options afterward will be ignored.
 .TP
 .B \-h, \-help
 A short usage summary.
@@ -31,116 +35,283 @@ A summary of all the possible options.
 .B \-version
 Print the version number (as major.minor.revision) and exit.
 .TP
-.B \-q float
-Specify the compression factor between 0 and 100. Small factor
-produce smaller file with lower quality. Best quality is achieved
-using a value of 100. The default is 75.
+.B \-lossless
+Encode the image without any loss. For images with fully transparent area,
+the invisible pixel values (R/G/B or Y/U/V) will be preserved only if the
+\-exact option is used.
 .TP
-.B \-f int
-Specify the strength of the deblocking filter, between 0 (no filtering)
-and 100 (maximum filtering). A value of 0 will turn off any filtering.
-Higher value will increase the strength of the filtering process applied
-after decoding the picture. The higher the smoother the picture will
-appear. Typical values are usually in the range of 20 to 50.
+.BI \-near_lossless " int
+Use near\-lossless image preprocessing. This option adjusts pixel values
+to help compressibility, but has minimal impact on the visual quality.
+It triggers lossless compression mode automatically.
+Range is 0 (maximum preprocessing) to 100 (no preprocessing, the default).
 .TP
-.B \-preset string
-Specify a set of pre-defined parameters to suit a particular type of
+.BI \-q " float
+Specify the compression factor for RGB channels between 0 and 100. The default
+is 75.
+.br
+In case of lossy compression (default), a small factor produces a smaller file
+with lower quality. Best quality is achieved by using a value of 100.
+.br
+In case of lossless compression (specified by the \fB\-lossless\fP option), a
+small factor enables faster compression speed, but produces a larger file.
+Maximum compression is achieved by using a value of 100.
+.TP
+.BI \-z " int
+Switch on \fBlossless\fP compression mode with the specified level between 0
+and 9, with level 0 being the fastest, 9 being the slowest. Fast mode
+produces larger file size than slower ones. A good default is \fB\-z 6\fP.
+This option is actually a shortcut for some predefined settings for quality
+and method. If options \fB\-q\fP  or \fB\-m\fP are subsequently used, they will
+invalidate the effect of this option.
+.TP
+.BI \-alpha_q " int
+Specify the compression factor for alpha compression between 0 and 100.
+Lossless compression of alpha is achieved using a value of 100, while the lower
+values result in a lossy compression. The default is 100.
+.TP
+.BI \-preset " string
+Specify a set of pre\-defined parameters to suit a particular type of
 source material. Possible values are:  \fBdefault\fP, \fBphoto\fP,
 \fBpicture\fP, \fBdrawing\fP, \fBicon\fP, \fBtext\fP. Since
-\fB\-preset\fP overwrites the other parameter's values (except the
+\fB\-preset\fP overwrites the other parameters' values (except the
 \fB\-q\fP one), this option should preferably appear first in the
 order of the arguments.
 .TP
-.B \-sns int
-Specify the amplitude of the spatial noise shaping. Spatial noise shaping
-(or \fBsns\fP for short) refers to a general collection of built-in algorithms
-used to decide which area of the picture should use relatively less bits,
-and where else to better transfer these bits. The possible range goes from
-0 (algorithm is off) to 100 (the maximal effect). The default value is 80.
-.TP
-.B \-m int
+.BI \-m " int
 Specify the compression method to use. This parameter controls the
-tradeoff between encoding speed and the compressed file size and quality.
+trade off between encoding speed and the compressed file size and quality.
 Possible values range from 0 to 6. Default value is 4.
 When higher values are used, the encoder will spend more time inspecting
 additional encoding possibilities and decide on the quality gain.
-Lower value can result is faster processing time at the expense of
-larger filesize and lower compression quality.
+Lower value can result in faster processing time at the expense of
+larger file size and lower compression quality.
+.TP
+.BI \-resize " width height
+Resize the source to a rectangle with size \fBwidth\fP x \fBheight\fP.
+If either (but not both) of the \fBwidth\fP or \fBheight\fP parameters is 0,
+the value will be calculated preserving the aspect\-ratio.
+.TP
+.BI \-crop " x_position y_position width height
+Crop the source to a rectangle with top\-left corner at coordinates
+(\fBx_position\fP, \fBy_position\fP) and size \fBwidth\fP x \fBheight\fP.
+This cropping area must be fully contained within the source rectangle.
+.TP
+.B \-mt
+Use multi\-threading for encoding, if possible. This option is only effective
+when using lossy compression on a source with a transparency channel.
+.TP
+.B \-low_memory
+Reduce memory usage of lossy encoding by saving four times the compressed
+size (typically). This will make the encoding slower and the output slightly
+different in size and distortion. This flag is only effective for methods
+3 and up, and is off by default. Note that leaving this flag off will have
+some side effects on the bitstream: it forces certain bitstream features
+like number of partitions (forced to 1). Note that a more detailed report
+of bitstream size is printed by \fBcwebp\fP when using this option.
+
+.SS LOSSY OPTIONS
+These options are only effective when doing lossy encoding (the default, with
+or without alpha).
+
+.TP
+.BI \-size " int
+Specify a target size (in bytes) to try and reach for the compressed output.
+The compressor will make several passes of partial encoding in order to get as
+close as possible to this target. If both \fB\-size\fP and \fB\-psnr\fP
+are used, \fB\-size\fP value will prevail.
+.TP
+.BI \-psnr " float
+Specify a target PSNR (in dB) to try and reach for the compressed output.
+The compressor will make several passes of partial encoding in order to get as
+close as possible to this target. If both \fB\-size\fP and \fB\-psnr\fP
+are used, \fB\-size\fP value will prevail.
+.TP
+.BI \-pass " int
+Set a maximum number of passes to use during the dichotomy used by
+options \fB\-size\fP or \fB\-psnr\fP. Maximum value is 10, default is 1.
+If options \fB\-size\fP or \fB\-psnr\fP were used, but \fB\-pass\fP wasn't
+specified, a default value of '6' passes will be used.
 .TP
 .B \-af
-Turns auto-filter on. This algorithm will spend additional time optimizing
-the filtering strength to reach a well-balanced quality.
-
-.SH ADDITIONAL OPTIONS
-More advanced options are:
+Turns auto\-filter on. This algorithm will spend additional time optimizing
+the filtering strength to reach a well\-balanced quality.
 .TP
-.B \-sharpness int
+.B \-jpeg_like
+Change the internal parameter mapping to better match the expected size
+of JPEG compression. This flag will generally produce an output file of
+similar size to its JPEG equivalent (for the same \fB\-q\fP setting), but
+with less visual distortion.
+
+.TP
+Advanced options:
+
+.TP
+.BI \-f " int
+Specify the strength of the deblocking filter, between 0 (no filtering)
+and 100 (maximum filtering). A value of 0 will turn off any filtering.
+Higher value will increase the strength of the filtering process applied
+after decoding the picture. The higher the value the smoother the picture will
+appear. Typical values are usually in the range of 20 to 50.
+.TP
+.BI \-sharpness " int
 Specify the sharpness of the filtering (if used).
 Range is 0 (sharpest) to 7 (least sharp). Default is 0.
 .TP
 .B \-strong
-Use a stronger filtering than the default one (if filtering is being
-used thanks to the \fB\-f\fP option). Strong filtering is off by default.
+Use strong filtering (if filtering is being used thanks to the
+\fB\-f\fP option). Strong filtering is on by default.
 .TP
-.B \-segments int
+.B \-nostrong
+Disable strong filtering (if filtering is being used thanks to the
+\fB\-f\fP option) and use simple filtering instead.
+.TP
+.B \-sharp_yuv
+Use more accurate and sharper RGB->YUV conversion if needed. Note that this
+process is slower than the default 'fast' RGB->YUV conversion.
+.TP
+.BI \-sns " int
+Specify the amplitude of the spatial noise shaping. Spatial noise shaping
+(or \fBsns\fP for short) refers to a general collection of built\-in algorithms
+used to decide which area of the picture should use relatively less bits,
+and where else to better transfer these bits. The possible range goes from
+0 (algorithm is off) to 100 (the maximal effect). The default value is 50.
+.TP
+.BI \-segments " int
 Change the number of partitions to use during the segmentation of the
 sns algorithm. Segments should be in range 1 to 4. Default value is 4.
+This option has no effect for methods 3 and up, unless \fB\-low_memory\fP
+is used.
 .TP
-.B \-size int
-Specify a target size (in bytes) to try and reach for the compressed output.
-Compressor will make several pass of partial encoding in order to get as
-close as possible to this target.
-.TP
-.B \-psnr float
-Specify a target PSNR (in dB) to try and reach for the compressed output.
-Compressor will make several pass of partial encoding in order to get as
-close as possible to this target.
-.TP
-.B \-pass int
-Set a maximum number of pass to use during the dichotomy used by
-options \fB\-size\fP or \fB\-psnr\fP. Maximum value is 10.
-.TP
-.B \-crop x_position y_position width height
-Crop the source to a rectangle with top-left corner at coordinates
-(x_position, y_position) and size width x height. This cropping area must
-be fully contained within the source rectangle.
-.B \-s width height
-Specify that the input file actually consists of raw Y'CbCr samples following
-the ITU-R BT.601 recommendation, in 4:2:0 linear format.
-The luma plane has size \fBwidth\fP x \fBheight\fP.
-.TP
-.B \-map int
-Output additional ASCII-map of encoding information. Possible map values
-range from 1 to 6. This is only meant to help debugging.
-.TP
-.B \-pre int
-Specify a pre-processing filter. This option is a placeholder
-and has currently no effect.
+.BI \-partition_limit " int
+Degrade quality by limiting the number of bits used by some macroblocks.
+Range is 0 (no degradation, the default) to 100 (full degradation).
+Useful values are usually around 30\-70 for moderately large images.
+In the VP8 format, the so\-called control partition has a limit of 512k and
+is used to store the following information: whether the macroblock is skipped,
+which segment it belongs to, whether it is coded as intra 4x4 or intra 16x16
+mode, and finally the prediction modes to use for each of the sub\-blocks.
+For a very large image, 512k only leaves room to few bits per 16x16 macroblock.
+The absolute minimum is 4 bits per macroblock. Skip, segment, and mode
+information can use up almost all these 4 bits (although the case is unlikely),
+which is problematic for very large images. The partition_limit factor controls
+how frequently the most bit\-costly mode (intra 4x4) will be used. This is
+useful in case the 512k limit is reached and the following message is displayed:
+\fIError code: 6 (PARTITION0_OVERFLOW: Partition #0 is too big to fit 512k)\fP.
+If using \fB\-partition_limit\fP is not enough to meet the 512k constraint, one
+should use less segments in order to save more header bits per macroblock.
+See the \fB\-segments\fP option.
+
+.SS LOGGING OPTIONS
+These options control the level of output:
 .TP
 .B \-v
 Print extra information (encoding time in particular).
 .TP
+.B \-print_psnr
+Compute and report average PSNR (Peak\-Signal\-To\-Noise ratio).
+.TP
+.B \-print_ssim
+Compute and report average SSIM (structural similarity
+metric, see http://en.wikipedia.org/wiki/SSIM for additional details).
+.TP
+.B \-print_lsim
+Compute and report local similarity metric (sum of lowest error amongst the
+collocated pixel neighbors).
+.TP
+.B \-progress
+Report encoding progress in percent.
+.TP
 .B \-quiet
 Do not print anything.
 .TP
 .B \-short
-Only print brief information (output file size and PSNR) for testing purpose.
+Only print brief information (output file size and PSNR) for testing purposes.
+.TP
+.BI \-map " int
+Output additional ASCII\-map of encoding information. Possible map values
+range from 1 to 6. This is only meant to help debugging.
 
-.SH Examples:
-cwebp -q 70 picture.png -o picture.webp
-.br
-cwebp -sns 70 -f 50 -strong -af -size 60000 picture.png -o picture.webp
+.SS ADDITIONAL OPTIONS
+More advanced options are:
+.TP
+.BI \-s " width height
+Specify that the input file actually consists of raw Y'CbCr samples following
+the ITU\-R BT.601 recommendation, in 4:2:0 linear format.
+The luma plane has size \fBwidth\fP x \fBheight\fP.
+.TP
+.BI \-pre " int
+Specify some preprocessing steps. Using a value of '2' will trigger
+quality\-dependent pseudo\-random dithering during RGBA\->YUVA conversion
+(lossy compression only).
+.TP
+.BI \-alpha_filter " string
+Specify the predictive filtering method for the alpha plane. One of 'none',
+\&'fast' or 'best', in increasing complexity and slowness order. Default is
+\&'fast'. Internally, alpha filtering is performed using four possible
+predictions (none, horizontal, vertical, gradient). The 'best' mode will try
+each mode in turn and pick the one which gives the smaller size. The 'fast'
+mode will just try to form an a priori guess without testing all modes.
+.TP
+.BI \-alpha_method " int
+Specify the algorithm used for alpha compression: 0 or 1. Algorithm 0 denotes
+no compression, 1 uses WebP lossless format for compression. The default is 1.
+.TP
+.B \-exact
+Preserve RGB values in transparent area. The default is off, to help
+compressibility.
+.TP
+.BI \-blend_alpha " int
+This option blends the alpha channel (if present) with the source using the
+background color specified in hexadecimal as 0xrrggbb. The alpha channel is
+afterward reset to the opaque value 255.
+.TP
+.B \-noalpha
+Using this option will discard the alpha channel.
+.TP
+.BI \-hint " string
+Specify the hint about input image type. Possible values are:
+\fBphoto\fP, \fBpicture\fP or \fBgraph\fP.
+.TP
+.BI \-metadata " string
+A comma separated list of metadata to copy from the input to the output if
+present.
+Valid values: \fBall\fP, \fBnone\fP, \fBexif\fP, \fBicc\fP, \fBxmp\fP.
+The default is \fBnone\fP.
 
-.SH
-.SH SEE ALSO
-.BR dwebp (1).
+Note: each input format may not support all combinations.
+.TP
+.B \-noasm
+Disable all assembly optimizations.
+
+.SH BUGS
+Please report all bugs to the issue tracker:
+https://bugs.chromium.org/p/webp
 .br
-Please refer to http://code.google.com/speed/webp/ for additional
-information.
-.SH AUTHOR
-\fBcwebp\fP was written by the WebP team.
+Patches welcome! See this page to get started:
+http://www.webmproject.org/code/contribute/submitting\-patches/
+
+.SH EXAMPLES
+cwebp \-q 50 -lossless picture.png \-o picture_lossless.webp
 .br
-The latest source tree is available at http://www.webmproject.org/code
+cwebp \-q 70 picture_with_alpha.png \-o picture_with_alpha.webp
+.br
+cwebp \-sns 70 \-f 50 \-size 60000 picture.png \-o picture.webp
+.br
+cwebp \-o picture.webp \-\- \-\-\-picture.png
+
+.SH AUTHORS
+\fBcwebp\fP is a part of libwebp and was written by the WebP team.
+.br
+The latest source tree is available at
+https://chromium.googlesource.com/webm/libwebp
 .PP
 This manual page was written by Pascal Massimino <pascal.massimino@gmail.com>,
 for the Debian project (and may be used by others).
+
+.SH SEE ALSO
+.BR dwebp (1),
+.BR gif2webp (1)
+.br
+Please refer to http://developers.google.com/speed/webp/ for additional
+information.

man/dwebp.1

@@ -1,7 +1,7 @@
 .\"                                      Hey, EMACS: -*- nroff -*-
-.TH DWEBP 1 "March  28, 2011"
+.TH DWEBP 1 "June 23, 2016"
 .SH NAME
-dwebp \- compress a WebP file to an image file
+dwebp \- decompress a WebP file to an image file
 .SH SYNOPSIS
 .B dwebp
 .RI [ options ] " input_file.webp
@@ -11,7 +11,7 @@ This manual page documents the
 .B dwebp
 command.
 .PP
-\fBdwebp\fP decompresses WebP files into PNG or PPM images.
+\fBdwebp\fP decompresses WebP files into PNG, PAM, PPM or PGM images.
 .SH OPTIONS
 The basic options are:
 .TP
@@ -21,35 +21,129 @@ Print usage summary.
 .B \-version
 Print the version number (as major.minor.revision) and exit.
 .TP
-.B \-o string
+.BI \-o " string
 Specify the name of the output file (as PNG format by default).
+Using "-" as output name will direct output to 'stdout'.
+.TP
+.BI \-\- " string
+Explicitly specify the input file. This option is useful if the input
+file starts with an '\-' for instance. This option must appear \fBlast\fP.
+Any other options afterward will be ignored. If the input file is "\-",
+the data will be read from \fIstdin\fP instead of a file.
+.TP
+.B \-bmp
+Change the output format to uncompressed BMP.
+.TP
+.B \-tiff
+Change the output format to uncompressed TIFF.
+.TP
+.B \-pam
+Change the output format to PAM (retains alpha).
 .TP
 .B \-ppm
-Change the output format to PPM.
+Change the output format to PPM (discards alpha).
 .TP
 .B \-pgm
-Change the output format to PGM. The output consist of luma/chroma
-samples instead of RGB, using the ICM4 layout. This option is mainly
-for verification and debugging purpose.
+Change the output format to PGM. The output consists of luma/chroma
+samples instead of RGB, using the IMC4 layout. This option is mainly
+for verification and debugging purposes.
+.TP
+.B \-yuv
+Change the output format to raw YUV. The output consists of
+luma/chroma-U/chroma-V samples instead of RGB, saved sequentially as
+individual planes. This option is mainly for verification and debugging
+purposes.
+.TP
+.B \-nofancy
+Don't use the fancy upscaler for YUV420. This may lead to jaggy
+edges (especially the red ones), but should be faster.
+.TP
+.B \-nofilter
+Don't use the in-loop filtering process even if it is required by
+the bitstream. This may produce visible blocks on the non-compliant output,
+but it will make the decoding faster.
+.TP
+.BI \-dither " strength
+Specify a dithering \fBstrength\fP between 0 and 100. Dithering is a
+post-processing effect applied to chroma components in lossy compression.
+It helps by smoothing gradients and avoiding banding artifacts.
+.TP
+.BI \-alpha_dither
+If the compressed file contains a transparency plane that was quantized
+during compression, this flag will allow dithering the reconstructed plane
+in order to generate smoother transparency gradients.
+.TP
+.B \-nodither
+Disable all dithering (default).
+.TP
+.B \-mt
+Use multi-threading for decoding, if possible.
+.TP
+.BI \-crop " x_position y_position width height
+Crop the decoded picture to a rectangle with top-left corner at coordinates
+(\fBx_position\fP, \fBy_position\fP) and size \fBwidth\fP x \fBheight\fP.
+This cropping area must be fully contained within the source rectangle.
+The top-left corner will be snapped to even coordinates if needed.
+This option is meant to reduce the memory needed for cropping large images.
+Note: the cropping is applied \fIbefore\fP any scaling.
+.TP
+.B \-flip
+Flip decoded image vertically (can be useful for OpenGL textures for instance).
+.TP
+\fB\-resize\fR, \fB\-scale\fI width height\fR
+Rescale the decoded picture to dimension \fBwidth\fP x \fBheight\fP. This
+option is mostly intended to reducing the memory needed to decode large images,
+when only a small version is needed (thumbnail, preview, etc.). Note: scaling
+is applied \fIafter\fP cropping.
+If either (but not both) of the \fBwidth\fP or \fBheight\fP parameters is 0,
+the value will be calculated preserving the aspect-ratio.
+.TP
+.B \-quiet
+Do not print anything.
 .TP
 .B \-v
 Print extra information (decoding time in particular).
+.TP
+.B \-noasm
+Disable all assembly optimizations.
 
-.SH Examples:
-dwebp picture.webp -o output.png
+.SH BUGS
+Please report all bugs to the issue tracker:
+https://bugs.chromium.org/p/webp
 .br
-dwebp picture.webp -ppm -o output.ppm
+Patches welcome! See this page to get started:
+http://www.webmproject.org/code/contribute/submitting-patches/
 
-.SH
-.SH SEE ALSO
-.BR cwebp (1).
+.SH EXAMPLES
+dwebp picture.webp \-o output.png
 .br
-Please refer to http://code.google.com/speed/webp/ for additional
-information.
-.SH AUTHOR
-\fBdwebp\fP was written by the WebP team.
+dwebp picture.webp \-ppm \-o output.ppm
 .br
-The latest source tree is available at http://www.webmproject.org/code
+dwebp \-o output.ppm \-\- \-\-\-picture.webp
+.br
+cat picture.webp | dwebp \-o \- \-\- \- > output.ppm
+
+.SH AUTHORS
+\fBdwebp\fP is a part of libwebp and was written by the WebP team.
+.br
+The latest source tree is available at
+https://chromium.googlesource.com/webm/libwebp
 .PP
 This manual page was written by Pascal Massimino <pascal.massimino@gmail.com>,
 for the Debian project (and may be used by others).
+
+.SH SEE ALSO
+.BR cwebp (1),
+.BR gif2webp (1),
+.BR webpmux (1)
+.br
+Please refer to http://developers.google.com/speed/webp/ for additional
+information.
+.SS Output file format details
+PAM: http://netpbm.sourceforge.net/doc/pam.html
+.br
+PGM: http://netpbm.sourceforge.net/doc/pgm.html
+.br
+PPM: http://netpbm.sourceforge.net/doc/ppm.html
+.br
+PNG: http://www.libpng.org/pub/png/png-sitemap.html#info

man/gif2webp.1

@@ -0,0 +1,153 @@
+.\"                                      Hey, EMACS: -*- nroff -*-
+.TH GIF2WEBP 1 "January 25, 2017"
+.SH NAME
+gif2webp \- Convert a GIF image to WebP
+.SH SYNOPSIS
+.B gif2webp
+.RI [ options ] " input_file.gif \-o output_file.webp
+.br
+.SH DESCRIPTION
+This manual page documents the
+.B gif2webp
+command.
+.PP
+\fBgif2webp\fP converts a GIF image to a WebP image.
+.SH OPTIONS
+The basic options are:
+.TP
+.BI \-o " string
+Specify the name of the output WebP file. If omitted, \fBgif2webp\fP will
+perform conversion but only report statistics.
+Using "\-" as output name will direct output to 'stdout'.
+.TP
+.B \-h, \-help
+Usage information.
+.TP
+.B \-version
+Print the version number (as major.minor.revision) and exit.
+.TP
+.B \-lossy
+Encode the image using lossy compression.
+.TP
+.B \-mixed
+Mixed compression mode: optimize compression of the image by picking either
+lossy or lossless compression for each frame heuristically.
+.TP
+.BI \-q " float
+Specify the compression factor for RGB channels between 0 and 100. The default
+is 75.
+.br
+In case of lossless compression (default), a small factor enables faster
+compression speed, but produces a larger file. Maximum compression is achieved
+by using a value of 100.
+.br
+In case of lossy compression (specified by the \-lossy option), a small factor
+produces a smaller file with lower quality. Best quality is achieved by using a
+value of 100.
+.TP
+.BI \-m " int
+Specify the compression method to use. This parameter controls the
+trade off between encoding speed and the compressed file size and quality.
+Possible values range from 0 to 6. Default value is 4.
+When higher values are used, the encoder will spend more time inspecting
+additional encoding possibilities and decide on the quality gain.
+Lower value can result is faster processing time at the expense of
+larger file size and lower compression quality.
+.TP
+.BI \-min_size
+Encode image to achieve smallest size. This disables key frame insertion and
+picks the dispose method resulting in smallest output for each frame. It uses
+lossless compression by default, but can be combined with \-q, \-m, \-lossy or
+\-mixed options.
+.TP
+.BI \-kmin " int
+.TP
+.BI \-kmax " int
+Specify the minimum and maximum distance between consecutive key frames
+(independently decodable frames) in the output animation. The tool will insert
+some key frames into the output animation as needed so that this criteria is
+satisfied.
+.br
+A 'kmax' value of 0 will turn off insertion of key frames. A 'kmax' value of 1
+will result in all frames being key frames. 'kmin' value is not taken into
+account in both these special cases.
+Typical values are in the range 3 to 30. Default values are kmin = 9,
+kmax = 17 for lossless compression and kmin = 3, kmax = 5 for lossy compression.
+.br
+These two options are relevant only for animated images with large number of
+frames (>50).
+.br
+When lower values are used, more frames will be converted to key frames. This
+may lead to smaller number of frames required to decode a frame on average,
+thereby improving the decoding performance. But this may lead to slightly bigger
+file sizes.
+Higher values may lead to worse decoding performance, but smaller file sizes.
+.br
+Some restrictions:
+.br
+(i) kmin < kmax,
+.br
+(ii) kmin >= kmax / 2 + 1 and
+.br
+(iii) kmax - kmin <= 30.
+.br
+If any of these restrictions are not met, they will be enforced automatically.
+.TP
+.BI \-metadata " string
+A comma separated list of metadata to copy from the input to the output if
+present.
+Valid values: \fBall\fP, \fBnone\fP, \fBicc\fP, \fBxmp\fP.
+The default is \fBxmp\fP.
+.TP
+.BI \-f " int
+For lossy encoding only (specified by the \-lossy option). Specify the strength
+of the deblocking filter, between 0 (no filtering) and 100 (maximum filtering).
+A value of 0 will turn off any filtering. Higher value will increase the
+strength of the filtering process applied after decoding the picture. The higher
+the value the smoother the picture will appear. Typical values are usually in
+the range of 20 to 50.
+.TP
+.B \-mt
+Use multi-threading for encoding, if possible. This option is only effective
+when using lossy compression.
+.TP
+.B \-v
+Print extra information.
+.TP
+.B \-quiet
+Do not print anything.
+
+.SH BUGS
+Please report all bugs to the issue tracker:
+https://bugs.chromium.org/p/webp
+.br
+Patches welcome! See this page to get started:
+http://www.webmproject.org/code/contribute/submitting-patches/
+
+.SH EXAMPLES
+gif2webp picture.gif \-o picture.webp
+.br
+gif2webp \-q 70 picture.gif \-o picture.webp
+.br
+gif2webp \-lossy \-m 3 picture.gif \-o picture_lossy.webp
+.br
+gif2webp \-lossy \-f 50 picture.gif \-o picture.webp
+.br
+gif2webp \-q 70 \-o picture.webp \-\- \-\-\-picture.gif
+
+.SH AUTHORS
+\fBgif2webp\fP is a part of libwebp and was written by the WebP team.
+.br
+The latest source tree is available at
+https://chromium.googlesource.com/webm/libwebp
+.PP
+This manual page was written by Urvang Joshi <urvang@google.com>, for the
+Debian project (and may be used by others).
+
+.SH SEE ALSO
+.BR cwebp (1),
+.BR dwebp (1),
+.BR webpmux (1)
+.br
+Please refer to http://developers.google.com/speed/webp/ for additional
+information.

man/img2webp.1

@@ -0,0 +1,97 @@
+.\"                                      Hey, EMACS: -*- nroff -*-
+.TH IMG2WEBP 1 "January 23, 2017"
+.SH NAME
+img2webp \- create animated WebP file from a sequence of input images.
+.SH SYNOPSIS
+.B img2webp
+[file_level_options] [files] [per_frame_options...]
+.br
+.SH DESCRIPTION
+This manual page documents the
+.B img2webp
+command.
+.PP
+\fBimg2webp\fP compresses a sequence of images using the animated WebP format.
+Input images can either be PNG, JPEG, TIFF or WebP.
+.SH FILE-LEVEL OPTIONS
+The file-level options are applied at the beginning of the compression process,
+before the input frames are read.
+.TP
+.BI \-o " string
+Specify the name of the output WebP file.
+.TP
+.BI \-min_size
+Encode images to achieve smallest size. This disables key frame insertion and
+picks the parameters resulting in smallest output for each frame. It uses
+lossless compression by default, but can be combined with \-q, \-m, \-lossy or
+\-mixed options.
+.TP
+.BI \-kmin " int
+.TP
+.BI \-kmax " int
+Specify the minimum and maximum distance between consecutive key frames
+(independently decodable frames) in the output animation. The tool will insert
+some key frames into the output animation as needed so that this criteria is
+satisfied.
+.br
+.B \-mixed
+Mixed compression mode: optimize compression of the image by picking either
+lossy or lossless compression for each frame heuristically. This global
+option disables the local option \fB-lossy\fP and \fB-lossless\fP .
+.TP
+.BI \-loop " int
+Specifies the number of times the animation should loop. Using '0' means
+'loop indefinitely'.
+.TP
+.BI \-v
+Be more verbose.
+.TP
+.B \-h, \-help
+A short usage summary.
+
+.SH PER-FRAME OPTIONS
+The per-frame options are applied for the images following as arguments in the
+command line. They can be modified any number of times preceding each particular
+input image.
+.TP
+.BI \-d " int
+Specify the image duration in milliseconds.
+.TP
+.B \-lossless, \-lossy
+Compress the next image(s) using lossless or lossy compression mode. The
+default mode is lossless.
+.TP
+.BI \-q " float
+Specify the compression factor between 0 and 100. The default is 75.
+.TP
+.BI \-m " int
+Specify the compression method to use. This parameter controls the
+trade off between encoding speed and the compressed file size and quality.
+Possible values range from 0 to 6. Default value is 4.
+
+.SH EXAMPLE
+img2webp -loop 2 in0.png -lossy in1.jpg -d 80 in2.tiff -o out.webp
+.br
+
+.SH BUGS
+Please report all bugs to the issue tracker:
+https://bugs.chromium.org/p/webp
+.br
+Patches welcome! See this page to get started:
+http://www.webmproject.org/code/contribute/submitting\-patches/
+
+.SH AUTHORS
+\fBimg2webp\fP is a part of libwebp and was written by the WebP team.
+.br
+The latest source tree is available at
+https://chromium.googlesource.com/webm/libwebp
+.PP
+This manual page was written by Pascal Massimino <pascal.massimino@gmail.com>,
+for the Debian project (and may be used by others).
+
+.SH SEE ALSO
+.BR webpmux (1),
+.BR gif2webp (1)
+.br
+Please refer to http://developers.google.com/speed/webp/ for additional
+information.

man/vwebp.1

@@ -0,0 +1,94 @@
+.\"                                      Hey, EMACS: -*- nroff -*-
+.TH VWEBP 1 "November 25, 2016"
+.SH NAME
+vwebp \- decompress a WebP file and display it in a window
+.SH SYNOPSIS
+.B vwebp
+.RI [ options ] " input_file.webp
+.br
+.SH DESCRIPTION
+This manual page documents the
+.B vwebp
+command.
+.PP
+\fBvwebp\fP decompresses a WebP file and displays it in a window using OpenGL.
+.SH OPTIONS
+.TP
+.B \-h
+Print usage summary.
+.TP
+.B \-version
+Print version number and exit.
+.TP
+.B \-noicc
+Don't use the ICC profile if present.
+.TP
+.B \-nofancy
+Don't use the fancy YUV420 upscaler.
+.TP
+.B \-nofilter
+Disable in-loop filtering.
+.TP
+.BI \-dither " strength
+Specify a dithering \fBstrength\fP between 0 and 100. Dithering is a
+post-processing effect applied to chroma components in lossy compression.
+It helps by smoothing gradients and avoiding banding artifacts. Default: 50.
+.TP
+.BI \-noalphadither
+By default, quantized transparency planes are dithered during decompression,
+to smooth the gradients. This flag will prevent this dithering.
+.TP
+.B \-mt
+Use multi-threading for decoding, if possible.
+.TP
+.B \-info
+Display image information on top of the decoded image.
+.TP
+.BI \-\- " string
+Explicitly specify the input file. This option is useful if the input
+file starts with an '\-' for instance. This option must appear \fBlast\fP.
+Any other options afterward will be ignored. If the input file is "\-",
+the data will be read from \fIstdin\fP instead of a file.
+.TP
+
+.SH KEYBOARD SHORTCUTS
+.TP
+.B 'c'
+Toggle use of color profile.
+.TP
+.B 'i'
+Overlay file information.
+.TP
+.B 'd'
+Disable blending and disposal process, for debugging purposes.
+.TP
+.B 'q' / 'Q' / ESC
+Quit.
+
+.SH BUGS
+Please report all bugs to the issue tracker:
+https://bugs.chromium.org/p/webp
+.br
+Patches welcome! See this page to get started:
+http://www.webmproject.org/code/contribute/submitting-patches/
+
+.SH EXAMPLES
+vwebp picture.webp
+.br
+vwebp picture.webp -mt -dither 0
+.br
+vwebp \-\- \-\-\-picture.webp
+
+.SH AUTHORS
+\fBvwebp\fP is a part of libwebp and was written by the WebP team.
+.br
+The latest source tree is available at
+https://chromium.googlesource.com/webm/libwebp
+.PP
+This manual page was written for the Debian project (and may be used by others).
+
+.SH SEE ALSO
+.BR dwebp (1)
+.br
+Please refer to http://developers.google.com/speed/webp/ for additional
+information.

man/webpmux.1

@@ -0,0 +1,255 @@
+.\"                                      Hey, EMACS: -*- nroff -*-
+.TH WEBPMUX 1 "November 10, 2016"
+.SH NAME
+webpmux \- create animated WebP files from non\-animated WebP images, extract
+frames from animated WebP images, and manage XMP/EXIF metadata and ICC profile.
+.SH SYNOPSIS
+.B webpmux \-get
+.I GET_OPTIONS
+.I INPUT
+.B \-o
+.I OUTPUT
+.br
+.B webpmux \-set
+.I SET_OPTIONS
+.I INPUT
+.B \-o
+.I OUTPUT
+.br
+.B webpmux \-strip
+.I STRIP_OPTIONS
+.I INPUT
+.B \-o
+.I OUTPUT
+.br
+.B webpmux \-frame
+.I FRAME_OPTIONS
+.B [ \-frame ... ] [ \-loop
+.I LOOP_COUNT
+.B ]
+.br
+.RS 8
+.B [ \-bgcolor
+.I BACKGROUND_COLOR
+.B ] \-o
+.I OUTPUT
+.RE
+.br
+.B webpmux \-duration
+.I DURATION OPTIONS
+.B [ \-duration ... ]
+.I INPUT
+.B \-o
+.I OUTPUT
+.br
+.B webpmux \-info
+.I INPUT
+.br
+.B webpmux [\-h|\-help]
+.br
+.B webpmux \-version
+.SH DESCRIPTION
+This manual page documents the
+.B webpmux
+command.
+.PP
+\fBwebpmux\fP can be used to create/extract from animated WebP files, as well as
+to add/extract/strip XMP/EXIF metadata and ICC profile.
+.SH OPTIONS
+.SS GET_OPTIONS (\-get):
+.TP
+.B icc
+Get ICC profile.
+.TP
+.B exif
+Get EXIF metadata.
+.TP
+.B xmp
+Get XMP metadata.
+.TP
+.BI frame " n
+Get nth frame from an animated image. (n = 0 has a special meaning: last frame).
+
+.SS SET_OPTIONS (\-set)
+.TP
+.BI icc " file.icc
+Set ICC profile.
+.P
+Where: 'file.icc' contains the ICC profile to be set.
+.TP
+.BI exif " file.exif
+Set EXIF metadata.
+.P
+Where: 'file.exif' contains the EXIF metadata to be set.
+.TP
+.BI xmp " file.xmp
+Set XMP metadata.
+.P
+Where: 'file.xmp' contains the XMP metadata to be set.
+
+.SS STRIP_OPTIONS (\-strip)
+.TP
+.B icc
+Strip ICC profile.
+.TP
+.B exif
+Strip EXIF metadata.
+.TP
+.B xmp
+Strip XMP metadata.
+
+.SS DURATION_OPTIONS (\-duration)
+Amend the duration of a specific interval of frames. This option is only
+effective on animated WebP and has no effect on a single-frame file.
+.TP
+.I duration[,start[,end]]
+Where:
+.br
+.B duration
+is the duration for the interval in milliseconds (mandatory).
+Must be non-negative.
+.br
+.B start
+is the starting frame index of the interval (optional).
+.br
+.B end
+is the ending frame index (inclusive) of the interval (optional).
+.TP
+The three typical usages of this option are:
+.br
+.B -duration d
+     set the duration to 'd' for the whole animation.
+.br
+.B -duration d,f
+     set the duration of frame 'f' to 'd'.
+.br
+.B -duration d,start,end
+     set the duration to 'd' for the whole [start,end] interval.
+.TP
+.P
+Note that the frames outside of the [start, end] interval will remain untouched.
+The 'end' value '0' has the special meaning 'last frame of the animation'.
+.TP
+.I Reminder:
+frame indexing starts at '1'.
+.br
+
+.SS FRAME_OPTIONS (\-frame)
+Create an animated WebP file from multiple (non\-animated) WebP images.
+.TP
+.I file_i +di[+xi+yi[+mi[bi]]]
+Where: 'file_i' is the i'th frame (WebP format), 'xi','yi' specify the image
+offset for this frame, 'di' is the pause duration before next frame, 'mi' is
+the dispose method for this frame (0 for NONE or 1 for BACKGROUND) and 'bi' is
+the blending method for this frame (+b for BLEND or \-b for NO_BLEND).
+Argument 'bi' can be omitted and will default to +b (BLEND).
+Also, 'mi' can be omitted if 'bi' is omitted and will default to 0 (NONE).
+Finally, if 'mi' and 'bi' are omitted then 'xi' and 'yi' can be omitted and will
+default to +0+0.
+.TP
+.BI \-loop " n
+Loop the frames n number of times. 0 indicates the frames should loop forever.
+Valid range is 0 to 65535 [Default: 0 (infinite)].
+.TP
+.BI \-bgcolor " A,R,G,B
+Background color of the canvas.
+.br
+where: 'A', 'R', 'G' and 'B' are integers in the range 0 to 255 specifying the
+Alpha, Red, Green and Blue component values respectively
+[Default: 255,255,255,255].
+
+.SS INPUT
+.TP
+Input file in WebP format.
+
+.SS OUTPUT (\-o)
+.TP
+Output file in WebP format.
+
+.SS Note:
+.TP
+The nature of EXIF, XMP and ICC data is not checked and is assumed to be valid.
+
+.SH BUGS
+Please report all bugs to the issue tracker:
+https://bugs.chromium.org/p/webp
+.br
+Patches welcome! See this page to get started:
+http://www.webmproject.org/code/contribute/submitting\-patches/
+
+.SH EXAMPLES
+.P
+Add ICC profile:
+.br
+webpmux \-set icc image_profile.icc in.webp \-o icc_container.webp
+.P
+Extract ICC profile:
+.br
+webpmux \-get icc icc_container.webp \-o image_profile.icc
+.P
+Strip ICC profile:
+.br
+webpmux \-strip icc icc_container.webp \-o without_icc.webp
+.P
+Add XMP metadata:
+.br
+webpmux \-set xmp image_metadata.xmp in.webp \-o xmp_container.webp
+.P
+Extract XMP metadata:
+.br
+webpmux \-get xmp xmp_container.webp \-o image_metadata.xmp
+.P
+Strip XMP metadata:
+.br
+webpmux \-strip xmp xmp_container.webp \-o without_xmp.webp
+.P
+Add EXIF metadata:
+.br
+webpmux \-set exif image_metadata.exif in.webp \-o exif_container.webp
+.P
+Extract EXIF metadata:
+.br
+webpmux \-get exif exif_container.webp \-o image_metadata.exif
+.P
+Strip EXIF metadata:
+.br
+webpmux \-strip exif exif_container.webp \-o without_exif.webp
+.P
+Create an animated WebP file from 3 (non\-animated) WebP images:
+.br
+webpmux \-frame 1.webp +100 \-frame 2.webp +100+50+50
+.br
+.RS 8
+\-frame 3.webp +100+50+50+1+b \-loop 10 \-bgcolor 255,255,255,255
+.br
+\-o anim_container.webp
+.RE
+.P
+Get the 2nd frame from an animated WebP file:
+.br
+webpmux \-get frame 2 anim_container.webp \-o frame_2.webp
+.P
+Using \-get/\-set/\-strip with input file name starting with '\-':
+.br
+webpmux \-set icc image_profile.icc \-o icc_container.webp \-\- \-\-\-in.webp
+.br
+webpmux \-get icc \-o image_profile.icc \-\- \-\-\-icc_container.webp
+.br
+webpmux \-strip icc \-o without_icc.webp \-\- \-\-\-icc_container.webp
+
+.SH AUTHORS
+\fBwebpmux\fP is a part of libwebp and was written by the WebP team.
+.br
+The latest source tree is available at
+https://chromium.googlesource.com/webm/libwebp
+.PP
+This manual page was written by Vikas Arora <vikaas.arora@gmail.com>,
+for the Debian project (and may be used by others).
+
+.SH SEE ALSO
+.BR cwebp (1),
+.BR dwebp (1),
+.BR gif2webp (1)
+.br
+Please refer to http://developers.google.com/speed/webp/ for additional
+information.

src/.gitignore

@@ -1 +0,0 @@
-/*.pc

src/Makefile.am

@@ -1,16 +1,54 @@
-SUBDIRS = dec enc
+# The mux and demux libraries depend on libwebp, thus the '.' to force
+# the build order so it's available to them.
+SUBDIRS = dec enc dsp utils .
+if WANT_MUX
+  SUBDIRS += mux
+endif
+if WANT_DEMUX
+  SUBDIRS += demux
+endif
 
-AM_CPPFLAGS = -I$(top_srcdir)/src
 lib_LTLIBRARIES = libwebp.la
 
-libwebp_la_SOURCES =
-libwebp_la_LIBADD = dec/libwebpdecode.la \
-                    enc/libwebpencode.la
-libwebp_la_LDFLAGS = -version-info 0:0:0
-libwebpinclude_HEADERS = webp/types.h webp/decode.h webp/decode_vp8.h \
-                         webp/encode.h
-libwebpincludedir = $(includedir)/webp
+if BUILD_LIBWEBPDECODER
+  lib_LTLIBRARIES += libwebpdecoder.la
+endif
 
+common_HEADERS =
+common_HEADERS += webp/decode.h
+common_HEADERS += webp/types.h
+commondir = $(includedir)/webp
+
+libwebp_la_SOURCES =
+libwebpinclude_HEADERS =
+libwebpinclude_HEADERS += webp/encode.h
+noinst_HEADERS =
+noinst_HEADERS += webp/format_constants.h
+
+libwebp_la_LIBADD =
+libwebp_la_LIBADD += dec/libwebpdecode.la
+libwebp_la_LIBADD += dsp/libwebpdsp.la
+libwebp_la_LIBADD += enc/libwebpencode.la
+libwebp_la_LIBADD += utils/libwebputils.la
+
+# Use '-no-undefined' to declare that libwebp does not depend on any libraries
+# other than the ones listed on the command line, i.e., after linking, it will
+# not have unresolved symbols. Some platforms (Windows among them) require all
+# symbols in shared libraries to be resolved at library creation.
+libwebp_la_LDFLAGS = -no-undefined -version-info 7:0:0
+libwebpincludedir = $(includedir)/webp
 pkgconfig_DATA = libwebp.pc
 
+if BUILD_LIBWEBPDECODER
+  libwebpdecoder_la_SOURCES =
+
+  libwebpdecoder_la_LIBADD =
+  libwebpdecoder_la_LIBADD += dec/libwebpdecode.la
+  libwebpdecoder_la_LIBADD += dsp/libwebpdspdecode.la
+  libwebpdecoder_la_LIBADD += utils/libwebputilsdecode.la
+
+  libwebpdecoder_la_LDFLAGS = -no-undefined -version-info 3:0:0
+  pkgconfig_DATA += libwebpdecoder.pc
+endif
+
 ${pkgconfig_DATA}: ${top_builddir}/config.status

src/dec/Makefile.am

@@ -1,14 +1,28 @@
-AM_CPPFLAGS = -I$(top_srcdir)/src
-
-libwebpdecode_la_SOURCES = bits.h vp8i.h yuv.h bits.c dsp.c frame.c \
-                          quant.c tree.c vp8.c webp.c yuv.c idec.c
-libwebpdecode_la_LDFLAGS = -version-info 0:0:0
-libwebpdecodeinclude_HEADERS = ../webp/decode.h ../webp/decode_vp8.h ../webp/types.h
-libwebpdecodeincludedir = $(includedir)/webp
-
-noinst_HEADERS = bits.h vp8i.h webpi.h yuv.h
-
 noinst_LTLIBRARIES = libwebpdecode.la
-# uncomment the following line (and comment the above) if you want
-# to install libwebpdecode library.
-#lib_LTLIBRARIES = libwebpdecode.la
+
+libwebpdecode_la_SOURCES =
+libwebpdecode_la_SOURCES += alpha_dec.c
+libwebpdecode_la_SOURCES += alphai_dec.h
+libwebpdecode_la_SOURCES += buffer_dec.c
+libwebpdecode_la_SOURCES += common_dec.h
+libwebpdecode_la_SOURCES += vp8_dec.h
+libwebpdecode_la_SOURCES += frame_dec.c
+libwebpdecode_la_SOURCES += idec_dec.c
+libwebpdecode_la_SOURCES += io_dec.c
+libwebpdecode_la_SOURCES += quant_dec.c
+libwebpdecode_la_SOURCES += tree_dec.c
+libwebpdecode_la_SOURCES += vp8_dec.c
+libwebpdecode_la_SOURCES += vp8i_dec.h
+libwebpdecode_la_SOURCES += vp8l_dec.c
+libwebpdecode_la_SOURCES += vp8li_dec.h
+libwebpdecode_la_SOURCES += webp_dec.c
+libwebpdecode_la_SOURCES += webpi_dec.h
+
+libwebpdecodeinclude_HEADERS =
+libwebpdecodeinclude_HEADERS += ../webp/decode.h
+libwebpdecodeinclude_HEADERS += ../webp/types.h
+noinst_HEADERS =
+noinst_HEADERS += ../webp/format_constants.h
+
+libwebpdecode_la_CPPFLAGS = $(AM_CPPFLAGS) $(USE_EXPERIMENTAL_CODE)
+libwebpdecodeincludedir = $(includedir)/webp

src/dec/alpha_dec.c

@@ -0,0 +1,232 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Alpha-plane decompression.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <stdlib.h>
+#include "./alphai_dec.h"
+#include "./vp8i_dec.h"
+#include "./vp8li_dec.h"
+#include "../dsp/dsp.h"
+#include "../utils/quant_levels_dec_utils.h"
+#include "../utils/utils.h"
+#include "../webp/format_constants.h"
+
+//------------------------------------------------------------------------------
+// ALPHDecoder object.
+
+// Allocates a new alpha decoder instance.
+static ALPHDecoder* ALPHNew(void) {
+  ALPHDecoder* const dec = (ALPHDecoder*)WebPSafeCalloc(1ULL, sizeof(*dec));
+  return dec;
+}
+
+// Clears and deallocates an alpha decoder instance.
+static void ALPHDelete(ALPHDecoder* const dec) {
+  if (dec != NULL) {
+    VP8LDelete(dec->vp8l_dec_);
+    dec->vp8l_dec_ = NULL;
+    WebPSafeFree(dec);
+  }
+}
+
+//------------------------------------------------------------------------------
+// Decoding.
+
+// Initialize alpha decoding by parsing the alpha header and decoding the image
+// header for alpha data stored using lossless compression.
+// Returns false in case of error in alpha header (data too short, invalid
+// compression method or filter, error in lossless header data etc).
+static int ALPHInit(ALPHDecoder* const dec, const uint8_t* data,
+                    size_t data_size, const VP8Io* const src_io,
+                    uint8_t* output) {
+  int ok = 0;
+  const uint8_t* const alpha_data = data + ALPHA_HEADER_LEN;
+  const size_t alpha_data_size = data_size - ALPHA_HEADER_LEN;
+  int rsrv;
+  VP8Io* const io = &dec->io_;
+
+  assert(data != NULL && output != NULL && src_io != NULL);
+
+  VP8FiltersInit();
+  dec->output_ = output;
+  dec->width_ = src_io->width;
+  dec->height_ = src_io->height;
+  assert(dec->width_ > 0 && dec->height_ > 0);
+
+  if (data_size <= ALPHA_HEADER_LEN) {
+    return 0;
+  }
+
+  dec->method_ = (data[0] >> 0) & 0x03;
+  dec->filter_ = (WEBP_FILTER_TYPE)((data[0] >> 2) & 0x03);
+  dec->pre_processing_ = (data[0] >> 4) & 0x03;
+  rsrv = (data[0] >> 6) & 0x03;
+  if (dec->method_ < ALPHA_NO_COMPRESSION ||
+      dec->method_ > ALPHA_LOSSLESS_COMPRESSION ||
+      dec->filter_ >= WEBP_FILTER_LAST ||
+      dec->pre_processing_ > ALPHA_PREPROCESSED_LEVELS ||
+      rsrv != 0) {
+    return 0;
+  }
+
+  // Copy the necessary parameters from src_io to io
+  VP8InitIo(io);
+  WebPInitCustomIo(NULL, io);
+  io->opaque = dec;
+  io->width = src_io->width;
+  io->height = src_io->height;
+
+  io->use_cropping = src_io->use_cropping;
+  io->crop_left = src_io->crop_left;
+  io->crop_right = src_io->crop_right;
+  io->crop_top = src_io->crop_top;
+  io->crop_bottom = src_io->crop_bottom;
+  // No need to copy the scaling parameters.
+
+  if (dec->method_ == ALPHA_NO_COMPRESSION) {
+    const size_t alpha_decoded_size = dec->width_ * dec->height_;
+    ok = (alpha_data_size >= alpha_decoded_size);
+  } else {
+    assert(dec->method_ == ALPHA_LOSSLESS_COMPRESSION);
+    ok = VP8LDecodeAlphaHeader(dec, alpha_data, alpha_data_size);
+  }
+
+  return ok;
+}
+
+// Decodes, unfilters and dequantizes *at least* 'num_rows' rows of alpha
+// starting from row number 'row'. It assumes that rows up to (row - 1) have
+// already been decoded.
+// Returns false in case of bitstream error.
+static int ALPHDecode(VP8Decoder* const dec, int row, int num_rows) {
+  ALPHDecoder* const alph_dec = dec->alph_dec_;
+  const int width = alph_dec->width_;
+  const int height = alph_dec->io_.crop_bottom;
+  if (alph_dec->method_ == ALPHA_NO_COMPRESSION) {
+    int y;
+    const uint8_t* prev_line = dec->alpha_prev_line_;
+    const uint8_t* deltas = dec->alpha_data_ + ALPHA_HEADER_LEN + row * width;
+    uint8_t* dst = dec->alpha_plane_ + row * width;
+    assert(deltas <= &dec->alpha_data_[dec->alpha_data_size_]);
+    if (alph_dec->filter_ != WEBP_FILTER_NONE) {
+      assert(WebPUnfilters[alph_dec->filter_] != NULL);
+      for (y = 0; y < num_rows; ++y) {
+        WebPUnfilters[alph_dec->filter_](prev_line, deltas, dst, width);
+        prev_line = dst;
+        dst += width;
+        deltas += width;
+      }
+    } else {
+      for (y = 0; y < num_rows; ++y) {
+        memcpy(dst, deltas, width * sizeof(*dst));
+        prev_line = dst;
+        dst += width;
+        deltas += width;
+      }
+    }
+    dec->alpha_prev_line_ = prev_line;
+  } else {  // alph_dec->method_ == ALPHA_LOSSLESS_COMPRESSION
+    assert(alph_dec->vp8l_dec_ != NULL);
+    if (!VP8LDecodeAlphaImageStream(alph_dec, row + num_rows)) {
+      return 0;
+    }
+  }
+
+  if (row + num_rows >= height) {
+    dec->is_alpha_decoded_ = 1;
+  }
+  return 1;
+}
+
+static int AllocateAlphaPlane(VP8Decoder* const dec, const VP8Io* const io) {
+  const int stride = io->width;
+  const int height = io->crop_bottom;
+  const uint64_t alpha_size = (uint64_t)stride * height;
+  assert(dec->alpha_plane_mem_ == NULL);
+  dec->alpha_plane_mem_ =
+      (uint8_t*)WebPSafeMalloc(alpha_size, sizeof(*dec->alpha_plane_));
+  if (dec->alpha_plane_mem_ == NULL) {
+    return 0;
+  }
+  dec->alpha_plane_ = dec->alpha_plane_mem_;
+  dec->alpha_prev_line_ = NULL;
+  return 1;
+}
+
+void WebPDeallocateAlphaMemory(VP8Decoder* const dec) {
+  assert(dec != NULL);
+  WebPSafeFree(dec->alpha_plane_mem_);
+  dec->alpha_plane_mem_ = NULL;
+  dec->alpha_plane_ = NULL;
+  ALPHDelete(dec->alph_dec_);
+  dec->alph_dec_ = NULL;
+}
+
+//------------------------------------------------------------------------------
+// Main entry point.
+
+const uint8_t* VP8DecompressAlphaRows(VP8Decoder* const dec,
+                                      const VP8Io* const io,
+                                      int row, int num_rows) {
+  const int width = io->width;
+  const int height = io->crop_bottom;
+
+  assert(dec != NULL && io != NULL);
+
+  if (row < 0 || num_rows <= 0 || row + num_rows > height) {
+    return NULL;    // sanity check.
+  }
+
+  if (!dec->is_alpha_decoded_) {
+    if (dec->alph_dec_ == NULL) {    // Initialize decoder.
+      dec->alph_dec_ = ALPHNew();
+      if (dec->alph_dec_ == NULL) return NULL;
+      if (!AllocateAlphaPlane(dec, io)) goto Error;
+      if (!ALPHInit(dec->alph_dec_, dec->alpha_data_, dec->alpha_data_size_,
+                    io, dec->alpha_plane_)) {
+        goto Error;
+      }
+      // if we allowed use of alpha dithering, check whether it's needed at all
+      if (dec->alph_dec_->pre_processing_ != ALPHA_PREPROCESSED_LEVELS) {
+        dec->alpha_dithering_ = 0;   // disable dithering
+      } else {
+        num_rows = height - row;     // decode everything in one pass
+      }
+    }
+
+    assert(dec->alph_dec_ != NULL);
+    assert(row + num_rows <= height);
+    if (!ALPHDecode(dec, row, num_rows)) goto Error;
+
+    if (dec->is_alpha_decoded_) {   // finished?
+      ALPHDelete(dec->alph_dec_);
+      dec->alph_dec_ = NULL;
+      if (dec->alpha_dithering_ > 0) {
+        uint8_t* const alpha = dec->alpha_plane_ + io->crop_top * width
+                             + io->crop_left;
+        if (!WebPDequantizeLevels(alpha,
+                                  io->crop_right - io->crop_left,
+                                  io->crop_bottom - io->crop_top,
+                                  width, dec->alpha_dithering_)) {
+          goto Error;
+        }
+      }
+    }
+  }
+
+  // Return a pointer to the current decoded row.
+  return dec->alpha_plane_ + row * width;
+
+ Error:
+  WebPDeallocateAlphaMemory(dec);
+  return NULL;
+}

src/dec/alphai_dec.h

@@ -0,0 +1,54 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Alpha decoder: internal header.
+//
+// Author: Urvang (urvang@google.com)
+
+#ifndef WEBP_DEC_ALPHAI_H_
+#define WEBP_DEC_ALPHAI_H_
+
+#include "./webpi_dec.h"
+#include "../utils/filters_utils.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct VP8LDecoder;  // Defined in dec/vp8li.h.
+
+typedef struct ALPHDecoder ALPHDecoder;
+struct ALPHDecoder {
+  int width_;
+  int height_;
+  int method_;
+  WEBP_FILTER_TYPE filter_;
+  int pre_processing_;
+  struct VP8LDecoder* vp8l_dec_;
+  VP8Io io_;
+  int use_8b_decode_;  // Although alpha channel requires only 1 byte per
+                       // pixel, sometimes VP8LDecoder may need to allocate
+                       // 4 bytes per pixel internally during decode.
+  uint8_t* output_;
+  const uint8_t* prev_line_;   // last output row (or NULL)
+};
+
+//------------------------------------------------------------------------------
+// internal functions. Not public.
+
+// Deallocate memory associated to dec->alpha_plane_ decoding
+void WebPDeallocateAlphaMemory(VP8Decoder* const dec);
+
+//------------------------------------------------------------------------------
+
+#ifdef __cplusplus
+}    // extern "C"
+#endif
+
+#endif  /* WEBP_DEC_ALPHAI_H_ */

src/dec/bits.c

@@ -1,79 +0,0 @@
-// Copyright 2010 Google Inc.
-//
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
-// -----------------------------------------------------------------------------
-//
-// Boolean decoder
-//
-// Author: Skal (pascal.massimino@gmail.com)
-
-#include "bits.h"
-
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
-//-----------------------------------------------------------------------------
-// VP8BitReader
-
-void VP8InitBitReader(VP8BitReader* const br,
-                      const uint8_t* const start, const uint8_t* const end) {
-  assert(br);
-  assert(start);
-  assert(start <= end);
-  br->range_   = 255 - 1;
-  br->buf_     = start;
-  br->buf_end_ = end;
-  br->value_   = 0;
-  br->missing_ = 8;
-  br->eof_     = 0;
-}
-
-const uint8_t kVP8Log2Range[128] = {
-     7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
-  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
-  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
-  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-  0
-};
-
-// range = ((range + 1) << kVP8Log2Range[range]) - 1
-const uint8_t kVP8NewRange[128] = {
-  127, 127, 191, 127, 159, 191, 223, 127, 143, 159, 175, 191, 207, 223, 239,
-  127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, 239,
-  247, 127, 131, 135, 139, 143, 147, 151, 155, 159, 163, 167, 171, 175, 179,
-  183, 187, 191, 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239,
-  243, 247, 251, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149,
-  151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179,
-  181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201, 203, 205, 207, 209,
-  211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231, 233, 235, 237, 239,
-  241, 243, 245, 247, 249, 251, 253, 127
-};
-
-//-----------------------------------------------------------------------------
-// Higher-level calls
-
-uint32_t VP8GetValue(VP8BitReader* const br, int bits) {
-  uint32_t v = 0;
-  while (bits-- > 0) {
-    v |= VP8GetBit(br, 0x80) << bits;
-  }
-  return v;
-}
-
-int32_t VP8GetSignedValue(VP8BitReader* const br, int bits) {
-  const int value = VP8GetValue(br, bits);
-  return VP8Get(br) ? -value : value;
-}
-
-//-----------------------------------------------------------------------------
-
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif

src/dec/bits.h

@@ -1,107 +0,0 @@
-// Copyright 2010 Google Inc.
-//
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
-// -----------------------------------------------------------------------------
-//
-// Boolean decoder
-//
-// Author: Skal (pascal.massimino@gmail.com)
-
-#ifndef WEBP_DEC_BITS_H_
-#define WEBP_DEC_BITS_H_
-
-#include <assert.h>
-#include "webp/decode_vp8.h"
-
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
-//-----------------------------------------------------------------------------
-// Bitreader and code-tree reader
-
-typedef struct {
-  const uint8_t* buf_;        // next byte to be read
-  const uint8_t* buf_end_;    // end of read buffer
-  int eof_;                   // true if input is exhausted
-
-  // boolean decoder
-  uint32_t range_;            // current range minus 1. In [127, 254] interval.
-  uint32_t value_;            // current value
-  int missing_;               // number of missing bits in value_ (8bit)
-} VP8BitReader;
-
-// Initialize the bit reader and the boolean decoder.
-void VP8InitBitReader(VP8BitReader* const br,
-                      const uint8_t* const start, const uint8_t* const end);
-
-// return the next value made of 'num_bits' bits
-uint32_t VP8GetValue(VP8BitReader* const br, int num_bits);
-static inline uint32_t VP8Get(VP8BitReader* const br) {
-  return VP8GetValue(br, 1);
-}
-
-// return the next value with sign-extension.
-int32_t VP8GetSignedValue(VP8BitReader* const br, int num_bits);
-
-// Read a bit with proba 'prob'. Speed-critical function!
-extern const uint8_t kVP8Log2Range[128];
-extern const uint8_t kVP8NewRange[128];
-static inline uint32_t VP8GetByte(VP8BitReader* const br) {
-  assert(br);
-  if (br->buf_ < br->buf_end_) {
-    assert(br->buf_);
-    return *br->buf_++;
-  }
-  br->eof_ = 1;
-  return 0xff;
-}
-
-static inline uint32_t VP8BitUpdate(VP8BitReader* const br, uint32_t split) {
-  uint32_t bit;
-  // Make sure we have a least 8 bits in 'value_'
-  if (br->missing_ > 0) {
-    br->value_ |= VP8GetByte(br) << br->missing_;
-    br->missing_ -= 8;
-  }
-  bit = ((br->value_ >> 8) > split);
-  if (bit) {
-    br->range_ -= split + 1;
-    br->value_ -= (split + 1) << 8;
-  } else {
-    br->range_ = split;
-  }
-  return bit;
-}
-
-static inline void VP8Shift(VP8BitReader* const br) {
-  // range_ is in [0..127] interval here.
-  const int shift = kVP8Log2Range[br->range_];
-  br->range_ = kVP8NewRange[br->range_];
-  br->value_ <<= shift;
-  br->missing_ += shift;
-}
-
-static inline uint32_t VP8GetBit(VP8BitReader* const br, int prob) {
-  const uint32_t split = (br->range_ * prob) >> 8;
-  const uint32_t bit = VP8BitUpdate(br, split);
-  if (br->range_ < 0x7f) {
-    VP8Shift(br);
-  }
-  return bit;
-}
-
-static inline int VP8GetSigned(VP8BitReader* const br, int v) {
-  const uint32_t split = br->range_ >> 1;
-  const uint32_t bit = VP8BitUpdate(br, split);
-  VP8Shift(br);
-  return bit ? -v : v;
-}
-
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif
-
-#endif  // WEBP_DEC_BITS_H_

src/dec/buffer_dec.c

@@ -0,0 +1,300 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Everything about WebPDecBuffer
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <stdlib.h>
+
+#include "./vp8i_dec.h"
+#include "./webpi_dec.h"
+#include "../utils/utils.h"
+
+//------------------------------------------------------------------------------
+// WebPDecBuffer
+
+// Number of bytes per pixel for the different color-spaces.
+static const int kModeBpp[MODE_LAST] = {
+  3, 4, 3, 4, 4, 2, 2,
+  4, 4, 4, 2,    // pre-multiplied modes
+  1, 1 };
+
+// Check that webp_csp_mode is within the bounds of WEBP_CSP_MODE.
+// Convert to an integer to handle both the unsigned/signed enum cases
+// without the need for casting to remove type limit warnings.
+static int IsValidColorspace(int webp_csp_mode) {
+  return (webp_csp_mode >= MODE_RGB && webp_csp_mode < MODE_LAST);
+}
+
+// strictly speaking, the very last (or first, if flipped) row
+// doesn't require padding.
+#define MIN_BUFFER_SIZE(WIDTH, HEIGHT, STRIDE)       \
+    (uint64_t)(STRIDE) * ((HEIGHT) - 1) + (WIDTH)
+
+static VP8StatusCode CheckDecBuffer(const WebPDecBuffer* const buffer) {
+  int ok = 1;
+  const WEBP_CSP_MODE mode = buffer->colorspace;
+  const int width = buffer->width;
+  const int height = buffer->height;
+  if (!IsValidColorspace(mode)) {
+    ok = 0;
+  } else if (!WebPIsRGBMode(mode)) {   // YUV checks
+    const WebPYUVABuffer* const buf = &buffer->u.YUVA;
+    const int uv_width  = (width  + 1) / 2;
+    const int uv_height = (height + 1) / 2;
+    const int y_stride = abs(buf->y_stride);
+    const int u_stride = abs(buf->u_stride);
+    const int v_stride = abs(buf->v_stride);
+    const int a_stride = abs(buf->a_stride);
+    const uint64_t y_size = MIN_BUFFER_SIZE(width, height, y_stride);
+    const uint64_t u_size = MIN_BUFFER_SIZE(uv_width, uv_height, u_stride);
+    const uint64_t v_size = MIN_BUFFER_SIZE(uv_width, uv_height, v_stride);
+    const uint64_t a_size = MIN_BUFFER_SIZE(width, height, a_stride);
+    ok &= (y_size <= buf->y_size);
+    ok &= (u_size <= buf->u_size);
+    ok &= (v_size <= buf->v_size);
+    ok &= (y_stride >= width);
+    ok &= (u_stride >= uv_width);
+    ok &= (v_stride >= uv_width);
+    ok &= (buf->y != NULL);
+    ok &= (buf->u != NULL);
+    ok &= (buf->v != NULL);
+    if (mode == MODE_YUVA) {
+      ok &= (a_stride >= width);
+      ok &= (a_size <= buf->a_size);
+      ok &= (buf->a != NULL);
+    }
+  } else {    // RGB checks
+    const WebPRGBABuffer* const buf = &buffer->u.RGBA;
+    const int stride = abs(buf->stride);
+    const uint64_t size = MIN_BUFFER_SIZE(width, height, stride);
+    ok &= (size <= buf->size);
+    ok &= (stride >= width * kModeBpp[mode]);
+    ok &= (buf->rgba != NULL);
+  }
+  return ok ? VP8_STATUS_OK : VP8_STATUS_INVALID_PARAM;
+}
+#undef MIN_BUFFER_SIZE
+
+static VP8StatusCode AllocateBuffer(WebPDecBuffer* const buffer) {
+  const int w = buffer->width;
+  const int h = buffer->height;
+  const WEBP_CSP_MODE mode = buffer->colorspace;
+
+  if (w <= 0 || h <= 0 || !IsValidColorspace(mode)) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+
+  if (buffer->is_external_memory <= 0 && buffer->private_memory == NULL) {
+    uint8_t* output;
+    int uv_stride = 0, a_stride = 0;
+    uint64_t uv_size = 0, a_size = 0, total_size;
+    // We need memory and it hasn't been allocated yet.
+    // => initialize output buffer, now that dimensions are known.
+    const int stride = w * kModeBpp[mode];
+    const uint64_t size = (uint64_t)stride * h;
+
+    if (!WebPIsRGBMode(mode)) {
+      uv_stride = (w + 1) / 2;
+      uv_size = (uint64_t)uv_stride * ((h + 1) / 2);
+      if (mode == MODE_YUVA) {
+        a_stride = w;
+        a_size = (uint64_t)a_stride * h;
+      }
+    }
+    total_size = size + 2 * uv_size + a_size;
+
+    // Security/sanity checks
+    output = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*output));
+    if (output == NULL) {
+      return VP8_STATUS_OUT_OF_MEMORY;
+    }
+    buffer->private_memory = output;
+
+    if (!WebPIsRGBMode(mode)) {   // YUVA initialization
+      WebPYUVABuffer* const buf = &buffer->u.YUVA;
+      buf->y = output;
+      buf->y_stride = stride;
+      buf->y_size = (size_t)size;
+      buf->u = output + size;
+      buf->u_stride = uv_stride;
+      buf->u_size = (size_t)uv_size;
+      buf->v = output + size + uv_size;
+      buf->v_stride = uv_stride;
+      buf->v_size = (size_t)uv_size;
+      if (mode == MODE_YUVA) {
+        buf->a = output + size + 2 * uv_size;
+      }
+      buf->a_size = (size_t)a_size;
+      buf->a_stride = a_stride;
+    } else {  // RGBA initialization
+      WebPRGBABuffer* const buf = &buffer->u.RGBA;
+      buf->rgba = output;
+      buf->stride = stride;
+      buf->size = (size_t)size;
+    }
+  }
+  return CheckDecBuffer(buffer);
+}
+
+VP8StatusCode WebPFlipBuffer(WebPDecBuffer* const buffer) {
+  if (buffer == NULL) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+  if (WebPIsRGBMode(buffer->colorspace)) {
+    WebPRGBABuffer* const buf = &buffer->u.RGBA;
+    buf->rgba += (buffer->height - 1) * buf->stride;
+    buf->stride = -buf->stride;
+  } else {
+    WebPYUVABuffer* const buf = &buffer->u.YUVA;
+    const int H = buffer->height;
+    buf->y += (H - 1) * buf->y_stride;
+    buf->y_stride = -buf->y_stride;
+    buf->u += ((H - 1) >> 1) * buf->u_stride;
+    buf->u_stride = -buf->u_stride;
+    buf->v += ((H - 1) >> 1) * buf->v_stride;
+    buf->v_stride = -buf->v_stride;
+    if (buf->a != NULL) {
+      buf->a += (H - 1) * buf->a_stride;
+      buf->a_stride = -buf->a_stride;
+    }
+  }
+  return VP8_STATUS_OK;
+}
+
+VP8StatusCode WebPAllocateDecBuffer(int w, int h,
+                                    const WebPDecoderOptions* const options,
+                                    WebPDecBuffer* const out) {
+  VP8StatusCode status;
+  if (out == NULL || w <= 0 || h <= 0) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+  if (options != NULL) {    // First, apply options if there is any.
+    if (options->use_cropping) {
+      const int cw = options->crop_width;
+      const int ch = options->crop_height;
+      const int x = options->crop_left & ~1;
+      const int y = options->crop_top & ~1;
+      if (x < 0 || y < 0 || cw <= 0 || ch <= 0 || x + cw > w || y + ch > h) {
+        return VP8_STATUS_INVALID_PARAM;   // out of frame boundary.
+      }
+      w = cw;
+      h = ch;
+    }
+    if (options->use_scaling) {
+      int scaled_width = options->scaled_width;
+      int scaled_height = options->scaled_height;
+      if (!WebPRescalerGetScaledDimensions(
+              w, h, &scaled_width, &scaled_height)) {
+        return VP8_STATUS_INVALID_PARAM;
+      }
+      w = scaled_width;
+      h = scaled_height;
+    }
+  }
+  out->width = w;
+  out->height = h;
+
+  // Then, allocate buffer for real.
+  status = AllocateBuffer(out);
+  if (status != VP8_STATUS_OK) return status;
+
+  // Use the stride trick if vertical flip is needed.
+  if (options != NULL && options->flip) {
+    status = WebPFlipBuffer(out);
+  }
+  return status;
+}
+
+//------------------------------------------------------------------------------
+// constructors / destructors
+
+int WebPInitDecBufferInternal(WebPDecBuffer* buffer, int version) {
+  if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) {
+    return 0;  // version mismatch
+  }
+  if (buffer == NULL) return 0;
+  memset(buffer, 0, sizeof(*buffer));
+  return 1;
+}
+
+void WebPFreeDecBuffer(WebPDecBuffer* buffer) {
+  if (buffer != NULL) {
+    if (buffer->is_external_memory <= 0) {
+      WebPSafeFree(buffer->private_memory);
+    }
+    buffer->private_memory = NULL;
+  }
+}
+
+void WebPCopyDecBuffer(const WebPDecBuffer* const src,
+                       WebPDecBuffer* const dst) {
+  if (src != NULL && dst != NULL) {
+    *dst = *src;
+    if (src->private_memory != NULL) {
+      dst->is_external_memory = 1;   // dst buffer doesn't own the memory.
+      dst->private_memory = NULL;
+    }
+  }
+}
+
+// Copy and transfer ownership from src to dst (beware of parameter order!)
+void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst) {
+  if (src != NULL && dst != NULL) {
+    *dst = *src;
+    if (src->private_memory != NULL) {
+      src->is_external_memory = 1;   // src relinquishes ownership
+      src->private_memory = NULL;
+    }
+  }
+}
+
+VP8StatusCode WebPCopyDecBufferPixels(const WebPDecBuffer* const src_buf,
+                                      WebPDecBuffer* const dst_buf) {
+  assert(src_buf != NULL && dst_buf != NULL);
+  assert(src_buf->colorspace == dst_buf->colorspace);
+
+  dst_buf->width = src_buf->width;
+  dst_buf->height = src_buf->height;
+  if (CheckDecBuffer(dst_buf) != VP8_STATUS_OK) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+  if (WebPIsRGBMode(src_buf->colorspace)) {
+    const WebPRGBABuffer* const src = &src_buf->u.RGBA;
+    const WebPRGBABuffer* const dst = &dst_buf->u.RGBA;
+    WebPCopyPlane(src->rgba, src->stride, dst->rgba, dst->stride,
+                  src_buf->width * kModeBpp[src_buf->colorspace],
+                  src_buf->height);
+  } else {
+    const WebPYUVABuffer* const src = &src_buf->u.YUVA;
+    const WebPYUVABuffer* const dst = &dst_buf->u.YUVA;
+    WebPCopyPlane(src->y, src->y_stride, dst->y, dst->y_stride,
+                  src_buf->width, src_buf->height);
+    WebPCopyPlane(src->u, src->u_stride, dst->u, dst->u_stride,
+                  (src_buf->width + 1) / 2, (src_buf->height + 1) / 2);
+    WebPCopyPlane(src->v, src->v_stride, dst->v, dst->v_stride,
+                  (src_buf->width + 1) / 2, (src_buf->height + 1) / 2);
+    if (WebPIsAlphaMode(src_buf->colorspace)) {
+      WebPCopyPlane(src->a, src->a_stride, dst->a, dst->a_stride,
+                    src_buf->width, src_buf->height);
+    }
+  }
+  return VP8_STATUS_OK;
+}
+
+int WebPAvoidSlowMemory(const WebPDecBuffer* const output,
+                        const WebPBitstreamFeatures* const features) {
+  assert(output != NULL);
+  return (output->is_external_memory >= 2) &&
+         WebPIsPremultipliedMode(output->colorspace) &&
+         (features != NULL && features->has_alpha);
+}
+
+//------------------------------------------------------------------------------

src/dec/common_dec.h

@@ -0,0 +1,54 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Definitions and macros common to encoding and decoding
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#ifndef WEBP_DEC_COMMON_H_
+#define WEBP_DEC_COMMON_H_
+
+// intra prediction modes
+enum { B_DC_PRED = 0,   // 4x4 modes
+       B_TM_PRED = 1,
+       B_VE_PRED = 2,
+       B_HE_PRED = 3,
+       B_RD_PRED = 4,
+       B_VR_PRED = 5,
+       B_LD_PRED = 6,
+       B_VL_PRED = 7,
+       B_HD_PRED = 8,
+       B_HU_PRED = 9,
+       NUM_BMODES = B_HU_PRED + 1 - B_DC_PRED,  // = 10
+
+       // Luma16 or UV modes
+       DC_PRED = B_DC_PRED, V_PRED = B_VE_PRED,
+       H_PRED = B_HE_PRED, TM_PRED = B_TM_PRED,
+       B_PRED = NUM_BMODES,   // refined I4x4 mode
+       NUM_PRED_MODES = 4,
+
+       // special modes
+       B_DC_PRED_NOTOP = 4,
+       B_DC_PRED_NOLEFT = 5,
+       B_DC_PRED_NOTOPLEFT = 6,
+       NUM_B_DC_MODES = 7 };
+
+enum { MB_FEATURE_TREE_PROBS = 3,
+       NUM_MB_SEGMENTS = 4,
+       NUM_REF_LF_DELTAS = 4,
+       NUM_MODE_LF_DELTAS = 4,    // I4x4, ZERO, *, SPLIT
+       MAX_NUM_PARTITIONS = 8,
+       // Probabilities
+       NUM_TYPES = 4,   // 0: i16-AC,  1: i16-DC,  2:chroma-AC,  3:i4-AC
+       NUM_BANDS = 8,
+       NUM_CTX = 3,
+       NUM_PROBAS = 11
+     };
+
+#endif    // WEBP_DEC_COMMON_H_

src/dec/dsp.c

@@ -1,696 +0,0 @@
-// Copyright 2010 Google Inc.
-//
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
-// -----------------------------------------------------------------------------
-//
-// speed-critical functions.
-//
-// Author: Skal (pascal.massimino@gmail.com)
-
-#include "vp8i.h"
-
-#if defined(__SSE2__)
-#include <emmintrin.h>
-#endif
-
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
-//-----------------------------------------------------------------------------
-// run-time tables (~4k)
-
-static uint8_t abs0[255 + 255 + 1];     // abs(i)
-static uint8_t abs1[255 + 255 + 1];     // abs(i)>>1
-static int8_t sclip1[1020 + 1020 + 1];  // clips [-1020, 1020] to [-128, 127]
-static int8_t sclip2[112 + 112 + 1];    // clips [-112, 112] to [-16, 15]
-static uint8_t clip1[255 + 510 + 1];    // clips [-255,510] to [0,255]
-
-// We declare this variable 'volatile' to prevent instruction reordering
-// and make sure it's set to true _last_ (so as to be thread-safe)
-static volatile int tables_ok = 0;
-
-void VP8DspInitTables(void) {
-  if (!tables_ok) {
-    int i;
-    for (i = -255; i <= 255; ++i) {
-      abs0[255 + i] = (i < 0) ? -i : i;
-      abs1[255 + i] = abs0[255 + i] >> 1;
-    }
-    for (i = -1020; i <= 1020; ++i) {
-      sclip1[1020 + i] = (i < -128) ? -128 : (i > 127) ? 127 : i;
-    }
-    for (i = -112; i <= 112; ++i) {
-      sclip2[112 + i] = (i < -16) ? -16 : (i > 15) ? 15 : i;
-    }
-    for (i = -255; i <= 255 + 255; ++i) {
-      clip1[255 + i] = (i < 0) ? 0 : (i > 255) ? 255 : i;
-    }
-    tables_ok = 1;
-  }
-}
-
-static inline uint8_t clip_8b(int v) {
-  return (!(v & ~0xff)) ? v : (v < 0) ? 0 : 255;
-}
-
-//-----------------------------------------------------------------------------
-// Transforms (Paragraph 14.4)
-
-#define STORE(x, y, v) \
-  dst[x + y * BPS] = clip_8b(dst[x + y * BPS] + ((v) >> 3))
-
-static const int kC1 = 20091 + (1 << 16);
-static const int kC2 = 35468;
-#define MUL(a, b) (((a) * (b)) >> 16)
-
-static void Transform(const int16_t* in, uint8_t* dst) {
-  int C[4 * 4], *tmp;
-  int i;
-  tmp = C;
-  for (i = 0; i < 4; ++i) {    // vertical pass
-    const int a = in[0] + in[8];    // [-4096, 4094]
-    const int b = in[0] - in[8];    // [-4095, 4095]
-    const int c = MUL(in[4], kC2) - MUL(in[12], kC1);   // [-3783, 3783]
-    const int d = MUL(in[4], kC1) + MUL(in[12], kC2);   // [-3785, 3781]
-    tmp[0] = a + d;   // [-7881, 7875]
-    tmp[1] = b + c;   // [-7878, 7878]
-    tmp[2] = b - c;   // [-7878, 7878]
-    tmp[3] = a - d;   // [-7877, 7879]
-    tmp += 4;
-    in++;
-  }
-  // Each pass is expanding the dynamic range by ~3.85 (upper bound).
-  // The exact value is (2. + (kC1 + kC2) / 65536).
-  // After the second pass, maximum interval is [-3794, 3794], assuming
-  // an input in [-2048, 2047] interval. We then need to add a dst value
-  // in the [0, 255] range.
-  // In the worst case scenario, the input to clip_8b() can be as large as
-  // [-60713, 60968].
-  tmp = C;
-  for (i = 0; i < 4; ++i) {    // horizontal pass
-    const int dc = tmp[0] + 4;
-    const int a =  dc +  tmp[8];
-    const int b =  dc -  tmp[8];
-    const int c = MUL(tmp[4], kC2) - MUL(tmp[12], kC1);
-    const int d = MUL(tmp[4], kC1) + MUL(tmp[12], kC2);
-    STORE(0, 0, a + d);
-    STORE(1, 0, b + c);
-    STORE(2, 0, b - c);
-    STORE(3, 0, a - d);
-    tmp++;
-    dst += BPS;
-  }
-}
-#undef MUL
-
-static void TransformUV(const int16_t* in, uint8_t* dst) {
-  Transform(in + 0 * 16, dst);
-  Transform(in + 1 * 16, dst + 4);
-  Transform(in + 2 * 16, dst + 4 * BPS);
-  Transform(in + 3 * 16, dst + 4 * BPS + 4);
-}
-
-static void TransformDC(const int16_t *in, uint8_t* dst) {
-  const int DC = in[0] + 4;
-  int i, j;
-  for (j = 0; j < 4; ++j) {
-    for (i = 0; i < 4; ++i) {
-      STORE(i, j, DC);
-    }
-  }
-}
-
-static void TransformDCUV(const int16_t* in, uint8_t* dst) {
-  if (in[0 * 16]) TransformDC(in + 0 * 16, dst);
-  if (in[1 * 16]) TransformDC(in + 1 * 16, dst + 4);
-  if (in[2 * 16]) TransformDC(in + 2 * 16, dst + 4 * BPS);
-  if (in[3 * 16]) TransformDC(in + 3 * 16, dst + 4 * BPS + 4);
-}
-
-#undef STORE
-
-// default C implementations:
-VP8Idct VP8Transform = Transform;
-VP8Idct VP8TransformUV = TransformUV;
-VP8Idct VP8TransformDC = TransformDC;
-VP8Idct VP8TransformDCUV = TransformDCUV;
-
-//-----------------------------------------------------------------------------
-// Paragraph 14.3
-
-static void TransformWHT(const int16_t* in, int16_t* out) {
-  int tmp[16];
-  int i;
-  for (i = 0; i < 4; ++i) {
-    const int a0 = in[0 + i] + in[12 + i];
-    const int a1 = in[4 + i] + in[ 8 + i];
-    const int a2 = in[4 + i] - in[ 8 + i];
-    const int a3 = in[0 + i] - in[12 + i];
-    tmp[0  + i] = a0 + a1;
-    tmp[8  + i] = a0 - a1;
-    tmp[4  + i] = a3 + a2;
-    tmp[12 + i] = a3 - a2;
-  }
-  for (i = 0; i < 4; ++i) {
-    const int dc = tmp[0 + i * 4] + 3;    // w/ rounder
-    const int a0 = dc             + tmp[3 + i * 4];
-    const int a1 = tmp[1 + i * 4] + tmp[2 + i * 4];
-    const int a2 = tmp[1 + i * 4] - tmp[2 + i * 4];
-    const int a3 = dc             - tmp[3 + i * 4];
-    out[ 0] = (a0 + a1) >> 3;
-    out[16] = (a3 + a2) >> 3;
-    out[32] = (a0 - a1) >> 3;
-    out[48] = (a3 - a2) >> 3;
-    out += 64;
-  }
-}
-
-void (*VP8TransformWHT)(const int16_t* in, int16_t* out) = TransformWHT;
-
-//-----------------------------------------------------------------------------
-// Intra predictions
-
-#define OUT(x, y) dst[(x) + (y) * BPS]
-
-static inline void TrueMotion(uint8_t *dst, int size) {
-  const uint8_t* top = dst - BPS;
-  const uint8_t* const clip0 = clip1 + 255 - top[-1];
-  int y;
-  for (y = 0; y < size; ++y) {
-    const uint8_t* const clip = clip0 + dst[-1];
-    int x;
-    for (x = 0; x < size; ++x) {
-      dst[x] = clip[top[x]];
-    }
-    dst += BPS;
-  }
-}
-static void TM4(uint8_t *dst)   { TrueMotion(dst, 4); }
-static void TM8uv(uint8_t *dst) { TrueMotion(dst, 8); }
-static void TM16(uint8_t *dst)  { TrueMotion(dst, 16); }
-
-//-----------------------------------------------------------------------------
-// 16x16
-
-static void VE16(uint8_t *dst) {     // vertical
-  int j;
-  for (j = 0; j < 16; ++j) {
-    memcpy(dst + j * BPS, dst - BPS, 16);
-  }
-}
-
-static void HE16(uint8_t *dst) {     // horizontal
-  int j;
-  for (j = 16; j > 0; --j) {
-    memset(dst, dst[-1], 16);
-    dst += BPS;
-  }
-}
-
-static inline void Put16(int v, uint8_t* dst) {
-  int j;
-  for (j = 0; j < 16; ++j) {
-    memset(dst + j * BPS, v, 16);
-  }
-}
-
-static void DC16(uint8_t *dst) {    // DC
-  int DC = 16;
-  int j;
-  for (j = 0; j < 16; ++j) {
-    DC += dst[-1 + j * BPS] + dst[j - BPS];
-  }
-  Put16(DC >> 5, dst);
-}
-
-static void DC16NoTop(uint8_t *dst) {   // DC with top samples not available
-  int DC = 8;
-  int j;
-  for (j = 0; j < 16; ++j) {
-    DC += dst[-1 + j * BPS];
-  }
-  Put16(DC >> 4, dst);
-}
-
-static void DC16NoLeft(uint8_t *dst) {  // DC with left samples not available
-  int DC = 8;
-  int i;
-  for (i = 0; i < 16; ++i) {
-    DC += dst[i - BPS];
-  }
-  Put16(DC >> 4, dst);
-}
-
-static void DC16NoTopLeft(uint8_t *dst) {  // DC with no top and left samples
-  Put16(0x80, dst);
-}
-
-//-----------------------------------------------------------------------------
-// 4x4
-
-#define AVG3(a, b, c) (((a) + 2 * (b) + (c) + 2) >> 2)
-#define AVG2(a, b) (((a) + (b) + 1) >> 1)
-
-static void VE4(uint8_t *dst) {    // vertical
-  const uint8_t* top = dst - BPS;
-  const uint8_t vals[4] = {
-    AVG3(top[-1], top[0], top[1]),
-    AVG3(top[ 0], top[1], top[2]),
-    AVG3(top[ 1], top[2], top[3]),
-    AVG3(top[ 2], top[3], top[4])
-  };
-  int i;
-  for (i = 0; i < 4; ++i) {
-    memcpy(dst + i * BPS, vals, sizeof(vals));
-  }
-}
-
-static void HE4(uint8_t *dst) {    // horizontal
-  const int A = dst[-1 - BPS];
-  const int B = dst[-1];
-  const int C = dst[-1 + BPS];
-  const int D = dst[-1 + 2 * BPS];
-  const int E = dst[-1 + 3 * BPS];
-  *(uint32_t*)(dst + 0 * BPS) = 0x01010101U * AVG3(A, B, C);
-  *(uint32_t*)(dst + 1 * BPS) = 0x01010101U * AVG3(B, C, D);
-  *(uint32_t*)(dst + 2 * BPS) = 0x01010101U * AVG3(C, D, E);
-  *(uint32_t*)(dst + 3 * BPS) = 0x01010101U * AVG3(D, E, E);
-}
-
-static void DC4(uint8_t *dst) {   // DC
-  uint32_t dc = 4;
-  int i;
-  for (i = 0; i < 4; ++i) dc += dst[i - BPS] + dst[-1 + i * BPS];
-  dc >>= 3;
-  for (i = 0; i < 4; ++i) memset(dst + i * BPS, dc, 4);
-}
-
-static void RD4(uint8_t *dst) {   // Down-right
-  const int I = dst[-1 + 0 * BPS];
-  const int J = dst[-1 + 1 * BPS];
-  const int K = dst[-1 + 2 * BPS];
-  const int L = dst[-1 + 3 * BPS];
-  const int X = dst[-1 - BPS];
-  const int A = dst[0 - BPS];
-  const int B = dst[1 - BPS];
-  const int C = dst[2 - BPS];
-  const int D = dst[3 - BPS];
-  OUT(0, 3)                                     = AVG3(J, K, L);
-  OUT(0, 2) = OUT(1, 3)                         = AVG3(I, J, K);
-  OUT(0, 1) = OUT(1, 2) = OUT(2, 3)             = AVG3(X, I, J);
-  OUT(0, 0) = OUT(1, 1) = OUT(2, 2) = OUT(3, 3) = AVG3(A, X, I);
-  OUT(1, 0) = OUT(2, 1) = OUT(3, 2)             = AVG3(B, A, X);
-  OUT(2, 0) = OUT(3, 1)                         = AVG3(C, B, A);
-  OUT(3, 0)                                     = AVG3(D, C, B);
-}
-
-static void LD4(uint8_t *dst) {   // Down-Left
-  const int A = dst[0 - BPS];
-  const int B = dst[1 - BPS];
-  const int C = dst[2 - BPS];
-  const int D = dst[3 - BPS];
-  const int E = dst[4 - BPS];
-  const int F = dst[5 - BPS];
-  const int G = dst[6 - BPS];
-  const int H = dst[7 - BPS];
-  OUT(0, 0)                                     = AVG3(A, B, C);
-  OUT(1, 0) = OUT(0, 1)                         = AVG3(B, C, D);
-  OUT(2, 0) = OUT(1, 1) = OUT(0, 2)             = AVG3(C, D, E);
-  OUT(3, 0) = OUT(2, 1) = OUT(1, 2) = OUT(0, 3) = AVG3(D, E, F);
-  OUT(3, 1) = OUT(2, 2) = OUT(1, 3)             = AVG3(E, F, G);
-  OUT(3, 2) = OUT(2, 3)                         = AVG3(F, G, H);
-  OUT(3, 3)                                     = AVG3(G, H, H);
-}
-
-static void VR4(uint8_t *dst) {   // Vertical-Right
-  const int I = dst[-1 + 0 * BPS];
-  const int J = dst[-1 + 1 * BPS];
-  const int K = dst[-1 + 2 * BPS];
-  const int X = dst[-1 - BPS];
-  const int A = dst[0 - BPS];
-  const int B = dst[1 - BPS];
-  const int C = dst[2 - BPS];
-  const int D = dst[3 - BPS];
-  OUT(0, 0) = OUT(1, 2) = AVG2(X, A);
-  OUT(1, 0) = OUT(2, 2) = AVG2(A, B);
-  OUT(2, 0) = OUT(3, 2) = AVG2(B, C);
-  OUT(3, 0)             = AVG2(C, D);
-
-  OUT(0, 3) =             AVG3(K, J, I);
-  OUT(0, 2) =             AVG3(J, I, X);
-  OUT(0, 1) = OUT(1, 3) = AVG3(I, X, A);
-  OUT(1, 1) = OUT(2, 3) = AVG3(X, A, B);
-  OUT(2, 1) = OUT(3, 3) = AVG3(A, B, C);
-  OUT(3, 1) =             AVG3(B, C, D);
-}
-
-static void VL4(uint8_t *dst) {   // Vertical-Left
-  const int A = dst[0 - BPS];
-  const int B = dst[1 - BPS];
-  const int C = dst[2 - BPS];
-  const int D = dst[3 - BPS];
-  const int E = dst[4 - BPS];
-  const int F = dst[5 - BPS];
-  const int G = dst[6 - BPS];
-  const int H = dst[7 - BPS];
-  OUT(0, 0) =             AVG2(A, B);
-  OUT(1, 0) = OUT(0, 2) = AVG2(B, C);
-  OUT(2, 0) = OUT(1, 2) = AVG2(C, D);
-  OUT(3, 0) = OUT(2, 2) = AVG2(D, E);
-
-  OUT(0, 1) =             AVG3(A, B, C);
-  OUT(1, 1) = OUT(0, 3) = AVG3(B, C, D);
-  OUT(2, 1) = OUT(1, 3) = AVG3(C, D, E);
-  OUT(3, 1) = OUT(2, 3) = AVG3(D, E, F);
-              OUT(3, 2) = AVG3(E, F, G);
-              OUT(3, 3) = AVG3(F, G, H);
-}
-
-static void HU4(uint8_t *dst) {   // Horizontal-Up
-  const int I = dst[-1 + 0 * BPS];
-  const int J = dst[-1 + 1 * BPS];
-  const int K = dst[-1 + 2 * BPS];
-  const int L = dst[-1 + 3 * BPS];
-  OUT(0, 0) =             AVG2(I, J);
-  OUT(2, 0) = OUT(0, 1) = AVG2(J, K);
-  OUT(2, 1) = OUT(0, 2) = AVG2(K, L);
-  OUT(1, 0) =             AVG3(I, J, K);
-  OUT(3, 0) = OUT(1, 1) = AVG3(J, K, L);
-  OUT(3, 1) = OUT(1, 2) = AVG3(K, L, L);
-  OUT(3, 2) = OUT(2, 2) =
-    OUT(0, 3) = OUT(1, 3) = OUT(2, 3) = OUT(3, 3) = L;
-}
-
-static void HD4(uint8_t *dst) {  // Horizontal-Down
-  const int I = dst[-1 + 0 * BPS];
-  const int J = dst[-1 + 1 * BPS];
-  const int K = dst[-1 + 2 * BPS];
-  const int L = dst[-1 + 3 * BPS];
-  const int X = dst[-1 - BPS];
-  const int A = dst[0 - BPS];
-  const int B = dst[1 - BPS];
-  const int C = dst[2 - BPS];
-
-  OUT(0, 0) = OUT(2, 1) = AVG2(I, X);
-  OUT(0, 1) = OUT(2, 2) = AVG2(J, I);
-  OUT(0, 2) = OUT(2, 3) = AVG2(K, J);
-  OUT(0, 3)             = AVG2(L, K);
-
-  OUT(3, 0)             = AVG3(A, B, C);
-  OUT(2, 0)             = AVG3(X, A, B);
-  OUT(1, 0) = OUT(3, 1) = AVG3(I, X, A);
-  OUT(1, 1) = OUT(3, 2) = AVG3(J, I, X);
-  OUT(1, 2) = OUT(3, 3) = AVG3(K, J, I);
-  OUT(1, 3)             = AVG3(L, K, J);
-}
-
-#undef AVG3
-#undef AVG2
-
-//-----------------------------------------------------------------------------
-// Chroma
-
-static void VE8uv(uint8_t *dst) {    // vertical
-  int j;
-  for (j = 0; j < 8; ++j) {
-    memcpy(dst + j * BPS, dst - BPS, 8);
-  }
-}
-
-static void HE8uv(uint8_t *dst) {    // horizontal
-  int j;
-  for (j = 0; j < 8; ++j) {
-    memset(dst, dst[-1], 8);
-    dst += BPS;
-  }
-}
-
-// helper for chroma-DC predictions
-static inline void Put8x8uv(uint64_t v, uint8_t* dst) {
-  int j;
-  for (j = 0; j < 8; ++j) {
-    *(uint64_t*)(dst + j * BPS) = v;
-  }
-}
-
-static void DC8uv(uint8_t *dst) {     // DC
-  int dc0 = 8;
-  int i;
-  for (i = 0; i < 8; ++i) {
-    dc0 += dst[i - BPS] + dst[-1 + i * BPS];
-  }
-  Put8x8uv((uint64_t)((dc0 >> 4) * 0x0101010101010101ULL), dst);
-}
-
-static void DC8uvNoLeft(uint8_t *dst) {   // DC with no left samples
-  int dc0 = 4;
-  int i;
-  for (i = 0; i < 8; ++i) {
-    dc0 += dst[i - BPS];
-  }
-  Put8x8uv((uint64_t)((dc0 >> 3) * 0x0101010101010101ULL), dst);
-}
-
-static void DC8uvNoTop(uint8_t *dst) {  // DC with no top samples
-  int dc0 = 4;
-  int i;
-  for (i = 0; i < 8; ++i) {
-    dc0 += dst[-1 + i * BPS];
-  }
-  Put8x8uv((uint64_t)((dc0 >> 3) * 0x0101010101010101ULL), dst);
-}
-
-static void DC8uvNoTopLeft(uint8_t *dst) {    // DC with nothing
-  Put8x8uv(0x8080808080808080ULL, dst);
-}
-
-//-----------------------------------------------------------------------------
-// default C implementations
-
-VP8PredFunc VP8PredLuma4[NUM_BMODES] = {
-  DC4, TM4, VE4, HE4, RD4, VR4, LD4, VL4, HD4, HU4
-};
-
-VP8PredFunc VP8PredLuma16[NUM_B_DC_MODES] = {
-  DC16, TM16, VE16, HE16,
-  DC16NoTop, DC16NoLeft, DC16NoTopLeft
-};
-
-VP8PredFunc VP8PredChroma8[NUM_B_DC_MODES] = {
-  DC8uv, TM8uv, VE8uv, HE8uv,
-  DC8uvNoTop, DC8uvNoLeft, DC8uvNoTopLeft
-};
-
-//-----------------------------------------------------------------------------
-// Edge filtering functions
-
-// 4 pixels in, 2 pixels out
-static inline void do_filter2(uint8_t* p, int step) {
-  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
-  const int a = 3 * (q0 - p0) + sclip1[1020 + p1 - q1];
-  const int a1 = sclip2[112 + ((a + 4) >> 3)];
-  const int a2 = sclip2[112 + ((a + 3) >> 3)];
-  p[-step] = clip1[255 + p0 + a2];
-  p[    0] = clip1[255 + q0 - a1];
-}
-
-// 4 pixels in, 4 pixels out
-static inline void do_filter4(uint8_t* p, int step) {
-  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
-  const int a = 3 * (q0 - p0);
-  const int a1 = sclip2[112 + ((a + 4) >> 3)];
-  const int a2 = sclip2[112 + ((a + 3) >> 3)];
-  const int a3 = (a1 + 1) >> 1;
-  p[-2*step] = clip1[255 + p1 + a3];
-  p[-  step] = clip1[255 + p0 + a2];
-  p[      0] = clip1[255 + q0 - a1];
-  p[   step] = clip1[255 + q1 - a3];
-}
-
-// 6 pixels in, 6 pixels out
-static inline void do_filter6(uint8_t* p, int step) {
-  const int p2 = p[-3*step], p1 = p[-2*step], p0 = p[-step];
-  const int q0 = p[0], q1 = p[step], q2 = p[2*step];
-  const int a = sclip1[1020 + 3 * (q0 - p0) + sclip1[1020 + p1 - q1]];
-  const int a1 = (27 * a + 63) >> 7;  // eq. to ((3 * a + 7) * 9) >> 7
-  const int a2 = (18 * a + 63) >> 7;  // eq. to ((2 * a + 7) * 9) >> 7
-  const int a3 = (9  * a + 63) >> 7;  // eq. to ((1 * a + 7) * 9) >> 7
-  p[-3*step] = clip1[255 + p2 + a3];
-  p[-2*step] = clip1[255 + p1 + a2];
-  p[-  step] = clip1[255 + p0 + a1];
-  p[      0] = clip1[255 + q0 - a1];
-  p[   step] = clip1[255 + q1 - a2];
-  p[ 2*step] = clip1[255 + q2 - a3];
-}
-
-static inline int hev(const uint8_t* p, int step, int thresh) {
-  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
-  return (abs0[255 + p1 - p0] > thresh) || (abs0[255 + q1 - q0] > thresh);
-}
-
-static inline int needs_filter(const uint8_t* p, int step, int thresh) {
-  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
-  return (2 * abs0[255 + p0 - q0] + abs1[255 + p1 - q1]) <= thresh;
-}
-
-static inline int needs_filter2(const uint8_t* p, int step, int t, int it) {
-  const int p3 = p[-4*step], p2 = p[-3*step], p1 = p[-2*step], p0 = p[-step];
-  const int q0 = p[0], q1 = p[step], q2 = p[2*step], q3 = p[3*step];
-  if ((2 * abs0[255 + p0 - q0] + abs1[255 + p1 - q1]) > t)
-    return 0;
-  return abs0[255 + p3 - p2] <= it && abs0[255 + p2 - p1] <= it &&
-         abs0[255 + p1 - p0] <= it && abs0[255 + q3 - q2] <= it &&
-         abs0[255 + q2 - q1] <= it && abs0[255 + q1 - q0] <= it;
-}
-
-//-----------------------------------------------------------------------------
-// Simple In-loop filtering (Paragraph 15.2)
-
-static void SimpleVFilter16(uint8_t* p, int stride, int thresh) {
-  int i;
-  for (i = 0; i < 16; ++i) {
-    if (needs_filter(p + i, stride, thresh)) {
-      do_filter2(p + i, stride);
-    }
-  }
-}
-
-static void SimpleHFilter16(uint8_t* p, int stride, int thresh) {
-  int i;
-  for (i = 0; i < 16; ++i) {
-    if (needs_filter(p + i * stride, 1, thresh)) {
-      do_filter2(p + i * stride, 1);
-    }
-  }
-}
-
-static void SimpleVFilter16i(uint8_t* p, int stride, int thresh) {
-  int k;
-  for (k = 3; k > 0; --k) {
-    p += 4 * stride;
-    SimpleVFilter16(p, stride, thresh);
-  }
-}
-
-static void SimpleHFilter16i(uint8_t* p, int stride, int thresh) {
-  int k;
-  for (k = 3; k > 0; --k) {
-    p += 4;
-    SimpleHFilter16(p, stride, thresh);
-  }
-}
-
-//-----------------------------------------------------------------------------
-// Complex In-loop filtering (Paragraph 15.3)
-
-static inline void FilterLoop26(uint8_t* p, int hstride, int vstride, int size,
-                                int thresh, int ithresh, int hev_thresh) {
-  while (size-- > 0) {
-    if (needs_filter2(p, hstride, thresh, ithresh)) {
-      if (hev(p, hstride, hev_thresh)) {
-        do_filter2(p, hstride);
-      } else {
-        do_filter6(p, hstride);
-      }
-    }
-    p += vstride;
-  }
-}
-
-static inline void FilterLoop24(uint8_t* p, int hstride, int vstride, int size,
-                                int thresh, int ithresh, int hev_thresh) {
-  while (size-- > 0) {
-    if (needs_filter2(p, hstride, thresh, ithresh)) {
-      if (hev(p, hstride, hev_thresh)) {
-        do_filter2(p, hstride);
-      } else {
-        do_filter4(p, hstride);
-      }
-    }
-    p += vstride;
-  }
-}
-
-// on macroblock edges
-static void VFilter16(uint8_t* p, int stride,
-                      int thresh, int ithresh, int hev_thresh) {
-  FilterLoop26(p, stride, 1, 16, thresh, ithresh, hev_thresh);
-}
-
-static void HFilter16(uint8_t* p, int stride,
-                      int thresh, int ithresh, int hev_thresh) {
-  FilterLoop26(p, 1, stride, 16, thresh, ithresh, hev_thresh);
-}
-
-// on three inner edges
-static void VFilter16i(uint8_t* p, int stride,
-                       int thresh, int ithresh, int hev_thresh) {
-  int k;
-  for (k = 3; k > 0; --k) {
-    p += 4 * stride;
-    FilterLoop24(p, stride, 1, 16, thresh, ithresh, hev_thresh);
-  }
-}
-
-static void HFilter16i(uint8_t* p, int stride,
-                       int thresh, int ithresh, int hev_thresh) {
-  int k;
-  for (k = 3; k > 0; --k) {
-    p += 4;
-    FilterLoop24(p, 1, stride, 16, thresh, ithresh, hev_thresh);
-  }
-}
-
-// 8-pixels wide variant, for chroma filtering
-static void VFilter8(uint8_t* u, uint8_t* v, int stride,
-                     int thresh, int ithresh, int hev_thresh) {
-  FilterLoop26(u, stride, 1, 8, thresh, ithresh, hev_thresh);
-  FilterLoop26(v, stride, 1, 8, thresh, ithresh, hev_thresh);
-}
-
-static void HFilter8(uint8_t* u, uint8_t* v, int stride,
-                     int thresh, int ithresh, int hev_thresh) {
-  FilterLoop26(u, 1, stride, 8, thresh, ithresh, hev_thresh);
-  FilterLoop26(v, 1, stride, 8, thresh, ithresh, hev_thresh);
-}
-
-static void VFilter8i(uint8_t* u, uint8_t* v, int stride,
-                      int thresh, int ithresh, int hev_thresh) {
-  FilterLoop24(u + 4 * stride, stride, 1, 8, thresh, ithresh, hev_thresh);
-  FilterLoop24(v + 4 * stride, stride, 1, 8, thresh, ithresh, hev_thresh);
-}
-
-static void HFilter8i(uint8_t* u, uint8_t* v, int stride,
-                      int thresh, int ithresh, int hev_thresh) {
-  FilterLoop24(u + 4, 1, stride, 8, thresh, ithresh, hev_thresh);
-  FilterLoop24(v + 4, 1, stride, 8, thresh, ithresh, hev_thresh);
-}
-
-//-----------------------------------------------------------------------------
-
-void (*VP8VFilter16)(uint8_t*, int, int, int, int) = VFilter16;
-void (*VP8HFilter16)(uint8_t*, int, int, int, int) = HFilter16;
-void (*VP8VFilter8)(uint8_t*, uint8_t*, int, int, int, int) = VFilter8;
-void (*VP8HFilter8)(uint8_t*, uint8_t*, int, int, int, int) = HFilter8;
-void (*VP8VFilter16i)(uint8_t*, int, int, int, int) = VFilter16i;
-void (*VP8HFilter16i)(uint8_t*, int, int, int, int) = HFilter16i;
-void (*VP8VFilter8i)(uint8_t*, uint8_t*, int, int, int, int) = VFilter8i;
-void (*VP8HFilter8i)(uint8_t*, uint8_t*, int, int, int, int) = HFilter8i;
-
-void (*VP8SimpleVFilter16)(uint8_t*, int, int) = SimpleVFilter16;
-void (*VP8SimpleHFilter16)(uint8_t*, int, int) = SimpleHFilter16;
-void (*VP8SimpleVFilter16i)(uint8_t*, int, int) = SimpleVFilter16i;
-void (*VP8SimpleHFilter16i)(uint8_t*, int, int) = SimpleHFilter16i;
-
-//-----------------------------------------------------------------------------
-
-void VP8DspInit(void) {
-  // later we'll plug some SSE2 variant here
-}
-
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif

src/dec/frame.c

@@ -1,417 +0,0 @@
-// Copyright 2010 Google Inc.
-//
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
-// -----------------------------------------------------------------------------
-//
-// Frame-reconstruction function. Memory allocation.
-//
-// Author: Skal (pascal.massimino@gmail.com)
-
-#include <stdlib.h>
-#include "vp8i.h"
-
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
-#define ALIGN_MASK (32 - 1)
-
-//-----------------------------------------------------------------------------
-// Memory setup
-
-// how many extra luma lines are needed for caching, given a filtering level
-static const uint8_t kFilterExtraRows[3] = { 0, 4, 8 };
-
-int VP8InitFrame(VP8Decoder* const dec, VP8Io* io) {
-  const int mb_w = dec->mb_w_;
-  const int intra_pred_mode_size = 4 * mb_w * sizeof(uint8_t);
-  const int top_size = (16 + 8 + 8) * mb_w;
-  const int info_size = (mb_w + 1) * sizeof(VP8MB);
-  const int yuv_size = YUV_SIZE * sizeof(*dec->yuv_b_);
-  const int coeffs_size = 384 * sizeof(*dec->coeffs_);
-  const int cache_height = (16 + kFilterExtraRows[dec->filter_type_]) * 3 / 2;
-  const int cache_size = top_size * cache_height;
-  const int needed = intra_pred_mode_size
-                   + top_size + info_size
-                   + yuv_size + coeffs_size
-                   + cache_size + ALIGN_MASK;
-  uint8_t* mem;
-
-  if (needed > dec->mem_size_) {
-    free(dec->mem_);
-    dec->mem_size_ = 0;
-    dec->mem_ = (uint8_t*)malloc(needed);
-    if (dec->mem_ == NULL) {
-      return VP8SetError(dec, VP8_STATUS_OUT_OF_MEMORY,
-                         "no memory during frame initialization.");
-    }
-    dec->mem_size_ = needed;
-  }
-
-  mem = (uint8_t*)dec->mem_;
-  dec->intra_t_ = (uint8_t*)mem;
-  mem += intra_pred_mode_size;
-
-  dec->y_t_ = (uint8_t*)mem;
-  mem += 16 * mb_w;
-  dec->u_t_ = (uint8_t*)mem;
-  mem += 8 * mb_w;
-  dec->v_t_ = (uint8_t*)mem;
-  mem += 8 * mb_w;
-
-  dec->mb_info_ = ((VP8MB*)mem) + 1;
-  mem += info_size;
-
-  mem = (uint8_t*)((uintptr_t)(mem + ALIGN_MASK) & ~ALIGN_MASK);
-  assert((yuv_size & ALIGN_MASK) == 0);
-  dec->yuv_b_ = (uint8_t*)mem;
-  mem += yuv_size;
-
-  dec->coeffs_ = (int16_t*)mem;
-  mem += coeffs_size;
-
-  dec->cache_y_stride_ = 16 * mb_w;
-  dec->cache_uv_stride_ = 8 * mb_w;
-  {
-    const int extra_rows = kFilterExtraRows[dec->filter_type_];
-    const int extra_y = extra_rows * dec->cache_y_stride_;
-    const int extra_uv = (extra_rows / 2) * dec->cache_uv_stride_;
-    dec->cache_y_ = ((uint8_t*)mem) + extra_y;
-    dec->cache_u_ = dec->cache_y_ + 16 * dec->cache_y_stride_ + extra_uv;
-    dec->cache_v_ = dec->cache_u_ + 8 * dec->cache_uv_stride_ + extra_uv;
-  }
-  mem += cache_size;
-
-  // note: left-info is initialized once for all.
-  memset(dec->mb_info_ - 1, 0, (mb_w + 1) * sizeof(*dec->mb_info_));
-
-  // initialize top
-  memset(dec->intra_t_, B_DC_PRED, intra_pred_mode_size);
-
-  // prepare 'io'
-  io->width = dec->pic_hdr_.width_;
-  io->height = dec->pic_hdr_.height_;
-  io->mb_y = 0;
-  io->y = dec->cache_y_;
-  io->u = dec->cache_u_;
-  io->v = dec->cache_v_;
-  io->y_stride = dec->cache_y_stride_;
-  io->uv_stride = dec->cache_uv_stride_;
-  io->fancy_upscaling = 0;    // default
-
-  // Init critical function pointers and look-up tables.
-  VP8DspInitTables();
-  VP8DspInit();
-
-  return 1;
-}
-
-//-----------------------------------------------------------------------------
-// Filtering
-
-static inline int hev_thresh_from_level(int level, int keyframe) {
-  if (keyframe) {
-    return (level >= 40) ? 2 : (level >= 15) ? 1 : 0;
-  } else {
-    return (level >= 40) ? 3 : (level >= 20) ? 2 : (level >= 15) ? 1 : 0;
-  }
-}
-
-static void DoFilter(VP8Decoder* const dec, int mb_x, int mb_y) {
-  VP8MB* const mb = dec->mb_info_ + mb_x;
-  uint8_t* const y_dst = dec->cache_y_ + mb_x * 16;
-  const int y_bps = dec->cache_y_stride_;
-  const int level = mb->f_level_;
-  const int ilevel = mb->f_ilevel_;
-  const int limit = 2 * level + ilevel;
-  if (level == 0) {
-    return;
-  }
-  if (dec->filter_type_ == 1) {   // simple
-    if (mb_x > 0) {
-      VP8SimpleHFilter16(y_dst, y_bps, limit + 4);
-    }
-    if (mb->f_inner_) {
-      VP8SimpleHFilter16i(y_dst, y_bps, limit);
-    }
-    if (mb_y > 0) {
-      VP8SimpleVFilter16(y_dst, y_bps, limit + 4);
-    }
-    if (mb->f_inner_) {
-      VP8SimpleVFilter16i(y_dst, y_bps, limit);
-    }
-  } else {    // complex
-    uint8_t* const u_dst = dec->cache_u_ + mb_x * 8;
-    uint8_t* const v_dst = dec->cache_v_ + mb_x * 8;
-    const int uv_bps = dec->cache_uv_stride_;
-    const int hev_thresh =
-        hev_thresh_from_level(level, dec->frm_hdr_.key_frame_);
-    if (mb_x > 0) {
-      VP8HFilter16(y_dst, y_bps, limit + 4, ilevel, hev_thresh);
-      VP8HFilter8(u_dst, v_dst, uv_bps, limit + 4, ilevel, hev_thresh);
-    }
-    if (mb->f_inner_) {
-      VP8HFilter16i(y_dst, y_bps, limit, ilevel, hev_thresh);
-      VP8HFilter8i(u_dst, v_dst, uv_bps, limit, ilevel, hev_thresh);
-    }
-    if (mb_y > 0) {
-      VP8VFilter16(y_dst, y_bps, limit + 4, ilevel, hev_thresh);
-      VP8VFilter8(u_dst, v_dst, uv_bps, limit + 4, ilevel, hev_thresh);
-    }
-    if (mb->f_inner_) {
-      VP8VFilter16i(y_dst, y_bps, limit, ilevel, hev_thresh);
-      VP8VFilter8i(u_dst, v_dst, uv_bps, limit, ilevel, hev_thresh);
-    }
-  }
-}
-
-void VP8StoreBlock(VP8Decoder* const dec) {
-  if (dec->filter_type_ > 0) {
-    VP8MB* const info = dec->mb_info_ + dec->mb_x_;
-    int level = dec->filter_levels_[dec->segment_];
-    if (dec->filter_hdr_.use_lf_delta_) {
-      // TODO(skal): only CURRENT is handled for now.
-      level += dec->filter_hdr_.ref_lf_delta_[0];
-      if (dec->is_i4x4_) {
-        level += dec->filter_hdr_.mode_lf_delta_[0];
-      }
-    }
-    level = (level < 0) ? 0 : (level > 63) ? 63 : level;
-    info->f_level_ = level;
-
-    if (dec->filter_hdr_.sharpness_ > 0) {
-      if (dec->filter_hdr_.sharpness_ > 4) {
-        level >>= 2;
-      } else {
-        level >>= 1;
-      }
-      if (level > 9 - dec->filter_hdr_.sharpness_) {
-        level = 9 - dec->filter_hdr_.sharpness_;
-      }
-    }
-
-    info->f_ilevel_ = (level < 1) ? 1 : level;
-    info->f_inner_ = (!info->skip_ || dec->is_i4x4_);
-  }
-  {
-    // Transfer samples to row cache
-    int y;
-    uint8_t* const ydst = dec->cache_y_ + dec->mb_x_ * 16;
-    uint8_t* const udst = dec->cache_u_ + dec->mb_x_ * 8;
-    uint8_t* const vdst = dec->cache_v_ + dec->mb_x_ * 8;
-    for (y = 0; y < 16; ++y) {
-      memcpy(ydst + y * dec->cache_y_stride_,
-             dec->yuv_b_ + Y_OFF + y * BPS, 16);
-    }
-    for (y = 0; y < 8; ++y) {
-      memcpy(udst + y * dec->cache_uv_stride_,
-           dec->yuv_b_ + U_OFF + y * BPS, 8);
-      memcpy(vdst + y * dec->cache_uv_stride_,
-           dec->yuv_b_ + V_OFF + y * BPS, 8);
-    }
-  }
-}
-
-int VP8FinishRow(VP8Decoder* const dec, VP8Io* io) {
-  const int extra_y_rows = kFilterExtraRows[dec->filter_type_];
-  const int ysize = extra_y_rows * dec->cache_y_stride_;
-  const int uvsize = (extra_y_rows / 2) * dec->cache_uv_stride_;
-  const int first_row = (dec->mb_y_ == 0);
-  const int last_row = (dec->mb_y_ >= dec->mb_h_ - 1);
-  uint8_t* const ydst = dec->cache_y_ - ysize;
-  uint8_t* const udst = dec->cache_u_ - uvsize;
-  uint8_t* const vdst = dec->cache_v_ - uvsize;
-  if (dec->filter_type_ > 0) {
-    int mb_x;
-    for (mb_x = 0; mb_x < dec->mb_w_; ++mb_x) {
-      DoFilter(dec, mb_x, dec->mb_y_);
-    }
-  }
-  if (io->put) {
-    int y_start = dec->mb_y_ * 16;
-    int y_end = y_start + 16;
-    if (!first_row) {
-      y_start -= extra_y_rows;
-      io->y = ydst;
-      io->u = udst;
-      io->v = vdst;
-    } else {
-      io->y = dec->cache_y_;
-      io->u = dec->cache_u_;
-      io->v = dec->cache_v_;
-    }
-    if (!last_row) {
-      y_end -= extra_y_rows;
-    }
-    if (y_end > io->height) {
-      y_end = io->height;
-    }
-    io->mb_y = y_start;
-    io->mb_h = y_end - y_start;
-    if (!io->put(io)) {
-      return 0;
-    }
-  }
-    // rotate top samples
-  if (!last_row) {
-    memcpy(ydst, ydst + 16 * dec->cache_y_stride_, ysize);
-    memcpy(udst, udst + 8 * dec->cache_uv_stride_, uvsize);
-    memcpy(vdst, vdst + 8 * dec->cache_uv_stride_, uvsize);
-  }
-  return 1;
-}
-
-//-----------------------------------------------------------------------------
-// Main reconstruction function.
-
-static const int kScan[16] = {
-  0 +  0 * BPS,  4 +  0 * BPS, 8 +  0 * BPS, 12 +  0 * BPS,
-  0 +  4 * BPS,  4 +  4 * BPS, 8 +  4 * BPS, 12 +  4 * BPS,
-  0 +  8 * BPS,  4 +  8 * BPS, 8 +  8 * BPS, 12 +  8 * BPS,
-  0 + 12 * BPS,  4 + 12 * BPS, 8 + 12 * BPS, 12 + 12 * BPS
-};
-
-static inline int CheckMode(VP8Decoder* const dec, int mode) {
-  if (mode == B_DC_PRED) {
-    if (dec->mb_x_ == 0) {
-      return (dec->mb_y_ == 0) ? B_DC_PRED_NOTOPLEFT : B_DC_PRED_NOLEFT;
-    } else {
-      return (dec->mb_y_ == 0) ? B_DC_PRED_NOTOP : B_DC_PRED;
-    }
-  }
-  return mode;
-}
-
-static inline void Copy32b(uint8_t* dst, uint8_t* src) {
-  *(uint32_t*)dst = *(uint32_t*)src;
-}
-
-void VP8ReconstructBlock(VP8Decoder* const dec) {
-  uint8_t* const y_dst = dec->yuv_b_ + Y_OFF;
-  uint8_t* const u_dst = dec->yuv_b_ + U_OFF;
-  uint8_t* const v_dst = dec->yuv_b_ + V_OFF;
-
-  // Rotate in the left samples from previously decoded block. We move four
-  // pixels at a time for alignment reason, and because of in-loop filter.
-  if (dec->mb_x_ > 0) {
-    int j;
-    for (j = -1; j < 16; ++j) {
-      Copy32b(&y_dst[j * BPS - 4], &y_dst[j * BPS + 12]);
-    }
-    for (j = -1; j < 8; ++j) {
-      Copy32b(&u_dst[j * BPS - 4], &u_dst[j * BPS + 4]);
-      Copy32b(&v_dst[j * BPS - 4], &v_dst[j * BPS + 4]);
-    }
-  } else {
-    int j;
-    for (j = 0; j < 16; ++j) {
-      y_dst[j * BPS - 1] = 129;
-    }
-    for (j = 0; j < 8; ++j) {
-      u_dst[j * BPS - 1] = 129;
-      v_dst[j * BPS - 1] = 129;
-    }
-    // Init top-left sample on left column too
-    if (dec->mb_y_ > 0) {
-      y_dst[-1 - BPS] = u_dst[-1 - BPS] = v_dst[-1 - BPS] = 129;
-    }
-  }
-  {
-    // bring top samples into the cache
-    uint8_t* const top_y = dec->y_t_ + dec->mb_x_ * 16;
-    uint8_t* const top_u = dec->u_t_ + dec->mb_x_ * 8;
-    uint8_t* const top_v = dec->v_t_ + dec->mb_x_ * 8;
-    const int16_t* coeffs = dec->coeffs_;
-    int n;
-
-    if (dec->mb_y_ > 0) {
-      memcpy(y_dst - BPS, top_y, 16);
-      memcpy(u_dst - BPS, top_u, 8);
-      memcpy(v_dst - BPS, top_v, 8);
-    } else if (dec->mb_x_ == 0) {
-      // we only need to do this init once at block (0,0).
-      // Afterward, it remains valid for the whole topmost row.
-      memset(y_dst - BPS - 1, 127, 16 + 4 + 1);
-      memset(u_dst - BPS - 1, 127, 8 + 1);
-      memset(v_dst - BPS - 1, 127, 8 + 1);
-    }
-
-    // predict and add residuals
-
-    if (dec->is_i4x4_) {   // 4x4
-      uint32_t* const top_right = (uint32_t*)(y_dst - BPS + 16);
-
-      if (dec->mb_y_ > 0) {
-        if (dec->mb_x_ >= dec->mb_w_ - 1) {    // on rightmost border
-          top_right[0] = top_y[15] * 0x01010101u;
-        } else {
-          memcpy(top_right, top_y + 16, sizeof(*top_right));
-        }
-      }
-      // replicate the top-right pixels below
-      top_right[BPS] = top_right[2 * BPS] = top_right[3 * BPS] = top_right[0];
-
-      // predict and add residues for all 4x4 blocks in turn.
-      for (n = 0; n < 16; n++) {
-        uint8_t* const dst = y_dst + kScan[n];
-        VP8PredLuma4[dec->imodes_[n]](dst);
-        if (dec->non_zero_ac_ & (1 << n)) {
-          VP8Transform(coeffs + n * 16, dst);
-        } else if (dec->non_zero_ & (1 << n)) {  // only DC is present
-          VP8TransformDC(coeffs + n * 16, dst);
-        }
-      }
-    } else {    // 16x16
-      const int pred_func = CheckMode(dec, dec->imodes_[0]);
-      VP8PredLuma16[pred_func](y_dst);
-      if (dec->non_zero_) {
-        for (n = 0; n < 16; n++) {
-          uint8_t* const dst = y_dst + kScan[n];
-          if (dec->non_zero_ac_ & (1 << n)) {
-            VP8Transform(coeffs + n * 16, dst);
-          } else if (dec->non_zero_ & (1 << n)) {  // only DC is present
-            VP8TransformDC(coeffs + n * 16, dst);
-          }
-        }
-      }
-    }
-    {
-      // Chroma
-      const int pred_func = CheckMode(dec, dec->uvmode_);
-      VP8PredChroma8[pred_func](u_dst);
-      VP8PredChroma8[pred_func](v_dst);
-
-      if (dec->non_zero_ & 0x0f0000) {   // chroma-U
-        const int16_t* const u_coeffs = dec->coeffs_ + 16 * 16;
-        if (dec->non_zero_ac_ & 0x0f0000) {
-          VP8TransformUV(u_coeffs, u_dst);
-        } else {
-          VP8TransformDCUV(u_coeffs, u_dst);
-        }
-      }
-      if (dec->non_zero_ & 0xf00000) {   // chroma-V
-        const int16_t* const v_coeffs = dec->coeffs_ + 20 * 16;
-        if (dec->non_zero_ac_ & 0xf00000) {
-          VP8TransformUV(v_coeffs, v_dst);
-        } else {
-          VP8TransformDCUV(v_coeffs, v_dst);
-        }
-      }
-
-      // stash away top samples for next block
-      if (dec->mb_y_ < dec->mb_h_ - 1) {
-        memcpy(top_y, y_dst + 15 * BPS, 16);
-        memcpy(top_u, u_dst +  7 * BPS,  8);
-        memcpy(top_v, v_dst +  7 * BPS,  8);
-      }
-    }
-  }
-}
-
-//-----------------------------------------------------------------------------
-
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif

src/dec/frame_dec.c

@@ -0,0 +1,812 @@
+// Copyright 2010 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Frame-reconstruction function. Memory allocation.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <stdlib.h>
+#include "./vp8i_dec.h"
+#include "../utils/utils.h"
+
+//------------------------------------------------------------------------------
+// Main reconstruction function.
+
+static const int kScan[16] = {
+  0 +  0 * BPS,  4 +  0 * BPS, 8 +  0 * BPS, 12 +  0 * BPS,
+  0 +  4 * BPS,  4 +  4 * BPS, 8 +  4 * BPS, 12 +  4 * BPS,
+  0 +  8 * BPS,  4 +  8 * BPS, 8 +  8 * BPS, 12 +  8 * BPS,
+  0 + 12 * BPS,  4 + 12 * BPS, 8 + 12 * BPS, 12 + 12 * BPS
+};
+
+static int CheckMode(int mb_x, int mb_y, int mode) {
+  if (mode == B_DC_PRED) {
+    if (mb_x == 0) {
+      return (mb_y == 0) ? B_DC_PRED_NOTOPLEFT : B_DC_PRED_NOLEFT;
+    } else {
+      return (mb_y == 0) ? B_DC_PRED_NOTOP : B_DC_PRED;
+    }
+  }
+  return mode;
+}
+
+static void Copy32b(uint8_t* const dst, const uint8_t* const src) {
+  memcpy(dst, src, 4);
+}
+
+static WEBP_INLINE void DoTransform(uint32_t bits, const int16_t* const src,
+                                    uint8_t* const dst) {
+  switch (bits >> 30) {
+    case 3:
+      VP8Transform(src, dst, 0);
+      break;
+    case 2:
+      VP8TransformAC3(src, dst);
+      break;
+    case 1:
+      VP8TransformDC(src, dst);
+      break;
+    default:
+      break;
+  }
+}
+
+static void DoUVTransform(uint32_t bits, const int16_t* const src,
+                          uint8_t* const dst) {
+  if (bits & 0xff) {    // any non-zero coeff at all?
+    if (bits & 0xaa) {  // any non-zero AC coefficient?
+      VP8TransformUV(src, dst);   // note we don't use the AC3 variant for U/V
+    } else {
+      VP8TransformDCUV(src, dst);
+    }
+  }
+}
+
+static void ReconstructRow(const VP8Decoder* const dec,
+                           const VP8ThreadContext* ctx) {
+  int j;
+  int mb_x;
+  const int mb_y = ctx->mb_y_;
+  const int cache_id = ctx->id_;
+  uint8_t* const y_dst = dec->yuv_b_ + Y_OFF;
+  uint8_t* const u_dst = dec->yuv_b_ + U_OFF;
+  uint8_t* const v_dst = dec->yuv_b_ + V_OFF;
+
+  // Initialize left-most block.
+  for (j = 0; j < 16; ++j) {
+    y_dst[j * BPS - 1] = 129;
+  }
+  for (j = 0; j < 8; ++j) {
+    u_dst[j * BPS - 1] = 129;
+    v_dst[j * BPS - 1] = 129;
+  }
+
+  // Init top-left sample on left column too.
+  if (mb_y > 0) {
+    y_dst[-1 - BPS] = u_dst[-1 - BPS] = v_dst[-1 - BPS] = 129;
+  } else {
+    // we only need to do this init once at block (0,0).
+    // Afterward, it remains valid for the whole topmost row.
+    memset(y_dst - BPS - 1, 127, 16 + 4 + 1);
+    memset(u_dst - BPS - 1, 127, 8 + 1);
+    memset(v_dst - BPS - 1, 127, 8 + 1);
+  }
+
+  // Reconstruct one row.
+  for (mb_x = 0; mb_x < dec->mb_w_; ++mb_x) {
+    const VP8MBData* const block = ctx->mb_data_ + mb_x;
+
+    // Rotate in the left samples from previously decoded block. We move four
+    // pixels at a time for alignment reason, and because of in-loop filter.
+    if (mb_x > 0) {
+      for (j = -1; j < 16; ++j) {
+        Copy32b(&y_dst[j * BPS - 4], &y_dst[j * BPS + 12]);
+      }
+      for (j = -1; j < 8; ++j) {
+        Copy32b(&u_dst[j * BPS - 4], &u_dst[j * BPS + 4]);
+        Copy32b(&v_dst[j * BPS - 4], &v_dst[j * BPS + 4]);
+      }
+    }
+    {
+      // bring top samples into the cache
+      VP8TopSamples* const top_yuv = dec->yuv_t_ + mb_x;
+      const int16_t* const coeffs = block->coeffs_;
+      uint32_t bits = block->non_zero_y_;
+      int n;
+
+      if (mb_y > 0) {
+        memcpy(y_dst - BPS, top_yuv[0].y, 16);
+        memcpy(u_dst - BPS, top_yuv[0].u, 8);
+        memcpy(v_dst - BPS, top_yuv[0].v, 8);
+      }
+
+      // predict and add residuals
+      if (block->is_i4x4_) {   // 4x4
+        uint32_t* const top_right = (uint32_t*)(y_dst - BPS + 16);
+
+        if (mb_y > 0) {
+          if (mb_x >= dec->mb_w_ - 1) {    // on rightmost border
+            memset(top_right, top_yuv[0].y[15], sizeof(*top_right));
+          } else {
+            memcpy(top_right, top_yuv[1].y, sizeof(*top_right));
+          }
+        }
+        // replicate the top-right pixels below
+        top_right[BPS] = top_right[2 * BPS] = top_right[3 * BPS] = top_right[0];
+
+        // predict and add residuals for all 4x4 blocks in turn.
+        for (n = 0; n < 16; ++n, bits <<= 2) {
+          uint8_t* const dst = y_dst + kScan[n];
+          VP8PredLuma4[block->imodes_[n]](dst);
+          DoTransform(bits, coeffs + n * 16, dst);
+        }
+      } else {    // 16x16
+        const int pred_func = CheckMode(mb_x, mb_y, block->imodes_[0]);
+        VP8PredLuma16[pred_func](y_dst);
+        if (bits != 0) {
+          for (n = 0; n < 16; ++n, bits <<= 2) {
+            DoTransform(bits, coeffs + n * 16, y_dst + kScan[n]);
+          }
+        }
+      }
+      {
+        // Chroma
+        const uint32_t bits_uv = block->non_zero_uv_;
+        const int pred_func = CheckMode(mb_x, mb_y, block->uvmode_);
+        VP8PredChroma8[pred_func](u_dst);
+        VP8PredChroma8[pred_func](v_dst);
+        DoUVTransform(bits_uv >> 0, coeffs + 16 * 16, u_dst);
+        DoUVTransform(bits_uv >> 8, coeffs + 20 * 16, v_dst);
+      }
+
+      // stash away top samples for next block
+      if (mb_y < dec->mb_h_ - 1) {
+        memcpy(top_yuv[0].y, y_dst + 15 * BPS, 16);
+        memcpy(top_yuv[0].u, u_dst +  7 * BPS,  8);
+        memcpy(top_yuv[0].v, v_dst +  7 * BPS,  8);
+      }
+    }
+    // Transfer reconstructed samples from yuv_b_ cache to final destination.
+    {
+      const int y_offset = cache_id * 16 * dec->cache_y_stride_;
+      const int uv_offset = cache_id * 8 * dec->cache_uv_stride_;
+      uint8_t* const y_out = dec->cache_y_ + mb_x * 16 + y_offset;
+      uint8_t* const u_out = dec->cache_u_ + mb_x * 8 + uv_offset;
+      uint8_t* const v_out = dec->cache_v_ + mb_x * 8 + uv_offset;
+      for (j = 0; j < 16; ++j) {
+        memcpy(y_out + j * dec->cache_y_stride_, y_dst + j * BPS, 16);
+      }
+      for (j = 0; j < 8; ++j) {
+        memcpy(u_out + j * dec->cache_uv_stride_, u_dst + j * BPS, 8);
+        memcpy(v_out + j * dec->cache_uv_stride_, v_dst + j * BPS, 8);
+      }
+    }
+  }
+}
+
+//------------------------------------------------------------------------------
+// Filtering
+
+// kFilterExtraRows[] = How many extra lines are needed on the MB boundary
+// for caching, given a filtering level.
+// Simple filter:  up to 2 luma samples are read and 1 is written.
+// Complex filter: up to 4 luma samples are read and 3 are written. Same for
+//                 U/V, so it's 8 samples total (because of the 2x upsampling).
+static const uint8_t kFilterExtraRows[3] = { 0, 2, 8 };
+
+static void DoFilter(const VP8Decoder* const dec, int mb_x, int mb_y) {
+  const VP8ThreadContext* const ctx = &dec->thread_ctx_;
+  const int cache_id = ctx->id_;
+  const int y_bps = dec->cache_y_stride_;
+  const VP8FInfo* const f_info = ctx->f_info_ + mb_x;
+  uint8_t* const y_dst = dec->cache_y_ + cache_id * 16 * y_bps + mb_x * 16;
+  const int ilevel = f_info->f_ilevel_;
+  const int limit = f_info->f_limit_;
+  if (limit == 0) {
+    return;
+  }
+  assert(limit >= 3);
+  if (dec->filter_type_ == 1) {   // simple
+    if (mb_x > 0) {
+      VP8SimpleHFilter16(y_dst, y_bps, limit + 4);
+    }
+    if (f_info->f_inner_) {
+      VP8SimpleHFilter16i(y_dst, y_bps, limit);
+    }
+    if (mb_y > 0) {
+      VP8SimpleVFilter16(y_dst, y_bps, limit + 4);
+    }
+    if (f_info->f_inner_) {
+      VP8SimpleVFilter16i(y_dst, y_bps, limit);
+    }
+  } else {    // complex
+    const int uv_bps = dec->cache_uv_stride_;
+    uint8_t* const u_dst = dec->cache_u_ + cache_id * 8 * uv_bps + mb_x * 8;
+    uint8_t* const v_dst = dec->cache_v_ + cache_id * 8 * uv_bps + mb_x * 8;
+    const int hev_thresh = f_info->hev_thresh_;
+    if (mb_x > 0) {
+      VP8HFilter16(y_dst, y_bps, limit + 4, ilevel, hev_thresh);
+      VP8HFilter8(u_dst, v_dst, uv_bps, limit + 4, ilevel, hev_thresh);
+    }
+    if (f_info->f_inner_) {
+      VP8HFilter16i(y_dst, y_bps, limit, ilevel, hev_thresh);
+      VP8HFilter8i(u_dst, v_dst, uv_bps, limit, ilevel, hev_thresh);
+    }
+    if (mb_y > 0) {
+      VP8VFilter16(y_dst, y_bps, limit + 4, ilevel, hev_thresh);
+      VP8VFilter8(u_dst, v_dst, uv_bps, limit + 4, ilevel, hev_thresh);
+    }
+    if (f_info->f_inner_) {
+      VP8VFilter16i(y_dst, y_bps, limit, ilevel, hev_thresh);
+      VP8VFilter8i(u_dst, v_dst, uv_bps, limit, ilevel, hev_thresh);
+    }
+  }
+}
+
+// Filter the decoded macroblock row (if needed)
+static void FilterRow(const VP8Decoder* const dec) {
+  int mb_x;
+  const int mb_y = dec->thread_ctx_.mb_y_;
+  assert(dec->thread_ctx_.filter_row_);
+  for (mb_x = dec->tl_mb_x_; mb_x < dec->br_mb_x_; ++mb_x) {
+    DoFilter(dec, mb_x, mb_y);
+  }
+}
+
+//------------------------------------------------------------------------------
+// Precompute the filtering strength for each segment and each i4x4/i16x16 mode.
+
+static void PrecomputeFilterStrengths(VP8Decoder* const dec) {
+  if (dec->filter_type_ > 0) {
+    int s;
+    const VP8FilterHeader* const hdr = &dec->filter_hdr_;
+    for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
+      int i4x4;
+      // First, compute the initial level
+      int base_level;
+      if (dec->segment_hdr_.use_segment_) {
+        base_level = dec->segment_hdr_.filter_strength_[s];
+        if (!dec->segment_hdr_.absolute_delta_) {
+          base_level += hdr->level_;
+        }
+      } else {
+        base_level = hdr->level_;
+      }
+      for (i4x4 = 0; i4x4 <= 1; ++i4x4) {
+        VP8FInfo* const info = &dec->fstrengths_[s][i4x4];
+        int level = base_level;
+        if (hdr->use_lf_delta_) {
+          level += hdr->ref_lf_delta_[0];
+          if (i4x4) {
+            level += hdr->mode_lf_delta_[0];
+          }
+        }
+        level = (level < 0) ? 0 : (level > 63) ? 63 : level;
+        if (level > 0) {
+          int ilevel = level;
+          if (hdr->sharpness_ > 0) {
+            if (hdr->sharpness_ > 4) {
+              ilevel >>= 2;
+            } else {
+              ilevel >>= 1;
+            }
+            if (ilevel > 9 - hdr->sharpness_) {
+              ilevel = 9 - hdr->sharpness_;
+            }
+          }
+          if (ilevel < 1) ilevel = 1;
+          info->f_ilevel_ = ilevel;
+          info->f_limit_ = 2 * level + ilevel;
+          info->hev_thresh_ = (level >= 40) ? 2 : (level >= 15) ? 1 : 0;
+        } else {
+          info->f_limit_ = 0;  // no filtering
+        }
+        info->f_inner_ = i4x4;
+      }
+    }
+  }
+}
+
+//------------------------------------------------------------------------------
+// Dithering
+
+// minimal amp that will provide a non-zero dithering effect
+#define MIN_DITHER_AMP 4
+
+#define DITHER_AMP_TAB_SIZE 12
+static const int kQuantToDitherAmp[DITHER_AMP_TAB_SIZE] = {
+  // roughly, it's dqm->uv_mat_[1]
+  8, 7, 6, 4, 4, 2, 2, 2, 1, 1, 1, 1
+};
+
+void VP8InitDithering(const WebPDecoderOptions* const options,
+                      VP8Decoder* const dec) {
+  assert(dec != NULL);
+  if (options != NULL) {
+    const int d = options->dithering_strength;
+    const int max_amp = (1 << VP8_RANDOM_DITHER_FIX) - 1;
+    const int f = (d < 0) ? 0 : (d > 100) ? max_amp : (d * max_amp / 100);
+    if (f > 0) {
+      int s;
+      int all_amp = 0;
+      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
+        VP8QuantMatrix* const dqm = &dec->dqm_[s];
+        if (dqm->uv_quant_ < DITHER_AMP_TAB_SIZE) {
+          // TODO(skal): should we specially dither more for uv_quant_ < 0?
+          const int idx = (dqm->uv_quant_ < 0) ? 0 : dqm->uv_quant_;
+          dqm->dither_ = (f * kQuantToDitherAmp[idx]) >> 3;
+        }
+        all_amp |= dqm->dither_;
+      }
+      if (all_amp != 0) {
+        VP8InitRandom(&dec->dithering_rg_, 1.0f);
+        dec->dither_ = 1;
+      }
+    }
+    // potentially allow alpha dithering
+    dec->alpha_dithering_ = options->alpha_dithering_strength;
+    if (dec->alpha_dithering_ > 100) {
+      dec->alpha_dithering_ = 100;
+    } else if (dec->alpha_dithering_ < 0) {
+      dec->alpha_dithering_ = 0;
+    }
+  }
+}
+
+// Convert to range: [-2,2] for dither=50, [-4,4] for dither=100
+static void Dither8x8(VP8Random* const rg, uint8_t* dst, int bps, int amp) {
+  uint8_t dither[64];
+  int i;
+  for (i = 0; i < 8 * 8; ++i) {
+    dither[i] = VP8RandomBits2(rg, VP8_DITHER_AMP_BITS + 1, amp);
+  }
+  VP8DitherCombine8x8(dither, dst, bps);
+}
+
+static void DitherRow(VP8Decoder* const dec) {
+  int mb_x;
+  assert(dec->dither_);
+  for (mb_x = dec->tl_mb_x_; mb_x < dec->br_mb_x_; ++mb_x) {
+    const VP8ThreadContext* const ctx = &dec->thread_ctx_;
+    const VP8MBData* const data = ctx->mb_data_ + mb_x;
+    const int cache_id = ctx->id_;
+    const int uv_bps = dec->cache_uv_stride_;
+    if (data->dither_ >= MIN_DITHER_AMP) {
+      uint8_t* const u_dst = dec->cache_u_ + cache_id * 8 * uv_bps + mb_x * 8;
+      uint8_t* const v_dst = dec->cache_v_ + cache_id * 8 * uv_bps + mb_x * 8;
+      Dither8x8(&dec->dithering_rg_, u_dst, uv_bps, data->dither_);
+      Dither8x8(&dec->dithering_rg_, v_dst, uv_bps, data->dither_);
+    }
+  }
+}
+
+//------------------------------------------------------------------------------
+// This function is called after a row of macroblocks is finished decoding.
+// It also takes into account the following restrictions:
+//  * In case of in-loop filtering, we must hold off sending some of the bottom
+//    pixels as they are yet unfiltered. They will be when the next macroblock
+//    row is decoded. Meanwhile, we must preserve them by rotating them in the
+//    cache area. This doesn't hold for the very bottom row of the uncropped
+//    picture of course.
+//  * we must clip the remaining pixels against the cropping area. The VP8Io
+//    struct must have the following fields set correctly before calling put():
+
+#define MACROBLOCK_VPOS(mb_y)  ((mb_y) * 16)    // vertical position of a MB
+
+// Finalize and transmit a complete row. Return false in case of user-abort.
+static int FinishRow(VP8Decoder* const dec, VP8Io* const io) {
+  int ok = 1;
+  const VP8ThreadContext* const ctx = &dec->thread_ctx_;
+  const int cache_id = ctx->id_;
+  const int extra_y_rows = kFilterExtraRows[dec->filter_type_];
+  const int ysize = extra_y_rows * dec->cache_y_stride_;
+  const int uvsize = (extra_y_rows / 2) * dec->cache_uv_stride_;
+  const int y_offset = cache_id * 16 * dec->cache_y_stride_;
+  const int uv_offset = cache_id * 8 * dec->cache_uv_stride_;
+  uint8_t* const ydst = dec->cache_y_ - ysize + y_offset;
+  uint8_t* const udst = dec->cache_u_ - uvsize + uv_offset;
+  uint8_t* const vdst = dec->cache_v_ - uvsize + uv_offset;
+  const int mb_y = ctx->mb_y_;
+  const int is_first_row = (mb_y == 0);
+  const int is_last_row = (mb_y >= dec->br_mb_y_ - 1);
+
+  if (dec->mt_method_ == 2) {
+    ReconstructRow(dec, ctx);
+  }
+
+  if (ctx->filter_row_) {
+    FilterRow(dec);
+  }
+
+  if (dec->dither_) {
+    DitherRow(dec);
+  }
+
+  if (io->put != NULL) {
+    int y_start = MACROBLOCK_VPOS(mb_y);
+    int y_end = MACROBLOCK_VPOS(mb_y + 1);
+    if (!is_first_row) {
+      y_start -= extra_y_rows;
+      io->y = ydst;
+      io->u = udst;
+      io->v = vdst;
+    } else {
+      io->y = dec->cache_y_ + y_offset;
+      io->u = dec->cache_u_ + uv_offset;
+      io->v = dec->cache_v_ + uv_offset;
+    }
+
+    if (!is_last_row) {
+      y_end -= extra_y_rows;
+    }
+    if (y_end > io->crop_bottom) {
+      y_end = io->crop_bottom;    // make sure we don't overflow on last row.
+    }
+    io->a = NULL;
+    if (dec->alpha_data_ != NULL && y_start < y_end) {
+      // TODO(skal): testing presence of alpha with dec->alpha_data_ is not a
+      // good idea.
+      io->a = VP8DecompressAlphaRows(dec, io, y_start, y_end - y_start);
+      if (io->a == NULL) {
+        return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
+                           "Could not decode alpha data.");
+      }
+    }
+    if (y_start < io->crop_top) {
+      const int delta_y = io->crop_top - y_start;
+      y_start = io->crop_top;
+      assert(!(delta_y & 1));
+      io->y += dec->cache_y_stride_ * delta_y;
+      io->u += dec->cache_uv_stride_ * (delta_y >> 1);
+      io->v += dec->cache_uv_stride_ * (delta_y >> 1);
+      if (io->a != NULL) {
+        io->a += io->width * delta_y;
+      }
+    }
+    if (y_start < y_end) {
+      io->y += io->crop_left;
+      io->u += io->crop_left >> 1;
+      io->v += io->crop_left >> 1;
+      if (io->a != NULL) {
+        io->a += io->crop_left;
+      }
+      io->mb_y = y_start - io->crop_top;
+      io->mb_w = io->crop_right - io->crop_left;
+      io->mb_h = y_end - y_start;
+      ok = io->put(io);
+    }
+  }
+  // rotate top samples if needed
+  if (cache_id + 1 == dec->num_caches_) {
+    if (!is_last_row) {
+      memcpy(dec->cache_y_ - ysize, ydst + 16 * dec->cache_y_stride_, ysize);
+      memcpy(dec->cache_u_ - uvsize, udst + 8 * dec->cache_uv_stride_, uvsize);
+      memcpy(dec->cache_v_ - uvsize, vdst + 8 * dec->cache_uv_stride_, uvsize);
+    }
+  }
+
+  return ok;
+}
+
+#undef MACROBLOCK_VPOS
+
+//------------------------------------------------------------------------------
+
+int VP8ProcessRow(VP8Decoder* const dec, VP8Io* const io) {
+  int ok = 1;
+  VP8ThreadContext* const ctx = &dec->thread_ctx_;
+  const int filter_row =
+      (dec->filter_type_ > 0) &&
+      (dec->mb_y_ >= dec->tl_mb_y_) && (dec->mb_y_ <= dec->br_mb_y_);
+  if (dec->mt_method_ == 0) {
+    // ctx->id_ and ctx->f_info_ are already set
+    ctx->mb_y_ = dec->mb_y_;
+    ctx->filter_row_ = filter_row;
+    ReconstructRow(dec, ctx);
+    ok = FinishRow(dec, io);
+  } else {
+    WebPWorker* const worker = &dec->worker_;
+    // Finish previous job *before* updating context
+    ok &= WebPGetWorkerInterface()->Sync(worker);
+    assert(worker->status_ == OK);
+    if (ok) {   // spawn a new deblocking/output job
+      ctx->io_ = *io;
+      ctx->id_ = dec->cache_id_;
+      ctx->mb_y_ = dec->mb_y_;
+      ctx->filter_row_ = filter_row;
+      if (dec->mt_method_ == 2) {  // swap macroblock data
+        VP8MBData* const tmp = ctx->mb_data_;
+        ctx->mb_data_ = dec->mb_data_;
+        dec->mb_data_ = tmp;
+      } else {
+        // perform reconstruction directly in main thread
+        ReconstructRow(dec, ctx);
+      }
+      if (filter_row) {            // swap filter info
+        VP8FInfo* const tmp = ctx->f_info_;
+        ctx->f_info_ = dec->f_info_;
+        dec->f_info_ = tmp;
+      }
+      // (reconstruct)+filter in parallel
+      WebPGetWorkerInterface()->Launch(worker);
+      if (++dec->cache_id_ == dec->num_caches_) {
+        dec->cache_id_ = 0;
+      }
+    }
+  }
+  return ok;
+}
+
+//------------------------------------------------------------------------------
+// Finish setting up the decoding parameter once user's setup() is called.
+
+VP8StatusCode VP8EnterCritical(VP8Decoder* const dec, VP8Io* const io) {
+  // Call setup() first. This may trigger additional decoding features on 'io'.
+  // Note: Afterward, we must call teardown() no matter what.
+  if (io->setup != NULL && !io->setup(io)) {
+    VP8SetError(dec, VP8_STATUS_USER_ABORT, "Frame setup failed");
+    return dec->status_;
+  }
+
+  // Disable filtering per user request
+  if (io->bypass_filtering) {
+    dec->filter_type_ = 0;
+  }
+  // TODO(skal): filter type / strength / sharpness forcing
+
+  // Define the area where we can skip in-loop filtering, in case of cropping.
+  //
+  // 'Simple' filter reads two luma samples outside of the macroblock
+  // and filters one. It doesn't filter the chroma samples. Hence, we can
+  // avoid doing the in-loop filtering before crop_top/crop_left position.
+  // For the 'Complex' filter, 3 samples are read and up to 3 are filtered.
+  // Means: there's a dependency chain that goes all the way up to the
+  // top-left corner of the picture (MB #0). We must filter all the previous
+  // macroblocks.
+  // TODO(skal): add an 'approximate_decoding' option, that won't produce
+  // a 1:1 bit-exactness for complex filtering?
+  {
+    const int extra_pixels = kFilterExtraRows[dec->filter_type_];
+    if (dec->filter_type_ == 2) {
+      // For complex filter, we need to preserve the dependency chain.
+      dec->tl_mb_x_ = 0;
+      dec->tl_mb_y_ = 0;
+    } else {
+      // For simple filter, we can filter only the cropped region.
+      // We include 'extra_pixels' on the other side of the boundary, since
+      // vertical or horizontal filtering of the previous macroblock can
+      // modify some abutting pixels.
+      dec->tl_mb_x_ = (io->crop_left - extra_pixels) >> 4;
+      dec->tl_mb_y_ = (io->crop_top - extra_pixels) >> 4;
+      if (dec->tl_mb_x_ < 0) dec->tl_mb_x_ = 0;
+      if (dec->tl_mb_y_ < 0) dec->tl_mb_y_ = 0;
+    }
+    // We need some 'extra' pixels on the right/bottom.
+    dec->br_mb_y_ = (io->crop_bottom + 15 + extra_pixels) >> 4;
+    dec->br_mb_x_ = (io->crop_right + 15 + extra_pixels) >> 4;
+    if (dec->br_mb_x_ > dec->mb_w_) {
+      dec->br_mb_x_ = dec->mb_w_;
+    }
+    if (dec->br_mb_y_ > dec->mb_h_) {
+      dec->br_mb_y_ = dec->mb_h_;
+    }
+  }
+  PrecomputeFilterStrengths(dec);
+  return VP8_STATUS_OK;
+}
+
+int VP8ExitCritical(VP8Decoder* const dec, VP8Io* const io) {
+  int ok = 1;
+  if (dec->mt_method_ > 0) {
+    ok = WebPGetWorkerInterface()->Sync(&dec->worker_);
+  }
+
+  if (io->teardown != NULL) {
+    io->teardown(io);
+  }
+  return ok;
+}
+
+//------------------------------------------------------------------------------
+// For multi-threaded decoding we need to use 3 rows of 16 pixels as delay line.
+//
+// Reason is: the deblocking filter cannot deblock the bottom horizontal edges
+// immediately, and needs to wait for first few rows of the next macroblock to
+// be decoded. Hence, deblocking is lagging behind by 4 or 8 pixels (depending
+// on strength).
+// With two threads, the vertical positions of the rows being decoded are:
+// Decode:  [ 0..15][16..31][32..47][48..63][64..79][...
+// Deblock:         [ 0..11][12..27][28..43][44..59][...
+// If we use two threads and two caches of 16 pixels, the sequence would be:
+// Decode:  [ 0..15][16..31][ 0..15!!][16..31][ 0..15][...
+// Deblock:         [ 0..11][12..27!!][-4..11][12..27][...
+// The problem occurs during row [12..15!!] that both the decoding and
+// deblocking threads are writing simultaneously.
+// With 3 cache lines, one get a safe write pattern:
+// Decode:  [ 0..15][16..31][32..47][ 0..15][16..31][32..47][0..
+// Deblock:         [ 0..11][12..27][28..43][-4..11][12..27][28...
+// Note that multi-threaded output _without_ deblocking can make use of two
+// cache lines of 16 pixels only, since there's no lagging behind. The decoding
+// and output process have non-concurrent writing:
+// Decode:  [ 0..15][16..31][ 0..15][16..31][...
+// io->put:         [ 0..15][16..31][ 0..15][...
+
+#define MT_CACHE_LINES 3
+#define ST_CACHE_LINES 1   // 1 cache row only for single-threaded case
+
+// Initialize multi/single-thread worker
+static int InitThreadContext(VP8Decoder* const dec) {
+  dec->cache_id_ = 0;
+  if (dec->mt_method_ > 0) {
+    WebPWorker* const worker = &dec->worker_;
+    if (!WebPGetWorkerInterface()->Reset(worker)) {
+      return VP8SetError(dec, VP8_STATUS_OUT_OF_MEMORY,
+                         "thread initialization failed.");
+    }
+    worker->data1 = dec;
+    worker->data2 = (void*)&dec->thread_ctx_.io_;
+    worker->hook = (WebPWorkerHook)FinishRow;
+    dec->num_caches_ =
+      (dec->filter_type_ > 0) ? MT_CACHE_LINES : MT_CACHE_LINES - 1;
+  } else {
+    dec->num_caches_ = ST_CACHE_LINES;
+  }
+  return 1;
+}
+
+int VP8GetThreadMethod(const WebPDecoderOptions* const options,
+                       const WebPHeaderStructure* const headers,
+                       int width, int height) {
+  if (options == NULL || options->use_threads == 0) {
+    return 0;
+  }
+  (void)headers;
+  (void)width;
+  (void)height;
+  assert(headers == NULL || !headers->is_lossless);
+#if defined(WEBP_USE_THREAD)
+  if (width < MIN_WIDTH_FOR_THREADS) return 0;
+  // TODO(skal): tune the heuristic further
+#if 0
+  if (height < 2 * width) return 2;
+#endif
+  return 2;
+#else   // !WEBP_USE_THREAD
+  return 0;
+#endif
+}
+
+#undef MT_CACHE_LINES
+#undef ST_CACHE_LINES
+
+//------------------------------------------------------------------------------
+// Memory setup
+
+static int AllocateMemory(VP8Decoder* const dec) {
+  const int num_caches = dec->num_caches_;
+  const int mb_w = dec->mb_w_;
+  // Note: we use 'size_t' when there's no overflow risk, uint64_t otherwise.
+  const size_t intra_pred_mode_size = 4 * mb_w * sizeof(uint8_t);
+  const size_t top_size = sizeof(VP8TopSamples) * mb_w;
+  const size_t mb_info_size = (mb_w + 1) * sizeof(VP8MB);
+  const size_t f_info_size =
+      (dec->filter_type_ > 0) ?
+          mb_w * (dec->mt_method_ > 0 ? 2 : 1) * sizeof(VP8FInfo)
+        : 0;
+  const size_t yuv_size = YUV_SIZE * sizeof(*dec->yuv_b_);
+  const size_t mb_data_size =
+      (dec->mt_method_ == 2 ? 2 : 1) * mb_w * sizeof(*dec->mb_data_);
+  const size_t cache_height = (16 * num_caches
+                            + kFilterExtraRows[dec->filter_type_]) * 3 / 2;
+  const size_t cache_size = top_size * cache_height;
+  // alpha_size is the only one that scales as width x height.
+  const uint64_t alpha_size = (dec->alpha_data_ != NULL) ?
+      (uint64_t)dec->pic_hdr_.width_ * dec->pic_hdr_.height_ : 0ULL;
+  const uint64_t needed = (uint64_t)intra_pred_mode_size
+                        + top_size + mb_info_size + f_info_size
+                        + yuv_size + mb_data_size
+                        + cache_size + alpha_size + WEBP_ALIGN_CST;
+  uint8_t* mem;
+
+  if (needed != (size_t)needed) return 0;  // check for overflow
+  if (needed > dec->mem_size_) {
+    WebPSafeFree(dec->mem_);
+    dec->mem_size_ = 0;
+    dec->mem_ = WebPSafeMalloc(needed, sizeof(uint8_t));
+    if (dec->mem_ == NULL) {
+      return VP8SetError(dec, VP8_STATUS_OUT_OF_MEMORY,
+                         "no memory during frame initialization.");
+    }
+    // down-cast is ok, thanks to WebPSafeMalloc() above.
+    dec->mem_size_ = (size_t)needed;
+  }
+
+  mem = (uint8_t*)dec->mem_;
+  dec->intra_t_ = (uint8_t*)mem;
+  mem += intra_pred_mode_size;
+
+  dec->yuv_t_ = (VP8TopSamples*)mem;
+  mem += top_size;
+
+  dec->mb_info_ = ((VP8MB*)mem) + 1;
+  mem += mb_info_size;
+
+  dec->f_info_ = f_info_size ? (VP8FInfo*)mem : NULL;
+  mem += f_info_size;
+  dec->thread_ctx_.id_ = 0;
+  dec->thread_ctx_.f_info_ = dec->f_info_;
+  if (dec->mt_method_ > 0) {
+    // secondary cache line. The deblocking process need to make use of the
+    // filtering strength from previous macroblock row, while the new ones
+    // are being decoded in parallel. We'll just swap the pointers.
+    dec->thread_ctx_.f_info_ += mb_w;
+  }
+
+  mem = (uint8_t*)WEBP_ALIGN(mem);
+  assert((yuv_size & WEBP_ALIGN_CST) == 0);
+  dec->yuv_b_ = (uint8_t*)mem;
+  mem += yuv_size;
+
+  dec->mb_data_ = (VP8MBData*)mem;
+  dec->thread_ctx_.mb_data_ = (VP8MBData*)mem;
+  if (dec->mt_method_ == 2) {
+    dec->thread_ctx_.mb_data_ += mb_w;
+  }
+  mem += mb_data_size;
+
+  dec->cache_y_stride_ = 16 * mb_w;
+  dec->cache_uv_stride_ = 8 * mb_w;
+  {
+    const int extra_rows = kFilterExtraRows[dec->filter_type_];
+    const int extra_y = extra_rows * dec->cache_y_stride_;
+    const int extra_uv = (extra_rows / 2) * dec->cache_uv_stride_;
+    dec->cache_y_ = ((uint8_t*)mem) + extra_y;
+    dec->cache_u_ = dec->cache_y_
+                  + 16 * num_caches * dec->cache_y_stride_ + extra_uv;
+    dec->cache_v_ = dec->cache_u_
+                  + 8 * num_caches * dec->cache_uv_stride_ + extra_uv;
+    dec->cache_id_ = 0;
+  }
+  mem += cache_size;
+
+  // alpha plane
+  dec->alpha_plane_ = alpha_size ? (uint8_t*)mem : NULL;
+  mem += alpha_size;
+  assert(mem <= (uint8_t*)dec->mem_ + dec->mem_size_);
+
+  // note: left/top-info is initialized once for all.
+  memset(dec->mb_info_ - 1, 0, mb_info_size);
+  VP8InitScanline(dec);   // initialize left too.
+
+  // initialize top
+  memset(dec->intra_t_, B_DC_PRED, intra_pred_mode_size);
+
+  return 1;
+}
+
+static void InitIo(VP8Decoder* const dec, VP8Io* io) {
+  // prepare 'io'
+  io->mb_y = 0;
+  io->y = dec->cache_y_;
+  io->u = dec->cache_u_;
+  io->v = dec->cache_v_;
+  io->y_stride = dec->cache_y_stride_;
+  io->uv_stride = dec->cache_uv_stride_;
+  io->a = NULL;
+}
+
+int VP8InitFrame(VP8Decoder* const dec, VP8Io* const io) {
+  if (!InitThreadContext(dec)) return 0;  // call first. Sets dec->num_caches_.
+  if (!AllocateMemory(dec)) return 0;
+  InitIo(dec, io);
+  VP8DspInit();  // Init critical function pointers and look-up tables.
+  return 1;
+}
+
+//------------------------------------------------------------------------------

src/dec/idec.c

@@ -1,577 +0,0 @@
-// Copyright 2011 Google Inc.
-//
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
-// -----------------------------------------------------------------------------
-//
-// Incremental decoding
-//
-// Author: somnath@google.com (Somnath Banerjee)
-
-#include <assert.h>
-#include <string.h>
-#include <stdlib.h>
-
-#include "webpi.h"
-#include "vp8i.h"
-#include "yuv.h"
-
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
-#define RIFF_HEADER_SIZE 20
-#define VP8_HEADER_SIZE 10
-#define WEBP_HEADER_SIZE (RIFF_HEADER_SIZE + VP8_HEADER_SIZE)
-#define CHUNK_SIZE 4096
-#define MAX_MB_SIZE 4096
-
-//------------------------------------------------------------------------------
-// Data structures for memory and states
-
-// Decoding states. State normally flows like HEADER->PARTS0->DATA->DONE.
-// If there is any error the decoder goes into state ERROR.
-typedef enum { STATE_HEADER = 0, STATE_PARTS0 = 1,
-               STATE_DATA = 2, STATE_DONE = 3,
-               STATE_ERROR = 4
-} DecState;
-
-// Operating state for the MemBuffer
-typedef enum { MEM_MODE_NONE = 0,
-               MEM_MODE_APPEND, MEM_MODE_MAP
-} MemBufferMode;
-
-// storage for partition #0 and partial data (in a rolling fashion)
-typedef struct {
-  MemBufferMode mode_;  // Operation mode
-  uint32_t start_;      // start location of the data to be decoded
-  uint32_t end_;        // end location
-  size_t buf_size_;     // size of the allocated buffer
-  uint8_t* buf_;        // We don't own this buffer in case WebPIUpdate()
-
-  size_t part0_size_;         // size of partition #0
-  const uint8_t* part0_buf_;  // buffer to store partition #0
-} MemBuffer;
-
-struct WebPIDecoder {
-  DecState state_;         // current decoding state
-  int w_, h_;              // width and height
-  WebPDecParams params_;   // Params to store output info
-  VP8Decoder* dec_;
-  VP8Io io_;
-
-  MemBuffer mem_;          // memory buffer
-};
-
-// MB context to restore in case VP8DecodeMB() fails
-typedef struct {
-  VP8MB left_;
-  VP8MB info_;
-  uint8_t intra_t_[4];
-  uint8_t intra_l_[4];
-  VP8BitReader br_;
-  VP8BitReader token_br_;
-} MBContext;
-
-//------------------------------------------------------------------------------
-// MemBuffer: incoming data handling
-
-#define REMAP(PTR, OLD_BASE, NEW_BASE) (PTR) = (NEW_BASE) + ((PTR) - OLD_BASE)
-
-static inline size_t MemDataSize(const MemBuffer* mem) {
-  return (mem->end_ - mem->start_);
-}
-
-// Appends data to the end of MemBuffer->buf_. It expands the allocated memory
-// size if required and also updates VP8BitReader's if new memory is allocated.
-static int AppendToMemBuffer(WebPIDecoder* const idec,
-                             const uint8_t* const data, size_t data_size) {
-  MemBuffer* const mem = &idec->mem_;
-  VP8Decoder* const dec = idec->dec_;
-  const int last_part = dec->num_parts_ - 1;
-  assert(mem->mode_ == MEM_MODE_APPEND);
-
-  if (mem->end_ + data_size > mem->buf_size_) {  // Need some free memory
-    int p;
-    uint8_t* new_buf = NULL;
-    const int num_chunks = (MemDataSize(mem) + data_size + CHUNK_SIZE - 1)
-        / CHUNK_SIZE;
-    const size_t new_size = num_chunks * CHUNK_SIZE;
-    const uint8_t* const base = mem->buf_ + mem->start_;
-
-    new_buf = (uint8_t*)malloc(new_size);
-    if (!new_buf) return 0;
-    memcpy(new_buf, base, MemDataSize(mem));
-
-    // adjust VP8BitReader pointers
-    for (p = 0; p <= last_part; ++p) {
-      if (dec->parts_[p].buf_) {
-        REMAP(dec->parts_[p].buf_, base, new_buf);
-        REMAP(dec->parts_[p].buf_end_, base, new_buf);
-      }
-    }
-
-    // adjust memory pointers
-    free(mem->buf_);
-    mem->buf_ = new_buf;
-    mem->buf_size_ = new_size;
-
-    mem->end_ = MemDataSize(mem);
-    mem->start_ = 0;
-  }
-
-  memcpy(mem->buf_ + mem->end_, data, data_size);
-  mem->end_ += data_size;
-  assert(mem->end_ <= mem->buf_size_);
-  dec->parts_[last_part].buf_end_ = mem->buf_ + mem->end_;
-
-  // note: setting up idec->io_ is only really needed at the beginning
-  // of the decoding, till partition #0 is complete.
-  idec->io_.data = mem->buf_ + mem->start_;
-  idec->io_.data_size = MemDataSize(mem);
-  return 1;
-}
-
-static int RemapMemBuffer(WebPIDecoder* const idec,
-                          const uint8_t* const data, size_t data_size) {
-  int p;
-  MemBuffer* const mem = &idec->mem_;
-  VP8Decoder* const dec = idec->dec_;
-  const int last_part = dec->num_parts_ - 1;
-  const uint8_t* base = mem->buf_;
-
-  assert(mem->mode_ == MEM_MODE_MAP);
-  if (data_size < mem->buf_size_) {
-    return 0;  // we cannot remap to a shorter buffer!
-  }
-
-  for (p = 0; p <= last_part; ++p) {
-    if (dec->parts_[p].buf_) {
-      REMAP(dec->parts_[p].buf_, base, data);
-      REMAP(dec->parts_[p].buf_end_, base, data);
-    }
-  }
-  dec->parts_[last_part].buf_end_ = data + data_size;
-
-  // Remap partition #0 data pointer to new offset.
-  if (dec->br_.buf_) {
-    REMAP(dec->br_.buf_, base, data);
-    REMAP(dec->br_.buf_end_, base, data);
-  }
-
-  mem->buf_ = (uint8_t*)data;
-  mem->end_ = mem->buf_size_ = data_size;
-
-  idec->io_.data = data;
-  idec->io_.data_size = data_size;
-  return 1;
-}
-
-static void InitMemBuffer(MemBuffer* const mem) {
-  mem->mode_       = MEM_MODE_NONE;
-  mem->buf_        = 0;
-  mem->buf_size_   = 0;
-  mem->part0_buf_  = 0;
-  mem->part0_size_ = 0;
-}
-
-static void ClearMemBuffer(MemBuffer* const mem) {
-  assert(mem);
-  if (mem->mode_ == MEM_MODE_APPEND) {
-    free(mem->buf_);
-    free((void*)mem->part0_buf_);
-  }
-}
-
-static int CheckMemBufferMode(MemBuffer* const mem, MemBufferMode expected) {
-  if (mem->mode_ == MEM_MODE_NONE) {
-    mem->mode_ = expected;    // switch to the expected mode
-  } else if (mem->mode_ != expected) {
-    return 0;         // we mixed the modes => error
-  }
-  assert(mem->mode_ == expected);   // mode is ok
-  return 1;
-}
-
-#undef REMAP
-
-//------------------------------------------------------------------------------
-// Macroblock-decoding contexts
-
-static void SaveContext(const VP8Decoder* dec, const VP8BitReader* token_br,
-                        MBContext* const context) {
-  const VP8BitReader* const br = &dec->br_;
-  const VP8MB* const left = dec->mb_info_ - 1;
-  const VP8MB* const info = dec->mb_info_ + dec->mb_x_;
-
-  context->left_ = *left;
-  context->info_ = *info;
-  context->br_ = *br;
-  context->token_br_ = *token_br;
-  memcpy(context->intra_t_, dec->intra_t_ + 4 * dec->mb_x_, 4);
-  memcpy(context->intra_l_, dec->intra_l_, 4);
-}
-
-static void RestoreContext(const MBContext* context, VP8Decoder* const dec,
-                           VP8BitReader* const token_br) {
-  VP8BitReader* const br = &dec->br_;
-  VP8MB* const left = dec->mb_info_ - 1;
-  VP8MB* const info = dec->mb_info_ + dec->mb_x_;
-
-  *left = context->left_;
-  *info = context->info_;
-  *br = context->br_;
-  *token_br = context->token_br_;
-  memcpy(dec->intra_t_ + 4 * dec->mb_x_, context->intra_t_, 4);
-  memcpy(dec->intra_l_, context->intra_l_, 4);
-}
-
-//------------------------------------------------------------------------------
-
-static VP8StatusCode IDecError(WebPIDecoder* idec, VP8StatusCode error) {
-  idec->state_ = STATE_ERROR;
-  return error;
-}
-
-// Header
-static VP8StatusCode DecodeHeader(WebPIDecoder* const idec) {
-  int width, height;
-  uint32_t curr_size, riff_header_size, bits;
-  WebPDecParams* params = &idec->params_;
-  const uint8_t* data = idec->mem_.buf_ + idec->mem_.start_;
-
-  if (MemDataSize(&idec->mem_) < WEBP_HEADER_SIZE) {
-    return VP8_STATUS_SUSPENDED;
-  }
-
-  if (!WebPInitDecParams(data, idec->mem_.end_, &width, &height, params)) {
-    return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
-  }
-
-  // Validate and Skip over RIFF header
-  curr_size = MemDataSize(&idec->mem_);
-  if (!WebPCheckRIFFHeader(&data, &curr_size)) {
-    return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
-  }
-  riff_header_size = idec->mem_.end_ - curr_size;
-  bits = data[0] | (data[1] << 8) | (data[2] << 16);
-
-  idec->mem_.part0_size_ = (bits >> 5) + VP8_HEADER_SIZE;
-  idec->mem_.start_ += riff_header_size;
-  assert(idec->mem_.start_ <= idec->mem_.end_);
-
-  idec->w_ = width;
-  idec->h_ = height;
-  idec->io_.data_size -= riff_header_size;
-  idec->io_.data = data;
-  idec->state_ = STATE_PARTS0;
-  return VP8_STATUS_OK;
-}
-
-// Partition #0
-static int CopyParts0Data(WebPIDecoder* idec) {
-  VP8BitReader* const br = &idec->dec_->br_;
-  const size_t psize = br->buf_end_ - br->buf_;
-  MemBuffer* const mem = &idec->mem_;
-  assert(!mem->part0_buf_);
-  assert(psize > 0);
-  assert(psize <= mem->part0_size_);
-  if (mem->mode_ == MEM_MODE_APPEND) {
-    // We copy and grab ownership of the partition #0 data.
-    uint8_t* const part0_buf = (uint8_t*)malloc(psize);
-    if (!part0_buf) {
-      return 0;
-    }
-    memcpy(part0_buf, br->buf_, psize);
-    mem->part0_buf_ = part0_buf;
-    mem->start_ += psize;
-    br->buf_ = part0_buf;
-    br->buf_end_ = part0_buf + psize;
-  } else {
-    // Else: just keep pointers to the partition #0's data in dec_->br_.
-  }
-  return 1;
-}
-
-static VP8StatusCode DecodePartition0(WebPIDecoder* const idec) {
-  VP8Decoder* const dec = idec->dec_;
-  VP8Io* const io = &idec->io_;
-  const WebPDecParams* const params = &idec->params_;
-  const WEBP_CSP_MODE mode = params->mode;
-
-  // Wait till we have enough data for the whole partition #0
-  if (MemDataSize(&idec->mem_) < idec->mem_.part0_size_) {
-    return VP8_STATUS_SUSPENDED;
-  }
-
-  io->opaque = &idec->params_;
-  if (!VP8GetHeaders(dec, io)) {
-    const VP8StatusCode status = dec->status_;
-    if (status == VP8_STATUS_SUSPENDED ||
-        status == VP8_STATUS_NOT_ENOUGH_DATA) {
-      // treating NOT_ENOUGH_DATA as SUSPENDED state
-      return VP8_STATUS_SUSPENDED;
-    }
-    return IDecError(idec, status);
-  }
-
-  if (!WebPCheckDecParams(io, params)) {
-    return IDecError(idec, VP8_STATUS_INVALID_PARAM);
-  }
-
-  if (mode != MODE_YUV) {
-    VP8YUVInit();
-  }
-
-  // allocate memory and prepare everything.
-  if (!VP8InitFrame(dec, io)) {
-    return IDecError(idec, VP8_STATUS_OUT_OF_MEMORY);
-  }
-  if (io->setup && !io->setup(io)) {
-    return IDecError(idec, VP8_STATUS_USER_ABORT);
-  }
-
-  // disable filtering per user request (_after_ setup() is called)
-  if (io->bypass_filtering) dec->filter_type_ = 0;
-
-  if (!CopyParts0Data(idec)) {
-    return IDecError(idec, VP8_STATUS_OUT_OF_MEMORY);
-  }
-
-  idec->state_ = STATE_DATA;
-  return VP8_STATUS_OK;
-}
-
-// Remaining partitions
-static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) {
-  VP8BitReader*  br;
-  VP8Decoder* const dec = idec->dec_;
-  VP8Io* const io = &idec->io_;
-
-  assert(dec->ready_);
-
-  br = &dec->br_;
-  for (; dec->mb_y_ < dec->mb_h_; ++dec->mb_y_) {
-    VP8BitReader* token_br = &dec->parts_[dec->mb_y_ & (dec->num_parts_ - 1)];
-    if (dec->mb_x_ == 0) {
-      VP8MB* const left = dec->mb_info_ - 1;
-      left->nz_ = 0;
-      left->dc_nz_ = 0;
-      memset(dec->intra_l_, B_DC_PRED, sizeof(dec->intra_l_));
-    }
-
-    for (; dec->mb_x_ < dec->mb_w_;  dec->mb_x_++) {
-      MBContext context;
-      SaveContext(dec, token_br, &context);
-
-      if (!VP8DecodeMB(dec, token_br)) {
-        RestoreContext(&context, dec, token_br);
-        // We shouldn't fail when MAX_MB data was available
-        if (dec->num_parts_ == 1 && MemDataSize(&idec->mem_) > MAX_MB_SIZE) {
-          return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
-        }
-        return VP8_STATUS_SUSPENDED;
-      }
-      VP8ReconstructBlock(dec);
-      // Store data and save block's filtering params
-      VP8StoreBlock(dec);
-
-      // Release buffer only if there is only one partition
-      if (dec->num_parts_ == 1) {
-        idec->mem_.start_ = token_br->buf_ - idec->mem_.buf_;
-        assert(idec->mem_.start_ <= idec->mem_.end_);
-      }
-    }
-    if (!VP8FinishRow(dec, io)) {
-      return IDecError(idec, VP8_STATUS_USER_ABORT);
-    }
-    dec->mb_x_ = 0;
-  }
-
-  if (io->teardown) {
-    io->teardown(io);
-  }
-  dec->ready_ = 0;
-  idec->state_ = STATE_DONE;
-
-  return VP8_STATUS_OK;
-}
-
-  // Main decoding loop
-static VP8StatusCode IDecode(WebPIDecoder* idec) {
-  VP8StatusCode status = VP8_STATUS_SUSPENDED;
-  assert(idec->dec_);
-
-  if (idec->state_ == STATE_HEADER) {
-    status = DecodeHeader(idec);
-  }
-  if (idec->state_ == STATE_PARTS0) {
-    status = DecodePartition0(idec);
-  }
-  if (idec->state_ == STATE_DATA) {
-    return DecodeRemaining(idec);
-  }
-  return status;
-}
-
-//------------------------------------------------------------------------------
-// Public functions
-
-WebPIDecoder* WebPINew(WEBP_CSP_MODE mode) {
-  WebPIDecoder* idec = (WebPIDecoder*)calloc(1, sizeof(WebPIDecoder));
-  if (!idec) return NULL;
-
-  idec->dec_ = VP8New();
-  if (idec->dec_ == NULL) {
-    free(idec);
-    return NULL;
-  }
-
-  idec->state_ = STATE_HEADER;
-  idec->params_.mode = mode;
-
-  InitMemBuffer(&idec->mem_);
-  VP8InitIo(&idec->io_);
-  WebPInitCustomIo(&idec->io_);
-  return idec;
-}
-
-void WebPIDelete(WebPIDecoder* const idec) {
-  if (!idec) return;
-  VP8Delete(idec->dec_);
-  WebPClearDecParams(&idec->params_);
-  ClearMemBuffer(&idec->mem_);
-  free(idec);
-}
-
-//------------------------------------------------------------------------------
-
-WebPIDecoder* WebPINewRGB(WEBP_CSP_MODE mode, uint8_t* output_buffer,
-                          int output_buffer_size, int output_stride) {
-  WebPIDecoder* idec;
-  if (mode == MODE_YUV) return NULL;
-  idec = WebPINew(mode);
-  if (idec == NULL) return NULL;
-  idec->params_.output = output_buffer;
-  idec->params_.stride = output_stride;
-  idec->params_.output_size = output_buffer_size;
-  idec->params_.external_buffer = 1;
-  return idec;
-}
-
-WebPIDecoder* WebPINewYUV(uint8_t* luma, int luma_size, int luma_stride,
-                          uint8_t* u, int u_size, int u_stride,
-                          uint8_t* v, int v_size, int v_stride) {
-  WebPIDecoder* idec = WebPINew(MODE_YUV);
-  if (idec == NULL) return NULL;
-  idec->params_.output = luma;
-  idec->params_.stride = luma_stride;
-  idec->params_.output_size = luma_size;
-  idec->params_.u = u;
-  idec->params_.u_stride = u_stride;
-  idec->params_.output_u_size = u_size;
-  idec->params_.v = v;
-  idec->params_.v_stride = v_stride;
-  idec->params_.output_v_size = v_size;
-  idec->params_.external_buffer = 1;
-  return idec;
-}
-
-//------------------------------------------------------------------------------
-
-static VP8StatusCode IDecCheckStatus(const WebPIDecoder* const idec) {
-  assert(idec);
-  if (idec->dec_ == NULL) {
-    return VP8_STATUS_USER_ABORT;
-  }
-  if (idec->state_ == STATE_ERROR) {
-    return VP8_STATUS_BITSTREAM_ERROR;
-  }
-  if (idec->state_ == STATE_DONE) {
-    return VP8_STATUS_OK;
-  }
-  return VP8_STATUS_SUSPENDED;
-}
-
-VP8StatusCode WebPIAppend(WebPIDecoder* const idec, const uint8_t* data,
-                          uint32_t data_size) {
-  VP8StatusCode status;
-  if (idec == NULL || data == NULL) {
-    return VP8_STATUS_INVALID_PARAM;
-  }
-  status = IDecCheckStatus(idec);
-  if (status != VP8_STATUS_SUSPENDED) {
-    return status;
-  }
-  // Check mixed calls between RemapMemBuffer and AppendToMemBuffer.
-  if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_APPEND)) {
-    return VP8_STATUS_INVALID_PARAM;
-  }
-  // Append data to memory buffer
-  if (!AppendToMemBuffer(idec, data, data_size)) {
-    return VP8_STATUS_OUT_OF_MEMORY;
-  }
-  return IDecode(idec);
-}
-
-VP8StatusCode WebPIUpdate(WebPIDecoder* const idec, const uint8_t* data,
-                          uint32_t data_size) {
-  VP8StatusCode status;
-  if (idec == NULL || data == NULL) {
-    return VP8_STATUS_INVALID_PARAM;
-  }
-  status = IDecCheckStatus(idec);
-  if (status != VP8_STATUS_SUSPENDED) {
-    return status;
-  }
-  // Check mixed calls between RemapMemBuffer and AppendToMemBuffer.
-  if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_MAP)) {
-    return VP8_STATUS_INVALID_PARAM;
-  }
-  // Make the memory buffer point to the new buffer
-  if (!RemapMemBuffer(idec, data, data_size)) {
-    return VP8_STATUS_INVALID_PARAM;
-  }
-  return IDecode(idec);
-}
-
-//------------------------------------------------------------------------------
-
-uint8_t* WebPIDecGetRGB(const WebPIDecoder* const idec, int *last_y,
-                        int* width, int* height, int* stride) {
-  if (!idec || !idec->dec_ || idec->params_.mode != MODE_RGB ||
-      idec->state_ <= STATE_PARTS0) {
-    return NULL;
-  }
-
-  if (last_y) *last_y = idec->params_.last_y;
-  if (width) *width = idec->w_;
-  if (height) *height = idec->h_;
-  if (stride) *stride = idec->params_.stride;
-
-  return idec->params_.output;
-}
-
-uint8_t* WebPIDecGetYUV(const WebPIDecoder* const idec, int *last_y,
-                        uint8_t** u, uint8_t** v, int* width, int* height,
-                        int *stride, int* uv_stride) {
-  if (!idec || !idec->dec_ || idec->params_.mode != MODE_YUV ||
-      idec->state_ <= STATE_PARTS0) {
-    return NULL;
-  }
-
-  if (last_y) *last_y = idec->params_.last_y;
-  if (u) *u = idec->params_.u;
-  if (v) *v = idec->params_.v;
-  if (width) *width = idec->w_;
-  if (height) *height = idec->h_;
-  if (stride) *stride = idec->params_.stride;
-  if (uv_stride) *uv_stride = idec->params_.u_stride;
-
-  return idec->params_.output;
-}
-
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif

src/dec/idec_dec.c

@@ -0,0 +1,892 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Incremental decoding
+//
+// Author: somnath@google.com (Somnath Banerjee)
+
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "./alphai_dec.h"
+#include "./webpi_dec.h"
+#include "./vp8i_dec.h"
+#include "../utils/utils.h"
+
+// In append mode, buffer allocations increase as multiples of this value.
+// Needs to be a power of 2.
+#define CHUNK_SIZE 4096
+#define MAX_MB_SIZE 4096
+
+//------------------------------------------------------------------------------
+// Data structures for memory and states
+
+// Decoding states. State normally flows as:
+// WEBP_HEADER->VP8_HEADER->VP8_PARTS0->VP8_DATA->DONE for a lossy image, and
+// WEBP_HEADER->VP8L_HEADER->VP8L_DATA->DONE for a lossless image.
+// If there is any error the decoder goes into state ERROR.
+typedef enum {
+  STATE_WEBP_HEADER,  // All the data before that of the VP8/VP8L chunk.
+  STATE_VP8_HEADER,   // The VP8 Frame header (within the VP8 chunk).
+  STATE_VP8_PARTS0,
+  STATE_VP8_DATA,
+  STATE_VP8L_HEADER,
+  STATE_VP8L_DATA,
+  STATE_DONE,
+  STATE_ERROR
+} DecState;
+
+// Operating state for the MemBuffer
+typedef enum {
+  MEM_MODE_NONE = 0,
+  MEM_MODE_APPEND,
+  MEM_MODE_MAP
+} MemBufferMode;
+
+// storage for partition #0 and partial data (in a rolling fashion)
+typedef struct {
+  MemBufferMode mode_;  // Operation mode
+  size_t start_;        // start location of the data to be decoded
+  size_t end_;          // end location
+  size_t buf_size_;     // size of the allocated buffer
+  uint8_t* buf_;        // We don't own this buffer in case WebPIUpdate()
+
+  size_t part0_size_;         // size of partition #0
+  const uint8_t* part0_buf_;  // buffer to store partition #0
+} MemBuffer;
+
+struct WebPIDecoder {
+  DecState state_;         // current decoding state
+  WebPDecParams params_;   // Params to store output info
+  int is_lossless_;        // for down-casting 'dec_'.
+  void* dec_;              // either a VP8Decoder or a VP8LDecoder instance
+  VP8Io io_;
+
+  MemBuffer mem_;          // input memory buffer.
+  WebPDecBuffer output_;   // output buffer (when no external one is supplied,
+                           // or if the external one has slow-memory)
+  WebPDecBuffer* final_output_;  // Slow-memory output to copy to eventually.
+  size_t chunk_size_;      // Compressed VP8/VP8L size extracted from Header.
+
+  int last_mb_y_;          // last row reached for intra-mode decoding
+};
+
+// MB context to restore in case VP8DecodeMB() fails
+typedef struct {
+  VP8MB left_;
+  VP8MB info_;
+  VP8BitReader token_br_;
+} MBContext;
+
+//------------------------------------------------------------------------------
+// MemBuffer: incoming data handling
+
+static WEBP_INLINE size_t MemDataSize(const MemBuffer* mem) {
+  return (mem->end_ - mem->start_);
+}
+
+// Check if we need to preserve the compressed alpha data, as it may not have
+// been decoded yet.
+static int NeedCompressedAlpha(const WebPIDecoder* const idec) {
+  if (idec->state_ == STATE_WEBP_HEADER) {
+    // We haven't parsed the headers yet, so we don't know whether the image is
+    // lossy or lossless. This also means that we haven't parsed the ALPH chunk.
+    return 0;
+  }
+  if (idec->is_lossless_) {
+    return 0;  // ALPH chunk is not present for lossless images.
+  } else {
+    const VP8Decoder* const dec = (VP8Decoder*)idec->dec_;
+    assert(dec != NULL);  // Must be true as idec->state_ != STATE_WEBP_HEADER.
+    return (dec->alpha_data_ != NULL) && !dec->is_alpha_decoded_;
+  }
+}
+
+static void DoRemap(WebPIDecoder* const idec, ptrdiff_t offset) {
+  MemBuffer* const mem = &idec->mem_;
+  const uint8_t* const new_base = mem->buf_ + mem->start_;
+  // note: for VP8, setting up idec->io_ is only really needed at the beginning
+  // of the decoding, till partition #0 is complete.
+  idec->io_.data = new_base;
+  idec->io_.data_size = MemDataSize(mem);
+
+  if (idec->dec_ != NULL) {
+    if (!idec->is_lossless_) {
+      VP8Decoder* const dec = (VP8Decoder*)idec->dec_;
+      const uint32_t last_part = dec->num_parts_minus_one_;
+      if (offset != 0) {
+        uint32_t p;
+        for (p = 0; p <= last_part; ++p) {
+          VP8RemapBitReader(dec->parts_ + p, offset);
+        }
+        // Remap partition #0 data pointer to new offset, but only in MAP
+        // mode (in APPEND mode, partition #0 is copied into a fixed memory).
+        if (mem->mode_ == MEM_MODE_MAP) {
+          VP8RemapBitReader(&dec->br_, offset);
+        }
+      }
+      {
+        const uint8_t* const last_start = dec->parts_[last_part].buf_;
+        VP8BitReaderSetBuffer(&dec->parts_[last_part], last_start,
+                              mem->buf_ + mem->end_ - last_start);
+      }
+      if (NeedCompressedAlpha(idec)) {
+        ALPHDecoder* const alph_dec = dec->alph_dec_;
+        dec->alpha_data_ += offset;
+        if (alph_dec != NULL) {
+          if (alph_dec->method_ == ALPHA_LOSSLESS_COMPRESSION) {
+            VP8LDecoder* const alph_vp8l_dec = alph_dec->vp8l_dec_;
+            assert(alph_vp8l_dec != NULL);
+            assert(dec->alpha_data_size_ >= ALPHA_HEADER_LEN);
+            VP8LBitReaderSetBuffer(&alph_vp8l_dec->br_,
+                                   dec->alpha_data_ + ALPHA_HEADER_LEN,
+                                   dec->alpha_data_size_ - ALPHA_HEADER_LEN);
+          } else {  // alph_dec->method_ == ALPHA_NO_COMPRESSION
+            // Nothing special to do in this case.
+          }
+        }
+      }
+    } else {    // Resize lossless bitreader
+      VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_;
+      VP8LBitReaderSetBuffer(&dec->br_, new_base, MemDataSize(mem));
+    }
+  }
+}
+
+// Appends data to the end of MemBuffer->buf_. It expands the allocated memory
+// size if required and also updates VP8BitReader's if new memory is allocated.
+static int AppendToMemBuffer(WebPIDecoder* const idec,
+                             const uint8_t* const data, size_t data_size) {
+  VP8Decoder* const dec = (VP8Decoder*)idec->dec_;
+  MemBuffer* const mem = &idec->mem_;
+  const int need_compressed_alpha = NeedCompressedAlpha(idec);
+  const uint8_t* const old_start = mem->buf_ + mem->start_;
+  const uint8_t* const old_base =
+      need_compressed_alpha ? dec->alpha_data_ : old_start;
+  assert(mem->mode_ == MEM_MODE_APPEND);
+  if (data_size > MAX_CHUNK_PAYLOAD) {
+    // security safeguard: trying to allocate more than what the format
+    // allows for a chunk should be considered a smoke smell.
+    return 0;
+  }
+
+  if (mem->end_ + data_size > mem->buf_size_) {  // Need some free memory
+    const size_t new_mem_start = old_start - old_base;
+    const size_t current_size = MemDataSize(mem) + new_mem_start;
+    const uint64_t new_size = (uint64_t)current_size + data_size;
+    const uint64_t extra_size = (new_size + CHUNK_SIZE - 1) & ~(CHUNK_SIZE - 1);
+    uint8_t* const new_buf =
+        (uint8_t*)WebPSafeMalloc(extra_size, sizeof(*new_buf));
+    if (new_buf == NULL) return 0;
+    memcpy(new_buf, old_base, current_size);
+    WebPSafeFree(mem->buf_);
+    mem->buf_ = new_buf;
+    mem->buf_size_ = (size_t)extra_size;
+    mem->start_ = new_mem_start;
+    mem->end_ = current_size;
+  }
+
+  memcpy(mem->buf_ + mem->end_, data, data_size);
+  mem->end_ += data_size;
+  assert(mem->end_ <= mem->buf_size_);
+
+  DoRemap(idec, mem->buf_ + mem->start_ - old_start);
+  return 1;
+}
+
+static int RemapMemBuffer(WebPIDecoder* const idec,
+                          const uint8_t* const data, size_t data_size) {
+  MemBuffer* const mem = &idec->mem_;
+  const uint8_t* const old_buf = mem->buf_;
+  const uint8_t* const old_start = old_buf + mem->start_;
+  assert(mem->mode_ == MEM_MODE_MAP);
+
+  if (data_size < mem->buf_size_) return 0;  // can't remap to a shorter buffer!
+
+  mem->buf_ = (uint8_t*)data;
+  mem->end_ = mem->buf_size_ = data_size;
+
+  DoRemap(idec, mem->buf_ + mem->start_ - old_start);
+  return 1;
+}
+
+static void InitMemBuffer(MemBuffer* const mem) {
+  mem->mode_       = MEM_MODE_NONE;
+  mem->buf_        = NULL;
+  mem->buf_size_   = 0;
+  mem->part0_buf_  = NULL;
+  mem->part0_size_ = 0;
+}
+
+static void ClearMemBuffer(MemBuffer* const mem) {
+  assert(mem);
+  if (mem->mode_ == MEM_MODE_APPEND) {
+    WebPSafeFree(mem->buf_);
+    WebPSafeFree((void*)mem->part0_buf_);
+  }
+}
+
+static int CheckMemBufferMode(MemBuffer* const mem, MemBufferMode expected) {
+  if (mem->mode_ == MEM_MODE_NONE) {
+    mem->mode_ = expected;    // switch to the expected mode
+  } else if (mem->mode_ != expected) {
+    return 0;         // we mixed the modes => error
+  }
+  assert(mem->mode_ == expected);   // mode is ok
+  return 1;
+}
+
+// To be called last.
+static VP8StatusCode FinishDecoding(WebPIDecoder* const idec) {
+  const WebPDecoderOptions* const options = idec->params_.options;
+  WebPDecBuffer* const output = idec->params_.output;
+
+  idec->state_ = STATE_DONE;
+  if (options != NULL && options->flip) {
+    const VP8StatusCode status = WebPFlipBuffer(output);
+    if (status != VP8_STATUS_OK) return status;
+  }
+  if (idec->final_output_ != NULL) {
+    WebPCopyDecBufferPixels(output, idec->final_output_);  // do the slow-copy
+    WebPFreeDecBuffer(&idec->output_);
+    *output = *idec->final_output_;
+    idec->final_output_ = NULL;
+  }
+  return VP8_STATUS_OK;
+}
+
+//------------------------------------------------------------------------------
+// Macroblock-decoding contexts
+
+static void SaveContext(const VP8Decoder* dec, const VP8BitReader* token_br,
+                        MBContext* const context) {
+  context->left_ = dec->mb_info_[-1];
+  context->info_ = dec->mb_info_[dec->mb_x_];
+  context->token_br_ = *token_br;
+}
+
+static void RestoreContext(const MBContext* context, VP8Decoder* const dec,
+                           VP8BitReader* const token_br) {
+  dec->mb_info_[-1] = context->left_;
+  dec->mb_info_[dec->mb_x_] = context->info_;
+  *token_br = context->token_br_;
+}
+
+//------------------------------------------------------------------------------
+
+static VP8StatusCode IDecError(WebPIDecoder* const idec, VP8StatusCode error) {
+  if (idec->state_ == STATE_VP8_DATA) {
+    VP8Io* const io = &idec->io_;
+    if (io->teardown != NULL) {
+      io->teardown(io);
+    }
+  }
+  idec->state_ = STATE_ERROR;
+  return error;
+}
+
+static void ChangeState(WebPIDecoder* const idec, DecState new_state,
+                        size_t consumed_bytes) {
+  MemBuffer* const mem = &idec->mem_;
+  idec->state_ = new_state;
+  mem->start_ += consumed_bytes;
+  assert(mem->start_ <= mem->end_);
+  idec->io_.data = mem->buf_ + mem->start_;
+  idec->io_.data_size = MemDataSize(mem);
+}
+
+// Headers
+static VP8StatusCode DecodeWebPHeaders(WebPIDecoder* const idec) {
+  MemBuffer* const mem = &idec->mem_;
+  const uint8_t* data = mem->buf_ + mem->start_;
+  size_t curr_size = MemDataSize(mem);
+  VP8StatusCode status;
+  WebPHeaderStructure headers;
+
+  headers.data = data;
+  headers.data_size = curr_size;
+  headers.have_all_data = 0;
+  status = WebPParseHeaders(&headers);
+  if (status == VP8_STATUS_NOT_ENOUGH_DATA) {
+    return VP8_STATUS_SUSPENDED;  // We haven't found a VP8 chunk yet.
+  } else if (status != VP8_STATUS_OK) {
+    return IDecError(idec, status);
+  }
+
+  idec->chunk_size_ = headers.compressed_size;
+  idec->is_lossless_ = headers.is_lossless;
+  if (!idec->is_lossless_) {
+    VP8Decoder* const dec = VP8New();
+    if (dec == NULL) {
+      return VP8_STATUS_OUT_OF_MEMORY;
+    }
+    idec->dec_ = dec;
+    dec->alpha_data_ = headers.alpha_data;
+    dec->alpha_data_size_ = headers.alpha_data_size;
+    ChangeState(idec, STATE_VP8_HEADER, headers.offset);
+  } else {
+    VP8LDecoder* const dec = VP8LNew();
+    if (dec == NULL) {
+      return VP8_STATUS_OUT_OF_MEMORY;
+    }
+    idec->dec_ = dec;
+    ChangeState(idec, STATE_VP8L_HEADER, headers.offset);
+  }
+  return VP8_STATUS_OK;
+}
+
+static VP8StatusCode DecodeVP8FrameHeader(WebPIDecoder* const idec) {
+  const uint8_t* data = idec->mem_.buf_ + idec->mem_.start_;
+  const size_t curr_size = MemDataSize(&idec->mem_);
+  int width, height;
+  uint32_t bits;
+
+  if (curr_size < VP8_FRAME_HEADER_SIZE) {
+    // Not enough data bytes to extract VP8 Frame Header.
+    return VP8_STATUS_SUSPENDED;
+  }
+  if (!VP8GetInfo(data, curr_size, idec->chunk_size_, &width, &height)) {
+    return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
+  }
+
+  bits = data[0] | (data[1] << 8) | (data[2] << 16);
+  idec->mem_.part0_size_ = (bits >> 5) + VP8_FRAME_HEADER_SIZE;
+
+  idec->io_.data = data;
+  idec->io_.data_size = curr_size;
+  idec->state_ = STATE_VP8_PARTS0;
+  return VP8_STATUS_OK;
+}
+
+// Partition #0
+static VP8StatusCode CopyParts0Data(WebPIDecoder* const idec) {
+  VP8Decoder* const dec = (VP8Decoder*)idec->dec_;
+  VP8BitReader* const br = &dec->br_;
+  const size_t part_size = br->buf_end_ - br->buf_;
+  MemBuffer* const mem = &idec->mem_;
+  assert(!idec->is_lossless_);
+  assert(mem->part0_buf_ == NULL);
+  // the following is a format limitation, no need for runtime check:
+  assert(part_size <= mem->part0_size_);
+  if (part_size == 0) {   // can't have zero-size partition #0
+    return VP8_STATUS_BITSTREAM_ERROR;
+  }
+  if (mem->mode_ == MEM_MODE_APPEND) {
+    // We copy and grab ownership of the partition #0 data.
+    uint8_t* const part0_buf = (uint8_t*)WebPSafeMalloc(1ULL, part_size);
+    if (part0_buf == NULL) {
+      return VP8_STATUS_OUT_OF_MEMORY;
+    }
+    memcpy(part0_buf, br->buf_, part_size);
+    mem->part0_buf_ = part0_buf;
+    VP8BitReaderSetBuffer(br, part0_buf, part_size);
+  } else {
+    // Else: just keep pointers to the partition #0's data in dec_->br_.
+  }
+  mem->start_ += part_size;
+  return VP8_STATUS_OK;
+}
+
+static VP8StatusCode DecodePartition0(WebPIDecoder* const idec) {
+  VP8Decoder* const dec = (VP8Decoder*)idec->dec_;
+  VP8Io* const io = &idec->io_;
+  const WebPDecParams* const params = &idec->params_;
+  WebPDecBuffer* const output = params->output;
+
+  // Wait till we have enough data for the whole partition #0
+  if (MemDataSize(&idec->mem_) < idec->mem_.part0_size_) {
+    return VP8_STATUS_SUSPENDED;
+  }
+
+  if (!VP8GetHeaders(dec, io)) {
+    const VP8StatusCode status = dec->status_;
+    if (status == VP8_STATUS_SUSPENDED ||
+        status == VP8_STATUS_NOT_ENOUGH_DATA) {
+      // treating NOT_ENOUGH_DATA as SUSPENDED state
+      return VP8_STATUS_SUSPENDED;
+    }
+    return IDecError(idec, status);
+  }
+
+  // Allocate/Verify output buffer now
+  dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options,
+                                       output);
+  if (dec->status_ != VP8_STATUS_OK) {
+    return IDecError(idec, dec->status_);
+  }
+  // This change must be done before calling VP8InitFrame()
+  dec->mt_method_ = VP8GetThreadMethod(params->options, NULL,
+                                       io->width, io->height);
+  VP8InitDithering(params->options, dec);
+
+  dec->status_ = CopyParts0Data(idec);
+  if (dec->status_ != VP8_STATUS_OK) {
+    return IDecError(idec, dec->status_);
+  }
+
+  // Finish setting up the decoding parameters. Will call io->setup().
+  if (VP8EnterCritical(dec, io) != VP8_STATUS_OK) {
+    return IDecError(idec, dec->status_);
+  }
+
+  // Note: past this point, teardown() must always be called
+  // in case of error.
+  idec->state_ = STATE_VP8_DATA;
+  // Allocate memory and prepare everything.
+  if (!VP8InitFrame(dec, io)) {
+    return IDecError(idec, dec->status_);
+  }
+  return VP8_STATUS_OK;
+}
+
+// Remaining partitions
+static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) {
+  VP8Decoder* const dec = (VP8Decoder*)idec->dec_;
+  VP8Io* const io = &idec->io_;
+
+  assert(dec->ready_);
+  for (; dec->mb_y_ < dec->mb_h_; ++dec->mb_y_) {
+    if (idec->last_mb_y_ != dec->mb_y_) {
+      if (!VP8ParseIntraModeRow(&dec->br_, dec)) {
+        // note: normally, error shouldn't occur since we already have the whole
+        // partition0 available here in DecodeRemaining(). Reaching EOF while
+        // reading intra modes really means a BITSTREAM_ERROR.
+        return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
+      }
+      idec->last_mb_y_ = dec->mb_y_;
+    }
+    for (; dec->mb_x_ < dec->mb_w_; ++dec->mb_x_) {
+      VP8BitReader* const token_br =
+          &dec->parts_[dec->mb_y_ & dec->num_parts_minus_one_];
+      MBContext context;
+      SaveContext(dec, token_br, &context);
+      if (!VP8DecodeMB(dec, token_br)) {
+        // We shouldn't fail when MAX_MB data was available
+        if (dec->num_parts_minus_one_ == 0 &&
+            MemDataSize(&idec->mem_) > MAX_MB_SIZE) {
+          return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
+        }
+        RestoreContext(&context, dec, token_br);
+        return VP8_STATUS_SUSPENDED;
+      }
+      // Release buffer only if there is only one partition
+      if (dec->num_parts_minus_one_ == 0) {
+        idec->mem_.start_ = token_br->buf_ - idec->mem_.buf_;
+        assert(idec->mem_.start_ <= idec->mem_.end_);
+      }
+    }
+    VP8InitScanline(dec);   // Prepare for next scanline
+
+    // Reconstruct, filter and emit the row.
+    if (!VP8ProcessRow(dec, io)) {
+      return IDecError(idec, VP8_STATUS_USER_ABORT);
+    }
+  }
+  // Synchronize the thread and check for errors.
+  if (!VP8ExitCritical(dec, io)) {
+    return IDecError(idec, VP8_STATUS_USER_ABORT);
+  }
+  dec->ready_ = 0;
+  return FinishDecoding(idec);
+}
+
+static VP8StatusCode ErrorStatusLossless(WebPIDecoder* const idec,
+                                         VP8StatusCode status) {
+  if (status == VP8_STATUS_SUSPENDED || status == VP8_STATUS_NOT_ENOUGH_DATA) {
+    return VP8_STATUS_SUSPENDED;
+  }
+  return IDecError(idec, status);
+}
+
+static VP8StatusCode DecodeVP8LHeader(WebPIDecoder* const idec) {
+  VP8Io* const io = &idec->io_;
+  VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_;
+  const WebPDecParams* const params = &idec->params_;
+  WebPDecBuffer* const output = params->output;
+  size_t curr_size = MemDataSize(&idec->mem_);
+  assert(idec->is_lossless_);
+
+  // Wait until there's enough data for decoding header.
+  if (curr_size < (idec->chunk_size_ >> 3)) {
+    dec->status_ = VP8_STATUS_SUSPENDED;
+    return ErrorStatusLossless(idec, dec->status_);
+  }
+
+  if (!VP8LDecodeHeader(dec, io)) {
+    if (dec->status_ == VP8_STATUS_BITSTREAM_ERROR &&
+        curr_size < idec->chunk_size_) {
+      dec->status_ = VP8_STATUS_SUSPENDED;
+    }
+    return ErrorStatusLossless(idec, dec->status_);
+  }
+  // Allocate/verify output buffer now.
+  dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options,
+                                       output);
+  if (dec->status_ != VP8_STATUS_OK) {
+    return IDecError(idec, dec->status_);
+  }
+
+  idec->state_ = STATE_VP8L_DATA;
+  return VP8_STATUS_OK;
+}
+
+static VP8StatusCode DecodeVP8LData(WebPIDecoder* const idec) {
+  VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_;
+  const size_t curr_size = MemDataSize(&idec->mem_);
+  assert(idec->is_lossless_);
+
+  // Switch to incremental decoding if we don't have all the bytes available.
+  dec->incremental_ = (curr_size < idec->chunk_size_);
+
+  if (!VP8LDecodeImage(dec)) {
+    return ErrorStatusLossless(idec, dec->status_);
+  }
+  assert(dec->status_ == VP8_STATUS_OK || dec->status_ == VP8_STATUS_SUSPENDED);
+  return (dec->status_ == VP8_STATUS_SUSPENDED) ? dec->status_
+                                                : FinishDecoding(idec);
+}
+
+  // Main decoding loop
+static VP8StatusCode IDecode(WebPIDecoder* idec) {
+  VP8StatusCode status = VP8_STATUS_SUSPENDED;
+
+  if (idec->state_ == STATE_WEBP_HEADER) {
+    status = DecodeWebPHeaders(idec);
+  } else {
+    if (idec->dec_ == NULL) {
+      return VP8_STATUS_SUSPENDED;    // can't continue if we have no decoder.
+    }
+  }
+  if (idec->state_ == STATE_VP8_HEADER) {
+    status = DecodeVP8FrameHeader(idec);
+  }
+  if (idec->state_ == STATE_VP8_PARTS0) {
+    status = DecodePartition0(idec);
+  }
+  if (idec->state_ == STATE_VP8_DATA) {
+    status = DecodeRemaining(idec);
+  }
+  if (idec->state_ == STATE_VP8L_HEADER) {
+    status = DecodeVP8LHeader(idec);
+  }
+  if (idec->state_ == STATE_VP8L_DATA) {
+    status = DecodeVP8LData(idec);
+  }
+  return status;
+}
+
+//------------------------------------------------------------------------------
+// Internal constructor
+
+static WebPIDecoder* NewDecoder(WebPDecBuffer* const output_buffer,
+                                const WebPBitstreamFeatures* const features) {
+  WebPIDecoder* idec = (WebPIDecoder*)WebPSafeCalloc(1ULL, sizeof(*idec));
+  if (idec == NULL) {
+    return NULL;
+  }
+
+  idec->state_ = STATE_WEBP_HEADER;
+  idec->chunk_size_ = 0;
+
+  idec->last_mb_y_ = -1;
+
+  InitMemBuffer(&idec->mem_);
+  WebPInitDecBuffer(&idec->output_);
+  VP8InitIo(&idec->io_);
+
+  WebPResetDecParams(&idec->params_);
+  if (output_buffer == NULL || WebPAvoidSlowMemory(output_buffer, features)) {
+    idec->params_.output = &idec->output_;
+    idec->final_output_ = output_buffer;
+    if (output_buffer != NULL) {
+      idec->params_.output->colorspace = output_buffer->colorspace;
+    }
+  } else {
+    idec->params_.output = output_buffer;
+    idec->final_output_ = NULL;
+  }
+  WebPInitCustomIo(&idec->params_, &idec->io_);  // Plug the I/O functions.
+
+  return idec;
+}
+
+//------------------------------------------------------------------------------
+// Public functions
+
+WebPIDecoder* WebPINewDecoder(WebPDecBuffer* output_buffer) {
+  return NewDecoder(output_buffer, NULL);
+}
+
+WebPIDecoder* WebPIDecode(const uint8_t* data, size_t data_size,
+                          WebPDecoderConfig* config) {
+  WebPIDecoder* idec;
+  WebPBitstreamFeatures tmp_features;
+  WebPBitstreamFeatures* const features =
+      (config == NULL) ? &tmp_features : &config->input;
+  memset(&tmp_features, 0, sizeof(tmp_features));
+
+  // Parse the bitstream's features, if requested:
+  if (data != NULL && data_size > 0) {
+    if (WebPGetFeatures(data, data_size, features) != VP8_STATUS_OK) {
+      return NULL;
+    }
+  }
+
+  // Create an instance of the incremental decoder
+  idec = (config != NULL) ? NewDecoder(&config->output, features)
+                          : NewDecoder(NULL, features);
+  if (idec == NULL) {
+    return NULL;
+  }
+  // Finish initialization
+  if (config != NULL) {
+    idec->params_.options = &config->options;
+  }
+  return idec;
+}
+
+void WebPIDelete(WebPIDecoder* idec) {
+  if (idec == NULL) return;
+  if (idec->dec_ != NULL) {
+    if (!idec->is_lossless_) {
+      if (idec->state_ == STATE_VP8_DATA) {
+        // Synchronize the thread, clean-up and check for errors.
+        VP8ExitCritical((VP8Decoder*)idec->dec_, &idec->io_);
+      }
+      VP8Delete((VP8Decoder*)idec->dec_);
+    } else {
+      VP8LDelete((VP8LDecoder*)idec->dec_);
+    }
+  }
+  ClearMemBuffer(&idec->mem_);
+  WebPFreeDecBuffer(&idec->output_);
+  WebPSafeFree(idec);
+}
+
+//------------------------------------------------------------------------------
+// Wrapper toward WebPINewDecoder
+
+WebPIDecoder* WebPINewRGB(WEBP_CSP_MODE mode, uint8_t* output_buffer,
+                          size_t output_buffer_size, int output_stride) {
+  const int is_external_memory = (output_buffer != NULL) ? 1 : 0;
+  WebPIDecoder* idec;
+
+  if (mode >= MODE_YUV) return NULL;
+  if (is_external_memory == 0) {    // Overwrite parameters to sane values.
+    output_buffer_size = 0;
+    output_stride = 0;
+  } else {  // A buffer was passed. Validate the other params.
+    if (output_stride == 0 || output_buffer_size == 0) {
+      return NULL;   // invalid parameter.
+    }
+  }
+  idec = WebPINewDecoder(NULL);
+  if (idec == NULL) return NULL;
+  idec->output_.colorspace = mode;
+  idec->output_.is_external_memory = is_external_memory;
+  idec->output_.u.RGBA.rgba = output_buffer;
+  idec->output_.u.RGBA.stride = output_stride;
+  idec->output_.u.RGBA.size = output_buffer_size;
+  return idec;
+}
+
+WebPIDecoder* WebPINewYUVA(uint8_t* luma, size_t luma_size, int luma_stride,
+                           uint8_t* u, size_t u_size, int u_stride,
+                           uint8_t* v, size_t v_size, int v_stride,
+                           uint8_t* a, size_t a_size, int a_stride) {
+  const int is_external_memory = (luma != NULL) ? 1 : 0;
+  WebPIDecoder* idec;
+  WEBP_CSP_MODE colorspace;
+
+  if (is_external_memory == 0) {    // Overwrite parameters to sane values.
+    luma_size = u_size = v_size = a_size = 0;
+    luma_stride = u_stride = v_stride = a_stride = 0;
+    u = v = a = NULL;
+    colorspace = MODE_YUVA;
+  } else {  // A luma buffer was passed. Validate the other parameters.
+    if (u == NULL || v == NULL) return NULL;
+    if (luma_size == 0 || u_size == 0 || v_size == 0) return NULL;
+    if (luma_stride == 0 || u_stride == 0 || v_stride == 0) return NULL;
+    if (a != NULL) {
+      if (a_size == 0 || a_stride == 0) return NULL;
+    }
+    colorspace = (a == NULL) ? MODE_YUV : MODE_YUVA;
+  }
+
+  idec = WebPINewDecoder(NULL);
+  if (idec == NULL) return NULL;
+
+  idec->output_.colorspace = colorspace;
+  idec->output_.is_external_memory = is_external_memory;
+  idec->output_.u.YUVA.y = luma;
+  idec->output_.u.YUVA.y_stride = luma_stride;
+  idec->output_.u.YUVA.y_size = luma_size;
+  idec->output_.u.YUVA.u = u;
+  idec->output_.u.YUVA.u_stride = u_stride;
+  idec->output_.u.YUVA.u_size = u_size;
+  idec->output_.u.YUVA.v = v;
+  idec->output_.u.YUVA.v_stride = v_stride;
+  idec->output_.u.YUVA.v_size = v_size;
+  idec->output_.u.YUVA.a = a;
+  idec->output_.u.YUVA.a_stride = a_stride;
+  idec->output_.u.YUVA.a_size = a_size;
+  return idec;
+}
+
+WebPIDecoder* WebPINewYUV(uint8_t* luma, size_t luma_size, int luma_stride,
+                          uint8_t* u, size_t u_size, int u_stride,
+                          uint8_t* v, size_t v_size, int v_stride) {
+  return WebPINewYUVA(luma, luma_size, luma_stride,
+                      u, u_size, u_stride,
+                      v, v_size, v_stride,
+                      NULL, 0, 0);
+}
+
+//------------------------------------------------------------------------------
+
+static VP8StatusCode IDecCheckStatus(const WebPIDecoder* const idec) {
+  assert(idec);
+  if (idec->state_ == STATE_ERROR) {
+    return VP8_STATUS_BITSTREAM_ERROR;
+  }
+  if (idec->state_ == STATE_DONE) {
+    return VP8_STATUS_OK;
+  }
+  return VP8_STATUS_SUSPENDED;
+}
+
+VP8StatusCode WebPIAppend(WebPIDecoder* idec,
+                          const uint8_t* data, size_t data_size) {
+  VP8StatusCode status;
+  if (idec == NULL || data == NULL) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+  status = IDecCheckStatus(idec);
+  if (status != VP8_STATUS_SUSPENDED) {
+    return status;
+  }
+  // Check mixed calls between RemapMemBuffer and AppendToMemBuffer.
+  if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_APPEND)) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+  // Append data to memory buffer
+  if (!AppendToMemBuffer(idec, data, data_size)) {
+    return VP8_STATUS_OUT_OF_MEMORY;
+  }
+  return IDecode(idec);
+}
+
+VP8StatusCode WebPIUpdate(WebPIDecoder* idec,
+                          const uint8_t* data, size_t data_size) {
+  VP8StatusCode status;
+  if (idec == NULL || data == NULL) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+  status = IDecCheckStatus(idec);
+  if (status != VP8_STATUS_SUSPENDED) {
+    return status;
+  }
+  // Check mixed calls between RemapMemBuffer and AppendToMemBuffer.
+  if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_MAP)) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+  // Make the memory buffer point to the new buffer
+  if (!RemapMemBuffer(idec, data, data_size)) {
+    return VP8_STATUS_INVALID_PARAM;
+  }
+  return IDecode(idec);
+}
+
+//------------------------------------------------------------------------------
+
+static const WebPDecBuffer* GetOutputBuffer(const WebPIDecoder* const idec) {
+  if (idec == NULL || idec->dec_ == NULL) {
+    return NULL;
+  }
+  if (idec->state_ <= STATE_VP8_PARTS0) {
+    return NULL;
+  }
+  if (idec->final_output_ != NULL) {
+    return NULL;   // not yet slow-copied
+  }
+  return idec->params_.output;
+}
+
+const WebPDecBuffer* WebPIDecodedArea(const WebPIDecoder* idec,
+                                      int* left, int* top,
+                                      int* width, int* height) {
+  const WebPDecBuffer* const src = GetOutputBuffer(idec);
+  if (left != NULL) *left = 0;
+  if (top != NULL) *top = 0;
+  if (src != NULL) {
+    if (width != NULL) *width = src->width;
+    if (height != NULL) *height = idec->params_.last_y;
+  } else {
+    if (width != NULL) *width = 0;
+    if (height != NULL) *height = 0;
+  }
+  return src;
+}
+
+uint8_t* WebPIDecGetRGB(const WebPIDecoder* idec, int* last_y,
+                        int* width, int* height, int* stride) {
+  const WebPDecBuffer* const src = GetOutputBuffer(idec);
+  if (src == NULL) return NULL;
+  if (src->colorspace >= MODE_YUV) {
+    return NULL;
+  }
+
+  if (last_y != NULL) *last_y = idec->params_.last_y;
+  if (width != NULL) *width = src->width;
+  if (height != NULL) *height = src->height;
+  if (stride != NULL) *stride = src->u.RGBA.stride;
+
+  return src->u.RGBA.rgba;
+}
+
+uint8_t* WebPIDecGetYUVA(const WebPIDecoder* idec, int* last_y,
+                         uint8_t** u, uint8_t** v, uint8_t** a,
+                         int* width, int* height,
+                         int* stride, int* uv_stride, int* a_stride) {
+  const WebPDecBuffer* const src = GetOutputBuffer(idec);
+  if (src == NULL) return NULL;
+  if (src->colorspace < MODE_YUV) {
+    return NULL;
+  }
+
+  if (last_y != NULL) *last_y = idec->params_.last_y;
+  if (u != NULL) *u = src->u.YUVA.u;
+  if (v != NULL) *v = src->u.YUVA.v;
+  if (a != NULL) *a = src->u.YUVA.a;
+  if (width != NULL) *width = src->width;
+  if (height != NULL) *height = src->height;
+  if (stride != NULL) *stride = src->u.YUVA.y_stride;
+  if (uv_stride != NULL) *uv_stride = src->u.YUVA.u_stride;
+  if (a_stride != NULL) *a_stride = src->u.YUVA.a_stride;
+
+  return src->u.YUVA.y;
+}
+
+int WebPISetIOHooks(WebPIDecoder* const idec,
+                    VP8IoPutHook put,
+                    VP8IoSetupHook setup,
+                    VP8IoTeardownHook teardown,
+                    void* user_data) {
+  if (idec == NULL || idec->state_ > STATE_WEBP_HEADER) {
+    return 0;
+  }
+
+  idec->io_.put = put;
+  idec->io_.setup = setup;
+  idec->io_.teardown = teardown;
+  idec->io_.opaque = user_data;
+
+  return 1;
+}

src/dec/io_dec.c

@@ -0,0 +1,645 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// functions for sample output.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <assert.h>
+#include <stdlib.h>
+#include "../dec/vp8i_dec.h"
+#include "./webpi_dec.h"
+#include "../dsp/dsp.h"
+#include "../dsp/yuv.h"
+#include "../utils/utils.h"
+
+//------------------------------------------------------------------------------
+// Main YUV<->RGB conversion functions
+
+static int EmitYUV(const VP8Io* const io, WebPDecParams* const p) {
+  WebPDecBuffer* output = p->output;
+  const WebPYUVABuffer* const buf = &output->u.YUVA;
+  uint8_t* const y_dst = buf->y + io->mb_y * buf->y_stride;
+  uint8_t* const u_dst = buf->u + (io->mb_y >> 1) * buf->u_stride;
+  uint8_t* const v_dst = buf->v + (io->mb_y >> 1) * buf->v_stride;
+  const int mb_w = io->mb_w;
+  const int mb_h = io->mb_h;
+  const int uv_w = (mb_w + 1) / 2;
+  const int uv_h = (mb_h + 1) / 2;
+  int j;
+  for (j = 0; j < mb_h; ++j) {
+    memcpy(y_dst + j * buf->y_stride, io->y + j * io->y_stride, mb_w);
+  }
+  for (j = 0; j < uv_h; ++j) {
+    memcpy(u_dst + j * buf->u_stride, io->u + j * io->uv_stride, uv_w);
+    memcpy(v_dst + j * buf->v_stride, io->v + j * io->uv_stride, uv_w);
+  }
+  return io->mb_h;
+}
+
+// Point-sampling U/V sampler.
+static int EmitSampledRGB(const VP8Io* const io, WebPDecParams* const p) {
+  WebPDecBuffer* const output = p->output;
+  WebPRGBABuffer* const buf = &output->u.RGBA;
+  uint8_t* const dst = buf->rgba + io->mb_y * buf->stride;
+  WebPSamplerProcessPlane(io->y, io->y_stride,
+                          io->u, io->v, io->uv_stride,
+                          dst, buf->stride, io->mb_w, io->mb_h,
+                          WebPSamplers[output->colorspace]);
+  return io->mb_h;
+}
+
+//------------------------------------------------------------------------------
+// Fancy upsampling
+
+#ifdef FANCY_UPSAMPLING
+static int EmitFancyRGB(const VP8Io* const io, WebPDecParams* const p) {
+  int num_lines_out = io->mb_h;   // a priori guess
+  const WebPRGBABuffer* const buf = &p->output->u.RGBA;
+  uint8_t* dst = buf->rgba + io->mb_y * buf->stride;
+  WebPUpsampleLinePairFunc upsample = WebPUpsamplers[p->output->colorspace];
+  const uint8_t* cur_y = io->y;
+  const uint8_t* cur_u = io->u;
+  const uint8_t* cur_v = io->v;
+  const uint8_t* top_u = p->tmp_u;
+  const uint8_t* top_v = p->tmp_v;
+  int y = io->mb_y;
+  const int y_end = io->mb_y + io->mb_h;
+  const int mb_w = io->mb_w;
+  const int uv_w = (mb_w + 1) / 2;
+
+  if (y == 0) {
+    // First line is special cased. We mirror the u/v samples at boundary.
+    upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, dst, NULL, mb_w);
+  } else {
+    // We can finish the left-over line from previous call.
+    upsample(p->tmp_y, cur_y, top_u, top_v, cur_u, cur_v,
+             dst - buf->stride, dst, mb_w);
+    ++num_lines_out;
+  }
+  // Loop over each output pairs of row.
+  for (; y + 2 < y_end; y += 2) {
+    top_u = cur_u;
+    top_v = cur_v;
+    cur_u += io->uv_stride;
+    cur_v += io->uv_stride;
+    dst += 2 * buf->stride;
+    cur_y += 2 * io->y_stride;
+    upsample(cur_y - io->y_stride, cur_y,
+             top_u, top_v, cur_u, cur_v,
+             dst - buf->stride, dst, mb_w);
+  }
+  // move to last row
+  cur_y += io->y_stride;
+  if (io->crop_top + y_end < io->crop_bottom) {
+    // Save the unfinished samples for next call (as we're not done yet).
+    memcpy(p->tmp_y, cur_y, mb_w * sizeof(*p->tmp_y));
+    memcpy(p->tmp_u, cur_u, uv_w * sizeof(*p->tmp_u));
+    memcpy(p->tmp_v, cur_v, uv_w * sizeof(*p->tmp_v));
+    // The fancy upsampler leaves a row unfinished behind
+    // (except for the very last row)
+    num_lines_out--;
+  } else {
+    // Process the very last row of even-sized picture
+    if (!(y_end & 1)) {
+      upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v,
+               dst + buf->stride, NULL, mb_w);
+    }
+  }
+  return num_lines_out;
+}
+
+#endif    /* FANCY_UPSAMPLING */
+
+//------------------------------------------------------------------------------
+
+static void FillAlphaPlane(uint8_t* dst, int w, int h, int stride) {
+  int j;
+  for (j = 0; j < h; ++j) {
+    memset(dst, 0xff, w * sizeof(*dst));
+    dst += stride;
+  }
+}
+
+static int EmitAlphaYUV(const VP8Io* const io, WebPDecParams* const p,
+                        int expected_num_lines_out) {
+  const uint8_t* alpha = io->a;
+  const WebPYUVABuffer* const buf = &p->output->u.YUVA;
+  const int mb_w = io->mb_w;
+  const int mb_h = io->mb_h;
+  uint8_t* dst = buf->a + io->mb_y * buf->a_stride;
+  int j;
+  (void)expected_num_lines_out;
+  assert(expected_num_lines_out == mb_h);
+  if (alpha != NULL) {
+    for (j = 0; j < mb_h; ++j) {
+      memcpy(dst, alpha, mb_w * sizeof(*dst));
+      alpha += io->width;
+      dst += buf->a_stride;
+    }
+  } else if (buf->a != NULL) {
+    // the user requested alpha, but there is none, set it to opaque.
+    FillAlphaPlane(dst, mb_w, mb_h, buf->a_stride);
+  }
+  return 0;
+}
+
+static int GetAlphaSourceRow(const VP8Io* const io,
+                             const uint8_t** alpha, int* const num_rows) {
+  int start_y = io->mb_y;
+  *num_rows = io->mb_h;
+
+  // Compensate for the 1-line delay of the fancy upscaler.
+  // This is similar to EmitFancyRGB().
+  if (io->fancy_upsampling) {
+    if (start_y == 0) {
+      // We don't process the last row yet. It'll be done during the next call.
+      --*num_rows;
+    } else {
+      --start_y;
+      // Fortunately, *alpha data is persistent, so we can go back
+      // one row and finish alpha blending, now that the fancy upscaler
+      // completed the YUV->RGB interpolation.
+      *alpha -= io->width;
+    }
+    if (io->crop_top + io->mb_y + io->mb_h == io->crop_bottom) {
+      // If it's the very last call, we process all the remaining rows!
+      *num_rows = io->crop_bottom - io->crop_top - start_y;
+    }
+  }
+  return start_y;
+}
+
+static int EmitAlphaRGB(const VP8Io* const io, WebPDecParams* const p,
+                        int expected_num_lines_out) {
+  const uint8_t* alpha = io->a;
+  if (alpha != NULL) {
+    const int mb_w = io->mb_w;
+    const WEBP_CSP_MODE colorspace = p->output->colorspace;
+    const int alpha_first =
+        (colorspace == MODE_ARGB || colorspace == MODE_Argb);
+    const WebPRGBABuffer* const buf = &p->output->u.RGBA;
+    int num_rows;
+    const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows);
+    uint8_t* const base_rgba = buf->rgba + start_y * buf->stride;
+    uint8_t* const dst = base_rgba + (alpha_first ? 0 : 3);
+    const int has_alpha = WebPDispatchAlpha(alpha, io->width, mb_w,
+                                            num_rows, dst, buf->stride);
+    (void)expected_num_lines_out;
+    assert(expected_num_lines_out == num_rows);
+    // has_alpha is true if there's non-trivial alpha to premultiply with.
+    if (has_alpha && WebPIsPremultipliedMode(colorspace)) {
+      WebPApplyAlphaMultiply(base_rgba, alpha_first,
+                             mb_w, num_rows, buf->stride);
+    }
+  }
+  return 0;
+}
+
+static int EmitAlphaRGBA4444(const VP8Io* const io, WebPDecParams* const p,
+                             int expected_num_lines_out) {
+  const uint8_t* alpha = io->a;
+  if (alpha != NULL) {
+    const int mb_w = io->mb_w;
+    const WEBP_CSP_MODE colorspace = p->output->colorspace;
+    const WebPRGBABuffer* const buf = &p->output->u.RGBA;
+    int num_rows;
+    const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows);
+    uint8_t* const base_rgba = buf->rgba + start_y * buf->stride;
+#ifdef WEBP_SWAP_16BIT_CSP
+    uint8_t* alpha_dst = base_rgba;
+#else
+    uint8_t* alpha_dst = base_rgba + 1;
+#endif
+    uint32_t alpha_mask = 0x0f;
+    int i, j;
+    for (j = 0; j < num_rows; ++j) {
+      for (i = 0; i < mb_w; ++i) {
+        // Fill in the alpha value (converted to 4 bits).
+        const uint32_t alpha_value = alpha[i] >> 4;
+        alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value;
+        alpha_mask &= alpha_value;
+      }
+      alpha += io->width;
+      alpha_dst += buf->stride;
+    }
+    (void)expected_num_lines_out;
+    assert(expected_num_lines_out == num_rows);
+    if (alpha_mask != 0x0f && WebPIsPremultipliedMode(colorspace)) {
+      WebPApplyAlphaMultiply4444(base_rgba, mb_w, num_rows, buf->stride);
+    }
+  }
+  return 0;
+}
+
+//------------------------------------------------------------------------------
+// YUV rescaling (no final RGB conversion needed)
+
+static int Rescale(const uint8_t* src, int src_stride,
+                   int new_lines, WebPRescaler* const wrk) {
+  int num_lines_out = 0;
+  while (new_lines > 0) {    // import new contributions of source rows.
+    const int lines_in = WebPRescalerImport(wrk, new_lines, src, src_stride);
+    src += lines_in * src_stride;
+    new_lines -= lines_in;
+    num_lines_out += WebPRescalerExport(wrk);    // emit output row(s)
+  }
+  return num_lines_out;
+}
+
+static int EmitRescaledYUV(const VP8Io* const io, WebPDecParams* const p) {
+  const int mb_h = io->mb_h;
+  const int uv_mb_h = (mb_h + 1) >> 1;
+  WebPRescaler* const scaler = p->scaler_y;
+  int num_lines_out = 0;
+  if (WebPIsAlphaMode(p->output->colorspace) && io->a != NULL) {
+    // Before rescaling, we premultiply the luma directly into the io->y
+    // internal buffer. This is OK since these samples are not used for
+    // intra-prediction (the top samples are saved in cache_y_/u_/v_).
+    // But we need to cast the const away, though.
+    WebPMultRows((uint8_t*)io->y, io->y_stride,
+                 io->a, io->width, io->mb_w, mb_h, 0);
+  }
+  num_lines_out = Rescale(io->y, io->y_stride, mb_h, scaler);
+  Rescale(io->u, io->uv_stride, uv_mb_h, p->scaler_u);
+  Rescale(io->v, io->uv_stride, uv_mb_h, p->scaler_v);
+  return num_lines_out;
+}
+
+static int EmitRescaledAlphaYUV(const VP8Io* const io, WebPDecParams* const p,
+                                int expected_num_lines_out) {
+  const WebPYUVABuffer* const buf = &p->output->u.YUVA;
+  uint8_t* const dst_a = buf->a + p->last_y * buf->a_stride;
+  if (io->a != NULL) {
+    uint8_t* const dst_y = buf->y + p->last_y * buf->y_stride;
+    const int num_lines_out = Rescale(io->a, io->width, io->mb_h, p->scaler_a);
+    assert(expected_num_lines_out == num_lines_out);
+    if (num_lines_out > 0) {   // unmultiply the Y
+      WebPMultRows(dst_y, buf->y_stride, dst_a, buf->a_stride,
+                   p->scaler_a->dst_width, num_lines_out, 1);
+    }
+  } else if (buf->a != NULL) {
+    // the user requested alpha, but there is none, set it to opaque.
+    assert(p->last_y + expected_num_lines_out <= io->scaled_height);
+    FillAlphaPlane(dst_a, io->scaled_width, expected_num_lines_out,
+                   buf->a_stride);
+  }
+  return 0;
+}
+
+static int InitYUVRescaler(const VP8Io* const io, WebPDecParams* const p) {
+  const int has_alpha = WebPIsAlphaMode(p->output->colorspace);
+  const WebPYUVABuffer* const buf = &p->output->u.YUVA;
+  const int out_width  = io->scaled_width;
+  const int out_height = io->scaled_height;
+  const int uv_out_width  = (out_width + 1) >> 1;
+  const int uv_out_height = (out_height + 1) >> 1;
+  const int uv_in_width  = (io->mb_w + 1) >> 1;
+  const int uv_in_height = (io->mb_h + 1) >> 1;
+  const size_t work_size = 2 * out_width;   // scratch memory for luma rescaler
+  const size_t uv_work_size = 2 * uv_out_width;  // and for each u/v ones
+  size_t tmp_size, rescaler_size;
+  rescaler_t* work;
+  WebPRescaler* scalers;
+  const int num_rescalers = has_alpha ? 4 : 3;
+
+  tmp_size = (work_size + 2 * uv_work_size) * sizeof(*work);
+  if (has_alpha) {
+    tmp_size += work_size * sizeof(*work);
+  }
+  rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST;
+
+  p->memory = WebPSafeMalloc(1ULL, tmp_size + rescaler_size);
+  if (p->memory == NULL) {
+    return 0;   // memory error
+  }
+  work = (rescaler_t*)p->memory;
+
+  scalers = (WebPRescaler*)WEBP_ALIGN((const uint8_t*)work + tmp_size);
+  p->scaler_y = &scalers[0];
+  p->scaler_u = &scalers[1];
+  p->scaler_v = &scalers[2];
+  p->scaler_a = has_alpha ? &scalers[3] : NULL;
+
+  WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h,
+                   buf->y, out_width, out_height, buf->y_stride, 1,
+                   work);
+  WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height,
+                   buf->u, uv_out_width, uv_out_height, buf->u_stride, 1,
+                   work + work_size);
+  WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height,
+                   buf->v, uv_out_width, uv_out_height, buf->v_stride, 1,
+                   work + work_size + uv_work_size);
+  p->emit = EmitRescaledYUV;
+
+  if (has_alpha) {
+    WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h,
+                     buf->a, out_width, out_height, buf->a_stride, 1,
+                     work + work_size + 2 * uv_work_size);
+    p->emit_alpha = EmitRescaledAlphaYUV;
+    WebPInitAlphaProcessing();
+  }
+  return 1;
+}
+
+//------------------------------------------------------------------------------
+// RGBA rescaling
+
+static int ExportRGB(WebPDecParams* const p, int y_pos) {
+  const WebPYUV444Converter convert =
+      WebPYUV444Converters[p->output->colorspace];
+  const WebPRGBABuffer* const buf = &p->output->u.RGBA;
+  uint8_t* dst = buf->rgba + y_pos * buf->stride;
+  int num_lines_out = 0;
+  // For RGB rescaling, because of the YUV420, current scan position
+  // U/V can be +1/-1 line from the Y one.  Hence the double test.
+  while (WebPRescalerHasPendingOutput(p->scaler_y) &&
+         WebPRescalerHasPendingOutput(p->scaler_u)) {
+    assert(y_pos + num_lines_out < p->output->height);
+    assert(p->scaler_u->y_accum == p->scaler_v->y_accum);
+    WebPRescalerExportRow(p->scaler_y);
+    WebPRescalerExportRow(p->scaler_u);
+    WebPRescalerExportRow(p->scaler_v);
+    convert(p->scaler_y->dst, p->scaler_u->dst, p->scaler_v->dst,
+            dst, p->scaler_y->dst_width);
+    dst += buf->stride;
+    ++num_lines_out;
+  }
+  return num_lines_out;
+}
+
+static int EmitRescaledRGB(const VP8Io* const io, WebPDecParams* const p) {
+  const int mb_h = io->mb_h;
+  const int uv_mb_h = (mb_h + 1) >> 1;
+  int j = 0, uv_j = 0;
+  int num_lines_out = 0;
+  while (j < mb_h) {
+    const int y_lines_in =
+        WebPRescalerImport(p->scaler_y, mb_h - j,
+                           io->y + j * io->y_stride, io->y_stride);
+    j += y_lines_in;
+    if (WebPRescaleNeededLines(p->scaler_u, uv_mb_h - uv_j)) {
+      const int u_lines_in =
+          WebPRescalerImport(p->scaler_u, uv_mb_h - uv_j,
+                             io->u + uv_j * io->uv_stride, io->uv_stride);
+      const int v_lines_in =
+          WebPRescalerImport(p->scaler_v, uv_mb_h - uv_j,
+                             io->v + uv_j * io->uv_stride, io->uv_stride);
+      (void)v_lines_in;   // remove a gcc warning
+      assert(u_lines_in == v_lines_in);
+      uv_j += u_lines_in;
+    }
+    num_lines_out += ExportRGB(p, p->last_y + num_lines_out);
+  }
+  return num_lines_out;
+}
+
+static int ExportAlpha(WebPDecParams* const p, int y_pos, int max_lines_out) {
+  const WebPRGBABuffer* const buf = &p->output->u.RGBA;
+  uint8_t* const base_rgba = buf->rgba + y_pos * buf->stride;
+  const WEBP_CSP_MODE colorspace = p->output->colorspace;
+  const int alpha_first =
+      (colorspace == MODE_ARGB || colorspace == MODE_Argb);
+  uint8_t* dst = base_rgba + (alpha_first ? 0 : 3);
+  int num_lines_out = 0;
+  const int is_premult_alpha = WebPIsPremultipliedMode(colorspace);
+  uint32_t non_opaque = 0;
+  const int width = p->scaler_a->dst_width;
+
+  while (WebPRescalerHasPendingOutput(p->scaler_a) &&
+         num_lines_out < max_lines_out) {
+    assert(y_pos + num_lines_out < p->output->height);
+    WebPRescalerExportRow(p->scaler_a);
+    non_opaque |= WebPDispatchAlpha(p->scaler_a->dst, 0, width, 1, dst, 0);
+    dst += buf->stride;
+    ++num_lines_out;
+  }
+  if (is_premult_alpha && non_opaque) {
+    WebPApplyAlphaMultiply(base_rgba, alpha_first,
+                           width, num_lines_out, buf->stride);
+  }
+  return num_lines_out;
+}
+
+static int ExportAlphaRGBA4444(WebPDecParams* const p, int y_pos,
+                               int max_lines_out) {
+  const WebPRGBABuffer* const buf = &p->output->u.RGBA;
+  uint8_t* const base_rgba = buf->rgba + y_pos * buf->stride;
+#ifdef WEBP_SWAP_16BIT_CSP
+  uint8_t* alpha_dst = base_rgba;
+#else
+  uint8_t* alpha_dst = base_rgba + 1;
+#endif
+  int num_lines_out = 0;
+  const WEBP_CSP_MODE colorspace = p->output->colorspace;
+  const int width = p->scaler_a->dst_width;
+  const int is_premult_alpha = WebPIsPremultipliedMode(colorspace);
+  uint32_t alpha_mask = 0x0f;
+
+  while (WebPRescalerHasPendingOutput(p->scaler_a) &&
+         num_lines_out < max_lines_out) {
+    int i;
+    assert(y_pos + num_lines_out < p->output->height);
+    WebPRescalerExportRow(p->scaler_a);
+    for (i = 0; i < width; ++i) {
+      // Fill in the alpha value (converted to 4 bits).
+      const uint32_t alpha_value = p->scaler_a->dst[i] >> 4;
+      alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value;
+      alpha_mask &= alpha_value;
+    }
+    alpha_dst += buf->stride;
+    ++num_lines_out;
+  }
+  if (is_premult_alpha && alpha_mask != 0x0f) {
+    WebPApplyAlphaMultiply4444(base_rgba, width, num_lines_out, buf->stride);
+  }
+  return num_lines_out;
+}
+
+static int EmitRescaledAlphaRGB(const VP8Io* const io, WebPDecParams* const p,
+                                int expected_num_out_lines) {
+  if (io->a != NULL) {
+    WebPRescaler* const scaler = p->scaler_a;
+    int lines_left = expected_num_out_lines;
+    const int y_end = p->last_y + lines_left;
+    while (lines_left > 0) {
+      const int row_offset = scaler->src_y - io->mb_y;
+      WebPRescalerImport(scaler, io->mb_h + io->mb_y - scaler->src_y,
+                         io->a + row_offset * io->width, io->width);
+      lines_left -= p->emit_alpha_row(p, y_end - lines_left, lines_left);
+    }
+  }
+  return 0;
+}
+
+static int InitRGBRescaler(const VP8Io* const io, WebPDecParams* const p) {
+  const int has_alpha = WebPIsAlphaMode(p->output->colorspace);
+  const int out_width  = io->scaled_width;
+  const int out_height = io->scaled_height;
+  const int uv_in_width  = (io->mb_w + 1) >> 1;
+  const int uv_in_height = (io->mb_h + 1) >> 1;
+  const size_t work_size = 2 * out_width;   // scratch memory for one rescaler
+  rescaler_t* work;  // rescalers work area
+  uint8_t* tmp;   // tmp storage for scaled YUV444 samples before RGB conversion
+  size_t tmp_size1, tmp_size2, total_size, rescaler_size;
+  WebPRescaler* scalers;
+  const int num_rescalers = has_alpha ? 4 : 3;
+
+  tmp_size1 = 3 * work_size;
+  tmp_size2 = 3 * out_width;
+  if (has_alpha) {
+    tmp_size1 += work_size;
+    tmp_size2 += out_width;
+  }
+  total_size = tmp_size1 * sizeof(*work) + tmp_size2 * sizeof(*tmp);
+  rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST;
+
+  p->memory = WebPSafeMalloc(1ULL, total_size + rescaler_size);
+  if (p->memory == NULL) {
+    return 0;   // memory error
+  }
+  work = (rescaler_t*)p->memory;
+  tmp = (uint8_t*)(work + tmp_size1);
+
+  scalers = (WebPRescaler*)WEBP_ALIGN((const uint8_t*)work + total_size);
+  p->scaler_y = &scalers[0];
+  p->scaler_u = &scalers[1];
+  p->scaler_v = &scalers[2];
+  p->scaler_a = has_alpha ? &scalers[3] : NULL;
+
+  WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h,
+                   tmp + 0 * out_width, out_width, out_height, 0, 1,
+                   work + 0 * work_size);
+  WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height,
+                   tmp + 1 * out_width, out_width, out_height, 0, 1,
+                   work + 1 * work_size);
+  WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height,
+                   tmp + 2 * out_width, out_width, out_height, 0, 1,
+                   work + 2 * work_size);
+  p->emit = EmitRescaledRGB;
+  WebPInitYUV444Converters();
+
+  if (has_alpha) {
+    WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h,
+                     tmp + 3 * out_width, out_width, out_height, 0, 1,
+                     work + 3 * work_size);
+    p->emit_alpha = EmitRescaledAlphaRGB;
+    if (p->output->colorspace == MODE_RGBA_4444 ||
+        p->output->colorspace == MODE_rgbA_4444) {
+      p->emit_alpha_row = ExportAlphaRGBA4444;
+    } else {
+      p->emit_alpha_row = ExportAlpha;
+    }
+    WebPInitAlphaProcessing();
+  }
+  return 1;
+}
+
+//------------------------------------------------------------------------------
+// Default custom functions
+
+static int CustomSetup(VP8Io* io) {
+  WebPDecParams* const p = (WebPDecParams*)io->opaque;
+  const WEBP_CSP_MODE colorspace = p->output->colorspace;
+  const int is_rgb = WebPIsRGBMode(colorspace);
+  const int is_alpha = WebPIsAlphaMode(colorspace);
+
+  p->memory = NULL;
+  p->emit = NULL;
+  p->emit_alpha = NULL;
+  p->emit_alpha_row = NULL;
+  if (!WebPIoInitFromOptions(p->options, io, is_alpha ? MODE_YUV : MODE_YUVA)) {
+    return 0;
+  }
+  if (is_alpha && WebPIsPremultipliedMode(colorspace)) {
+    WebPInitUpsamplers();
+  }
+  if (io->use_scaling) {
+    const int ok = is_rgb ? InitRGBRescaler(io, p) : InitYUVRescaler(io, p);
+    if (!ok) {
+      return 0;    // memory error
+    }
+  } else {
+    if (is_rgb) {
+      WebPInitSamplers();
+      p->emit = EmitSampledRGB;   // default
+      if (io->fancy_upsampling) {
+#ifdef FANCY_UPSAMPLING
+        const int uv_width = (io->mb_w + 1) >> 1;
+        p->memory = WebPSafeMalloc(1ULL, (size_t)(io->mb_w + 2 * uv_width));
+        if (p->memory == NULL) {
+          return 0;   // memory error.
+        }
+        p->tmp_y = (uint8_t*)p->memory;
+        p->tmp_u = p->tmp_y + io->mb_w;
+        p->tmp_v = p->tmp_u + uv_width;
+        p->emit = EmitFancyRGB;
+        WebPInitUpsamplers();
+#endif
+      }
+    } else {
+      p->emit = EmitYUV;
+    }
+    if (is_alpha) {  // need transparency output
+      p->emit_alpha =
+          (colorspace == MODE_RGBA_4444 || colorspace == MODE_rgbA_4444) ?
+              EmitAlphaRGBA4444
+          : is_rgb ? EmitAlphaRGB
+          : EmitAlphaYUV;
+      if (is_rgb) {
+        WebPInitAlphaProcessing();
+      }
+    }
+  }
+
+  if (is_rgb) {
+    VP8YUVInit();
+  }
+  return 1;
+}
+
+//------------------------------------------------------------------------------
+
+static int CustomPut(const VP8Io* io) {
+  WebPDecParams* const p = (WebPDecParams*)io->opaque;
+  const int mb_w = io->mb_w;
+  const int mb_h = io->mb_h;
+  int num_lines_out;
+  assert(!(io->mb_y & 1));
+
+  if (mb_w <= 0 || mb_h <= 0) {
+    return 0;
+  }
+  num_lines_out = p->emit(io, p);
+  if (p->emit_alpha != NULL) {
+    p->emit_alpha(io, p, num_lines_out);
+  }
+  p->last_y += num_lines_out;
+  return 1;
+}
+
+//------------------------------------------------------------------------------
+
+static void CustomTeardown(const VP8Io* io) {
+  WebPDecParams* const p = (WebPDecParams*)io->opaque;
+  WebPSafeFree(p->memory);
+  p->memory = NULL;
+}
+
+//------------------------------------------------------------------------------
+// Main entry point
+
+void WebPInitCustomIo(WebPDecParams* const params, VP8Io* const io) {
+  io->put      = CustomPut;
+  io->setup    = CustomSetup;
+  io->teardown = CustomTeardown;
+  io->opaque   = params;
+}
+
+//------------------------------------------------------------------------------

src/dec/quant_dec.c

@@ -1,21 +1,19 @@
-// Copyright 2010 Google Inc.
+// Copyright 2010 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
 // Quantizer initialization
 //
 // Author: Skal (pascal.massimino@gmail.com)
 
-#include "vp8i.h"
+#include "./vp8i_dec.h"
 
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
-static inline int clip(int v, int M) {
+static WEBP_INLINE int clip(int v, int M) {
   return v < 0 ? 0 : v > M ? M : v;
 }
 
@@ -58,7 +56,7 @@ static const uint16_t kAcTable[128] = {
   249, 254, 259, 264, 269, 274, 279, 284
 };
 
-//-----------------------------------------------------------------------------
+//------------------------------------------------------------------------------
 // Paragraph 9.6
 
 void VP8ParseQuant(VP8Decoder* const dec) {
@@ -94,18 +92,19 @@ void VP8ParseQuant(VP8Decoder* const dec) {
       m->y1_mat_[1] = kAcTable[clip(q + 0,       127)];
 
       m->y2_mat_[0] = kDcTable[clip(q + dqy2_dc, 127)] * 2;
-      // TODO(skal): make it another table?
-      m->y2_mat_[1] = kAcTable[clip(q + dqy2_ac, 127)] * 155 / 100;
+      // For all x in [0..284], x*155/100 is bitwise equal to (x*101581) >> 16.
+      // The smallest precision for that is '(x*6349) >> 12' but 16 is a good
+      // word size.
+      m->y2_mat_[1] = (kAcTable[clip(q + dqy2_ac, 127)] * 101581) >> 16;
       if (m->y2_mat_[1] < 8) m->y2_mat_[1] = 8;
 
       m->uv_mat_[0] = kDcTable[clip(q + dquv_dc, 117)];
       m->uv_mat_[1] = kAcTable[clip(q + dquv_ac, 127)];
+
+      m->uv_quant_ = q + dquv_ac;   // for dithering strength evaluation
     }
   }
 }
 
-//-----------------------------------------------------------------------------
+//------------------------------------------------------------------------------
 
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif

src/dec/tree_dec.c

@@ -1,20 +1,22 @@
-// Copyright 2010 Google Inc.
+// Copyright 2010 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
 // Coding trees and probas
 //
 // Author: Skal (pascal.massimino@gmail.com)
 
-#include "vp8i.h"
+#include "./vp8i_dec.h"
+#include "../utils/bit_reader_inl_utils.h"
 
+#if !defined(__arm__) && !defined(_M_ARM) && !defined(__aarch64__)
+// using a table is ~1-2% slower on ARM. Prefer the coded-tree approach then.
 #define USE_GENERIC_TREE
-
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
 #endif
 
 #ifdef USE_GENERIC_TREE
@@ -31,61 +33,12 @@ static const int8_t kYModesIntra4[18] = {
 };
 #endif
 
-#ifndef ONLY_KEYFRAME_CODE
-
-// inter prediction modes
-enum {
-  LEFT4 = 0, ABOVE4 = 1, ZERO4 = 2, NEW4 = 3,
-  NEARESTMV, NEARMV, ZEROMV, NEWMV, SPLITMV };
-
-static const int8_t kYModesInter[8] = {
-  -DC_PRED, 1,
-    2, 3,
-      -V_PRED, -H_PRED,
-      -TM_PRED, -B_PRED
-};
-
-static const int8_t kMBSplit[6] = {
-  -3, 1,
-    -2, 2,
-      -0, -1
-};
-
-static const int8_t kMVRef[8] = {
-  -ZEROMV, 1,
-    -NEARESTMV, 2,
-      -NEARMV, 3,
-        -NEWMV, -SPLITMV
-};
-
-static const int8_t kMVRef4[6] = {
-  -LEFT4, 1
-    -ABOVE4, 2
-      -ZERO4, -NEW4
-};
-#endif
-
-//-----------------------------------------------------------------------------
+//------------------------------------------------------------------------------
 // Default probabilities
 
-// Inter
-#ifndef ONLY_KEYFRAME_CODE
-static const uint8_t kYModeProbaInter0[4] = { 112, 86, 140, 37 };
-static const uint8_t kUVModeProbaInter0[3] = { 162, 101, 204 };
-static const uint8_t kMVProba0[2][NUM_MV_PROBAS] = {
-  { 162, 128, 225, 146, 172, 147, 214,  39,
-    156, 128, 129, 132,  75, 145, 178, 206,
-    239, 254, 254 },
-  { 164, 128, 204, 170, 119, 235, 140, 230,
-    228, 128, 130, 130,  74, 148, 180, 203,
-    236, 254, 254 }
-};
-#endif
-
 // Paragraph 13.5
 static const uint8_t
   CoeffsProba0[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS] = {
-  // genereated using vp8_default_coef_probs() in entropy.c:129
   { { { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
       { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
       { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 }
@@ -326,28 +279,38 @@ static const uint8_t kBModesProba[NUM_BMODES][NUM_BMODES][NUM_BMODES - 1] = {
 
 void VP8ResetProba(VP8Proba* const proba) {
   memset(proba->segments_, 255u, sizeof(proba->segments_));
-  memcpy(proba->coeffs_, CoeffsProba0, sizeof(CoeffsProba0));
-#ifndef ONLY_KEYFRAME_CODE
-  memcpy(proba->mv_, kMVProba0, sizeof(kMVProba0));
-  memcpy(proba->ymode_, kYModeProbaInter0, sizeof(kYModeProbaInter0));
-  memcpy(proba->uvmode_, kUVModeProbaInter0, sizeof(kUVModeProbaInter0));
-#endif
+  // proba->bands_[][] is initialized later
 }
 
-void VP8ParseIntraMode(VP8BitReader* const br,  VP8Decoder* const dec) {
-  uint8_t* const top = dec->intra_t_ + 4 * dec->mb_x_;
+static void ParseIntraMode(VP8BitReader* const br,
+                           VP8Decoder* const dec, int mb_x) {
+  uint8_t* const top = dec->intra_t_ + 4 * mb_x;
   uint8_t* const left = dec->intra_l_;
-  // Hardcoded 16x16 intra-mode decision tree.
-  dec->is_i4x4_ = !VP8GetBit(br, 145);   // decide for B_PRED first
-  if (!dec->is_i4x4_) {
+  VP8MBData* const block = dec->mb_data_ + mb_x;
+
+  // Note: we don't save segment map (yet), as we don't expect
+  // to decode more than 1 keyframe.
+  if (dec->segment_hdr_.update_map_) {
+    // Hardcoded tree parsing
+    block->segment_ = !VP8GetBit(br, dec->proba_.segments_[0])
+                    ? VP8GetBit(br, dec->proba_.segments_[1])
+                    : 2 + VP8GetBit(br, dec->proba_.segments_[2]);
+  } else {
+    block->segment_ = 0;  // default for intra
+  }
+  if (dec->use_skip_proba_) block->skip_ = VP8GetBit(br, dec->skip_p_);
+
+  block->is_i4x4_ = !VP8GetBit(br, 145);   // decide for B_PRED first
+  if (!block->is_i4x4_) {
+    // Hardcoded 16x16 intra-mode decision tree.
     const int ymode =
         VP8GetBit(br, 156) ? (VP8GetBit(br, 128) ? TM_PRED : H_PRED)
                            : (VP8GetBit(br, 163) ? V_PRED : DC_PRED);
-    dec->imodes_[0] = ymode;
-    memset(top, ymode, 4 * sizeof(top[0]));
-    memset(left, ymode, 4 * sizeof(left[0]));
+    block->imodes_[0] = ymode;
+    memset(top, ymode, 4 * sizeof(*top));
+    memset(left, ymode, 4 * sizeof(*left));
   } else {
-    uint8_t* modes = dec->imodes_;
+    uint8_t* modes = block->imodes_;
     int y;
     for (y = 0; y < 4; ++y) {
       int ymode = left[y];
@@ -356,10 +319,10 @@ void VP8ParseIntraMode(VP8BitReader* const br,  VP8Decoder* const dec) {
         const uint8_t* const prob = kBModesProba[top[x]][ymode];
 #ifdef USE_GENERIC_TREE
         // Generic tree-parsing
-        int i = 0;
-        do {
+        int i = kYModesIntra4[VP8GetBit(br, prob[0])];
+        while (i > 0) {
           i = kYModesIntra4[2 * i + VP8GetBit(br, prob[i])];
-        } while (i > 0);
+        }
         ymode = -i;
 #else
         // Hardcoded tree parsing
@@ -374,18 +337,27 @@ void VP8ParseIntraMode(VP8BitReader* const br,  VP8Decoder* const dec) {
                             (!VP8GetBit(br, prob[8]) ? B_HD_PRED : B_HU_PRED)));
 #endif    // USE_GENERIC_TREE
         top[x] = ymode;
-        *modes++ = ymode;
       }
+      memcpy(modes, top, 4 * sizeof(*top));
+      modes += 4;
       left[y] = ymode;
     }
   }
   // Hardcoded UVMode decision tree
-  dec->uvmode_ = !VP8GetBit(br, 142) ? DC_PRED
-               : !VP8GetBit(br, 114) ? V_PRED
-               : VP8GetBit(br, 183) ? TM_PRED : H_PRED;
+  block->uvmode_ = !VP8GetBit(br, 142) ? DC_PRED
+                 : !VP8GetBit(br, 114) ? V_PRED
+                 : VP8GetBit(br, 183) ? TM_PRED : H_PRED;
 }
 
-//-----------------------------------------------------------------------------
+int VP8ParseIntraModeRow(VP8BitReader* const br, VP8Decoder* const dec) {
+  int mb_x;
+  for (mb_x = 0; mb_x < dec->mb_w_; ++mb_x) {
+    ParseIntraMode(br, dec, mb_x);
+  }
+  return !dec->br_.eof_;
+}
+
+//------------------------------------------------------------------------------
 // Paragraph 13
 
 static const uint8_t
@@ -524,18 +496,13 @@ static const uint8_t
   }
 };
 
-#ifndef ONLY_KEYFRAME_CODE
-static const uint8_t MVUpdateProba[2][NUM_MV_PROBAS] = {
-  { 237, 246, 253, 253, 254, 254, 254, 254,
-    254, 254, 254, 254, 254, 254, 250, 250,
-    252, 254, 254 },
-  { 231, 243, 245, 253, 254, 254, 254, 254,
-    254, 254, 254, 254, 254, 254, 251, 251,
-    254, 254, 254 }
-};
-#endif
-
 // Paragraph 9.9
+
+static const int kBands[16 + 1] = {
+  0, 1, 2, 3, 6, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7,
+  0  // extra entry as sentinel
+};
+
 void VP8ParseProba(VP8BitReader* const br, VP8Decoder* const dec) {
   VP8Proba* const proba = &dec->proba_;
   int t, b, c, p;
@@ -543,47 +510,19 @@ void VP8ParseProba(VP8BitReader* const br, VP8Decoder* const dec) {
     for (b = 0; b < NUM_BANDS; ++b) {
       for (c = 0; c < NUM_CTX; ++c) {
         for (p = 0; p < NUM_PROBAS; ++p) {
-          if (VP8GetBit(br, CoeffsUpdateProba[t][b][c][p])) {
-            proba->coeffs_[t][b][c][p] = VP8GetValue(br, 8);
-          }
+          const int v = VP8GetBit(br, CoeffsUpdateProba[t][b][c][p]) ?
+                        VP8GetValue(br, 8) : CoeffsProba0[t][b][c][p];
+          proba->bands_[t][b].probas_[c][p] = v;
         }
       }
     }
+    for (b = 0; b < 16 + 1; ++b) {
+      proba->bands_ptr_[t][b] = &proba->bands_[t][kBands[b]];
+    }
   }
   dec->use_skip_proba_ = VP8Get(br);
   if (dec->use_skip_proba_) {
     dec->skip_p_ = VP8GetValue(br, 8);
   }
-#ifndef ONLY_KEYFRAME_CODE
-  if (!dec->frm_hdr_.key_frame_) {
-    int i;
-    dec->intra_p_ = VP8GetValue(br, 8);
-    dec->last_p_ = VP8GetValue(br, 8);
-    dec->golden_p_ = VP8GetValue(br, 8);
-    if (VP8Get(br)) {   // update y-mode
-      for (i = 0; i < 4; ++i) {
-        proba->ymode_[i] = VP8GetValue(br, 8);
-      }
-    }
-    if (VP8Get(br)) {   // update uv-mode
-      for (i = 0; i < 3; ++i) {
-        proba->uvmode_[i] = VP8GetValue(br, 8);
-      }
-    }
-    // update MV
-    for (i = 0; i < 2; ++i) {
-      int k;
-      for (k = 0; k < NUM_MV_PROBAS; ++k) {
-        if (VP8GetBit(br, MVUpdateProba[i][k])) {
-          const int v = VP8GetValue(br, 7);
-          proba->mv_[i][k] = v ? v << 1 : 1;
-        }
-      }
-    }
-  }
-#endif
 }
 
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif

src/dec/vp8.c

@@ -1,693 +0,0 @@
-// Copyright 2010 Google Inc.
-//
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
-// -----------------------------------------------------------------------------
-//
-// main entry for the decoder
-//
-// Author: Skal (pascal.massimino@gmail.com)
-
-#include <stdlib.h>
-#include "vp8i.h"
-
-#if defined(__cplusplus) || defined(c_plusplus)
-extern "C" {
-#endif
-
-//-----------------------------------------------------------------------------
-
-int WebPGetDecoderVersion(void) {
-  return (DEC_MAJ_VERSION << 16) | (DEC_MIN_VERSION << 8) | DEC_REV_VERSION;
-}
-
-//-----------------------------------------------------------------------------
-// VP8Decoder
-
-static void SetOk(VP8Decoder* const dec) {
-  dec->status_ = VP8_STATUS_OK;
-  dec->error_msg_ = "OK";
-}
-
-int VP8InitIoInternal(VP8Io* const io, int version) {
-  if (version != WEBP_DECODER_ABI_VERSION)
-    return 0;  // mismatch error
-  if (io) {
-    memset(io, 0, sizeof(*io));
-  }
-  return 1;
-}
-
-VP8Decoder* VP8New(void) {
-  VP8Decoder* dec = (VP8Decoder*)calloc(1, sizeof(VP8Decoder));
-  if (dec) {
-    SetOk(dec);
-    dec->ready_ = 0;
-  }
-  return dec;
-}
-
-VP8StatusCode VP8Status(VP8Decoder* const dec) {
-  if (!dec) return VP8_STATUS_INVALID_PARAM;
-  return dec->status_;
-}
-
-const char* VP8StatusMessage(VP8Decoder* const dec) {
-  if (!dec) return "no object";
-  if (!dec->error_msg_) return "OK";
-  return dec->error_msg_;
-}
-
-void VP8Delete(VP8Decoder* const dec) {
-  if (dec) {
-    VP8Clear(dec);
-    free(dec);
-  }
-}
-
-int VP8SetError(VP8Decoder* const dec,
-                VP8StatusCode error, const char * const msg) {
-  dec->status_ = error;
-  dec->error_msg_ = msg;
-  dec->ready_ = 0;
-  return 0;
-}
-
-//-----------------------------------------------------------------------------
-// Header parsing
-
-static void ResetSegmentHeader(VP8SegmentHeader* const hdr) {
-  assert(hdr);
-  hdr->use_segment_ = 0;
-  hdr->update_map_ = 0;
-  hdr->absolute_delta_ = 1;
-  memset(hdr->quantizer_, 0, sizeof(hdr->quantizer_));
-  memset(hdr->filter_strength_, 0, sizeof(hdr->filter_strength_));
-}
-
-// Paragraph 9.3
-static int ParseSegmentHeader(VP8BitReader* br,
-                              VP8SegmentHeader* hdr, VP8Proba* proba) {
-  assert(br);
-  assert(hdr);
-  hdr->use_segment_ = VP8Get(br);
-  if (hdr->use_segment_) {
-    hdr->update_map_ = VP8Get(br);
-    if (VP8Get(br)) {   // update data
-      int s;
-      hdr->absolute_delta_ = VP8Get(br);
-      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
-        hdr->quantizer_[s] = VP8Get(br) ? VP8GetSignedValue(br, 7) : 0;
-      }
-      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
-        hdr->filter_strength_[s] = VP8Get(br) ? VP8GetSignedValue(br, 6) : 0;
-      }
-    }
-    if (hdr->update_map_) {
-      int s;
-      for (s = 0; s < MB_FEATURE_TREE_PROBS; ++s) {
-        proba->segments_[s] = VP8Get(br) ? VP8GetValue(br, 8) : 255u;
-      }
-    }
-  } else {
-    hdr->update_map_ = 0;
-  }
-  return !br->eof_;
-}
-
-// Paragraph 9.5
-// This function returns VP8_STATUS_SUSPENDED if we don't have all the
-// necessary data in 'buf'.
-// This case is not necessarily an error (for incremental decoding).
-// Still, no bitreader is ever initialized to make it possible to read
-// unavailable memory.
-// If we don't even have the partitions' sizes, than VP8_STATUS_NOT_ENOUGH_DATA
-// is returned, and this is an unrecoverable error.
-// If the partitions were positioned ok, VP8_STATUS_OK is returned.
-static VP8StatusCode ParsePartitions(VP8Decoder* const dec,
-                                     const uint8_t* buf, uint32_t size) {
-  VP8BitReader* const br = &dec->br_;
-  const uint8_t* sz = buf;
-  const uint8_t* buf_end = buf + size;
-  const uint8_t* part_start;
-  int last_part;
-  int p;
-
-  dec->num_parts_ = 1 << VP8GetValue(br, 2);
-  last_part = dec->num_parts_ - 1;
-  part_start = buf + last_part * 3;
-  if (buf_end < part_start) {
-    // we can't even read the sizes with sz[]! That's a failure.
-    return VP8_STATUS_NOT_ENOUGH_DATA;
-  }
-  for (p = 0; p < last_part; ++p) {
-    const uint32_t psize = sz[0] | (sz[1] << 8) | (sz[2] << 16);
-    const uint8_t* part_end = part_start + psize;
-    if (part_end > buf_end) part_end = buf_end;
-    VP8InitBitReader(dec->parts_ + p, part_start, part_end);
-    part_start = part_end;
-    sz += 3;
-  }
-  VP8InitBitReader(dec->parts_ + last_part, part_start, buf_end);
-  return (part_start < buf_end) ? VP8_STATUS_OK :
-           VP8_STATUS_SUSPENDED;   // Init is ok, but there's not enough data
-}
-
-// Paragraph 9.4
-static int ParseFilterHeader(VP8BitReader* br, VP8Decoder* const dec) {
-  VP8FilterHeader* const hdr = &dec->filter_hdr_;
-  hdr->simple_    = VP8Get(br);
-  hdr->level_     = VP8GetValue(br, 6);
-  hdr->sharpness_ = VP8GetValue(br, 3);
-  hdr->use_lf_delta_ = VP8Get(br);
-  if (hdr->use_lf_delta_) {
-    if (VP8Get(br)) {   // update lf-delta?
-      int i;
-      for (i = 0; i < NUM_REF_LF_DELTAS; ++i) {
-        if (VP8Get(br)) {
-          hdr->ref_lf_delta_[i] = VP8GetSignedValue(br, 6);
-        }
-      }
-      for (i = 0; i < NUM_MODE_LF_DELTAS; ++i) {
-        if (VP8Get(br)) {
-          hdr->mode_lf_delta_[i] = VP8GetSignedValue(br, 6);
-        }
-      }
-    }
-  }
-  dec->filter_type_ = (hdr->level_ == 0) ? 0 : hdr->simple_ ? 1 : 2;
-  if (dec->filter_type_ > 0) {    // precompute filter levels per segment
-    if (dec->segment_hdr_.use_segment_) {
-      int s;
-      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
-        int strength = dec->segment_hdr_.filter_strength_[s];
-        if (!dec->segment_hdr_.absolute_delta_) {
-          strength += hdr->level_;
-        }
-        dec->filter_levels_[s] = strength;
-      }
-    } else {
-      dec->filter_levels_[0] = hdr->level_;
-    }
-  }
-  return !br->eof_;
-}
-
-static inline uint32_t get_le32(const uint8_t* const data) {
-  return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
-}
-
-// Topmost call
-int VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io) {
-  uint8_t* buf;
-  uint32_t buf_size;
-  VP8FrameHeader* frm_hdr;
-  VP8PictureHeader* pic_hdr;
-  VP8BitReader* br;
-  VP8StatusCode status;
-
-  if (dec == NULL) {
-    return 0;
-  }
-  SetOk(dec);
-  if (io == NULL) {
-    return VP8SetError(dec, VP8_STATUS_INVALID_PARAM,
-                       "null VP8Io passed to VP8GetHeaders()");
-  }
-
-  buf = (uint8_t *)io->data;
-  buf_size = io->data_size;
-  if (buf == NULL || buf_size <= 4) {
-    return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                       "Not enough data to parse frame header");
-  }
-
-  // Skip over valid RIFF headers
-  if (!memcmp(buf, "RIFF", 4)) {
-    uint32_t riff_size;
-    uint32_t chunk_size;
-    if (buf_size < 20 + 4) {
-      return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                         "RIFF: Truncated header.");
-    }
-    if (memcmp(buf + 8, "WEBP", 4)) {   // wrong image file signature
-      return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                         "RIFF: WEBP signature not found.");
-    }
-    riff_size = get_le32(buf + 4);
-    if (riff_size < 12) {
-      return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                         "RIFF: Truncated header.");
-    }
-    if (memcmp(buf + 12, "VP8 ", 4)) {
-      return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                         "RIFF: Invalid compression format.");
-    }
-    chunk_size = get_le32(buf + 16);
-    if (chunk_size > riff_size - 12) {
-      return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                         "RIFF: Inconsistent size information.");
-    }
-    buf += 20;
-    buf_size -= 20;
-  }
-
-  // Paragraph 9.1
-  {
-    const uint32_t bits = buf[0] | (buf[1] << 8) | (buf[2] << 16);
-    frm_hdr = &dec->frm_hdr_;
-    frm_hdr->key_frame_ = !(bits & 1);
-    frm_hdr->profile_ = (bits >> 1) & 7;
-    frm_hdr->show_ = (bits >> 4) & 1;
-    frm_hdr->partition_length_ = (bits >> 5);
-    if (frm_hdr->profile_ > 3)
-      return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                         "Incorrect keyframe parameters.");
-    if (!frm_hdr->show_)
-      return VP8SetError(dec, VP8_STATUS_UNSUPPORTED_FEATURE,
-                         "Frame not displayable.");
-    buf += 3;
-    buf_size -= 3;
-  }
-
-  pic_hdr = &dec->pic_hdr_;
-  if (frm_hdr->key_frame_) {
-    // Paragraph 9.2
-    if (buf_size < 7) {
-      return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                         "cannot parse picture header");
-    }
-    if (buf[0] != 0x9d || buf[1] != 0x01 || buf[2] != 0x2a) {
-      return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                         "Bad code word");
-    }
-    pic_hdr->width_ = ((buf[4] << 8) | buf[3]) & 0x3fff;
-    pic_hdr->xscale_ = buf[4] >> 6;   // ratio: 1, 5/4 5/3 or 2
-    pic_hdr->height_ = ((buf[6] << 8) | buf[5]) & 0x3fff;
-    pic_hdr->yscale_ = buf[6] >> 6;
-    buf += 7;
-    buf_size -= 7;
-
-    dec->mb_w_ = (pic_hdr->width_ + 15) >> 4;
-    dec->mb_h_ = (pic_hdr->height_ + 15) >> 4;
-    io->width = pic_hdr->width_;
-    io->height = pic_hdr->height_;
-
-    VP8ResetProba(&dec->proba_);
-    ResetSegmentHeader(&dec->segment_hdr_);
-    dec->segment_ = 0;    // default for intra
-  }
-
-  // Check if we have all the partition #0 available, and initialize dec->br_
-  // to read this partition (and this partition only).
-  if (frm_hdr->partition_length_ > buf_size) {
-    return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                       "bad partition length");
-  }
-  br = &dec->br_;
-  VP8InitBitReader(br, buf, buf + frm_hdr->partition_length_);
-  buf += frm_hdr->partition_length_;
-  buf_size -= frm_hdr->partition_length_;
-
-  if (frm_hdr->key_frame_) {
-    pic_hdr->colorspace_ = VP8Get(br);
-    pic_hdr->clamp_type_ = VP8Get(br);
-  }
-  if (!ParseSegmentHeader(br, &dec->segment_hdr_, &dec->proba_)) {
-    return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                       "cannot parse segment header");
-  }
-  // Filter specs
-  if (!ParseFilterHeader(br, dec)) {
-    return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
-                       "cannot parse filter header");
-  }
-  status = ParsePartitions(dec, buf, buf_size);
-  if (status != VP8_STATUS_OK) {
-    return VP8SetError(dec, status, "cannot parse partitions");
-  }
-
-  // quantizer change
-  VP8ParseQuant(dec);
-
-  // Frame buffer marking
-  if (!frm_hdr->key_frame_) {
-    // Paragraph 9.7
-#ifndef ONLY_KEYFRAME_CODE
-    dec->buffer_flags_ = VP8Get(br) << 0;   // update golden
-    dec->buffer_flags_ |= VP8Get(br) << 1;  // update alt ref
-    if (!(dec->buffer_flags_ & 1)) {
-      dec->buffer_flags_ |= VP8GetValue(br, 2) << 2;
-    }
-    if (!(dec->buffer_flags_ & 2)) {
-      dec->buffer_flags_ |= VP8GetValue(br, 2) << 4;
-    }
-    dec->buffer_flags_ |= VP8Get(br) << 6;    // sign bias golden
-    dec->buffer_flags_ |= VP8Get(br) << 7;    // sign bias alt ref
-#else
-    return VP8SetError(dec, VP8_STATUS_UNSUPPORTED_FEATURE,
-                       "Not a key frame.");
-#endif
-  } else {
-    dec->buffer_flags_ = 0x003 | 0x100;
-  }
-
-  // Paragraph 9.8
-#ifndef ONLY_KEYFRAME_CODE
-  dec->update_proba_ = VP8Get(br);
-  if (!dec->update_proba_) {    // save for later restore
-    dec->proba_saved_ = dec->proba_;
-  }
-  dec->buffer_flags_ &= 1 << 8;
-  dec->buffer_flags_ |=
-      (frm_hdr->key_frame_ || VP8Get(br)) << 8;    // refresh last frame
-#else
-  VP8Get(br);   // just ignore the value of update_proba_
-#endif
-
-  VP8ParseProba(br, dec);
-
-  // sanitized state
-  dec->ready_ = 1;
-  return 1;
-}
-
-//-----------------------------------------------------------------------------
-// Residual decoding (Paragraph 13.2 / 13.3)
-
-static const uint8_t kBands[16 + 1] = {
-  0, 1, 2, 3, 6, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7,
-  0  // extra entry as sentinel
-};
-
-static const uint8_t kCat3[] = { 173, 148, 140, 0 };
-static const uint8_t kCat4[] = { 176, 155, 140, 135, 0 };
-static const uint8_t kCat5[] = { 180, 157, 141, 134, 130, 0 };
-static const uint8_t kCat6[] =
-  { 254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129, 0 };
-static const uint8_t * const kCat3456[] = { kCat3, kCat4, kCat5, kCat6 };
-static const uint8_t kZigzag[16] = {
-  0, 1, 4, 8,  5, 2, 3, 6,  9, 12, 13, 10,  7, 11, 14, 15
-};
-
-typedef const uint8_t (*ProbaArray)[NUM_CTX][NUM_PROBAS];  // for const-casting
-
-// Returns the position of the last non-zero coeff plus one
-// (and 0 if there's no coeff at all)
-static int GetCoeffs(VP8BitReader* const br, ProbaArray prob,
-                     int ctx, const uint16_t dq[2], int n, int16_t* out) {
-  const uint8_t* p = prob[kBands[n]][ctx];
-  if (!VP8GetBit(br, p[0])) {   // first EOB is more a 'CBP' bit.
-    return 0;
-  }
-  while (1) {
-    ++n;
-    if (!VP8GetBit(br, p[1])) {
-      p = prob[kBands[n]][0];
-    } else {  // non zero coeff
-      int v, j;
-      if (!VP8GetBit(br, p[2])) {
-        p = prob[kBands[n]][1];
-        v = 1;
-      } else {
-        if (!VP8GetBit(br, p[3])) {
-          if (!VP8GetBit(br, p[4])) {
-            v = 2;
-          } else {
-            v = 3 + VP8GetBit(br, p[5]);
-          }
-        } else {
-          if (!VP8GetBit(br, p[6])) {
-            if (!VP8GetBit(br, p[7])) {
-              v = 5 + VP8GetBit(br, 159);
-            } else {
-              v = 7 + 2 * VP8GetBit(br, 165) + VP8GetBit(br, 145);
-            }
-          } else {
-            const uint8_t* tab;
-            const int bit1 = VP8GetBit(br, p[8]);
-            const int bit0 = VP8GetBit(br, p[9 + bit1]);
-            const int cat = 2 * bit1 + bit0;
-            v = 0;
-            for (tab = kCat3456[cat]; *tab; ++tab) {
-              v += v + VP8GetBit(br, *tab);
-            }
-            v += 3 + (8 << cat);
-          }
-        }
-        p = prob[kBands[n]][2];
-      }
-      j = kZigzag[n - 1];
-      out[j] = VP8GetSigned(br, v) * dq[j > 0];
-      if (n == 16 || !VP8GetBit(br, p[0])) {   // EOB
-        return n;
-      }
-    }
-    if (n == 16) {
-      return 16;
-    }
-  }
-}
-
-// Alias-safe way of converting 4bytes to 32bits.
-typedef union {
-  uint8_t  i8[4];
-  uint32_t i32;
-} PackedNz;
-
-// Table to unpack four bits into four bytes
-static const PackedNz kUnpackTab[16] = {
-  {{0, 0, 0, 0}},  {{1, 0, 0, 0}},  {{0, 1, 0, 0}},  {{1, 1, 0, 0}},
-  {{0, 0, 1, 0}},  {{1, 0, 1, 0}},  {{0, 1, 1, 0}},  {{1, 1, 1, 0}},
-  {{0, 0, 0, 1}},  {{1, 0, 0, 1}},  {{0, 1, 0, 1}},  {{1, 1, 0, 1}},
-  {{0, 0, 1, 1}},  {{1, 0, 1, 1}},  {{0, 1, 1, 1}},  {{1, 1, 1, 1}} };
-
-// Macro to pack four LSB of four bytes into four bits.
-#if defined(__PPC__) || defined(_M_PPC) || defined(_ARCH_PPC) || \
-    defined(__BIG_ENDIAN__)
-#define PACK_CST 0x08040201U
-#else
-#define PACK_CST 0x01020408U
-#endif
-#define PACK(X, S) ((((X).i32 * PACK_CST) & 0xff000000) >> (S))
-
-static void ParseResiduals(VP8Decoder* const dec,
-                           VP8MB* const mb, VP8BitReader* const token_br) {
-  int out_t_nz, out_l_nz, first;
-  ProbaArray ac_prob;
-  const VP8QuantMatrix* q = &dec->dqm_[dec->segment_];
-  int16_t* dst = dec->coeffs_;
-  VP8MB* const left_mb = dec->mb_info_ - 1;
-  PackedNz nz_ac, nz_dc;
-  PackedNz tnz, lnz;
-  uint32_t non_zero_ac = 0;
-  uint32_t non_zero_dc = 0;
-  int x, y, ch;
-
-  memset(dst, 0, 384 * sizeof(*dst));
-  if (!dec->is_i4x4_) {    // parse DC
-    int16_t dc[16] = { 0 };
-    const int ctx = mb->dc_nz_ + left_mb->dc_nz_;
-    mb->dc_nz_ = left_mb->dc_nz_ =
-        (GetCoeffs(token_br, (ProbaArray)dec->proba_.coeffs_[1],
-                   ctx, q->y2_mat_, 0, dc) > 0);
-    first = 1;
-    ac_prob = (ProbaArray)dec->proba_.coeffs_[0];
-    VP8TransformWHT(dc, dst);
-  } else {
-    first = 0;
-    ac_prob = (ProbaArray)dec->proba_.coeffs_[3];
-  }
-
-  tnz = kUnpackTab[mb->nz_ & 0xf];
-  lnz = kUnpackTab[left_mb->nz_ & 0xf];
-  for (y = 0; y < 4; ++y) {
-    int l = lnz.i8[y];
-    for (x = 0; x < 4; ++x) {
-      const int ctx = l + tnz.i8[x];
-      const int nz = GetCoeffs(token_br, ac_prob, ctx,
-                               q->y1_mat_, first, dst);
-      tnz.i8[x] = l = (nz > 0);
-      nz_dc.i8[x] = (dst[0] != 0);
-      nz_ac.i8[x] = (nz > 1);
-      dst += 16;
-    }
-    lnz.i8[y] = l;
-    non_zero_dc |= PACK(nz_dc, 24 - y * 4);
-    non_zero_ac |= PACK(nz_ac, 24 - y * 4);
-  }
-  out_t_nz = PACK(tnz, 24);
-  out_l_nz = PACK(lnz, 24);
-
-  tnz = kUnpackTab[mb->nz_ >> 4];
-  lnz = kUnpackTab[left_mb->nz_ >> 4];
-  for (ch = 0; ch < 4; ch += 2) {
-    for (y = 0; y < 2; ++y) {
-      int l = lnz.i8[ch + y];
-      for (x = 0; x < 2; ++x) {
-        const int ctx = l + tnz.i8[ch + x];
-        const int nz =
-            GetCoeffs(token_br, (ProbaArray)dec->proba_.coeffs_[2],
-                      ctx, q->uv_mat_, 0, dst);
-        tnz.i8[ch + x] = l = (nz > 0);
-        nz_dc.i8[y * 2 + x] = (dst[0] != 0);
-        nz_ac.i8[y * 2 + x] = (nz > 1);
-        dst += 16;
-      }
-      lnz.i8[ch + y] = l;
-    }
-    non_zero_dc |= PACK(nz_dc, 8 - ch * 2);
-    non_zero_ac |= PACK(nz_ac, 8 - ch * 2);
-  }
-  out_t_nz |= PACK(tnz, 20);
-  out_l_nz |= PACK(lnz, 20);
-  mb->nz_ = out_t_nz;
-  left_mb->nz_ = out_l_nz;
-
-  dec->non_zero_ac_ = non_zero_ac;
-  dec->non_zero_ = non_zero_ac | non_zero_dc;
-  mb->skip_ = !dec->non_zero_;
-}
-#undef PACK
-
-//-----------------------------------------------------------------------------
-// Main loop
-
-int VP8DecodeMB(VP8Decoder* const dec, VP8BitReader* const token_br) {
-  VP8BitReader* const br = &dec->br_;
-  VP8MB* const left = dec->mb_info_ - 1;
-  VP8MB* const info = dec->mb_info_ + dec->mb_x_;
-
-  // Note: we don't save segment map (yet), as we don't expect
-  // to decode more than 1 keyframe.
-  if (dec->segment_hdr_.update_map_) {
-    // Hardcoded tree parsing
-    dec->segment_ = !VP8GetBit(br, dec->proba_.segments_[0]) ?
-        VP8GetBit(br, dec->proba_.segments_[1]) :
-        2 + VP8GetBit(br, dec->proba_.segments_[2]);
-  }
-  info->skip_ = dec->use_skip_proba_ ? VP8GetBit(br, dec->skip_p_) : 0;
-
-  VP8ParseIntraMode(br, dec);
-  if (br->eof_) {
-    return 0;
-  }
-
-  if (!info->skip_) {
-    ParseResiduals(dec, info, token_br);
-  } else {
-    left->nz_ = info->nz_ = 0;
-    if (!dec->is_i4x4_) {
-      left->dc_nz_ = info->dc_nz_ = 0;
-    }
-    dec->non_zero_ = 0;
-    dec->non_zero_ac_ = 0;
-  }
-
-  return (!token_br->eof_);
-}
-
-static int ParseFrame(VP8Decoder* const dec, VP8Io* io) {
-  for (dec->mb_y_ = 0; dec->mb_y_ < dec->mb_h_; ++dec->mb_y_) {
-    VP8MB* const left = dec->mb_info_ - 1;
-    VP8BitReader* const token_br =
-        &dec->parts_[dec->mb_y_ & (dec->num_parts_ - 1)];
-
-    left->nz_ = 0;
-    left->dc_nz_ = 0;
-    memset(dec->intra_l_, B_DC_PRED, sizeof(dec->intra_l_));
-
-    for (dec->mb_x_ = 0; dec->mb_x_ < dec->mb_w_;  dec->mb_x_++) {
-      if (!VP8DecodeMB(dec, token_br)) {
-        return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
-                           "Premature end-of-file encountered.");
-      }
-      VP8ReconstructBlock(dec);
-
-      // Store data and save block's filtering params
-      VP8StoreBlock(dec);
-    }
-    if (!VP8FinishRow(dec, io)) {
-      return VP8SetError(dec, VP8_STATUS_USER_ABORT,
-                         "Output aborted.");
-    }
-  }
-
-  // Finish
-#ifndef ONLY_KEYFRAME_CODE
-  if (!dec->update_proba_) {
-    dec->proba_ = dec->proba_saved_;
-  }
-#endif
-
-  return 1;
-}
-
-// Main entry point
-int VP8Decode(VP8Decoder* const dec, VP8Io* const io) {
-  if (dec == NULL) {
-    return 0;
-  }
-  if (io == NULL) {
-    return VP8SetError(dec, VP8_STATUS_INVALID_PARAM,
-                       "NULL VP8Io parameter in VP8Decode().");
-  }
-
-  if (!dec->ready_) {
-    if (!VP8GetHeaders(dec, io)) {
-      return 0;
-    }
-  }
-  assert(dec->ready_);
-
-  // will allocate memory and prepare everything.
-  if (!VP8InitFrame(dec, io)) {
-    VP8Clear(dec);
-    return VP8SetError(dec, VP8_STATUS_OUT_OF_MEMORY,
-                       "Allocation failed");
-  }
-
-  if (io->setup && !io->setup(io)) {
-    VP8Clear(dec);
-    return VP8SetError(dec, VP8_STATUS_USER_ABORT,
-                       "Frame setup failed");
-  }
-
-  // Disable filtering per user request (_after_ setup() is called)
-  if (io->bypass_filtering) dec->filter_type_ = 0;
-
-  // Main decoding loop
-  {
-    const int ret = ParseFrame(dec, io);
-    if (io->teardown) {
-      io->teardown(io);
-    }
-    if (!ret) {
-      VP8Clear(dec);
-      return 0;
-    }
-  }
-
-  dec->ready_ = 0;
-  return 1;
-}
-
-void VP8Clear(VP8Decoder* const dec) {
-  if (dec == NULL) {
-    return;
-  }
-  if (dec->mem_) {
-    free(dec->mem_);
-  }
-  dec->mem_ = NULL;
-  dec->mem_size_ = 0;
-  memset(&dec->br_, 0, sizeof(dec->br_));
-  dec->ready_ = 0;
-}
-
-//-----------------------------------------------------------------------------
-
-#if defined(__cplusplus) || defined(c_plusplus)
-}    // extern "C"
-#endif

src/dec/vp8_dec.c

@@ -0,0 +1,721 @@
+// Copyright 2010 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// main entry for the decoder
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <stdlib.h>
+
+#include "./alphai_dec.h"
+#include "./vp8i_dec.h"
+#include "./vp8li_dec.h"
+#include "./webpi_dec.h"
+#include "../utils/bit_reader_inl_utils.h"
+#include "../utils/utils.h"
+
+//------------------------------------------------------------------------------
+
+int WebPGetDecoderVersion(void) {
+  return (DEC_MAJ_VERSION << 16) | (DEC_MIN_VERSION << 8) | DEC_REV_VERSION;
+}
+
+//------------------------------------------------------------------------------
+// Signature and pointer-to-function for GetCoeffs() variants below.
+
+typedef int (*GetCoeffsFunc)(VP8BitReader* const br,
+                             const VP8BandProbas* const prob[],
+                             int ctx, const quant_t dq, int n, int16_t* out);
+static volatile GetCoeffsFunc GetCoeffs = NULL;
+
+static void InitGetCoeffs(void);
+
+//------------------------------------------------------------------------------
+// VP8Decoder
+
+static void SetOk(VP8Decoder* const dec) {
+  dec->status_ = VP8_STATUS_OK;
+  dec->error_msg_ = "OK";
+}
+
+int VP8InitIoInternal(VP8Io* const io, int version) {
+  if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) {
+    return 0;  // mismatch error
+  }
+  if (io != NULL) {
+    memset(io, 0, sizeof(*io));
+  }
+  return 1;
+}
+
+VP8Decoder* VP8New(void) {
+  VP8Decoder* const dec = (VP8Decoder*)WebPSafeCalloc(1ULL, sizeof(*dec));
+  if (dec != NULL) {
+    SetOk(dec);
+    WebPGetWorkerInterface()->Init(&dec->worker_);
+    dec->ready_ = 0;
+    dec->num_parts_minus_one_ = 0;
+    InitGetCoeffs();
+  }
+  return dec;
+}
+
+VP8StatusCode VP8Status(VP8Decoder* const dec) {
+  if (!dec) return VP8_STATUS_INVALID_PARAM;
+  return dec->status_;
+}
+
+const char* VP8StatusMessage(VP8Decoder* const dec) {
+  if (dec == NULL) return "no object";
+  if (!dec->error_msg_) return "OK";
+  return dec->error_msg_;
+}
+
+void VP8Delete(VP8Decoder* const dec) {
+  if (dec != NULL) {
+    VP8Clear(dec);
+    WebPSafeFree(dec);
+  }
+}
+
+int VP8SetError(VP8Decoder* const dec,
+                VP8StatusCode error, const char* const msg) {
+  // The oldest error reported takes precedence over the new one.
+  if (dec->status_ == VP8_STATUS_OK) {
+    dec->status_ = error;
+    dec->error_msg_ = msg;
+    dec->ready_ = 0;
+  }
+  return 0;
+}
+
+//------------------------------------------------------------------------------
+
+int VP8CheckSignature(const uint8_t* const data, size_t data_size) {
+  return (data_size >= 3 &&
+          data[0] == 0x9d && data[1] == 0x01 && data[2] == 0x2a);
+}
+
+int VP8GetInfo(const uint8_t* data, size_t data_size, size_t chunk_size,
+               int* const width, int* const height) {
+  if (data == NULL || data_size < VP8_FRAME_HEADER_SIZE) {
+    return 0;         // not enough data
+  }
+  // check signature
+  if (!VP8CheckSignature(data + 3, data_size - 3)) {
+    return 0;         // Wrong signature.
+  } else {
+    const uint32_t bits = data[0] | (data[1] << 8) | (data[2] << 16);
+    const int key_frame = !(bits & 1);
+    const int w = ((data[7] << 8) | data[6]) & 0x3fff;
+    const int h = ((data[9] << 8) | data[8]) & 0x3fff;
+
+    if (!key_frame) {   // Not a keyframe.
+      return 0;
+    }
+
+    if (((bits >> 1) & 7) > 3) {
+      return 0;         // unknown profile
+    }
+    if (!((bits >> 4) & 1)) {
+      return 0;         // first frame is invisible!
+    }
+    if (((bits >> 5)) >= chunk_size) {  // partition_length
+      return 0;         // inconsistent size information.
+    }
+    if (w == 0 || h == 0) {
+      return 0;         // We don't support both width and height to be zero.
+    }
+
+    if (width) {
+      *width = w;
+    }
+    if (height) {
+      *height = h;
+    }
+
+    return 1;
+  }
+}
+
+//------------------------------------------------------------------------------
+// Header parsing
+
+static void ResetSegmentHeader(VP8SegmentHeader* const hdr) {
+  assert(hdr != NULL);
+  hdr->use_segment_ = 0;
+  hdr->update_map_ = 0;
+  hdr->absolute_delta_ = 1;
+  memset(hdr->quantizer_, 0, sizeof(hdr->quantizer_));
+  memset(hdr->filter_strength_, 0, sizeof(hdr->filter_strength_));
+}
+
+// Paragraph 9.3
+static int ParseSegmentHeader(VP8BitReader* br,
+                              VP8SegmentHeader* hdr, VP8Proba* proba) {
+  assert(br != NULL);
+  assert(hdr != NULL);
+  hdr->use_segment_ = VP8Get(br);
+  if (hdr->use_segment_) {
+    hdr->update_map_ = VP8Get(br);
+    if (VP8Get(br)) {   // update data
+      int s;
+      hdr->absolute_delta_ = VP8Get(br);
+      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
+        hdr->quantizer_[s] = VP8Get(br) ? VP8GetSignedValue(br, 7) : 0;
+      }
+      for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
+        hdr->filter_strength_[s] = VP8Get(br) ? VP8GetSignedValue(br, 6) : 0;
+      }
+    }
+    if (hdr->update_map_) {
+      int s;
+      for (s = 0; s < MB_FEATURE_TREE_PROBS; ++s) {
+        proba->segments_[s] = VP8Get(br) ? VP8GetValue(br, 8) : 255u;
+      }
+    }
+  } else {
+    hdr->update_map_ = 0;
+  }
+  return !br->eof_;
+}
+
+// Paragraph 9.5
+// This function returns VP8_STATUS_SUSPENDED if we don't have all the
+// necessary data in 'buf'.
+// This case is not necessarily an error (for incremental decoding).
+// Still, no bitreader is ever initialized to make it possible to read
+// unavailable memory.
+// If we don't even have the partitions' sizes, than VP8_STATUS_NOT_ENOUGH_DATA
+// is returned, and this is an unrecoverable error.
+// If the partitions were positioned ok, VP8_STATUS_OK is returned.
+static VP8StatusCode ParsePartitions(VP8Decoder* const dec,
+                                     const uint8_t* buf, size_t size) {
+  VP8BitReader* const br = &dec->br_;
+  const uint8_t* sz = buf;
+  const uint8_t* buf_end = buf + size;
+  const uint8_t* part_start;
+  size_t size_left = size;
+  size_t last_part;
+  size_t p;
+
+  dec->num_parts_minus_one_ = (1 << VP8GetValue(br, 2)) - 1;
+  last_part = dec->num_parts_minus_one_;
+  if (size < 3 * last_part) {
+    // we can't even read the sizes with sz[]! That's a failure.
+    return VP8_STATUS_NOT_ENOUGH_DATA;
+  }
+  part_start = buf + last_part * 3;
+  size_left -= last_part * 3;
+  for (p = 0; p < last_part; ++p) {
+    size_t psize = sz[0] | (sz[1] << 8) | (sz[2] << 16);
+    if (psize > size_left) psize = size_left;
+    VP8InitBitReader(dec->parts_ + p, part_start, psize);
+    part_start += psize;
+    size_left -= psize;
+    sz += 3;
+  }
+  VP8InitBitReader(dec->parts_ + last_part, part_start, size_left);
+  return (part_start < buf_end) ? VP8_STATUS_OK :
+           VP8_STATUS_SUSPENDED;   // Init is ok, but there's not enough data
+}
+
+// Paragraph 9.4
+static int ParseFilterHeader(VP8BitReader* br, VP8Decoder* const dec) {
+  VP8FilterHeader* const hdr = &dec->filter_hdr_;
+  hdr->simple_    = VP8Get(br);
+  hdr->level_     = VP8GetValue(br, 6);
+  hdr->sharpness_ = VP8GetValue(br, 3);
+  hdr->use_lf_delta_ = VP8Get(br);
+  if (hdr->use_lf_delta_) {
+    if (VP8Get(br)) {   // update lf-delta?
+      int i;
+      for (i = 0; i < NUM_REF_LF_DELTAS; ++i) {
+        if (VP8Get(br)) {
+          hdr->ref_lf_delta_[i] = VP8GetSignedValue(br, 6);
+        }
+      }
+      for (i = 0; i < NUM_MODE_LF_DELTAS; ++i) {
+        if (VP8Get(br)) {
+          hdr->mode_lf_delta_[i] = VP8GetSignedValue(br, 6);
+        }
+      }
+    }
+  }
+  dec->filter_type_ = (hdr->level_ == 0) ? 0 : hdr->simple_ ? 1 : 2;
+  return !br->eof_;
+}
+
+// Topmost call
+int VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io) {
+  const uint8_t* buf;
+  size_t buf_size;
+  VP8FrameHeader* frm_hdr;
+  VP8PictureHeader* pic_hdr;
+  VP8BitReader* br;
+  VP8StatusCode status;
+
+  if (dec == NULL) {
+    return 0;
+  }
+  SetOk(dec);
+  if (io == NULL) {
+    return VP8SetError(dec, VP8_STATUS_INVALID_PARAM,
+                       "null VP8Io passed to VP8GetHeaders()");
+  }
+  buf = io->data;
+  buf_size = io->data_size;
+  if (buf_size < 4) {
+    return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
+                       "Truncated header.");
+  }
+
+  // Paragraph 9.1
+  {
+    const uint32_t bits = buf[0] | (buf[1] << 8) | (buf[2] << 16);
+    frm_hdr = &dec->frm_hdr_;
+    frm_hdr->key_frame_ = !(bits & 1);
+    frm_hdr->profile_ = (bits >> 1) & 7;
+    frm_hdr->show_ = (bits >> 4) & 1;
+    frm_hdr->partition_length_ = (bits >> 5);
+    if (frm_hdr->profile_ > 3) {
+      return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
+                         "Incorrect keyframe parameters.");
+    }
+    if (!frm_hdr->show_) {
+      return VP8SetError(dec, VP8_STATUS_UNSUPPORTED_FEATURE,
+                         "Frame not displayable.");
+    }
+    buf += 3;
+    buf_size -= 3;
+  }
+
+  pic_hdr = &dec->pic_hdr_;
+  if (frm_hdr->key_frame_) {
+    // Paragraph 9.2
+    if (buf_size < 7) {
+      return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
+                         "cannot parse picture header");
+    }
+    if (!VP8CheckSignature(buf, buf_size)) {
+      return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
+                         "Bad code word");
+    }
+    pic_hdr->width_ = ((buf[4] << 8) | buf[3]) & 0x3fff;
+    pic_hdr->xscale_ = buf[4] >> 6;   // ratio: 1, 5/4 5/3 or 2
+    pic_hdr->height_ = ((buf[6] << 8) | buf[5]) & 0x3fff;
+    pic_hdr->yscale_ = buf[6] >> 6;
+    buf += 7;
+    buf_size -= 7;
+
+    dec->mb_w_ = (pic_hdr->width_ + 15) >> 4;
+    dec->mb_h_ = (pic_hdr->height_ + 15) >> 4;
+
+    // Setup default output area (can be later modified during io->setup())
+    io->width = pic_hdr->width_;
+    io->height = pic_hdr->height_;
+    // IMPORTANT! use some sane dimensions in crop_* and scaled_* fields.
+    // So they can be used interchangeably without always testing for
+    // 'use_cropping'.
+    io->use_cropping = 0;
+    io->crop_top  = 0;
+    io->crop_left = 0;
+    io->crop_right  = io->width;
+    io->crop_bottom = io->height;
+    io->use_scaling  = 0;
+    io->scaled_width = io->width;
+    io->scaled_height = io->height;
+
+    io->mb_w = io->width;   // sanity check
+    io->mb_h = io->height;  // ditto
+
+    VP8ResetProba(&dec->proba_);
+    ResetSegmentHeader(&dec->segment_hdr_);
+  }
+
+  // Check if we have all the partition #0 available, and initialize dec->br_
+  // to read this partition (and this partition only).
+  if (frm_hdr->partition_length_ > buf_size) {
+    return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
+                       "bad partition length");
+  }
+
+  br = &dec->br_;
+  VP8InitBitReader(br, buf, frm_hdr->partition_length_);
+  buf += frm_hdr->partition_length_;
+  buf_size -= frm_hdr->partition_length_;
+
+  if (frm_hdr->key_frame_) {
+    pic_hdr->colorspace_ = VP8Get(br);
+    pic_hdr->clamp_type_ = VP8Get(br);
+  }
+  if (!ParseSegmentHeader(br, &dec->segment_hdr_, &dec->proba_)) {
+    return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
+                       "cannot parse segment header");
+  }
+  // Filter specs
+  if (!ParseFilterHeader(br, dec)) {
+    return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
+                       "cannot parse filter header");
+  }
+  status = ParsePartitions(dec, buf, buf_size);
+  if (status != VP8_STATUS_OK) {
+    return VP8SetError(dec, status, "cannot parse partitions");
+  }
+
+  // quantizer change
+  VP8ParseQuant(dec);
+
+  // Frame buffer marking
+  if (!frm_hdr->key_frame_) {
+    return VP8SetError(dec, VP8_STATUS_UNSUPPORTED_FEATURE,
+                       "Not a key frame.");
+  }
+
+  VP8Get(br);   // ignore the value of update_proba_
+
+  VP8ParseProba(br, dec);
+
+  // sanitized state
+  dec->ready_ = 1;
+  return 1;
+}
+
+//------------------------------------------------------------------------------
+// Residual decoding (Paragraph 13.2 / 13.3)
+
+static const uint8_t kCat3[] = { 173, 148, 140, 0 };
+static const uint8_t kCat4[] = { 176, 155, 140, 135, 0 };
+static const uint8_t kCat5[] = { 180, 157, 141, 134, 130, 0 };
+static const uint8_t kCat6[] =
+  { 254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129, 0 };
+static const uint8_t* const kCat3456[] = { kCat3, kCat4, kCat5, kCat6 };
+static const uint8_t kZigzag[16] = {
+  0, 1, 4, 8,  5, 2, 3, 6,  9, 12, 13, 10,  7, 11, 14, 15
+};
+
+// See section 13-2: http://tools.ietf.org/html/rfc6386#section-13.2
+static int GetLargeValue(VP8BitReader* const br, const uint8_t* const p) {
+  int v;
+  if (!VP8GetBit(br, p[3])) {
+    if (!VP8GetBit(br, p[4])) {
+      v = 2;
+    } else {
+      v = 3 + VP8GetBit(br, p[5]);
+    }
+  } else {
+    if (!VP8GetBit(br, p[6])) {
+      if (!VP8GetBit(br, p[7])) {
+        v = 5 + VP8GetBit(br, 159);
+      } else {
+        v = 7 + 2 * VP8GetBit(br, 165);
+        v += VP8GetBit(br, 145);
+      }
+    } else {
+      const uint8_t* tab;
+      const int bit1 = VP8GetBit(br, p[8]);
+      const int bit0 = VP8GetBit(br, p[9 + bit1]);
+      const int cat = 2 * bit1 + bit0;
+      v = 0;
+      for (tab = kCat3456[cat]; *tab; ++tab) {
+        v += v + VP8GetBit(br, *tab);
+      }
+      v += 3 + (8 << cat);
+    }
+  }
+  return v;
+}
+
+// Returns the position of the last non-zero coeff plus one
+static int GetCoeffsFast(VP8BitReader* const br,
+                         const VP8BandProbas* const prob[],
+                         int ctx, const quant_t dq, int n, int16_t* out) {
+  const uint8_t* p = prob[n]->probas_[ctx];
+  for (; n < 16; ++n) {
+    if (!VP8GetBit(br, p[0])) {
+      return n;  // previous coeff was last non-zero coeff
+    }
+    while (!VP8GetBit(br, p[1])) {       // sequence of zero coeffs
+      p = prob[++n]->probas_[0];
+      if (n == 16) return 16;
+    }
+    {        // non zero coeff
+      const VP8ProbaArray* const p_ctx = &prob[n + 1]->probas_[0];
+      int v;
+      if (!VP8GetBit(br, p[2])) {
+        v = 1;
+        p = p_ctx[1];
+      } else {
+        v = GetLargeValue(br, p);
+        p = p_ctx[2];
+      }
+      out[kZigzag[n]] = VP8GetSigned(br, v) * dq[n > 0];
+    }
+  }
+  return 16;
+}
+
+// This version of GetCoeffs() uses VP8GetBitAlt() which is an alternate version
+// of VP8GetBitAlt() targeting specific platforms.
+static int GetCoeffsAlt(VP8BitReader* const br,
+                        const VP8BandProbas* const prob[],
+                        int ctx, const quant_t dq, int n, int16_t* out) {
+  const uint8_t* p = prob[n]->probas_[ctx];
+  for (; n < 16; ++n) {
+    if (!VP8GetBitAlt(br, p[0])) {
+      return n;  // previous coeff was last non-zero coeff
+    }
+    while (!VP8GetBitAlt(br, p[1])) {       // sequence of zero coeffs
+      p = prob[++n]->probas_[0];
+      if (n == 16) return 16;
+    }
+    {        // non zero coeff
+      const VP8ProbaArray* const p_ctx = &prob[n + 1]->probas_[0];
+      int v;
+      if (!VP8GetBitAlt(br, p[2])) {
+        v = 1;
+        p = p_ctx[1];
+      } else {
+        v = GetLargeValue(br, p);
+        p = p_ctx[2];
+      }
+      out[kZigzag[n]] = VP8GetSigned(br, v) * dq[n > 0];
+    }
+  }
+  return 16;
+}
+
+WEBP_TSAN_IGNORE_FUNCTION static void InitGetCoeffs(void) {
+  if (GetCoeffs == NULL) {
+    if (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kSlowSSSE3)) {
+      GetCoeffs = GetCoeffsAlt;
+    } else {
+      GetCoeffs = GetCoeffsFast;
+    }
+  }
+}
+
+static WEBP_INLINE uint32_t NzCodeBits(uint32_t nz_coeffs, int nz, int dc_nz) {
+  nz_coeffs <<= 2;
+  nz_coeffs |= (nz > 3) ? 3 : (nz > 1) ? 2 : dc_nz;
+  return nz_coeffs;
+}
+
+static int ParseResiduals(VP8Decoder* const dec,
+                          VP8MB* const mb, VP8BitReader* const token_br) {
+  const VP8BandProbas* (* const bands)[16 + 1] = dec->proba_.bands_ptr_;
+  const VP8BandProbas* const * ac_proba;
+  VP8MBData* const block = dec->mb_data_ + dec->mb_x_;
+  const VP8QuantMatrix* const q = &dec->dqm_[block->segment_];
+  int16_t* dst = block->coeffs_;
+  VP8MB* const left_mb = dec->mb_info_ - 1;
+  uint8_t tnz, lnz;
+  uint32_t non_zero_y = 0;
+  uint32_t non_zero_uv = 0;
+  int x, y, ch;
+  uint32_t out_t_nz, out_l_nz;
+  int first;
+
+  memset(dst, 0, 384 * sizeof(*dst));
+  if (!block->is_i4x4_) {    // parse DC
+    int16_t dc[16] = { 0 };
+    const int ctx = mb->nz_dc_ + left_mb->nz_dc_;
+    const int nz = GetCoeffs(token_br, bands[1], ctx, q->y2_mat_, 0, dc);
+    mb->nz_dc_ = left_mb->nz_dc_ = (nz > 0);
+    if (nz > 1) {   // more than just the DC -> perform the full transform
+      VP8TransformWHT(dc, dst);
+    } else {        // only DC is non-zero -> inlined simplified transform
+      int i;
+      const int dc0 = (dc[0] + 3) >> 3;
+      for (i = 0; i < 16 * 16; i += 16) dst[i] = dc0;
+    }
+    first = 1;
+    ac_proba = bands[0];
+  } else {
+    first = 0;
+    ac_proba = bands[3];
+  }
+
+  tnz = mb->nz_ & 0x0f;
+  lnz = left_mb->nz_ & 0x0f;
+  for (y = 0; y < 4; ++y) {
+    int l = lnz & 1;
+    uint32_t nz_coeffs = 0;
+    for (x = 0; x < 4; ++x) {
+      const int ctx = l + (tnz & 1);
+      const int nz = GetCoeffs(token_br, ac_proba, ctx, q->y1_mat_, first, dst);
+      l = (nz > first);
+      tnz = (tnz >> 1) | (l << 7);
+      nz_coeffs = NzCodeBits(nz_coeffs, nz, dst[0] != 0);
+      dst += 16;
+    }
+    tnz >>= 4;
+    lnz = (lnz >> 1) | (l << 7);
+    non_zero_y = (non_zero_y << 8) | nz_coeffs;
+  }
+  out_t_nz = tnz;
+  out_l_nz = lnz >> 4;
+
+  for (ch = 0; ch < 4; ch += 2) {
+    uint32_t nz_coeffs = 0;
+    tnz = mb->nz_ >> (4 + ch);
+    lnz = left_mb->nz_ >> (4 + ch);
+    for (y = 0; y < 2; ++y) {
+      int l = lnz & 1;
+      for (x = 0; x < 2; ++x) {
+        const int ctx = l + (tnz & 1);
+        const int nz = GetCoeffs(token_br, bands[2], ctx, q->uv_mat_, 0, dst);
+        l = (nz > 0);
+        tnz = (tnz >> 1) | (l << 3);
+        nz_coeffs = NzCodeBits(nz_coeffs, nz, dst[0] != 0);
+        dst += 16;
+      }
+      tnz >>= 2;
+      lnz = (lnz >> 1) | (l << 5);
+    }
+    // Note: we don't really need the per-4x4 details for U/V blocks.
+    non_zero_uv |= nz_coeffs << (4 * ch);
+    out_t_nz |= (tnz << 4) << ch;
+    out_l_nz |= (lnz & 0xf0) << ch;
+  }
+  mb->nz_ = out_t_nz;
+  left_mb->nz_ = out_l_nz;
+
+  block->non_zero_y_ = non_zero_y;
+  block->non_zero_uv_ = non_zero_uv;
+
+  // We look at the mode-code of each block and check if some blocks have less
+  // than three non-zero coeffs (code < 2). This is to avoid dithering flat and
+  // empty blocks.
+  block->dither_ = (non_zero_uv & 0xaaaa) ? 0 : q->dither_;
+
+  return !(non_zero_y | non_zero_uv);  // will be used for further optimization
+}
+
+//------------------------------------------------------------------------------
+// Main loop
+
+int VP8DecodeMB(VP8Decoder* const dec, VP8BitReader* const token_br) {
+  VP8MB* const left = dec->mb_info_ - 1;
+  VP8MB* const mb = dec->mb_info_ + dec->mb_x_;
+  VP8MBData* const block = dec->mb_data_ + dec->mb_x_;
+  int skip = dec->use_skip_proba_ ? block->skip_ : 0;
+
+  if (!skip) {
+    skip = ParseResiduals(dec, mb, token_br);
+  } else {
+    left->nz_ = mb->nz_ = 0;
+    if (!block->is_i4x4_) {
+      left->nz_dc_ = mb->nz_dc_ = 0;
+    }
+    block->non_zero_y_ = 0;
+    block->non_zero_uv_ = 0;
+    block->dither_ = 0;
+  }
+
+  if (dec->filter_type_ > 0) {  // store filter info
+    VP8FInfo* const finfo = dec->f_info_ + dec->mb_x_;
+    *finfo = dec->fstrengths_[block->segment_][block->is_i4x4_];
+    finfo->f_inner_ |= !skip;
+  }
+
+  return !token_br->eof_;
+}
+
+void VP8InitScanline(VP8Decoder* const dec) {
+  VP8MB* const left = dec->mb_info_ - 1;
+  left->nz_ = 0;
+  left->nz_dc_ = 0;
+  memset(dec->intra_l_, B_DC_PRED, sizeof(dec->intra_l_));
+  dec->mb_x_ = 0;
+}
+
+static int ParseFrame(VP8Decoder* const dec, VP8Io* io) {
+  for (dec->mb_y_ = 0; dec->mb_y_ < dec->br_mb_y_; ++dec->mb_y_) {
+    // Parse bitstream for this row.
+    VP8BitReader* const token_br =
+        &dec->parts_[dec->mb_y_ & dec->num_parts_minus_one_];
+    if (!VP8ParseIntraModeRow(&dec->br_, dec)) {
+      return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
+                         "Premature end-of-partition0 encountered.");
+    }
+    for (; dec->mb_x_ < dec->mb_w_; ++dec->mb_x_) {
+      if (!VP8DecodeMB(dec, token_br)) {
+        return VP8SetError(dec, VP8_STATUS_NOT_ENOUGH_DATA,
+                           "Premature end-of-file encountered.");
+      }
+    }
+    VP8InitScanline(dec);   // Prepare for next scanline
+
+    // Reconstruct, filter and emit the row.
+    if (!VP8ProcessRow(dec, io)) {
+      return VP8SetError(dec, VP8_STATUS_USER_ABORT, "Output aborted.");
+    }
+  }
+  if (dec->mt_method_ > 0) {
+    if (!WebPGetWorkerInterface()->Sync(&dec->worker_)) return 0;
+  }
+
+  return 1;
+}
+
+// Main entry point
+int VP8Decode(VP8Decoder* const dec, VP8Io* const io) {
+  int ok = 0;
+  if (dec == NULL) {
+    return 0;
+  }
+  if (io == NULL) {
+    return VP8SetError(dec, VP8_STATUS_INVALID_PARAM,
+                       "NULL VP8Io parameter in VP8Decode().");
+  }
+
+  if (!dec->ready_) {
+    if (!VP8GetHeaders(dec, io)) {
+      return 0;
+    }
+  }
+  assert(dec->ready_);
+
+  // Finish setting up the decoding parameter. Will call io->setup().
+  ok = (VP8EnterCritical(dec, io) == VP8_STATUS_OK);
+  if (ok) {   // good to go.
+    // Will allocate memory and prepare everything.
+    if (ok) ok = VP8InitFrame(dec, io);
+
+    // Main decoding loop
+    if (ok) ok = ParseFrame(dec, io);
+
+    // Exit.
+    ok &= VP8ExitCritical(dec, io);
+  }
+
+  if (!ok) {
+    VP8Clear(dec);
+    return 0;
+  }
+
+  dec->ready_ = 0;
+  return ok;
+}
+
+void VP8Clear(VP8Decoder* const dec) {
+  if (dec == NULL) {
+    return;
+  }
+  WebPGetWorkerInterface()->End(&dec->worker_);
+  WebPDeallocateAlphaMemory(dec);
+  WebPSafeFree(dec->mem_);
+  dec->mem_ = NULL;
+  dec->mem_size_ = 0;
+  memset(&dec->br_, 0, sizeof(dec->br_));
+  dec->ready_ = 0;
+}
+
+//------------------------------------------------------------------------------