imageio: add limited PNM support for reading

see: http://netpbm.sourceforge.net/

Only reads P5 and P6 pnm files for now.

Change-Id: I2332a623f803df67455047f570f1cff9f464480a

CMakeLists.txt

@@ -124,6 +124,8 @@ if(WEBP_BUILD_CWEBP OR WEBP_BUILD_DWEBP OR
     ${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/pnmdec.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/imageio/pnmdec.h
     ${CMAKE_CURRENT_SOURCE_DIR}/imageio/tiffdec.c
     ${CMAKE_CURRENT_SOURCE_DIR}/imageio/tiffdec.h
     ${CMAKE_CURRENT_SOURCE_DIR}/imageio/webpdec.c

Makefile.vc

@@ -263,6 +263,7 @@ IMAGEIO_DEC_OBJS = \
     $(DIROBJ)\imageio\jpegdec.obj \
     $(DIROBJ)\imageio\metadata.obj \
     $(DIROBJ)\imageio\pngdec.obj \
+    $(DIROBJ)\imageio\pnmdec.obj \
     $(DIROBJ)\imageio\tiffdec.obj \
     $(DIROBJ)\imageio\webpdec.obj \
     $(DIROBJ)\imageio\wicdec.obj \

build.gradle

@@ -288,6 +288,7 @@ model {
             include "jpegdec.c"
             include "metadata.c"
             include "pngdec.c"
+            include "pnmdec.c"
             include "tiffdec.c"
             include "webpdec.c"
           }

imageio/Android.mk

@@ -25,6 +25,7 @@ LOCAL_SRC_FILES := \
     jpegdec.c \
     metadata.c \
     pngdec.c \
+    pnmdec.c \
     tiffdec.c \
     webpdec.c \
 

imageio/Makefile.am

@@ -11,6 +11,7 @@ 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 += pnmdec.c pnmdec.h
 libimagedec_la_SOURCES += tiffdec.c tiffdec.h
 libimagedec_la_SOURCES += webpdec.c webpdec.h
 libimagedec_la_SOURCES += wicdec.c wicdec.h

imageio/image_dec.c

@@ -29,6 +29,10 @@ WebPInputFileFormat WebPGuessImageType(const uint8_t* const data,
       format = WEBP_TIFF_FORMAT;
     } else if (magic1 == 0x52494646 && magic2 == 0x57454250) {
       format = WEBP_WEBP_FORMAT;
+    } else if (((magic1 >> 24) & 0xff) == 'P') {
+      const int type = (magic1 >> 16) & 0xff;
+      // we only support 'P5' and 'P6' for now.
+      if (type >= '5' && type <= '6') format = WEBP_PNM_FORMAT;
     }
   }
   return format;
@@ -51,6 +55,7 @@ WebPImageReader WebPGetImageReader(WebPInputFileFormat format) {
     case WEBP_JPEG_FORMAT: return ReadJPEG;
     case WEBP_TIFF_FORMAT: return ReadTIFF;
     case WEBP_WEBP_FORMAT: return ReadWebP;
+    case WEBP_PNM_FORMAT: return ReadPNM;
     default: return FailReader;
   }
 }

imageio/image_dec.h

@@ -23,6 +23,7 @@
 #include "./metadata.h"
 #include "./jpegdec.h"
 #include "./pngdec.h"
+#include "./pnmdec.h"
 #include "./tiffdec.h"
 #include "./webpdec.h"
 #include "./wicdec.h"
@@ -36,6 +37,7 @@ typedef enum {
   WEBP_JPEG_FORMAT,
   WEBP_TIFF_FORMAT,
   WEBP_WEBP_FORMAT,
+  WEBP_PNM_FORMAT,
   WEBP_UNSUPPORTED_FORMAT
 } WebPInputFileFormat;
 

imageio/pnmdec.c

@@ -0,0 +1,142 @@
+// Copyright 2017 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.
+// -----------------------------------------------------------------------------
+//
+// (limited) PNM decoder
+
+#include "./pnmdec.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "webp/encode.h"
+#include "./imageio_util.h"
+
+// -----------------------------------------------------------------------------
+// PNM decoding
+
+#define MAX_LINE_SIZE 1024
+static const size_t kMinPNMHeaderSize = 3;
+
+static size_t ReadLine(const uint8_t* const data, size_t off, size_t data_size,
+                       char out[MAX_LINE_SIZE + 1], size_t* const out_size) {
+  size_t i = 0;
+  *out_size = 0;
+ redo:
+  for (i = 0; i < MAX_LINE_SIZE && off < data_size; ++i) {
+    out[i] = data[off++];
+    if (out[i] == '\n') break;
+  }
+  if (off < data_size) {
+    if (i == 0) goto redo;         // empty line
+    if (out[0] == '#') goto redo;  // skip comment
+  }
+  out[i] = 0;   // safety sentinel
+  *out_size = i;
+  return off;
+}
+
+static size_t ReadHeader(const uint8_t* const data, size_t data_size,
+                         int* const width, int* const height,
+                         int* const type, int* const max_value) {
+  size_t off = 0;
+  char out[MAX_LINE_SIZE + 1];
+  size_t out_size;
+  if (width == NULL || height == NULL || type == NULL || max_value == NULL) {
+    return 0;
+  }
+  *width = 0;
+  *height = 0;
+  *type = -1;
+  *max_value = 0;
+  if (data == NULL || data_size < kMinPNMHeaderSize) return 0;
+  off = ReadLine(data, off, data_size, out, &out_size);
+  if (off == 0 || sscanf(out, "P%d", type) != 1) return 0;
+  off = ReadLine(data, off, data_size, out, &out_size);
+  if (off == 0 || sscanf(out, "%d %d", width, height) != 2) return 0;
+  off = ReadLine(data, off, data_size, out, &out_size);
+  if (off == 0 || sscanf(out, "%d", max_value) != 1) return 0;
+  return off;
+}
+
+int ReadPNM(const uint8_t* const data, size_t data_size,
+            WebPPicture* const pic, int keep_alpha,
+            struct Metadata* const metadata) {
+  int ok = 0;
+  int width, height, type, max_value;
+  int i, j;
+  uint64_t stride;
+  uint8_t* rgb = NULL, *tmp_rgb;
+  size_t offset;
+
+  offset = ReadHeader(data, data_size, &width, &height,
+                      &type, &max_value);
+  if (offset == 0) goto End;
+  if (type != 5 && type != 6) {
+    fprintf(stderr, "Unsupported P%d PNM format.\n", type);
+    goto End;
+  }
+
+  // Some basic validations.
+  if (pic == NULL) goto End;
+  if (width <= 0 || height <= 0 ||
+      width > WEBP_MAX_DIMENSION || height > WEBP_MAX_DIMENSION) {
+    fprintf(stderr, "Invalid %dx%d dimension for PNM\n", width, height);
+    goto End;
+  }
+
+  stride = 3LL * width;
+  if (stride != (size_t)stride ||
+      !ImgIoUtilCheckSizeArgumentsOverflow(stride, height)) {
+    goto End;
+  }
+  if ((type == 5 && offset + 1LL * width * height > data_size) ||
+      (type == 6 && offset + 3LL * width * height > data_size)) {
+    fprintf(stderr, "Truncated PNM file (P%d).\n", type);
+    goto End;
+  }
+
+  rgb = (uint8_t*)malloc((size_t)stride * height);
+  if (rgb == NULL) goto End;
+
+  // Convert input
+  tmp_rgb = rgb;
+  for (j = 0; j < height; ++j) {
+    if (type == 5) {
+      assert(offset + width <= data_size);
+      for (i = 0; i < width; ++i) {
+        const uint8_t v = data[offset + i];
+        tmp_rgb[3 * i + 0] = tmp_rgb[3 * i + 1] = tmp_rgb[3 * i + 2] = v;
+      }
+      offset += width;
+    } else if (type == 6) {
+      assert(offset + 3LL * width <= data_size);
+      memcpy(tmp_rgb, data + offset, 3 * width * sizeof(*data));
+      offset += 3 * width;
+    }
+    tmp_rgb += stride;
+  }
+
+  // WebP conversion.
+  pic->width = width;
+  pic->height = height;
+  ok = WebPPictureImportRGB(pic, rgb, (int)stride);
+  if (!ok) goto End;
+
+  ok = 1;
+ End:
+  free((void*)rgb);
+
+  (void)metadata;
+  (void)keep_alpha;
+  return ok;
+}
+
+// -----------------------------------------------------------------------------

imageio/pnmdec.h

@@ -0,0 +1,37 @@
+// Copyright 2017 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.
+// -----------------------------------------------------------------------------
+//
+// partial PNM format decoder (ppm/pgm)
+
+#ifndef WEBP_IMAGEIO_PNMDEC_H_
+#define WEBP_IMAGEIO_PNMDEC_H_
+
+#include "webp/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct Metadata;
+struct WebPPicture;
+
+// Reads a PNM file from 'data', returning the decoded output in 'pic'.
+// The output is RGB or YUV depending on pic->use_argb value.
+// Returns true on success.
+// 'metadata' has no effect, but is kept for coherence with other signatures
+// for image readers.
+int ReadPNM(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_PNMDEC_H_

makefile.unix

@@ -223,6 +223,7 @@ EX_FORMAT_DEC_OBJS = \
     imageio/jpegdec.o \
     imageio/metadata.o \
     imageio/pngdec.o \
+    imageio/pnmdec.o \
     imageio/tiffdec.o \
     imageio/webpdec.o \