Earlier, all lossless images were assumed to contain alpha.
Now, we use the 'alpha_is_used' bit from the VP8L bitstream to determine
the
same.
Detecting an absence of alpha can sometimes lead to much more efficient
rendering, especially for animated images.
Related: refine mux code to read width/height/has_alpha information only
once
per frame/fragment. This avoid frequent calls to VP8(L)GetInfo().
Change-Id: I4e0eef4db7d94425396c7dff6ca5599d5bca8297
Speed up HashChainFindCopy by optimizing on number of calls to
FindMatchLength method.
This change speeds up the lossless & lossy (Alpha) encoding by 20%
without loss of compression density.
At method=3, lossy (Alpha) compression speed (and density) remains
unchanged, as at that settings, the costly Backward Refs method is not
called
Change-Id: Ia1797148e9e4ee2787011837fa248afbae2242cb
Disable costly 'BackwardReferencesTraceBackwards' for encoding Alpha plane.
Increase the threshold for triggering 'BackwardReferencesTraceBackwards' to
quality 25 and above. Also lower the Alpha quality (at method 3) to be
lesser than this threshold (25).
Change-Id: Ic29fb2e6943472c564223df9fe099b19ccda0f31
This speeds up WebP lossless decoding by 20%. In particular, the
photographic images get 35% speedup.
Change-Id: Idb94750342a140ec05df52c07e12be4bba335adc
speeds up those codes that are not part of the main lookup.
This gives a 10 % speedup for a photographic image.
Change-Id: Ief54b0ad77db790a01314402ad351b40ac9a7be4
This is to ensure that the output WebP image is consistent with original
GIF when displayed against any background color.
Change-Id: I14218848153eb40358aa4ce331b2543d2fc2e86c
+ some revamp and cleanup of the alpha-filter trial loop
+ EncodeAlphaInternal() now just takes a FilterTrial param
Change-Id: Ief84385083b1cba02678bbcd3dbf707245ee962f
Specialize and simplify the alpha-decoding case, which is used when:
- no color-cache is use
- all red/blue/alpha values are the same (and hence their Huffman tree has
only 1 symbol. We don't need to consume any bits for reading these).
+ revamped the loop to use size_t and offsets instead of pointers.
~2-3% faster on Unix (gcc) but up to 25% faster lossy+alpha decoding
on Mac (llvm) and ARM.
Change-Id: I43c9688d1e4811cab0ecf0108a5b8f45781083e6
* 0.3.0: (57 commits)
update ChangeLog
Regression fix for alpha channels using color cache:
wicdec: silence a format warning
muxedit: silence some uninitialized warnings
update ChangeLog
update NEWS
bump version to 0.3.1
Revert "add WebPBlendAlpha() function to blend colors against background"
Simplify forward-WHT + SSE2 version
probe input file and quick-check for WebP format.
configure: improve gl/glut library test
update copyright text
configure: remove use of AS_VAR_APPEND
fix EXIF parsing in PNG
add doc precision for WebPPictureCopy() and WebPPictureView()
remove datatype qualifier for vmnv
fix a memory leak in gif2webp
fix two minor memory leaks in webpmux
remove some cruft from swig/libwebp.jar
README: update swig notes
...
Conflicts:
NEWS
examples/gif2webp.c
src/dec/alpha.c
src/dec/idec.c
src/dec/vp8l.c
src/enc/alpha.c
src/enc/vp8l.c
Change-Id: Ib202fad7825a090c3b3a5169acd171369cface47
+ split AllocateInternalBuffers() into two 32b/8b variants instead of
trying to do everything in one function.
Change-Id: I35cac9fcd990a2194c95da4b2a4046ca3a514343
Considering the fact that insert to/lookup from the color cache is always 32
bit, use DecodeImageData() variant in that case.
Conflicts:
src/dec/vp8l.c
Change-Id: I6c665a6cfbd9bd10651c1e82fa54e687cbd54a2b
(cherry picked from commit a37eff47d6)
from x86_64-w64-mingw32-gcc
examples/wicdec.c: In function ‘ExtractICCP’:
examples/wicdec.c:131:21: warning: format ‘%u’ expects argument of type
‘unsigned int’, but argument 4 has type ‘size_t’ [-Wformat]
Change-Id: I6642dae62265a2276ae9ac96dd8ce6f1e2d37ca5
(cherry picked from commit ffae9f31e8)
src/mux/muxedit.c:490: warning: 'x_offset' may be used uninitialized in this function
src/mux/muxedit.c:490: warning: 'y_offset' may be used uninitialized in this function
Change-Id: I4fd27f717e59a556354d0560b633d0edafe7a4d8
(cherry picked from commit 14cd5c6c40)
Considering the fact that insert to/lookup from the color cache is always 32
bit, use DecodeImageData() variant in that case.
Change-Id: I6c665a6cfbd9bd10651c1e82fa54e687cbd54a2b
src/mux/muxedit.c:490: warning: 'x_offset' may be used uninitialized in this function
src/mux/muxedit.c:490: warning: 'y_offset' may be used uninitialized in this function
Change-Id: I4fd27f717e59a556354d0560b633d0edafe7a4d8
src\dec\vp8l.c(816) : warning C4244: '=' : conversion from '__int64' to
'int', possible loss of data
src\dec\vp8l.c(817) : warning C4244: '=' : conversion from '__int64' to
'int', possible loss of data
Change-Id: I1d376d5dea909395bff8741aba16e8eed83a6e8f
from x86_64-w64-mingw32-gcc
examples/wicdec.c: In function ‘ExtractICCP’:
examples/wicdec.c:131:21: warning: format ‘%u’ expects argument of type
‘unsigned int’, but argument 4 has type ‘size_t’ [-Wformat]
Change-Id: I6642dae62265a2276ae9ac96dd8ce6f1e2d37ca5
no precision loss observed
speed is not really faster (0.5% at max), as forward-WHT isn't called often.
also: replaced a "int << 3" (undefined by C-spec) by a "int * 8"
( supersedes https://gerrit.chromium.org/gerrit/#/c/48739/ )
Change-Id: I2d980ec2f20f4ff6be5636105ff4f1c70ffde401
(cherry picked from commit 9c4ce971a8)
