Even at high quality setting, the U/V quantizer step is limited
to 4 which can lead to banding on gradient.
This option allows to selectively apply some randomness to
potentially flattened-out U/V blocks and attenuate the banding.
This option is off by default in 'dwebp', but set to -dither 50
by default in 'vwebp'.
Note: depending on the number of blocks selectively dithered,
we can have up to a 10% slow-down in decoding speed it seems.
Change-Id: Icc2446007f33ddacb60b3a80a9e63f2d5ad162de
...and make gif2webp and vwebp compile without them.
Makefile.vc still to be updated...
Meanwhile the CL environment variable can be supplemented with
set CL=/DWEBP_HAVE_GL /IC:\opt\freeglut\include
Change-Id: I37a60b8c32aafd125bffa98b6cc9f57c022ebbd0
rather than symlink the webm/vpx terms, use the same header as libvpx to
reference in-tree files
based on the discussion in:
https://codereview.chromium.org/12771026/
Change-Id: Ia3067ecddefaa7ee01550136e00f7b3f086d4af4
They went out of sync some time ago, and are
no longer really required since we have them
buildable from makefile.unix
Change-Id: Ica2dcf5c55f44365598f832f55204d123d7aa601
buffer the last frame's details to perform DISPOSE_BACKGROUND on the
image's area, rather than the entire canvas.
also fixes transparent backgrounds with animated images
Change-Id: I53e4d70c441e1eeb136f1d01e7c88de4f9ecff53
- Separate out mux.h and demux.h
- muxtypes.h: new header for data types common to mux/demux
- Move some misc read/write utilities to utils/utils.h
- Remove some duplicate methods.
- Separate out mux/demux libraries
Change-Id: If9b9569b10d55d922ad9317ef51710544315d6de
* fix gif2webp to handle disposal method and odd offset correctly
+ remove -scale and -crop option from vwebp, since it'll be broken
with offsets and fragments. Needs a revisit.
+ remove a warning in gif2web
Change-Id: If04c6d085806e32540f2f15a37244c4407b719b3
- Also, use the term 'fragments' instead of 'tiling' in code
- This makes code consistent with the spec.
Change-Id: Ibeccffc35db23bbedb88cc5e18e29e51621931f8
- Match offsets, duration, width/height for frames/tiles and enforce
some constraints.
- Note that this also means using 'int's instead of 'uint32_t's for
16-bit and 24-bit fields.
Change-Id: If0b229ad9fce296372d961104aa36731a3b1304b
'Set' and 'Get' methods for images take/return a bitstream as input,
instead of separate 'image' and 'alpha' arguments.
Also,
- Make WebPDataCopy() a public API
- Use WebPData for storing data in WebPChunk.
- Fix a potential memleak.
Change-Id: I4bf5ee6b39971384cb124b5b43921c27e9aabf3e
- Move TAG_ID to webp/mux.h
- Rename it to WebPChunkId
- Rename IDs to WEBP_CHUNK_<tag>
- Remove "name" param from ChunkInfo struct and related changes.
- Rename WebPMuxNumNamedElements to WebPMuxNumChunks().
- WebPMuxNumChunks() takes WebPChunkId as param.
Change-Id: Ic6546e4a9ab823b556cdbc600faa137076546a2b
it's using glutTimerFunc() for trigger next frame's decoding
Reminder: how to build and use manually (integration in makefile.unix coming soon)
Unix:
cd libwebp
make -f makefile.unix
cd examples
cc -o vwebp vwebp.c -framework GLUT -framework OpenGL -I../src/ ../src/libwebp.a ../src/mux/libwebpmux.a
Mac + xcode:
cd libwebp
make -f makefile.unix
cd examples
cc -o vwebp vwebp.c -lglut -lGL -lpthread -lm -I../src/ ../src/libwebp.a ../src/mux/libwebpmux.a
Change-Id: Id49e87c26628c2b58ec221f6030cbd2e46a807b4
Quite handy and simple (for now).
It's not yet incorporated within the build system (autotools or
makefile.unix), because it gets complicated with OpenGL. TODO(later).
For now, there's some ready-to-use command line for compiling on Linux
or Mac in the header of vwebp.c
Later, this tool will be supplemented with support for animation,
tiling, zooming, etc.
Change-Id: I292972cea4862536afbe8c9ec444c590d152f086
