It can be used to test if given pair of animated images (GIF and/or
WebP) are identical in terms of pixel match and other animation
properties.
Change-Id: I84adea145e9d062be6ad06a0d4fcdc9658cf52d4
When converting from video sources, the duration of current frame
is often unavailable until the next frame. So, we internally convert
timestamps to durations.
Change-Id: I20ad86361c22e014be7eb91f00d5d40108281351
this is in line with the recommendation in the spec, cf.,
5603947 webp-container-spec: clarify background clear on loop
Change-Id: Id3910395b05a1a1f2804be841b61f97bd4bac593
Updated the near-lossless level mapping and make it correlated to lossy
quality i.e 100 => minimum loss (in-fact no-loss) and the visual-quality loss
increases with decrease in near-lossless level (quality) till value 0.
The new mapping implies following (PSNR) loss-metric:
-near_lossless 100: No-loss (bit-stream same as -lossless).
-near_lossless 80: Very very high PSNR (around 54dB).
-near_lossless 60: Very high PSNR (around 48dB).
-near_lossless 40: High PSNR (around 42dB).
-near_lossless 20: Moderate PSNR (around 36dB).
-near_lossless 0: Low PSNR (around 30dB).
Change-Id: I930de4b18950faf2868c97d42e9e49ba0b642960
previously the first frame would be redisplayed, which might be
unexpected if the final frame was meant to be a composite, for example.
Change-Id: I4da795623c71501e2fa426e8fba8fb2ffcbab58a
Enable the WebP near-lossless feature by pre-processing the image to smoothen
the pixels.
On a 1000 PNG image corpus, for which WebP lossless (default settings) gets
25% compression gains, following is the performance of near-lossless feature
at various '-near_lossless' levels:
-near_lossless 90: 30% (very very high PSNR 54-60dB)
-near_lossless 75: 38% (very high PSNR 48-54dB)
-near_lossless 50: 45% (high PSNR 42-48dB)
-near_lossless 25: 48% (moderate PSNR 36-42dB)
-near_lossless 10: 50% (PSNR 30-36dB)
WebP near-lossless is specifically useful for discrete-tone images like
line-art, icons etc.
Change-Id: I7d12a2c9362ccd076d09710ea05c85fa64664c38
add additional return checks and asserts to avoid:
C6102: Using 'XXX' from failed function call ...
Change-Id: I51f5fa630324e0cd7b2d9fceefecb4f4021474b1
width / height are unsigned; fixes a warning with msvs /analyze:
C6340: Mismatch on sign: 'const unsigned int' passed as _Param_(4) when
some signed type is required in call to 'fprintf'.
Change-Id: I5f1fad4c93745baf17d70178a5e66579ccd2b155
This is because, FlattenSimilarBlocks() replaces some opaque pixels by
transparent ones. This results in an equivalent output only if blending
is turned on for the current frame.
Change-Id: I05612c952fdbd4b3a6e0ac9f3a7d49822f0cfb9b
Snapping odd offsets in GIF to even offsets in WebP was causing extra row/column
being disposed in such cases.
Code is rewritten to maintain previous and current canvas (it used to maintain
previous canvas and current frame earlier). And we recompute change rectangles
as those from GIF may no longer apply.
Also, this renders methods like ReduceTransparency() and ConvertToKeyFrame()
redundant, as internally maintained current canvas is always independent of
previous canvases.
Disposal method choice: we pick the disposal method that results in the smallest
change rectangle.
Change-Id: Ic31186d98fe1a2a790a89d1571b17e3abd127e79
For some GIF images, the first frame is missing the corresponding
graphic control extension. For such cases, we were never calling
GetBackgroundColor(), and default background color value (white) was being used
incorrectly.
So, we call GetBackgroundColor() when we encounter the first image
descriptor instead, to make sure that it is always called.
Change-Id: I00fc8e943d8a0c1578dcd718f3e74dec7de4ed61
put WebPMuxConfig on the stack in main() rather than allocating it in
InitializeConfig(); removes a level of indirection there.
Change-Id: I81d386f7472ebbd322dd3fdbfda9d78dbeb62a66
This compresses the uimage using lossless compression and controlable
decimating pre-process.
Code is under WEBP_EXPERIMENTAL_FEATURE while it's being experimented with.
Change-Id: I8b7f4cfcc3c6afc52a556102842bdbb045ed5ee8
* try to avoid trailing '.'
* rationalize capitalization
missed in:
0a8b886 dust up the help message
Change-Id: I6f80736cc8a2ff4f185f63d463a57d5bbf88a0db
+ vwebp's -help output
this is a future option; missed in:
793368e restore decode API compatibility
Change-Id: If920df2cf8de57ebad93a6b98830562149396d8d
We store the raw RGB samples decoded from JPEG, and avoid precision loss.
Note that this may increase the encoding time reported by
cwebp -v, since RGB->YUV now occur during WebPEncode call
(in case of lossy), instead of ReadJPEG().
This also increases the memory use, since we're carying the
source ARGB samples around.
Change-Id: Ic2180206cfc9f5574f391e91c3b89b9d81695d01
this defines WORDS_BIGENDIAN, replacing uses of
__BIG_ENDIAN__/__BYTE_ORDER__ with it
+ fixes lossless BGRA output with big-endian toolchains
that do not define __BIG_ENDIAN__ (codesourcery mips gcc)
Change-Id: Ieaccd623292d235343b5e34b7a720fc251c432d7
previously, the final canvas size was adjusted tightly from the
animation frames. Now, it can be specified separately (to be larger, in particular).
calling WebPMuxSetCanvasSize(mux, 0, 0) triggers the 'adjust tightly' behaviour.
This can be useful after calling WebPMuxCreate() if further image addition
is expected.
-> Fixed gif2webp accordingly.
also: made WebPMuxAssemble() more robust by systematically zero-ing WebPData.
Change-Id: Ib4f7eac372cf9dbf6e25cd686a77960e386a0b7f
Similarly to Chrome, we then use the first sub-rectangle
to set the canvas size.
Also: add check for too-large GIF dimensions (>MAX_CANVAS_SIZE)
Change-Id: Idce55f1e6f6982a8f0e082aac540e16b530e023e
We align with Blink/Chromium code by:
- checking for ANIMEXTS1.0 signature too
- using ByteCount >= 3 instead of requiring ByteCount==3
Change-Id: Idc484ca62878517df3dccb1fdb3bb45104a5e066
see: http://odur.let.rug.nl/kleiweg/gif/netscape.html
new options:
dwebp -alpha_dither
vwebp -noalphadither
When the source was marked as quantized, we use a threshold-averaging
filter to smooth the decoded alpha plane.
Note: this option forces the decoding of alpha data in one pass, and
might slow the decoding a bit.
The new field in WebPDecoderOptions struct is 'alpha_dithering_strength'
(0 by default, means: off). Max strength value is '100'.
Change-Id: I218e21af96360d4781587fede95f8ea4e2b7287a
User-hook can fail but error was not propagated back.
Change-Id: Ic79f9543bf767634a127eccfef90af855ff15c34
Also: some ad-hoc clean-up and API dusting. More to come later...
this change has the side-effect of using directory names in the
include, silencing a lint warning.
Change-Id: Ib91cf63a90534e32fadfa5c2372bfdb29f854d02
Needed to add 'volatile' and some casts.
Relevant excerpt from the 'man longjmp':
===============
The values of automatic variables are unspecified after a call to longjmp() if they meet all the following criteria:
· they are local to the function that made the corresponding setjmp(3) call;
· their values are changed between the calls to setjmp(3) and longjmp(); and
· they are not declared as volatile.
===============
Change-Id: Ic72dc92669513a820369ca52a038afa9ec88091f
on ExUtilLoadWebP() failure no allocated memory will be returned, so
it's safe to exit immediately. additionally, any webp specific problems
will already have been reported as part of the call to
WebPGetFeatures().
broken since:
4a0e739 dwebp: move webp decoding to example_util
Change-Id: Ibc632015a1f52bae7f96d063252624123fa7c2da
doing so is not part of ISO C; removes some pedantic warnings.
use webp/decode.h to pickup VP8StatusCode instead.
Change-Id: I19b35e0f8a36fb7c45944ae9ca86838e08b90548
there's still some malloc/free in the external example
This is an encoder API change because of the introduction
of WebPMemoryWriterClear() for symmetry reasons.
The MemoryWriter object should probably go in examples/ instead
of being in the main lib, though.
mux_types.h stil contain some inlined free()/malloc() that are
harder to remove (we need to put them in the libwebputils lib
and make sure link is ok). Left as a TODO for now.
Also: WebPDecodeRGB*() function are still returning a pointer
that needs to be free()'d. We should call WebPSafeFree() on
these, but it means exposing the whole mechanism. TODO(later).
Change-Id: Iad2c9060f7fa6040e3ba489c8b07f4caadfab77b
* allow reading from stdin for dwebp / vwebp
* allow writing to stdout for gif2webp
by introducing a new function ExUtilReadFromStdin()
Example use: cat in.webp | dwebp -o - -- - > out.png
Note that the '-- -' option must appear *last*
(as per general fashion for '--' option parsing)
Change-Id: I8df0f3a246cc325925d6b6f668ba060f7dd81d68
These are presets for lossless coding, similar to zlib.
The shortcut for lossless coding is now, e.g.:
cwebp -z 5 in.png -o out_lossless.webp
There are 10 possible values for -z parameter:
0 (fastest, lowest compression)
to 9 (slowest, best compression)
A reasonable tradeoff is -z 6, e.g.
-z 9 can be quite slow, so use with care.
This -z option is just a shortcut for some pre-defined
'-lossless -m xx -q yy' combinations.
Change-Id: I6ae716456456aea065469c916c2d5ca4d6c6cf04
New API options: WebPDecoderOptions.flip and 'dwebp -flip ...'
it uses negative stride trick.
Also changed the decoder code to support user-supplied
buffers with negative stride, independently of the
WebPDecoderOptions.flip value.
Change-Id: I4dc0d06f0c87e51a3f3428be4fee2d6b5ad76053
- 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.
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Merge tag 'v0.4.0'
libwebp 0.4.0
- 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.
* tag 'v0.4.0':
update ChangeLog
update NEWS description with new general features
gif2webp: don't use C99 %zu
cwebp: fix metadata output w/lossy+alpha
makefile.unix: clean up libgif2webp_util.a
update Changelog
bump version to 0.4.0
update AUTHORS & .mailmap
update NEWS for 0.4.0
Change-Id: I6df1b512fe0b697192f1f9b29431cd59aa6063d1
this would require a PRIuS or similar macro for proper platform
compatibility (Visual Studio for instance would be variants of %lu)
Change-Id: I2b9fcb1639db024775fb47dbcf79a2240f3d98f2
