- pic->picture in public header
- match implementation to declaration in PictureImport, WebPPictureRescale, WebpBlendAlpha
Change-Id: Ibf3771af22d671bba6fd657684add618c6f32978
A WebPPicture instance is necessary to call WebPReportProgress() which
sets WebPPicture::error_code so as well use WebPEncodingSetError() to
record errors too, instead of functions returning a WebPEncodingError.
However there must be one WebPPicture instance per thread, with error
codes merged at sync time. A mutex could simplify that but it is not
the objective of this change.
https://groups.google.com/a/webmproject.org/g/webp-discuss/c/yOiP8APubgc/m/vCTvxl6ODgAJ
Change-Id: Ia1a8f9d1199202e1c88484ce719b0180a80447ce
It's explicitly safe (and recommended!) to plug external data into
the pic->y/u/v/argb fields. They are guaranteed to be preserved
by the encoding process if no conversion is needed.
Change-Id: I325ca41a6a834f7f028431c605dddef67e9542cc
qmin / qmax are now using the pad[] spot at the end of the struct,
and we don't need to bump the ABI major number.
Change-Id: I41adcaf1600b29a5a05c9fe380bfd977cf425124
This is particularly useful for multi-pass search (but not only),
to prevent the search from going over or below a reasonable threshold.
E.g.: 'cwebp -qrange 50 80 ...' will prevent any unreasonable degradation.
new cwebp option: -qrange min max
Change-Id: I59f394533535fc20b6996bc0895f4301476d5eff
note that config.exact defaults to 0 and point users to WebPEncode() if
the default isn't acceptable.
BUG=webp:424
Change-Id: I179c34649834aeadc1606d0856f33e8255048ea1
including the type in the macro doesn't bring much benefit to ordering,
current platforms work with a prefix, this would be insufficient if the
attribute needed to follow the function prototype. this form makes it
easier to override on the command line.
BUG=webp:355
Change-Id: Iba41ec0bb319403054be0e899c4cc472dd932fd9
If "exact" is false, we can modify the luma samples in fully transparent
areas to facilitate lossy compression. Experiments on some PNG images
show compression improvement of more than 20%.
Change-Id: I1a728cfa920a6652bc1f600d87c01f7f648c4942
Make WebPPictureDistortion() only compute distortion on A/R/G/B planes, not Y/U/V(A).
(not just for SSIM, but PSNR too).
This is to avoid problems with using SSIM on U/V channels.
If Y/U/V distortion is needed, one can always use WebPPlaneDistortion() individually.
Change-Id: If8bc9c3ac12a8d2220f03224694fc389b16b7da9
Rename the flag to exact instead of the opposite cleanup_alpha. Add the flag to
WebPConfig. Do the cleanup in the webp encoder library rather than the cwebp
binary, this will be needed for the next stage: smarter alpha cleanup for
better compression which cannot be done as a preprocessing due to depending on
predictor choices in the encoder.
Change-Id: I2fbf57f918a35f2da6186ef0b5d85e5fd0020eef
using a *tmp_plane buffer to split a/r/g/b planes up appeared to
be the easiest route, compared to copy-pasting the whole code and
making it x_stride aware...
Change-Id: I0898ef1df62bd3e1713b77187b31b5eeef3832fe
this should be used in preference to free() for releasing memory
returned from WebPDecode*() / WebPEncode*(). this simplifies memory
management when working through language bindings
Change-Id: I15eb538a45390efc552fda8e5c251a3fbdc13c29
New function: WebPPictureSmartARGBToYUVA()
This implement smart RGB->YUV conversion.
This is rather undocumented for now, and is triggered using '-pre 4'
preprocessing option.
This is slow-ish and use quite some memory, but should be improvable.
This is somehow a usable beta version.
Change-Id: Ia50a8c30134e4cab8a7d3eb70aef13ce1f6187a1
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
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
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
the -alpha_cleanup flag was ineffective since we switched cwebp
to using ARGB input always.
Original idea by David Eckel (dvdckl at gmail dot com)
Change-Id: I0917a8b91ce15a43199728ff4ee2a163be443bab
-> helps debanding (sky, gradients, etc.)
This dithering can only be triggered when using -preset photo
or -pre 2 (as a preprocessing). Everything is unchanged otherwise.
Note that this change is likely to make the perceived PSNR/SSIM drop
since we're altering the input internally.
Change-Id: Id8d4326245d9b828141de162c94ba381b1fa5813
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
new option: -blend_alpha 0xrrggbb
also: don't force picture.use_argb value for lossless. Instead,
delay the YUVA<->ARGB conversion till WebPEncode() is called.
This make the blending more accurate when source is ARGB
and lossy compression is used (YUVA).
This has an effect on cropping/rescaling. E.g. for PNG, these
are now done in ARGB colorspace instead of YUV when lossy compression
is used.
Change-Id: I18571f1b1179881737a8dbd23ad0aa8cddae3c6b
using token-buffer (that is: slightly more memory. O(output_size))
This change is ON by default. To return to previous behaviour, use
'cwebp -low_memory' or set config.low_memory to true.
Side-effect of this new mode: it forces 1 partition only (which was
default anyway), and makes some statistics about the bitstream
no longer available. cwebp will no longer report 'intra4-coeffs', etc.
This mode also doesn't work (yet) with multi-pass, and -low_memory
is currently forced for multi-pass.
also: reversed the flag: USE_TOKEN_BUFFER -> DISABLE_TOKEN_BUFFER
also: fixed the kAverageBytesPerMB estimate
Change-Id: I4ea80382038d6df4309663e0cb7bd88d9bca9cf1
new option: 'cwebp -mt ...'
new config flag: config.thread_level
(allowed thread_level are 0 or 1 for now. Maybe more later...)
If -mt is activated (and WEBP_USE_THREAD is used for compile), the alpha-compression
will be done in parallel to RGB coding for lossy. Can save quite a bit of latency...
Has no effect for lossless encoding.
Change-Id: I769d0bf90e7380cf99344ad62cd77277f4df5a46
This option remaps internal parameters to better match
the expected compression curve of JPEG and produce output files
of similar size, but with better quality.
Change-Id: I96a1cbb480b1f6a0c6845a23c33dfd63f197b689
LSIM stands for "local similarity": before matching
a compressed pixel to the source, we search around in the source
and minimise the squared error. So, this is close to PSNR calculation,
but mitigates some of its limitations (pure translation and noise for instance).
There's a new -print_lsim option to cwebp too.
Change-Id: Ia38561034c7a90e71d2ea0f55bb1de527eda245b
Change-Id: I36d3765e94d2b5529b321c186ccee1744785c5b3
fixes:
error: ISO C++ forbids forward references to 'enum' types
since:
28d25c8 replace 'typedef struct {} X;" by "typedef struct X X; struct X {};"
