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
It will decode to raw (flat) YUV format, similar to what
cwebp can take as input. Makes the PSNR/SSIM calculation easier.
Change-Id: Iebfaedfc0bedc70c169b24ae4aabc701488d0644
currently has no effect except to disable metadata extraction from the
input when the value is 'none'.
Change-Id: Ic50d4c9d634cc1f6b72ae4e130e99736c85a6477
* commit 'v0.2.1':
Update ChangeLog
update NEWS
bump version to 0.2.1
libwebp: validate chunk size in ParseOptionalChunks
cwebp (windows): fix alpha image import on XP
autoconf/libwebp: enable dll builds for mingw
[cd]webp: always output windows errors
fix double to float conversion warning
cwebp: fix jpg encodes on XP
VP8LAllocateHistogramSet: fix overflow in size calculation
GetHistoBits: fix integer overflow
EncodeImageInternal: fix uninitialized free
fix the -g/O3 discrepancy for 32bit compile
fix the BITS=8 case
Make *InitSSE2() functions be empty on non-SSE2 platform
make *InitSSE2() functions be empty on non-SSE2 platform
make VP8DspInitNEON() public
Conflicts:
src/Makefile.am
src/dsp/dec_neon.c
Change-Id: Iddc5152e4a6892db96c12d7c3f74adbc85fe6178
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
For low-color images, it may be better to not use color-palettes.
Users should treat this as one another hint (as with Photo &
Picture) and another parameter for tuning the compression density.
The optimum compression can still be obtained by running (outer loop)
compression with all possible tunable parameters.
Change-Id: Icb1a4face2a84774e16e801aee4a8ae97e232e8a
These will report the 7x7-averaged PSNR or SSIM, using the
new internal function WebPPictureDistortion().
This is for information only. These flags have no encoding impact.
+misc opportunistic cosmetics
Change-Id: I64c0a7eca679134d39062e438886274b22bb643f
to 'clean up' the fully-transparent area and make it more compressible
new cwebp flags: -alpha_cleanup (off by default, since gain is not 100% guaranteed)
Change-Id: I74d77e1915eee146584cd61c9c1132a41db922eb
.. where only 2 filtering modes are potentially
tried, instead of all of them. This is fast than the exhaustive 'best'
mode, and not much worse.
Options for cwebp are:
-alpha_filter none
-alpha_filter fast (<- default)
-alpha_filter best (<- slow)
Change-Id: I8cb90ee11b8f981811e013ea4ad5bf72ba3ea7d4
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
Although it degrades quality, this option is useful to avoid the 512k
limit for partition #0.
If not enough to reach the lower bound of 4bits per macroblock header,
one should also limit the number of segments used (down to -segments 1)
See the man file for extra details.
Change-Id: Ia59ffac13176c85b809ddd6340d37b54ee9487ea
To be enabled with the flag WEBP_USE_THREAD.
For now it's only available on unix (pthread), when using Makefile.unix
Will be switched on more generally later.
In-loop filtering and output (=rescaling/yuv->rgb conversion)
is done in parallel to bitstream decoding, lagging 1 row behind.
Example:
examples/dwebp bryce.webp -v
Time to decode picture: 0.680s
examples/dwebp bryce.webp -v -mt
Time to decode picture: 0.515s
Change-Id: Ic30a897423137a3bdace9c4e30465ef758fe53f2
You can now use WebPDecBuffer, WebPBitstreamFeatures and WebPDecoderOptions
to have better control over the decoding process (and the speed/quality tradeoff).
WebPDecoderOptions allow to:
- turn fancy upsampler on/off
- turn in-loop filter on/off
- perform on-the-fly cropping
- perform on the-fly rescale
(and more to come. Not all features are implemented yet).
On-the-fly cropping and scaling allow to save quite some memory
(as the decoding operation will now scale with the output's size, not
the input's one). It saves some CPU too (since for instance,
in-loop filtering is partially turned off where it doesn't matter,
and some YUV->RGB conversion operations are ommitted too).
The scaler uses summed area, so is mainly meant to be used for
downscaling (like: for generating thumbnails or previews).
Incremental decoding works with these new options.
More doc to come soon.
dwebp is now using the new decoding interface, with the new flags:
-nofancy
-nofilter
-crop top left width height
-scale width height
Change-Id: I08baf2fa291941686f4ef70a9cc2e4137874e85e
Wrap WebPEncode???* to provide an interface similar to decode.
As only WebPGetEncoderVersion is wrapped directly from encode.h avoid
including it in the swig file to reduce %ignore's.
This change also removes unnecessary incremental decoding related enums.
Change-Id: I0b5424026aa6ae012c6a29ad2f2301c2681ca301
Currently only supports a subset of decode functions and likely only
works fully for java.
For java bindings:
The generated java source can be compiled and the class files added to
libwebp.jar.
The generated jni source can be compiled to, e.g., libwebp_jni.so, which
can then be loaded via System.loadLibrary("webp_jni").
Change-Id: I8225933cbaf85c9cfa4b78c2e5f167cee8b62408
This is a (minor) bitstream change: if the 'color_space' bit is set to '1'
(which is normally an undefined/invalid behaviour), we add extra data at the
end of partition #0 (so-called 'extensions')
Namely, we add the size of the extension data as 3 bytes (little-endian),
followed by a set of bits telling which extensions we're incorporating.
The data then _preceeds_ this trailing tags.
This is all experimental, and you'll need to have
'#define WEBP_EXPERIMENTAL_FEATURES' in webp/types.h to enable this code
(at your own risk! :))
Still, this hack produces almost-valid WebP file for decoders that don't
check this color_space bit. In particular, previous 'dwebp' (and for instance
Chrome) will recognize this files and decode them, but without the alpha
of course. Other decoder will just see random extra stuff at the end of
partition #0.
To experiment with the alpha-channel, you need to compile on Unix platform
and use PNGs for input/output.
If 'alpha.png' is a source with alpha channel, then you can try (on Unix):
cwebp alpha.png -o alpha.webp
dwebp alpha.webp -o test.png
cwebp now has a '-noalpha' flag to ignore any alpha information from the
source, if present.
More hacking and experimenting welcome!
Change-Id: I3c7b1fd8411c9e7a9f77690e898479ad85c52f3e
Makes things lighter at the expense of requiring the user
to be up-to-date for autotools.
patch by Jan Engelhardt (jengelh at medozas dot de)
Change-Id: Icfcab2d899828a213d9fade0dab350dacd0c070a
converts PNG & JPEG to WebP
This is an experimental early version, with lot of room
of later optimizations in both speed and quality.
Compile with the usual `./configure && make`
Command line example is examples/cwebp
Usage:
cwebp [options] -q quality input.png -o output.webp
where 'quality' is between 0 (poor) to 100 (very good).
Typical value is around 80.
More encoding options with 'cwebp -longhelp'
Change-Id: I577a94f6f622a0c44bdfa9daf1086ace89d45539
