Add predictive filtering option for Alpha plane.
Valid range for filter option is [0, 5] corresponding to prediction
methods none, horizontal, vertical, gradient & paeth filter.
The prediction method 5 will try all the prediction methods (0 to 4)
and pick the prediction method that gives best compression.
Change-Id: I9244d4a9c5017501a9696c7cec5045f04c16d49b
Add code for Alpha encoding & decoding. The alpha compression is done
via backward reference counts encoded with Arithmetic encoder (TCoder).
Also provided is lossy Alpha pre-processing option via level-quantizations
using kNN heuristic.
Change-Id: Ib6b13530c1a4ab6493edcb586ad29fe242bc1766
This change adds a command line tool (webpmux) which uses MUX library
for manipulating WebP Mux container. This tool can be used to create a
WebP container file and extract/strip relevant data from the container
file.
Change-Id: If17818239448a428703760747fc84f77586045e4
This change adds the WebP Mux library for manipulating the WebP Mux
Container. The library document and command line tool exhibiting the
usage of this libary will follow in subsequent Git change.
Change-Id: I4cba7dd12307483185ad5a68df33af6c36c154c8
Gathers all DSP-related function (and SSE2 implementations).
Clean-up some unwanted symbolic dependencies so that webp_encode,
webp_decode and webp_dsp are truly independent libraries.
+ opportunistic clean-up:
* remove unneeded VP8DspInitTables(), now integrated in VP8DspInit()
* make consistent use of VP8GetCPUInfo() in the various DspInit() funcs
* change OUT macro to DST
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
Rather than add bulk to test for the new flag, simply comment out -Wvla
to keep the base makefile simple.
-Wvla was added in gcc-4.3.0.
Change-Id: I21feb456d7498ea628defb436a50c3d828e7f971
~5-10% faster.
Heavy 8bit arithmetic trickery!
Patch by Somnath Banerjee (somnath at google dot com)
Change-Id: I9fd2c511d9f631e9cf4b008c46127b49fb527b47
HOSTTYPE is x86_64 on e.g.,
bash 3.2.48(1)-release
ProductName: Mac OS X
ProductVersion: 10.6.7
BuildVersion: 10J869
intel-mac seems to be the value under tcsh.
Change-Id: I814ad6d3b733933057cea605917b185ff6d423d0
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
+ add a simple rescaling function: WebPPictureRescale() for encoding
+ clean-up the memory managment around the alpha plane
+ fix some includes path by using "../webp/xxx.h" instead of "webp/xxx.h"
New flags for 'cwebp':
-resize <width> <height>
-444 (no effect)
-422 (no effect)
-400
Change-Id: I25a95f901493f939c2dd789e658493b83bd1abfa
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
For now, SSE2 functions are compiled a-minima: only on platforms
where __SSE2__ is defined. Let's later add some autoconf-based
config to enable/disable at will.
One can disable SSE2 at run-time by hooking-up VP8GetInfo.
There is a new option "-noasm" in cwebp for that.
Output should be binary the same between C and SSE2 version. If not,
that's a bug!
patch by Christian Duvivier (cduvivier at google dot com)
Change-Id: Iae006c3cdcb7e8280e846cedb94d239dab1e42ae
going down to strict -ansi c89 is quite overkill (no 'inline',
and /* */-style comments).
But with these fixes, the code compiles with the stringent flags:
-Wextra -Wold-style-definition -Wmissing-prototypes
-Wmissing-declarations and -Wdeclaration-after-statement
Change-Id: I36222f8f505bcba3d9d1309ad98b5ccb04ec17e3
The object WebPIDecoder is available to store the
decoding state. The flow is typically:
WebPIDecoder* const idec = WebPINew(mode);
while (has_more_data) {
// ... (get additional data)
status = WebPIAppend(idec, new_data, new_data_size);
if (status != VP8_STATUS_SUSPENDED ||
break;
}
// The above call decodes the current available buffer.
// Part of the image can now be refreshed by calling to
// WebPIDecGetRGB()/WebPIDecGetYUV() etc.
}
WebPIDelete(idec);
Doing so, one can try and decode new macroblocks everytime fresh
bytes are available.
There's two operating modes: either appending fresh bytes, or
updating the whole buffer with additional data in the end.
The latter requires less memcpy()'s
main patch by Somnath Banerjee (somnath at google.com)
Change-Id: Ie81cbd0b50f175743af06b1f964de838b9a10a4a
