Commit Graph

57 Commits

Author SHA1 Message Date
Pascal Massimino
900286e091 add a -partition_limit option to limit the number of bits used by intra4x4
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
2011-08-23 15:58:22 -07:00
Pascal Massimino
d260310511 add Advanced Decoding Interface
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
2011-06-20 15:30:52 -07:00
Pascal Massimino
cfbf88a6c4 add SSE2 functions. ~2x faster encoding on average.
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
2011-04-22 15:34:23 -07:00
Pascal Massimino
8aa50efd38 fix some 'man' typos 2011-04-18 18:50:34 -07:00
Pascal Massimino
14ceb6e803 add "-version" description to man pages
Change-Id: I699899b11db3b62628c9438f07c379d2ae413031
2011-03-28 11:12:39 -07:00
Pascal Massimino
4704146a1f add missing precision in the man
Change-Id: I55ae0547abf742b4620d9faae7fe5163d8459c19
2011-03-23 17:13:54 -07:00
Pascal Massimino
dd60138d20 add man pages for cwebp(1) and dwebp(1)
Change-Id: I450717fc82fff19f16df75aca6a9a567773afd00
2011-03-01 16:07:57 -08:00