Commit Graph

6 Commits

Author SHA1 Message Date
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
6d0e66c23e prepare experimentation with yuv444 / 422
+ 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
2011-05-04 15:41:08 -07:00
Pascal Massimino
efbc6c41fc update Android.mk
idec.c was missing

Change-Id: I18fe8eb6576c52b56519567b9905ad5ac2db60c0
2011-03-26 07:33:19 -07:00
Pascal Massimino
f61d14aabf a WebP encoder
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
2011-02-18 23:54:59 -08:00
Pierre Joye
c8d15efa12 convert to ANSI-C 2010-10-06 14:37:28 -07:00
Pascal Massimino
c3f41cb47e Initial commit
Change-Id: I4712afb3912625e7aaccfa5160dcf78ee252f159
2010-09-30 09:55:07 -04:00