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
This is a temporary workaround for issue #80.
Currently dec/dsp_sse2 is not included in Makefile.vc. Simply adding it
will cause a build error, however, as cl does not support aligning
function parameters producing, e.g.,
src\dec\dsp_sse2.c(228) : error C2719: 'q1': formal parameter with
__declspec(align('16')) won't be aligned
Change-Id: Id29e6802dd29110e59c4f6d13ffa5d4793c750a0
There was 1 unneeded sample line allocated for the filter cache in of simple filtering.
+ Add an explaining comment.
Change-Id: I775a596c8b8643e773e0eade8aa341dc23fb290f
Only builds with --enable-experimental require zlib currently.
A base install of mingw will not include the development headers and
library. libwebp itself will now build in such environments.
Additionally, remove -lz from **/Makefile.am, -lz will be added to LIBS
by AC_CHECK_LIB when necessary.
Change-Id: Iae8319cdf00162ecb7ed44661c02f40beb34f155
Use _MSC_VER as the intrinsics compile without /arch:SSE2 on x86.
Also avoids applying the same flag to all files which defeated the
purpose of the runtime cpu-detection.
Thanks to Frank B. for the suggestion!
Change-Id: Iae9933a3cee704e663d9bbd53d0fa68e8c025425
picture->error_code can be looked up for finer error diagnose.
Added readable error messages to cwebp too.
Should close bug #75 (http://code.google.com/p/webp/issues/detail?id=75)
Change-Id: I8889d06642d90702f698cd5c27441a058ddb3636
sometimes, gcc insert sse2 storeu instructions (like in VP8InitFilter())
with aligment requirements.
Bug was visible 'sometimes' in non-debug mode, when trying to use -af.
Change-Id: If3ec282bbbb9f9d0d33ca4b2c4bed46cd26fe495
we were reading past the end of the dqs[] array.
reported by Mathias Schindler (on cygwin only)
http://code.google.com/p/webp/issues/detail?id=71
Change-Id: Ib38c4c139e3cac3e8915626d63e16b403d6bbd63
+ 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
