On the non-fast path (use_8b_decode_=0) for decoding the alpha-mask,
we could end up requesting ApplyInverseTransform() with more rows
to process than NUM_ARGB_CACHE_ROWS. This could only happen on the
very last bottom rows of the image.
* ProcessRows() doesn't need to be fixed, since we never request more
than NUM_ARGB_CACHE_ROWS rows. Added an assert for that.
* the use_8b_decode_=1 case doesn't use argb_cache_, but rather does
the palette-decoding call directly. So, no problem here too.
Only the generic (and rather rare) case of calling ExtractAlphaRows()
was affected.
Change-Id: I58e28d590dcc08c24d237429b79614abcef1db7c
This is getting back to the old behavior which is actually better for
compression and speed with the latest patches.
Change-Id: I35884bab02589297c25d6e1e66dc5f13e05f7aa7
This was defined (slightly differently) at two places. Created a common
method and moved to utils/utils.[hc].
Change-Id: I66c3ac6dea24e0cd2c0eaa5440f3142b4dbbe23b
we don't need to store the resulting histogram, so no need to
call HistogramAddEval().
Allows some signature simplifications...
Change-Id: I3fff6c45f4a7c6179499c6078ff159df4ca0ac53
In case where the same offset is found in consecutive pixels,
the cost computation from one pixel can be re-used for the next.
Change-Id: Ic03c7d4ab95f3612eafc703349cfefd75273c3d7
and also recycle the malloc'd intervals
This avoids quite some malloc/free cycles during interval managment.
Change-Id: Ic2892e7c0260d0fca0e455d4728f261fb4c3800e
In a lot of cases, only one interval is used. This can cause
a lot of malloc/free cycles for only 56 bytes. By caching this
single interval and re-using it, we remove this cycle in most
frequent cases.
Change-Id: Ia22d583f60ae438c216612062316b20ecb34f029
As per the spec
(https://developers.google.com/speed/webp/docs/riff_container), only the
extended file format can contain an unknown chunk. So, when assembling a
WebP file with muxer, whenever there is an unknown chunk present, we
should create a VP8X chunk (even though none of the features are
present).
BUG=webp:294
Change-Id: I5da52d311e1853d40063d0f5026100d4325effaa
In some cases, the hash chain for a function is filled several
times:
- GetBackwardReferences -> CalculateBestCacheSize ->
BackwardReferencesLz77 that computes the hash chain
- GetBackwardReferences ->
(not always) BackwardReferencesTraceBackwards ->
BackwardReferencesHashChainDistanceOnly that computes the hash
chain in a slightly different way
Speed and compression performance are slightly changed (+ or -)
but will be homogneized in a later patch.
Change-Id: I43f0ecc7a9312c2ed6cdba1c0fabc6c5ad91c953
-> WebPImageReader
Introduce a variant of image-guessing function that returns a reader
directly: WebPGuessImageReader()
Change-Id: I5ddc53024fcf941e33d997b2be6aa1a963d939ab
adds a generic examples/image_dec.[ch] entry point too.
WebPGuessImageType() can be used to infer image type.
Change-Id: I8337e7b6ad91863c9cf118e4791668d2d175079b
