We can switch at run-time between the standard GetCoeffs() critical
function, that uses a fast variant of VP8GetBit().
However, some platforms have slow instructions that make standard
VP8GetBit() slow. GetCoeffs() is the right level of branching to
switch to GetCoeffsAlt() that avoids these slow instructions in some
not-frequent cases.
Next patch will upgrade VP8GetBit() to use clz, after this one
is proved to be neutral speed-wise.
Change-Id: Ia6cef5de9de6131574d2202bbc0bea8559c9b693
vmlal_u8() is prone to overflow during the accumulation.
There was a mismatch happening at low q mostly. Because in this
case the distortion is important and the accumulated sum was
later than 16bit-unsigned.
Change-Id: I1a08a2f744bcdf0b26647e61b9ee92a0c2e28fe8
This makes the structure more generic, without the hard-coded
internal structure.
This is a borderline incompatible ABI change, even if WebPIDecoder structure
is opaque.
Change-Id: I518765c3f76fc17a136cef045a5a8aa70ed70e85
30% faster on x86, 5% faster on N5.
New generic function: WebPLog2FloorC()
This function is called as fallback for BitsLog2Floor() when there's
no clz() available.
Change-Id: Ica15c6092112e514c0e200fab89c434de48d4b19
This is meant to be used for run-time detection of slow platforms
regarding instructions like pshufb and bsr.
Adapted from libvpx patch: https://chromium-review.googlesource.com/#/c/367731
Change-Id: I2c22fbb9aae699d87a041393ba1ad5f1f21ff640
and 15% faster MultARGBRow()
by switching to formulae:
X / 255 = (X + 1 + (X >> 8)) >> 8 for any 16bit value X.
(X / 255 + .5) = (XX + (XX >> 8)) >> 8, with XX = X + 128
Change-Id: Ia4a7408aee74d7f61b58f5dff304d05546c04e81
The previous optimization was performing dichotomy on a function that
is anything in practice, hence a bit of randomness.
Also, two magic constants were used, one for an extra constant cost,
one for an extra linear cost. Both values/models were empirical.
A brute force search for the best cache size is now performed.
To have less CPU impact, a speed optimization is also made by not
inserting a value again and again.
This makes sense but it's also the most common case of when LZ77 is
useful hence an overall improvement sometimes.
Change-Id: I57de5750ad2313b2feecbcd15cd6e4feeb98e5c8
- 12/13/2016: version 0.5.2
This is a binary compatible release.
This release covers CVE-2016-8888 and CVE-2016-9085.
* further security related hardening in the tools; fixes to
gif2webp/AnimEncoder (issues #310, #314, #316, #322), cwebp/libwebp (issue
#312)
* full libwebp (encoder & decoder) iOS framework; libwebpdecoder
WebP.framework renamed to WebPDecoder.framework (issue #307)
* CMake support for Android Studio (2.2)
* miscellaneous build related fixes (issue #306, #313)
* miscellaneous documentation improvements (issue #225)
* minor lossy encoder fixes and improvements
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Merge tag 'v0.5.2'
libwebp-0.5.2
- 12/13/2016: version 0.5.2
This is a binary compatible release.
This release covers CVE-2016-8888 and CVE-2016-9085.
* further security related hardening in the tools; fixes to
gif2webp/AnimEncoder (issues #310, #314, #316, #322), cwebp/libwebp (issue
#312)
* full libwebp (encoder & decoder) iOS framework; libwebpdecoder
WebP.framework renamed to WebPDecoder.framework (issue #307)
* CMake support for Android Studio (2.2)
* miscellaneous build related fixes (issue #306, #313)
* miscellaneous documentation improvements (issue #225)
* minor lossy encoder fixes and improvements
* tag 'v0.5.2': (54 commits)
update ChangeLog
anim_util: quiet implicit conv warnings in 32-bit
jpegdec: correct ContextFill signature
Remove some errors when compiling the code as C++.
vwebp: clear canvas during resize w/o animation
tiffdec: restore libtiff 3.9.x compatibility
update NEWS
AnimEncoder: avoid freeing uninitialized memory pointer.
WebPAnimEncoder: If 'minimize_size' and 'allow_mixed' on, try lossy + lossless.
fix a potential overflow with MALLOC_LIMIT
bump version to 0.5.2
update AUTHORS & .mailmap
iosbuild.sh: add WebPDecoder.framework + encoder
AnimEncoder: Correctly skip a frame when sub-rectangle is empty.
Fix assertions in WebPRescalerExportRow()
fix a typo in WebPPictureYUVAToARGB's doc
systematically call WebPDemuxReleaseIterator() on dec->prev_iter_
doc: use two's complement explicitly for uint8->int8 conversion
Anim_encoder: correctly handle enc->prev_candidate_undecided_
WebPPictureDistortion(): free() -> WebPSafeFree()
...
Change-Id: I16bcf54af41ce8fad98d4fbc8aa1df58f338fc23
This is duplicating code from compiler flag checking that was once
added (then reverted to CMake) as the problem seem to be on the
clang side as detailed in:
http://public.kitware.com/Bug/view.php?id=13194
I also tried to remove a similar warning with pthreads but there
is also an issue on the clang side:
https://llvm.org/bugs/show_bug.cgi?id=7798
Change-Id: I5b0061f0f71e49b493c5ee0c98f70533c28164bd
the sizes are already validated by CheckSizeForOverflow(), add casts to
size_t to avoid -Wshorten-64-to-32
Change-Id: Ida9102c2104f4a334a0ad16d6e01a12bedfd4eec
(cherry picked from commit 1e2e25b0d4)
this corrects the checkboard pattern displayed with transparent images
Change-Id: I5f46dbc9fa3893d61f5f1d4fda643ac030238f94
(cherry picked from commit 67c25ad5b4)
In GenerateCandidates(), when candidate_ll->evaluate_ and
candidate_lossy->evaluate_ are both true, if lossless encoding
exits on error, candidate_ll->evaluate_ would not be correctly
reset. This will cause freeing uninitialized memory pointer in
SetFrame().
BUG=webp:322
Change-Id: I481b49a186e4fa3607ce71b4543a481083edf444
(cherry picked from commit 3ebe1c0003)
This improves compression by ~5% at default quality.
If only 'allow_mixed' is on (but 'minimize_size' isn't), we continue to
use a heuristic to try one of the two or both.
Change-Id: Ia573a73ea26ad25f9debff759eed69d2b0449e82
(cherry picked from commit 3f4042b52a)
