the original change triggered several internal API modifs.
This is to ensure that we're never computing pointer that can
possibly wrap around, or differences between pointers that can
overflow.
no observed speed difference
Change-Id: I9c94dda38d94fecc010305e4ad12f13b8fda5380
DitherRow() only checks this value, not 'skip_' so previously it was
uninitialized for these blocks.
Change-Id: I0f698b81854ee9d91edacb51c1e3bdab9cba96f2
* remove LEFT/RIGHT_JUSTIFY distinction. It's all RIGHT_JUSTIFY now.
* simplify VP8GetSigned(), and add some masking branch-less code. Much
faster on ARM (~13% speed-up). 8% on x86-64, 5% on MacBook.
* split critical implementation into separate bit_reader_inl.h file that
is only included where needed (vp8.c / tree.c / bit_reader.c)
* bumped BITS value from 16 to 24 for x86-32b too, since it's a bit faster.
Change-Id: If41ca1da3e5c3dadacf2379d1ba419b151e7fce8
there's still some malloc/free in the external example
This is an encoder API change because of the introduction
of WebPMemoryWriterClear() for symmetry reasons.
The MemoryWriter object should probably go in examples/ instead
of being in the main lib, though.
mux_types.h stil contain some inlined free()/malloc() that are
harder to remove (we need to put them in the libwebputils lib
and make sure link is ok). Left as a TODO for now.
Also: WebPDecodeRGB*() function are still returning a pointer
that needs to be free()'d. We should call WebPSafeFree() on
these, but it means exposing the whole mechanism. TODO(later).
Change-Id: Iad2c9060f7fa6040e3ba489c8b07f4caadfab77b
(instead of per-macroblock)
speed unchanged.
simplified the context-saving for incremental decoding
Change-Id: I301be581bab581ff68de14c4ffe5bc0ec63f34be
Even at high quality setting, the U/V quantizer step is limited
to 4 which can lead to banding on gradient.
This option allows to selectively apply some randomness to
potentially flattened-out U/V blocks and attenuate the banding.
This option is off by default in 'dwebp', but set to -dither 50
by default in 'vwebp'.
Note: depending on the number of blocks selectively dithered,
we can have up to a 10% slow-down in decoding speed it seems.
Change-Id: Icc2446007f33ddacb60b3a80a9e63f2d5ad162de
method 1 grouping: [parse + reconstruction] // [filtering + output]
method 2 grouping: [parse] // [reconstruction+filtering + output]
Depending on some heuristics (see VP8ThreadMethod()), we
can pick one of the other when -mt flag (or option.use_threads)
is selected.
Conservatively, we always use method #2 for now until the heuristic
is refined (so, timing should be the same the before this patch)
+ replace 'use_threads' by 'mt_method'
+ define MIN_WIDTH_FOR_THREADS constant
+ fix comment alignment
Change-Id: I11a756dea9070d6e21b1a9481d357a1e8aa0663e
Mostly visible for large images.
Reconstruction+filtering is now done in parallel to bitstream-parsing.
Change-Id: I4cc4483d803b255f4d97a2fcd9158b1c291dd900
Needs more memory but allows for future parallelization.
Noticeably faster on ARM, slightly faster on x86
also: remove dec->filter_row_ unnecessary field
Change-Id: I044a808839b4e000c838a477e3e8688820436d9a
happens surprisingly often at low quality, so we might
as well hard-code a simplified TransformWHT() directly.
Change-Id: Ib7a858ef74e8f334bd59d6512bf5bd3e455c5459
rather than symlink the webm/vpx terms, use the same header as libvpx to
reference in-tree files
based on the discussion in:
https://codereview.chromium.org/12771026/
Change-Id: Ia3067ecddefaa7ee01550136e00f7b3f086d4af4
Removed a call to WebPParseHeaders() inside VP8GetHeaders(). This was not needed
anyway, as all call flows already call WebPParseHeaders() before calling
VP8GetHeaders().
This avoids duplicate calls to WebPParseHeaders().
Change-Id: Icb2d618bd26c44220d956c17a69c9c45a62d5237
- precompute filtering strength once for all at the beginning
instead of per-macroblock
- reduce size of VP8MB struct from 8 bytes to 4.
- removed VP8StoreBlock() accordingly
Change-Id: Icf3d329473e21c464770be3d72a04c9ee4c321f2
GetCoeffs is (by far) the most consuming function of the decoder.
No speed change (unfortunately), but the main loop is somehow clearer.
Change-Id: I78f1c10cadc2c8696c041f5cbda86cab92cc6598
minor revision shouldn't matter, we only check major revision number.
Bumped all version numbers so that incompatibility starts *now*
Change-Id: Id06c20f03039845ae4cfb3fd121807b931d67ee4
Previously, it used to assume any raw bitstream is a VP8 one.
Also,
- Factor out VP8CheckSignature() & VP8LCheckSignature().
- Use a local var for *data_ptr in ParseVP8Header() for
readability.
Change-Id: I0fa8aa177dad7865e00c8898f7e7ce76a9db19d5
* each with their own decoder instances.
* Refactor the incremental buffer-update code a lot.
* remove br_offset_ for VP8LDecoder along the way
* make VP8GetHeaders() be used only for VP8, not VP8L bitstream
* remove VP8LInitDecoder()
* rename VP8LBitReaderResize() to VP8LBitReaderSetBuffer()
(cherry picked from commit 5529a2e6d47212a721ca4ab003215f97bd88ebb4)
Change-Id: I58f0b8abe1ef31c8b0e1a6175d2d86b863793ead
import changes from experimental 5529a2e^
and enable build in autoconf and makefile.unix; windows will be treated
separately.
Change-Id: Ie2e177a99db63190b4cd647b3edee3b4e13719e9
A call to Append/Update would index the parts_ array w/-1 as num_parts_
had yet to be set by DecodePartition0. This would cause corruption
within the VP8Decoder member.
Fixes issue #106.
Change-Id: Ib9f2811594ff19e948a66fda862a4e0a384bb9aa
- remove some unused functions
- move global arrays from data to read only section
- explicitly cast malloc returns; not specifically necessary, but helps
show intent
- miscellaneous formatting
Change-Id: Ib15fe5b37fe6c29c369ad928bdc3a7290cd13c84
