[Basically, the condition "src - dist < data" can be wrongly evaluated
to be false if "src < dist" due to underflow. Instead, "src - data <
dist" is the correct condition, as "src > data" is always true and so
there would never be an underflow].
Change-Id: Ic9f64bfe76a9acae97abc1fb7c1f4868e81f1eb8
CompareHuffmanTrees() and SetBitDepths()):
- Move 'tree_size' initialization and malloc for 'tree + tree_pool'
outside the loop.
- Some renames/tweaks for readability.
Change-Id: I5cb3cc942afac6e9f51a0b97c57ee897677a48a2
The current implementation doesn't take care one byte
signature and associated one byte padding (for odd sized chunk).
Change-Id: I35b81d0644818cdba38189aa48c75db5f92e68f4
The new method VP8LGetBackwardReferences hides internal
heuristics used for choosing RLE or LZ77 based refs.
- Tuned VP8LHashChainFindCopy for better compression at higher Q.
- Refactored code.
- Removed the unused method VP8LVerifyBackwardReferences.
Change-Id: Ibb7bb072bab5a49a001577a20d88226f52e6c663
arrays can be passed directly as only their members are being modified.
this also reduces the allocation for bit_codes[] by taking the
sizeof(type)=2 rather than sizeof(ptr)=4/8 in one case.
Change-Id: Idad20cead58c218b58d90b71699374fefd01cad9
add proper cpu-detection for Android targets
Fixes issue #118 (and is a better solution for #117).
based on patch by pepijn vaneeckhoudt
Change-Id: I6b00ea6d51ca658ccf6a3d55b87b99c01c6805be
* lossless_encoder: (46 commits)
split StoreHuffmanCode() into smaller functions
more consolidation: introduce VP8LHistogramSet
big code clean-up and refactoring and optimization
Some cosmetics in histogram.c
Approximate FastLog between value range [256, 8192]
Forgot to update out_bit_costs to symbol_bit_costs at one instance.
Evaluate output cluster's bit_costs once in HistogramRefine.
Simple Huffman code changes.
Lossless decoder: remove an unneeded param in ReadHuffmanCodeLengths().
Reducing emerging palette size from 11 to 9 bits.
Move GetHistImageSymbols to histogram.c
Improve predict vs no-predict heuristic.
code-moving and clean-up
reduce memory usage by allocating only one histo
Restrict histo_bits to ensure histo_image size is under 32MB
further simplification for the meta-Huffman coding
A quick pass of cleanup in backward reference code
Make transform bits a function of encode method (-m).
introduce -lossless option, protected by USE_LOSSLESS_ENCODER
Run TraceBackwards for higher qualities.
...
Conflicts:
src/enc/webpenc.c
Change-Id: I9a5d98cba0889ea91d10699466939cc283da345a
VP8LHistogramSet is container for pointers to histograms that
we can shuffle around. Allocation is one big chunk of memory.
Downside is that we don't de-allocate memory on-the-go during
HistogramRefine().
+ renamed HistogramRefine() into HistogramRemap(), so we don't
confuse with "HistogramCombine"
+ made VP8LHistogramClear() static.
Change-Id: Idf1a748a871c3b942cca5c8050072ccd82c7511d
* de-inline some function
* make VP8LBackwardRefs be more like a vectorwith max capacity
* add bit_cost_ field to VP8LHistogram
* general code simplifications
* remove some memmov() from HistogramRefine
* simplify HistogramDistance()
...
Change-Id: I16904d9fa2380e1cf4a3fdddf56ed1fcadfa25dc
Profiled data: Profiled few images and found that in the function VP8LFastLog,
90% of time table lookup is performed, while rest of time (10%) call to log
function is made. Typical lookup accounts for 10 CPU instructions and call to
log 200 instruction counts. The weighted average comes out to be 30
instructions per call. For mid qualities (25-75), this function (VP8LFastLog)
accounts for 30-50% of total CPU cycles (via call path: VP8LCOlorSpaceTransform
-> PredictionCostCrossColor -> ShannonEntropy). After this change, the log is
called less that 1% of time, with average instructions being 15 per call.
Measured the performance over 1000 files for various qualities and found
overall compression speedup between 10-15% (in quality range [0, 75]). The
compression density loss is around 0.5% (though at some qualities, compression
is little better as well).
Change-Id: I247bc6a8d4351819c871f19d65455dc23aea8650
Avoid bit_costs evaluated every time in function HistogramDistance. Also moved
VP8LInitBackwardRefs and VP8LClearBackwardRefs to backward_references.h
Change-Id: Id507f164d0fc64480aebc4a3ea3e6950ed377a60
No empty trees are codified with the simple Huffman code. The simple Huffman
code is simplified to be either a 1-bit code or 8-bit code for symbols.
Change-Id: I3e2813027b5a643862729339303d80197c497aff
This improves compression density. For example, at quality 95 on 1000 PNGs:
bpp(before) = 2.447 and bpp(after) = 2.412
Change-Id: I19c343ba05cca48a6940293721066502a5c3d693
* removed use_lz77_ field, and added cache_bits_ one.
* use more BackwardRefs params
* move code around to organize more logically
* reduce memory use on histo
...
Change-Id: I833217a1b950189cf486704049e3fe28382ce335
instead of lz77+rle
* introduce VP8LBackwardRefs structure and simplify the code by not passing
around {PixOrCopy/int} pairs.
More functions should be turned into using this struct (TODO(later)).
Change-Id: I69c5c9fa61dddd61a2abc2824d70b8606a1c55b6
* don't transmit the number of Huffman tree group explicitly
* move color-cache information before the meta-Huffman block
* also add a check that color_cache_bits is in [1..11] range, as per spec.
Change-Id: I81d7711068653b509cdbc1151d93e229c4254580
(Essentially, there was no need of a separate 'argb_palette' array. And
argb_palette[0] was never being set).
Change-Id: Id0a8c7e063d3af41e39fc9b8661611b51ccc55cd
make elements of "Multiplier" struct unsigned, so that any negative values are
automatically converted to "mod 256" values.
Change-Id: Iab4f9bacc50dcd94a557944727d9338dbb0982f7
so that it uses original values of left, top etc for prediction rather than the
predicted values of the same. Also, do some renaming in the same to make it
more readable.
Change-Id: I2fe94e35a6700bd437f5c601e2af12323bf32445
- VP8LEncAnalyze, EvalAndApplySubtractGreen, ApplyPredictFilter,
ApplyCrossColorFilter
- Added palette handling and transform buffer management in VP8LEncodeImage()
- Add Transforms (subtract Green, Predict, cross_color) to dsp/lossless.c.
These are more-or-less copied from src/lossless code.
After this Change, will implement the EncodeImageInternal() method.
Change-Id: Idf71f803c24b3b5ae3b5079b15e019721784611d
no version of msvc currently implements log2(). unconditionally define
NOT_HAVE_LOG2 in this case to simplify building libwebp sources in other
projects.
Change-Id: Ia9d985b1125553c5a8271d7e539bc1b4f898d749
src/dec/Makefile.am: add missing reference to vp8li.h
src/{dec,dsp,enc}/Makefile.am: move some headers to noinst_
Change-Id: I0e2bc69980bd8175d99ad0ab63f537ef9e425b77
src/dsp/lossless.c: In function 'VP8LInverseTransform':
src/dsp/lossless.c:312:23: warning: 'packed_pixels' may be used
uninitialized in this function [-Wuninitialized]
src/dsp/lossless.c:304:16: note: 'packed_pixels' was declared here
src/dsp/lossless.c:258:34: warning: 'm.red_to_blue_' may be used
uninitialized in this function [-Wuninitialized]
src/dsp/lossless.c:275:17: note: 'm.red_to_blue_' was declared here
src/dsp/lossless.c:257:34: warning: 'm.green_to_blue_' may be used
uninitialized in this function [-Wuninitialized]
src/dsp/lossless.c:275:17: note: 'm.green_to_blue_' was declared here
src/dsp/lossless.c:255:33: warning: 'm.green_to_red_' may be used
uninitialized in this function [-Wuninitialized]
src/dsp/lossless.c:275:17: note: 'm.green_to_red_' was declared here
patch by pepijn vaneeckhoudt
Change-Id: Iffa4764487a75479df45e772169325cd9ee60d94
- use common file organization across subdir makefiles
- append lib/source/header list variables and sort
Change-Id: I0653e1c73a4552b0c43d21f321b22b4972d6e87b
* 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
Pulled from 5529a2e^.
The history of this and related files is a bit entangled so rather
trying to split the changes and introduce some noise in master's history
we'll start with a fresh snapshot.
The file progression is still available in the experimental branch.
Change-Id: I490a49cb0084d556a29d7c5257c986ea695ce60c
Pulled from the parent of the current version (5529a2e^).
The history of this and related files is a bit entangled so rather
trying to split the changes and introduce some noise in master's history
we'll start with a fresh snapshot.
The file progression is still available in the experimental branch.
Change-Id: I6dae97fc381cd6c1d1640c4c565b2084a41ec955
Pulled from the current HEAD (218c32e).
The history of this and related files is a bit entangled so rather
trying to split the changes and introduce some noise in master's history
we'll start with a fresh snapshot.
The file progression is still available in the experimental branch.
Change-Id: I40538799dbf999abb9408ac83f55b897d8e22498
Pulled from the current HEAD (218c32e).
The history of this and related files is a bit entangled so rather
trying to split the changes and introduce some noise in master's history
we'll start with a fresh snapshot.
The file progression is still available in the experimental branch.
Change-Id: Ie57be21bf50ad83808c72aeb5fc706d9954d01d8
Pulled from the current HEAD (218c32e).
The history of this and related files is a bit entangled so rather
trying to split the changes and introduce some noise in master's history
we'll start with a fresh snapshot.
The file progression is still available in the experimental branch.
Change-Id: Id879be453a94d9f44ec8d47747823ca7297ae008
by packing the symbol map more efficiently.
This is mainly useful in making it harder to generate invalid bitstream:
before this change, one could code the same symbol twice. Now, it's
impossible, since we code the position using empty symbol slots, instead
of total position.
* Fix the HasOnlyLeftChild() naming while at it.
Change-Id: I63c56c80a4f04a86ac83eded1e3306329815b6c9
group like parameters together in prototypes, comments, move variable
declarations closer to first use.
Change-Id: Idd6bd87d0366d783fed83f4dd21bd7968cbe6948
_byteswap_ulong is defined in stdlib.h, release builds seem to pull it
in through a different path.
Change-Id: I510d2624150f89a4a77734bf3dc5b4db60a4ba95
- const / move declarations closer to first use
- remove unnecessary ()s
- don't return int unnecessarily with internal Init/Release
- compact some lines
Change-Id: If7ab505e417221debc356f21f075506939110a84
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
If the first call to WebPIUpdate contained all of partition 0, but not
enough to decode a macroblock the test for max macro block size could
fail (4096 bytes) due to a memory buffer offset not being updated.
This change offsets the buffer in the same manner as Append().
Fixes issue #105.
Change-Id: I90ca3d0dde92eedc076933b8349d2d297f2469e8
- 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
As with the loop filter, implementing this with intrinsics is difficult
because we require subscript access for reading and writing 32 bits at a
time.
Approximately 5% decode speed improvement. This could be increased by
exposing TransformOne and rewriting TransformTwo to only handle dual
IDCTs.
Change-Id: Idd409264ab5d154a537107a1d54b419a48f7c1a8
