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
* 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
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
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
src/dec/Makefile.am: add missing reference to vp8li.h
src/{dec,dsp,enc}/Makefile.am: move some headers to noinst_
Change-Id: I0e2bc69980bd8175d99ad0ab63f537ef9e425b77
- use common file organization across subdir makefiles
- append lib/source/header list variables and sort
Change-Id: I0653e1c73a4552b0c43d21f321b22b4972d6e87b
