This is to help further optimizations.
(like in https://gerrit.chromium.org/gerrit/#/c/69787/)
There's a small slowdown (~0.5% at -z 9 quality) due to
function pointer usage. Note that, for speed, it's important
to return VP8LStreaks by value, and not pass a pointer.
Change-Id: Id4167366765fb7fc5dff89c1fd75dee456737000
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
Optimize and re-structured VP8LGetHistoImageSymbols method, by using the bin-hash
for merging the Histograms more efficiently, instead of the randomized
heuristic of existing method HistogramCombine.
This change speeds up the Lossless encoding by 40-50% (for method=4 and Q > 50)
with 0.8% penalty in compression density. For lower method, the speed up is 25-30%,
with 0.4% penalty in the compression density.
Change-Id: If61adadb1a041b95def6405aa1fe3b83c3cb25ce
Refactor code for HistogramCombine and optimize the code by calculating
the combined entropy and avoid un-necessary Histogram merges.
This speeds up lossless encoding by 1-2% and almost no impact on compression
density.
Change-Id: Iedfcf4c1f3e88077bc77fc7b8c780c4cd5d6362b
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
* merge cost calculation functions (BitsEntropy() and HuffmanCost())
* have HistogramAdd() specialized into separate functions
* use threshold to bail-out early
* revamp code a bit
* also: save memory by freeing free(histogram_image)
Change-Id: I8ee5d2cfa1462d5d6ea6361f5c89925a3720ef55
Order-by-cost mostly unchanged (up to a scaling constant 1/log(2))
(except for few minor diff in < 2% of cases)
+ remove unused field cost_mode->cache_bits_
Change-Id: I714f8ab12f49a23f5d499a64c741382c9b489a3e
Used when we don't code a Huffman Image.
-> Simplify the code quite some because we don't have to
deal with special cases of histo bits
Change-Id: I0c3f46cbf3b501e021c093e07253e7404c01ff4f
-> lot of simplifications ensue and we should be able to get rid of
ClearHuffmanTreeIfOnlyOneSymbol() too, in a subsequent patch.
Change-Id: Ic4c51d05e4b1970e37f94ffd85fae6a02e4a6422
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
- 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
