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Move the HuffmanCost() function to dsp lib

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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
This commit is contained in:
skal
2014-04-18 08:14:46 -07:00
parent 6653b601ef
commit 75b12006e3
4 changed files with 82 additions and 64 deletions
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18
src/dsp/lossless.h
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@ -139,14 +139,24 @@ static WEBP_INLINE float VP8LFastSLog2(int v) {
// -----------------------------------------------------------------------------
// Huffman-cost related functions.
typedef double (*VP8LCostFunc)(const int* const population, int length);
typedef double (*VP8LCostCombinedFunc)(const int* const X,
const int* const Y,
int length);
typedef double (*VP8LCostFunc)(const int* population, int length);
typedef double (*VP8LCostCombinedFunc)(const int* X, const int* Y, int length);
extern VP8LCostFunc VP8LExtraCost;
extern VP8LCostCombinedFunc VP8LExtraCostCombined;
typedef struct { // small struct to hold counters
int counts[2]; // index: 0=zero steak, 1=non-zero streak
int streaks[2][2]; // [zero/non-zero][streak<3 / streak>=3]
} VP8LStreaks;
typedef VP8LStreaks (*VP8LCostCountFunc)(const int* population, int length);
typedef VP8LStreaks (*VP8LCostCombinedCountFunc)(const int* X, const int* Y,
int length);
extern VP8LCostCountFunc VP8LHuffmanCostCount;
extern VP8LCostCombinedCountFunc VP8LHuffmanCostCombinedCount;
// -----------------------------------------------------------------------------
// PrefixEncode()