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Integrate a new LZ77 looking for matches in the neighborhood of a pixel only.

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Change-Id: Ie2bbfee0a8d154b58f4a3068f3f634b7dad4c12d
This commit is contained in:
Vincent Rabaud
2017-06-07 19:06:28 +02:00
parent a1779a017b
commit 355c3d1bc7
4 changed files with 162 additions and 20 deletions
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36
src/enc/vp8l_enc.c
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@ -356,13 +356,13 @@ static int GetTransformBits(int method, int histo_bits) {
return res;
}
// Se of parameters to be used in each iteration of the cruncher.
// Set of parameters to be used in each iteration of the cruncher.
typedef struct {
int entropy_idx_;
int lz77s_types_to_try_;
} CrunchConfig;
#define CRUNCH_CONFIGS_MAX kNumEntropyIx
#define CRUNCH_CONFIGS_MAX (kNumEntropyIx * 2)
static int AnalyzeAndInit(VP8LEncoder* const enc,
CrunchConfig crunch_configs[CRUNCH_CONFIGS_MAX],
@ -399,27 +399,33 @@ static int AnalyzeAndInit(VP8LEncoder* const enc,
*crunch_configs_size = 1;
} else {
EntropyIx min_entropy_ix;
int j;
// Try out multiple LZ77 on images with few colors.
const int n_lz77 = 1 + (enc->palette_size_ > 0 && enc->palette_size_ <= 16);
if (!AnalyzeEntropy(pic->argb, width, height, pic->argb_stride, use_palette,
enc->palette_size_, enc->transform_bits_,
&min_entropy_ix, red_and_blue_always_zero)) {
return 0;
}
*crunch_configs_size = 0;
if (method == 6 && config->quality == 100) {
// Go brute force on all transforms.
for (i = 0; i < kNumEntropyIx; ++i) {
if (i != kPalette || use_palette) {
crunch_configs[*crunch_configs_size].entropy_idx_ = i;
crunch_configs[(*crunch_configs_size)++].lz77s_types_to_try_ =
kLZ77Standard | kLZ77RLE;
assert(*crunch_configs_size <= CRUNCH_CONFIGS_MAX);
for (j = 0; j < n_lz77; ++j) {
if (method == 6 && config->quality == 100) {
// Go brute force on all transforms.
for (i = 0; i < kNumEntropyIx; ++i) {
if (i != kPalette || use_palette) {
assert(*crunch_configs_size < CRUNCH_CONFIGS_MAX);
crunch_configs[*crunch_configs_size].entropy_idx_ = i;
crunch_configs[(*crunch_configs_size)++].lz77s_types_to_try_ =
(j == 0) ? kLZ77Standard | kLZ77RLE : kLZ77Box;
}
}
} else {
// Only choose the guessed best transform.
assert(*crunch_configs_size < CRUNCH_CONFIGS_MAX);
crunch_configs[*crunch_configs_size].entropy_idx_ = min_entropy_ix;
crunch_configs[(*crunch_configs_size)++].lz77s_types_to_try_ =
(j == 0) ? kLZ77Standard | kLZ77RLE : kLZ77Box;
}
} else {
// Only choose the guessed best transform.
crunch_configs[*crunch_configs_size].entropy_idx_ = min_entropy_ix;
crunch_configs[(*crunch_configs_size)++].lz77s_types_to_try_ =
kLZ77Standard | kLZ77RLE;
}
}