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Some cosmetics in histogram.c
Change-Id: I5d5872a793759fad593dba88c3f593f72b328b0c
This commit is contained in:
Urvang Joshi
James Zern
parent
ada6ff77df
commit
41b5c8ff71
@ -195,40 +195,29 @@ double VP8LHistogramEstimateBitsHeader(const VP8LHistogram* const p) {
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HuffmanCost(&p->distance_[0], DISTANCE_CODES_MAX);
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}
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static int HistogramBuildImage(int xsize, int ysize,
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int histobits, int palettebits,
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static int HistogramBuildImage(int xsize, int histo_bits, int cache_bits,
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const VP8LBackwardRefs* const backward_refs,
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VP8LHistogram*** const image_arg,
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int* const image_size) {
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int histo_xsize = histobits ? (xsize + (1 << histobits) - 1) >> histobits : 1;
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int histo_ysize = histobits ? (ysize + (1 << histobits) - 1) >> histobits : 1;
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VP8LHistogram** const image,
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int image_size) {
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int i;
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const int histo_xsize =
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histo_bits ? (xsize + (1 << histo_bits) - 1) >> histo_bits : 1;
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int x = 0;
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int y = 0;
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VP8LHistogram** image;
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*image_arg = NULL;
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*image_size = histo_xsize * histo_ysize;
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image = (VP8LHistogram**)calloc(*image_size, sizeof(*image));
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if (image == NULL) {
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return 0;
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}
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for (i = 0; i < *image_size; ++i) {
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for (i = 0; i < image_size; ++i) {
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image[i] = (VP8LHistogram*)malloc(sizeof(*image[i]));
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if (!image[i]) {
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if (image[i] == NULL) {
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int k;
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for (k = 0; k < *image_size; ++k) {
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free(image[k]);
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}
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free(image);
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for (k = 0; k < i; ++k) free(image[k]);
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return 0;
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}
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VP8LHistogramInit(image[i], palettebits);
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VP8LHistogramInit(image[i], cache_bits);
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}
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// x and y trace the position in the image.
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for (i = 0; i < backward_refs->size; ++i) {
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const PixOrCopy v = backward_refs->refs[i];
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const int ix =
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histobits ? (y >> histobits) * histo_xsize + (x >> histobits) : 0;
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histo_bits ? (y >> histo_bits) * histo_xsize + (x >> histo_bits) : 0;
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VP8LHistogramAddSinglePixOrCopy(image[ix], v);
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x += PixOrCopyLength(&v);
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while (x >= xsize) {
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@ -236,83 +225,72 @@ static int HistogramBuildImage(int xsize, int ysize,
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++y;
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}
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}
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*image_arg = image;
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return 1;
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}
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static int HistogramCombine(VP8LHistogram** const in, int in_size, int quality,
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VP8LHistogram*** const out_arg,
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int* const out_size) {
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static int HistogramCombine(VP8LHistogram** const in, int in_size,
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int num_pairs, VP8LHistogram** const out,
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int* const out_size_arg) {
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int ok = 0;
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int i;
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unsigned int seed = 0;
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int tries_with_no_success = 0;
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int inner_iters = 10 + quality / 2;
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int iter;
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double* bit_costs = (double*)malloc(in_size * sizeof(*bit_costs));
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VP8LHistogram** out = (VP8LHistogram**)calloc(in_size, sizeof(*out));
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*out_arg = out;
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*out_size = in_size;
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if (bit_costs == NULL || out == NULL) {
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goto Error;
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}
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// Copy
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const int outer_iters = in_size * 3;
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double* const bit_costs = (double*)malloc(in_size * sizeof(*bit_costs));
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// TODO(urvang): 'bit_cost' should be part of VP8LHistogram.
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VP8LHistogram* const combo = (VP8LHistogram*)malloc(sizeof(*combo));
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int out_size = in_size;
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if (bit_costs == NULL || out == NULL || combo == NULL) goto End;
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// Copy histogram 'in' to 'out'.
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for (i = 0; i < in_size; ++i) {
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VP8LHistogram* new_histo = (VP8LHistogram*)malloc(sizeof(*new_histo));
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if (new_histo == NULL) {
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goto Error;
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}
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*new_histo = *(in[i]);
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out[i] = new_histo;
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VP8LHistogram* const temp = (VP8LHistogram*)malloc(sizeof(*temp));
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if (temp == NULL) goto End;
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*temp = *(in[i]);
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out[i] = temp;
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bit_costs[i] = VP8LHistogramEstimateBits(out[i]);
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}
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// Collapse similar histograms.
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for (iter = 0; iter < in_size * 3 && *out_size >= 2; ++iter) {
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double best_val = 0;
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int best_ix0 = 0;
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int best_ix1 = 0;
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// Try a few times.
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int k;
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for (k = 0; k < inner_iters; ++k) {
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// Choose two, build a combo out of them.
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double cost_val;
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VP8LHistogram* combo;
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int ix0 = rand_r(&seed) % *out_size;
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int ix1;
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int diff = ((k & 7) + 1) % (*out_size - 1);
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if (diff >= 3) {
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diff = rand_r(&seed) % (*out_size - 1);
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}
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ix1 = (ix0 + diff + 1) % *out_size;
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if (ix0 == ix1) {
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// Collapse similar histograms in 'out'.
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for (i = 0; i < outer_iters && out_size >= 2; ++i) {
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// We pick the best pair to be combined out of 'inner_iters' pairs.
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double best_cost_diff = 0;
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int best_idx1 = 0;
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int best_idx2 = 0;
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int j;
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for (j = 0; j < num_pairs; ++j) {
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double curr_cost_diff;
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// Choose two histograms at random and try to combine them.
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const int idx1 = rand_r(&seed) % out_size;
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const int tmp = ((j & 7) + 1) % (out_size - 1);
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const int diff = (tmp < 3) ? tmp : rand_r(&seed) % (out_size - 1);
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const int idx2 = (idx1 + diff + 1) % out_size;
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if (idx1 == idx2) {
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continue;
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}
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combo = (VP8LHistogram*)malloc(sizeof(*combo));
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if (combo == NULL) {
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goto Error;
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*combo = *out[idx1];
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VP8LHistogramAdd(combo, out[idx2]);
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// Calculate cost reduction on combining.
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curr_cost_diff =
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VP8LHistogramEstimateBits(combo) - bit_costs[idx1] - bit_costs[idx2];
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if (best_cost_diff > curr_cost_diff) {
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best_cost_diff = curr_cost_diff;
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best_idx1 = idx1;
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best_idx2 = idx2;
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}
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*combo = *out[ix0];
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VP8LHistogramAdd(combo, out[ix1]);
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cost_val =
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VP8LHistogramEstimateBits(combo) - bit_costs[ix0] - bit_costs[ix1];
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if (best_val > cost_val) {
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best_val = cost_val;
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best_ix0 = ix0;
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best_ix1 = ix1;
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}
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free(combo);
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}
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if (best_val < 0.0) {
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VP8LHistogramAdd(out[best_ix0], out[best_ix1]);
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bit_costs[best_ix0] =
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best_val + bit_costs[best_ix0] + bit_costs[best_ix1];
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// Erase (*out)[best_ix1]
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free(out[best_ix1]);
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memmove(&out[best_ix1], &out[best_ix1 + 1],
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(*out_size - best_ix1 - 1) * sizeof(out[0]));
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memmove(&bit_costs[best_ix1], &bit_costs[best_ix1 + 1],
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(*out_size - best_ix1 - 1) * sizeof(bit_costs[0]));
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--(*out_size);
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if (best_cost_diff < 0.0) {
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// Combine this pair and store the combined histogram at 'best_idx1'.
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VP8LHistogramAdd(out[best_idx1], out[best_idx2]);
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bit_costs[best_idx1] =
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best_cost_diff + bit_costs[best_idx1] + bit_costs[best_idx2];
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free(out[best_idx2]);
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memmove(&out[best_idx2], &out[best_idx2 + 1],
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(out_size - best_idx2 - 1) * sizeof(*out));
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memmove(&bit_costs[best_idx2], &bit_costs[best_idx2 + 1],
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(out_size - best_idx2 - 1) * sizeof(*bit_costs));
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--out_size;
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tries_with_no_success = 0;
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}
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if (++tries_with_no_success >= 50) {
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@ -320,16 +298,17 @@ static int HistogramCombine(VP8LHistogram** const in, int in_size, int quality,
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}
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}
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ok = 1;
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Error:
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End:
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free(bit_costs);
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free(combo);
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if (!ok) {
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if (out) {
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int i;
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for (i = 0; i < *out_size; ++i) {
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free(out[i]);
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}
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if (out != NULL) {
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for (i = 0; i < out_size; ++i) free(out[i]);
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free(out);
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}
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*out_size_arg = 0;
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} else {
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*out_size_arg = out_size;
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}
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return ok;
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}
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@ -407,44 +386,46 @@ static int HistogramRefine(VP8LHistogram** const raw, int raw_size,
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int VP8LGetHistImageSymbols(int xsize, int ysize,
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const VP8LBackwardRefs* const refs,
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int quality, int histogram_bits,
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int quality, int histo_bits,
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int cache_bits,
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VP8LHistogram*** const histogram_image,
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VP8LHistogram** const histogram_image,
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int* const histogram_image_size,
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uint32_t* const histogram_symbols) {
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// Build histogram image.
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int ok = 0;
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int i;
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int histogram_image_raw_size;
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VP8LHistogram** histogram_image_raw = NULL;
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const int histo_xsize = histo_bits ? VP8LSubSampleSize(xsize, histo_bits) : 1;
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const int histo_ysize = histo_bits ? VP8LSubSampleSize(ysize, histo_bits) : 1;
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const int num_histo_pairs = 10 + quality / 2; // For HistogramCombine().
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const int histo_image_raw_size = histo_xsize * histo_ysize;
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VP8LHistogram** const histo_image_raw =
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(VP8LHistogram**)calloc(histo_image_raw_size, sizeof(*histo_image_raw));
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if (histo_image_raw == NULL) return 0;
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*histogram_image = NULL;
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if (!HistogramBuildImage(xsize, ysize, histogram_bits, cache_bits, refs,
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&histogram_image_raw,
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&histogram_image_raw_size)) {
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// Build histogram image.
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if (!HistogramBuildImage(xsize, histo_bits, cache_bits, refs,
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histo_image_raw, histo_image_raw_size)) {
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goto Error;
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}
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// Collapse similar histograms.
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if (!HistogramCombine(histogram_image_raw, histogram_image_raw_size,
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quality, histogram_image, histogram_image_size)) {
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if (!HistogramCombine(histo_image_raw, histo_image_raw_size, num_histo_pairs,
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histogram_image, histogram_image_size)) {
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goto Error;
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}
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// Refine histogram image.
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for (i = 0; i < histogram_image_raw_size; ++i) {
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for (i = 0; i < histo_image_raw_size; ++i) {
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histogram_symbols[i] = -1;
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}
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if (!HistogramRefine(histogram_image_raw, histogram_image_raw_size,
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histogram_symbols,
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*histogram_image, *histogram_image_size)) {
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if (!HistogramRefine(histo_image_raw, histo_image_raw_size, histogram_symbols,
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histogram_image, *histogram_image_size)) {
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goto Error;
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}
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ok = 1;
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Error:
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if (!ok) {
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VP8LDeleteHistograms(*histogram_image, *histogram_image_size);
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VP8LDeleteHistograms(histogram_image, *histogram_image_size);
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}
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VP8LDeleteHistograms(histogram_image_raw, histogram_image_raw_size);
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VP8LDeleteHistograms(histo_image_raw, histo_image_raw_size);
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return ok;
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}
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@ -135,7 +135,7 @@ int VP8LGetHistImageSymbols(int xsize, int ysize,
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const VP8LBackwardRefs* const refs,
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int quality, int histogram_bits,
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int cache_bits,
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VP8LHistogram*** histogram_image,
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VP8LHistogram** const histogram_image,
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int* const histogram_image_size,
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uint32_t* const histogram_symbols);
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@ -652,7 +652,6 @@ static int EncodeImageInternal(VP8LBitWriter* const bw,
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int cache_bits, int histogram_bits) {
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int i;
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int ok = 0;
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int histogram_image_size;
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int write_histogram_image;
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int* bit_lengths_sizes = NULL;
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uint8_t** bit_lengths = NULL;
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@ -662,12 +661,14 @@ static int EncodeImageInternal(VP8LBitWriter* const bw,
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const int color_cache_size = use_color_cache ? (1 << cache_bits) : 0;
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const int histogram_image_xysize = VP8LSubSampleSize(width, histogram_bits) *
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VP8LSubSampleSize(height, histogram_bits);
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VP8LHistogram** histogram_image;
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VP8LHistogram** histogram_image =
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(VP8LHistogram**)calloc(histogram_image_xysize, sizeof(*histogram_image));
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int histogram_image_size;
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VP8LBackwardRefs refs;
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const size_t histo_size = histogram_image_xysize * sizeof(uint32_t);
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uint32_t* const histogram_symbols = (uint32_t*)calloc(1, histo_size);
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if (histogram_symbols == NULL) goto Error;
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if (histogram_image == NULL || histogram_symbols == NULL) goto Error;
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// Calculate backward references from ARGB image.
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if (!GetBackwardReferences(width, height, argb, quality,
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@ -678,7 +679,7 @@ static int EncodeImageInternal(VP8LBitWriter* const bw,
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// Build histogram image & symbols from backward references.
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if (!VP8LGetHistImageSymbols(width, height, &refs,
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quality, histogram_bits, cache_bits,
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&histogram_image, &histogram_image_size,
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histogram_image, &histogram_image_size,
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histogram_symbols)) {
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goto Error;
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}
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