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Speedup to HuffmanCostCombinedCount

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~3% speedup for lossless encoding
Improves compression ratio by ~0.03%

Change-Id: Ic6d05fb0b1099b5ca56689b92b1c6515d54a5d6b
This commit is contained in:
Pascal Massimino
2015-06-23 16:38:18 +02:00
parent f3d687e3fa
commit 32462a072c
2 changed files with 13 additions and 26 deletions
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16
src/dsp/lossless_enc.c
View File

@@ -1143,24 +1143,18 @@ static VP8LStreaks HuffmanCostCombinedCount(const uint32_t* X,
const uint32_t* Y, int length) {
int i;
int streak = 0;
uint32_t xy_prev = 0xffffffff;
VP8LStreaks stats;
memset(&stats, 0, sizeof(stats));
for (i = 0; i < length - 1; ++i) {
const int xy = X[i] + Y[i];
const int xy_next = X[i + 1] + Y[i + 1];
for (i = 0; i < length; ++i) {
const uint32_t xy = X[i] + Y[i];
++streak;
if (xy == xy_next) {
continue;
}
if (xy != xy_prev) {
stats.counts[xy != 0] += (streak > 3);
stats.streaks[xy != 0][(streak > 3)] += streak;
streak = 0;
xy_prev = xy;
}
{
const int xy = X[i] + Y[i];
++streak;
stats.counts[xy != 0] += (streak > 3);
stats.streaks[xy != 0][(streak > 3)] += streak;
}
return stats;
}

15
src/dsp/lossless_enc_mips32.c
View File

@@ -245,29 +245,22 @@ static VP8LStreaks HuffmanCostCombinedCount(const uint32_t* X,
const uint32_t* Y, int length) {
int i;
int streak = 0;
uint32_t xy_prev = 0xffffffff;
VP8LStreaks stats;
int* const pstreaks = &stats.streaks[0][0];
int* const pcnts = &stats.counts[0];
int temp0, temp1, temp2, temp3;
memset(&stats, 0, sizeof(stats));
for (i = 0; i < length - 1; ++i) {
for (i = 0; i < length; ++i) {
const uint32_t xy = X[i] + Y[i];
const uint32_t xy_next = X[i + 1] + Y[i + 1];
++streak;
if (xy == xy_next) {
continue;
}
if (xy != xy_prev) {
temp0 = (xy != 0);
HUFFMAN_COST_PASS
streak = 0;
xy_prev = xy;
}
{
const uint32_t xy = X[i] + Y[i];
++streak;
temp0 = (xy != 0);
HUFFMAN_COST_PASS
}
return stats;
}