[SCM] libav/experimental: more trellis quant optimizations
siretart at users.alioth.debian.org
siretart at users.alioth.debian.org
Sun Jun 30 15:38:48 UTC 2013
The following commit has been merged in the experimental branch:
commit fbb898067ff94323b758b70cae9377be9e810d64
Author: Michael Niedermayer <michaelni at gmx.at>
Date: Fri Jan 2 19:22:00 2004 +0000
more trellis quant optimizations
Originally committed as revision 2655 to svn://svn.ffmpeg.org/ffmpeg/trunk
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index 436f907..8c4938c 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -4642,26 +4642,26 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
int qscale, int *overflow){
const int *qmat;
const uint8_t *scantable= s->intra_scantable.scantable;
+ const uint8_t *perm_scantable= s->intra_scantable.permutated;
int max=0;
unsigned int threshold1, threshold2;
int bias=0;
int run_tab[65];
int level_tab[65];
int score_tab[65];
+ int survivor[65];
+ int survivor_count;
int last_run=0;
int last_level=0;
int last_score= 0;
- int last_i= 0;
+ int last_i;
int coeff[2][64];
int coeff_count[64];
int qmul, qadd, start_i, last_non_zero, i, dc;
const int esc_length= s->ac_esc_length;
uint8_t * length;
uint8_t * last_length;
- int score_limit=0;
- int left_limit= 0;
const int lambda= s->lambda2 >> (FF_LAMBDA_SHIFT - 6);
- const int patch_table= s->out_format == FMT_MPEG1 && !s->mb_intra;
s->dsp.fdct (block);
@@ -4700,6 +4700,7 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
length = s->inter_ac_vlc_length;
last_length= s->inter_ac_vlc_last_length;
}
+ last_i= start_i;
threshold1= (1<<QMAT_SHIFT) - bias - 1;
threshold2= (threshold1<<1);
@@ -4716,7 +4717,6 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
for(i=start_i; i<=last_non_zero; i++) {
const int j = scantable[i];
- const int k= i-start_i;
int level = block[j] * qmat[j];
// if( bias+level >= (1<<(QMAT_SHIFT - 3))
@@ -4724,21 +4724,21 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
if(((unsigned)(level+threshold1))>threshold2){
if(level>0){
level= (bias + level)>>QMAT_SHIFT;
- coeff[0][k]= level;
- coeff[1][k]= level-1;
+ coeff[0][i]= level;
+ coeff[1][i]= level-1;
// coeff[2][k]= level-2;
}else{
level= (bias - level)>>QMAT_SHIFT;
- coeff[0][k]= -level;
- coeff[1][k]= -level+1;
+ coeff[0][i]= -level;
+ coeff[1][i]= -level+1;
// coeff[2][k]= -level+2;
}
- coeff_count[k]= FFMIN(level, 2);
- assert(coeff_count[k]);
+ coeff_count[i]= FFMIN(level, 2);
+ assert(coeff_count[i]);
max |=level;
}else{
- coeff[0][k]= (level>>31)|1;
- coeff_count[k]= 1;
+ coeff[0][i]= (level>>31)|1;
+ coeff_count[i]= 1;
}
}
@@ -4749,19 +4749,15 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
return last_non_zero;
}
- score_tab[0]= 0;
+ score_tab[start_i]= 0;
+ survivor[0]= start_i;
+ survivor_count= 1;
- if(patch_table){
-// length[UNI_AC_ENC_INDEX(0, 63)]=
-// length[UNI_AC_ENC_INDEX(0, 65)]= 2;
- }
-
- for(i=0; i<=last_non_zero - start_i; i++){
- int level_index, run, j;
- const int dct_coeff= ABS(block[ scantable[i + start_i] ]);
+ for(i=start_i; i<=last_non_zero; i++){
+ int level_index, j;
+ const int dct_coeff= ABS(block[ scantable[i] ]);
const int zero_distoration= dct_coeff*dct_coeff;
int best_score=256*256*256*120;
-
for(level_index=0; level_index < coeff_count[i]; level_index++){
int distoration;
int level= coeff[level_index][i];
@@ -4773,7 +4769,7 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
if(s->out_format == FMT_H263){
unquant_coeff= alevel*qmul + qadd;
}else{ //MPEG1
- j= s->dsp.idct_permutation[ scantable[i + start_i] ]; //FIXME optimize
+ j= s->dsp.idct_permutation[ scantable[i] ]; //FIXME optimize
if(s->mb_intra){
unquant_coeff = (int)( alevel * qscale * s->intra_matrix[j]) >> 3;
unquant_coeff = (unquant_coeff - 1) | 1;
@@ -4787,20 +4783,21 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
distoration= (unquant_coeff - dct_coeff) * (unquant_coeff - dct_coeff) - zero_distoration;
level+=64;
if((level&(~127)) == 0){
- for(run=0; run<=i - left_limit; run++){
+ for(j=survivor_count-1; j>=0; j--){
+ int run= i - survivor[j];
int score= distoration + length[UNI_AC_ENC_INDEX(run, level)]*lambda;
score += score_tab[i-run];
if(score < best_score){
- best_score=
- score_tab[i+1]= score;
+ best_score= score;
run_tab[i+1]= run;
level_tab[i+1]= level-64;
}
}
if(s->out_format == FMT_H263){
- for(run=0; run<=i - left_limit; run++){
+ for(j=survivor_count-1; j>=0; j--){
+ int run= i - survivor[j];
int score= distoration + last_length[UNI_AC_ENC_INDEX(run, level)]*lambda;
score += score_tab[i-run];
if(score < last_score){
@@ -4813,19 +4810,20 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
}
}else{
distoration += esc_length*lambda;
- for(run=0; run<=i - left_limit; run++){
+ for(j=survivor_count-1; j>=0; j--){
+ int run= i - survivor[j];
int score= distoration + score_tab[i-run];
if(score < best_score){
- best_score=
- score_tab[i+1]= score;
+ best_score= score;
run_tab[i+1]= run;
level_tab[i+1]= level-64;
}
}
if(s->out_format == FMT_H263){
- for(run=0; run<=i - left_limit; run++){
+ for(j=survivor_count-1; j>=0; j--){
+ int run= i - survivor[j];
int score= distoration + score_tab[i-run];
if(score < last_score){
last_score= score;
@@ -4837,22 +4835,28 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
}
}
}
-
- if(score_tab[i+1] < score_limit)
- score_limit= score_tab[i+1];
+ score_tab[i+1]= best_score;
+
//Note: there is a vlc code in mpeg4 which is 1 bit shorter then another one with a shorter run and the same level
- while(score_tab[ left_limit ] > score_limit + lambda) left_limit++;
-
- if(patch_table){
-// length[UNI_AC_ENC_INDEX(0, 63)]=
-// length[UNI_AC_ENC_INDEX(0, 65)]= 3;
+ if(last_non_zero <= 27){
+ for(; survivor_count; survivor_count--){
+ if(score_tab[ survivor[survivor_count-1] ] <= best_score)
+ break;
+ }
+ }else{
+ for(; survivor_count; survivor_count--){
+ if(score_tab[ survivor[survivor_count-1] ] <= best_score + lambda)
+ break;
+ }
}
+
+ survivor[ survivor_count++ ]= i+1;
}
if(s->out_format != FMT_H263){
last_score= 256*256*256*120;
- for(i= left_limit; i<=last_non_zero - start_i + 1; i++){
+ for(i= survivor[0]; i<=last_non_zero + 1; i++){
int score= score_tab[i];
if(i) score += lambda*2; //FIXME exacter?
@@ -4868,7 +4872,7 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
s->coded_score[n] = last_score;
dc= ABS(block[0]);
- last_non_zero= last_i - 1 + start_i;
+ last_non_zero= last_i - 1;
memset(block + start_i, 0, (64-start_i)*sizeof(DCTELEM));
if(last_non_zero < start_i)
@@ -4910,15 +4914,12 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
i= last_i;
assert(last_level);
-//FIXME use permutated scantable
- block[ s->dsp.idct_permutation[ scantable[last_non_zero] ] ]= last_level;
+
+ block[ perm_scantable[last_non_zero] ]= last_level;
i -= last_run + 1;
- for(;i>0 ; i -= run_tab[i] + 1){
- const int j= s->dsp.idct_permutation[ scantable[i - 1 + start_i] ];
-
- block[j]= level_tab[i];
- assert(block[j]);
+ for(; i>start_i; i -= run_tab[i] + 1){
+ block[ perm_scantable[i-1] ]= level_tab[i];
}
return last_non_zero;
--
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