RepoMirrors
/
ffmpeg
mirror of https://git.ffmpeg.org/ffmpeg.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

more optimized trellis quantizer 

Originally committed as revision 1381 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2002-12-31 22:58:41 +00:00
parent 477ab036ad
commit 9981dfc662
1 changed files with 56 additions and 74 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

130
libavcodec/mpegvideo.c
View File

@ -3268,23 +3268,26 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
unsigned int threshold1, threshold2;
int bias=0;
int run_tab[65];
int last_run[65];
int level_tab[65];
int last_level[65];
int score_tab[65];
int last_score[65];
int coeff[4][64];
int last_run=0;
int last_level=0;
int last_score= 0;
int last_i= 0;
int coeff[3][64];
int coeff_count[64];
int lambda, qmul, qadd, start_i, best_i, best_score, last_non_zero, i;
int lambda, qmul, qadd, start_i, last_non_zero, i;
const int esc_length= s->ac_esc_length;
uint8_t * length;
uint8_t * last_length;
int score_limit=0;
int left_limit= 0;
s->fdct (block);
qmul= qscale*16;
qadd= ((qscale-1)|1)*8;
if (s->mb_intra) {
int q;
if (!s->h263_aic) {
@ -3318,7 +3321,7 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
threshold1= (1<<QMAT_SHIFT) - bias - 1;
threshold2= (threshold1<<1);
//printf("%d %d %d\n", qmat[1], QMAT_SHIFT, qscale);
for(i=start_i; i<64; i++) {
const int j = scantable[i];
const int k= i-start_i;
@ -3332,24 +3335,18 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
level= (bias + level)>>QMAT_SHIFT;
coeff[0][k]= level;
coeff[1][k]= level-1;
coeff[2][k]= level-2;
coeff[3][k]= level-3;
coeff_count[k]= FFMIN(level, 4);
// coeff[2][k]= level-2;
}else{
level= (bias - level)>>QMAT_SHIFT;
coeff[0][k]= -level;
coeff[1][k]= -level+1;
coeff[2][k]= -level+2;
coeff[3][k]= -level+3;
coeff_count[k]= FFMIN(level, 4);
// coeff[2][k]= -level+2;
}
coeff_count[k]= FFMIN(level, 2);
max |=level;
last_non_zero = i;
}else{
if(level < 0)
coeff[0][k]= -1;
else
coeff[0][k]= 1;
coeff[0][k]= (level>>31)|1;
coeff_count[k]= 1;
}
}
@ -3363,17 +3360,14 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
lambda= (qscale*qscale*64*82 + 50)/100; //FIXME finetune
score_tab[0]=
last_score[0]= 0;
//printf("qscale:%d\n", qscale);
score_tab[0]= 0;
for(i=0; i<=last_non_zero - start_i; i++){
int level_index, run, j;
const int dct_coeff= block[ scantable[i + start_i] ];
const int zero_distoration= dct_coeff*dct_coeff;
int best_score=256*256*256*120, best_last_score= 256*256*256*120;
//printf("%2d %5d ", i, dct_coeff);
int best_score=256*256*256*120;
last_score += zero_distoration;
for(level_index=0; level_index < coeff_count[i]; level_index++){
int distoration;
int level= coeff[level_index][i];
@ -3388,12 +3382,11 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
unquant_coeff= level*qmul - qadd;
}
} //FIXME else
//printf("(%d %d) ", level, unquant_coeff);
distoration= (unquant_coeff - dct_coeff) * (unquant_coeff - dct_coeff);
level+=64;
if((level&(~127)) == 0){
for(run=0; run<=i; run++){
for(run=0; run<=i - left_limit; run++){
int score= distoration + length[UNI_ENC_INDEX(run, level)]*lambda;
score += score_tab[i-run];
@ -3406,20 +3399,20 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
}
if(s->out_format == FMT_H263){
for(run=0; run<=i; run++){
for(run=0; run<=i - left_limit; run++){
int score= distoration + last_length[UNI_ENC_INDEX(run, level)]*lambda;
score += score_tab[i-run];
if(score < best_last_score){
best_last_score=
last_score[i+1]= score;
last_run[i+1]= run;
last_level[i+1]= level-64;
if(score < last_score){
last_score= score;
last_run= run;
last_level= level-64;
last_i= i+1;
}
}
}
}else{
distoration += esc_length*lambda;
for(run=0; run<=i; run++){
for(run=0; run<=i - left_limit; run++){
int score= distoration + score_tab[i-run];
if(score < best_score){
@ -3431,68 +3424,57 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
}
if(s->out_format == FMT_H263){
for(run=0; run<=i; run++){
for(run=0; run<=i - left_limit; run++){
int score= distoration + score_tab[i-run];
if(score < best_last_score){
best_last_score=
last_score[i+1]= score;
last_run[i+1]= run;
last_level[i+1]= level-64;
if(score < last_score){
last_score= score;
last_run= run;
last_level= level-64;
last_i= i+1;
}
}
}
}
}
for(j=0; j<=i; j++){
for(j=left_limit; j<=i; j++){
score_tab[j] += zero_distoration;
// printf("%6d ", score_tab[j]);
}
// printf("%6d ", score_tab[j]);
// printf("last: ");
if(s->out_format == FMT_H263){
for(j=0; j<=i; j++){
last_score[j] += zero_distoration;
// printf("%6d ", last_score[j]);
}
// printf("%6d ", last_score[j]);
}
// printf("\n");
score_limit+= zero_distoration;
if(score_tab[i+1] < score_limit)
score_limit= score_tab[i+1];
//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++;
}
//FIXME add some cbp penalty
if(s->out_format != FMT_H263){
last_score= 256*256*256*120;
for(i=0; i<=last_non_zero - start_i + 1; i++){
last_score[i]= score_tab[i];
if(i) last_score[i] += lambda*2; //FIXME exacter?
last_run[i]= run_tab[i];
last_level[i]= level_tab[i];
}
}
//FIXME add some cbp penalty
best_i= 0;
best_score= 256*256*256*120;
for(i=0; i<=last_non_zero - start_i + 1; i++){
int score= last_score[i];
if(score < best_score){
best_score= score;
best_i= i;
int score= score_tab[i];
if(score < last_score){
last_score= score;
if(i) last_score += lambda*2; //FIXME exacter?
last_i= i;
last_level= level_tab[i];
last_run= run_tab[i];
}
}
}
last_non_zero= best_i - 1 + start_i;
last_non_zero= last_i - 1 + start_i;
memset(block + start_i, 0, (64-start_i)*sizeof(DCTELEM));
if(last_non_zero < start_i)
return last_non_zero;
i= best_i;
//printf("%d %d %d %d %d\n", last_level[i], i, start_i, last_non_zero, best_score);
assert(last_level[i]);
i= last_i;
assert(last_level);
//FIXME use permutated scantable
block[ s->idct_permutation[ scantable[last_non_zero] ] ]= last_level[i];
i -= last_run[i] + 1;
block[ s->idct_permutation[ scantable[last_non_zero] ] ]= last_level;
i -= last_run + 1;
for(;i>0 ; i -= run_tab[i] + 1){
const int j= s->idct_permutation[ scantable[i - 1 + start_i] ];