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optimizing (trellis) quantizer

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Originally committed as revision 2650 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2004-01-02 02:39:05 +00:00
parent 2ad5d5a8c8
commit 7485d118f2
1 changed files with 31 additions and 23 deletions
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54
libavcodec/mpegvideo.c
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@ -4652,8 +4652,7 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
int last_level=0;
int last_score= 0;
int last_i= 0;
int not_coded_score= 0;
int coeff[3][64];
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;
@ -4668,7 +4667,6 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
if(s->dct_error_sum)
ff_denoise_dct(s, block);
qmul= qscale*16;
qadd= ((qscale-1)|1)*8;
@ -4706,11 +4704,20 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
threshold1= (1<<QMAT_SHIFT) - bias - 1;
threshold2= (threshold1<<1);
for(i=start_i; i<64; i++) {
for(i=63; i>=start_i; i--) {
const int j = scantable[i];
int level = block[j] * qmat[j];
if(((unsigned)(level+threshold1))>threshold2){
last_non_zero = i;
break;
}
}
for(i=start_i; i<=last_non_zero; i++) {
const int j = scantable[i];
const int k= i-start_i;
int level = block[j];
level = level * qmat[j];
int level = block[j] * qmat[j];
// if( bias+level >= (1<<(QMAT_SHIFT - 3))
// || bias-level >= (1<<(QMAT_SHIFT - 3))){
@ -4729,7 +4736,6 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
coeff_count[k]= FFMIN(level, 2);
assert(coeff_count[k]);
max |=level;
last_non_zero = i;
}else{
coeff[0][k]= (level>>31)|1;
coeff_count[k]= 1;
@ -4756,8 +4762,6 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
const int zero_distoration= dct_coeff*dct_coeff;
int best_score=256*256*256*120;
last_score += zero_distoration;
not_coded_score += zero_distoration;
for(level_index=0; level_index < coeff_count[i]; level_index++){
int distoration;
int level= coeff[level_index][i];
@ -4793,7 +4797,7 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
unquant_coeff<<= 3;
}
distoration= (unquant_coeff - dct_coeff) * (unquant_coeff - dct_coeff);
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++){
@ -4847,10 +4851,6 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
}
}
for(j=left_limit; j<=i; j++){
score_tab[j] += zero_distoration;
}
score_limit+= zero_distoration;
if(score_tab[i+1] < score_limit)
score_limit= score_tab[i+1];
@ -4878,7 +4878,7 @@ static int dct_quantize_trellis_c(MpegEncContext *s,
}
}
s->coded_score[n] = last_score - not_coded_score;
s->coded_score[n] = last_score;
dc= block[0];
last_non_zero= last_i - 1 + start_i;
@ -4951,7 +4951,7 @@ static int dct_quantize_c(MpegEncContext *s,
DCTELEM *block, int n,
int qscale, int *overflow)
{
int i, j, level, last_non_zero, q;
int i, j, level, last_non_zero, q, start_i;
const int *qmat;
const uint8_t *scantable= s->intra_scantable.scantable;
int bias;
@ -4976,23 +4976,32 @@ static int dct_quantize_c(MpegEncContext *s,
/* note: block[0] is assumed to be positive */
block[0] = (block[0] + (q >> 1)) / q;
i = 1;
start_i = 1;
last_non_zero = 0;
qmat = s->q_intra_matrix[qscale];
bias= s->intra_quant_bias<<(QMAT_SHIFT - QUANT_BIAS_SHIFT);
} else {
i = 0;
start_i = 0;
last_non_zero = -1;
qmat = s->q_inter_matrix[qscale];
bias= s->inter_quant_bias<<(QMAT_SHIFT - QUANT_BIAS_SHIFT);
}
threshold1= (1<<QMAT_SHIFT) - bias - 1;
threshold2= (threshold1<<1);
for(;i<64;i++) {
for(i=63;i>=start_i;i--) {
j = scantable[i];
level = block[j];
level = level * qmat[j];
level = block[j] * qmat[j];
if(((unsigned)(level+threshold1))>threshold2){
last_non_zero = i;
break;
}else{
block[j]=0;
}
}
for(i=start_i; i<=last_non_zero; i++) {
j = scantable[i];
level = block[j] * qmat[j];
// if( bias+level >= (1<<QMAT_SHIFT)
// || bias-level >= (1<<QMAT_SHIFT)){
@ -5005,7 +5014,6 @@ static int dct_quantize_c(MpegEncContext *s,
block[j]= -level;
}
max |=level;
last_non_zero = i;
}else{
block[j]=0;
}