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fixing ac prediction encoding with adaptive quantization

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Originally committed as revision 966 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2002-09-24 09:15:46 +00:00
parent 693b0e1d66
commit 9960903667
1 changed files with 62 additions and 16 deletions
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78
libavcodec/h263.c
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@ -281,22 +281,50 @@ static inline int decide_ac_pred(MpegEncContext * s, DCTELEM block[6][64], int d
ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
ac_val1= ac_val;
if(dir[n]){
const int xy= s->mb_x + s->mb_y*s->mb_width - s->mb_width;
/* top prediction */
ac_val-= s->block_wrap[n]*16;
for(i=1; i<8; i++){
const int level= block[n][block_permute_op(i )];
score0+= ABS(level);
score1+= ABS(level - ac_val[i+8]);
ac_val1[i ]= block[n][block_permute_op(i<<3)];
ac_val1[i+8]= level;
if(s->mb_y==0 || s->qscale == s->qscale_table[xy] || n==2 || n==3){
/* same qscale */
for(i=1; i<8; i++){
const int level= block[n][block_permute_op(i )];
score0+= ABS(level);
score1+= ABS(level - ac_val[i+8]);
ac_val1[i ]= block[n][block_permute_op(i<<3)];
ac_val1[i+8]= level;
}
}else{
/* different qscale, we must rescale */
for(i=1; i<8; i++){
const int level= block[n][block_permute_op(i )];
score0+= ABS(level);
score1+= ABS(level - ROUNDED_DIV(ac_val[i + 8]*s->qscale_table[xy], s->qscale));
ac_val1[i ]= block[n][block_permute_op(i<<3)];
ac_val1[i+8]= level;
}
}
}else{
const int xy= s->mb_x-1 + s->mb_y*s->mb_width;
/* left prediction */
ac_val-= 16;
for(i=1; i<8; i++){
const int level= block[n][block_permute_op(i<<3)];
score0+= ABS(level);
score1+= ABS(level - ac_val[i]);
ac_val1[i ]= level;
ac_val1[i+8]= block[n][block_permute_op(i )];
if(s->mb_x==0 || s->qscale == s->qscale_table[xy] || n==1 || n==3){
/* same qscale */
for(i=1; i<8; i++){
const int level= block[n][block_permute_op(i<<3)];
score0+= ABS(level);
score1+= ABS(level - ac_val[i]);
ac_val1[i ]= level;
ac_val1[i+8]= block[n][block_permute_op(i )];
}
}else{
/* different qscale, we must rescale */
for(i=1; i<8; i++){
const int level= block[n][block_permute_op(i<<3)];
score0+= ABS(level);
score1+= ABS(level - ROUNDED_DIV(ac_val[i]*s->qscale_table[xy], s->qscale));
ac_val1[i ]= level;
ac_val1[i+8]= block[n][block_permute_op(i )];
}
}
}
}
@ -1678,16 +1706,34 @@ static void mpeg4_inv_pred_ac(MpegEncContext * s, INT16 *block, int n,
ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
if (dir == 0) {
const int xy= s->mb_x-1 + s->mb_y*s->mb_width;
/* left prediction */
ac_val -= 16;
for(i=1;i<8;i++) {
block[block_permute_op(i*8)] -= ac_val[i];
if(s->mb_x==0 || s->qscale == s->qscale_table[xy] || n==1 || n==3){
/* same qscale */
for(i=1;i<8;i++) {
block[block_permute_op(i*8)] -= ac_val[i];
}
}else{
/* different qscale, we must rescale */
for(i=1;i<8;i++) {
block[block_permute_op(i*8)] -= ROUNDED_DIV(ac_val[i]*s->qscale_table[xy], s->qscale);
}
}
} else {
const int xy= s->mb_x + s->mb_y*s->mb_width - s->mb_width;
/* top prediction */
ac_val -= 16 * s->block_wrap[n];
for(i=1;i<8;i++) {
block[block_permute_op(i)] -= ac_val[i + 8];
if(s->mb_y==0 || s->qscale == s->qscale_table[xy] || n==2 || n==3){
/* same qscale */
for(i=1;i<8;i++) {
block[block_permute_op(i)] -= ac_val[i + 8];
}
}else{
/* different qscale, we must rescale */
for(i=1;i<8;i++) {
block[block_permute_op(i)] -= ROUNDED_DIV(ac_val[i + 8]*s->qscale_table[xy], s->qscale);
}
}
}
}