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adaptive quantization for mpeg1

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Originally committed as revision 968 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2002-09-24 12:33:37 +00:00
parent 5e746b9995
commit d87c0267e3
1 changed files with 39 additions and 4 deletions
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43
libavcodec/mpeg12.c
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@ -23,6 +23,12 @@
#include "mpeg12data.h"
#if 1
#define PRINT_QP(a, b) {}
#else
#define PRINT_QP(a, b) printf(a, b)
#endif
/* Start codes. */
#define SEQ_END_CODE 0x000001b7
#define SEQ_START_CODE 0x000001b3
@ -289,6 +295,7 @@ void mpeg1_encode_mb(MpegEncContext *s,
(!((mb_x | mb_y) == 0 ||
(mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
s->mb_incr++;
s->qscale -= s->dquant;
} else {
/* output mb incr */
mb_incr = s->mb_incr;
@ -301,17 +308,39 @@ void mpeg1_encode_mb(MpegEncContext *s,
mbAddrIncrTable[mb_incr - 1][0]);
if (s->pict_type == I_TYPE) {
put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
if(s->dquant && cbp){
put_bits(&s->pb, 2, 1); /* macroblock_type : macroblock_quant = 1 */
put_bits(&s->pb, 5, s->qscale);
}else{
put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
s->qscale -= s->dquant;
}
} else {
if (s->mb_intra) {
put_bits(&s->pb, 5, 0x03);
if(s->dquant && cbp){
put_bits(&s->pb, 6, 0x01);
put_bits(&s->pb, 5, s->qscale);
}else{
put_bits(&s->pb, 5, 0x03);
s->qscale -= s->dquant;
}
} else {
if (cbp != 0) {
if (motion_x == 0 && motion_y == 0) {
put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
if(s->dquant){
put_bits(&s->pb, 5, 1); /* macroblock_pattern & quant */
put_bits(&s->pb, 5, s->qscale);
}else{
put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
}
put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
} else {
put_bits(&s->pb, 1, 1); /* motion + cbp */
if(s->dquant){
put_bits(&s->pb, 5, 2); /* motion + cbp */
put_bits(&s->pb, 5, s->qscale);
}else{
put_bits(&s->pb, 1, 1); /* motion + cbp */
}
mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
@ -320,6 +349,7 @@ void mpeg1_encode_mb(MpegEncContext *s,
put_bits(&s->pb, 3, 1); /* motion only */
mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
s->qscale -= s->dquant;
}
}
}
@ -1502,6 +1532,11 @@ static int mpeg_decode_slice(AVCodecContext *avctx,
return -1;
if (ret == 1)
break;
if(s->mb_x==0)
PRINT_QP("%s", "\n");
PRINT_QP("%2d", s->qscale);
MPV_decode_mb(s, s->block);
}
emms_c();