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coefficient saturation fix

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Originally committed as revision 3224 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2004-06-14 23:41:41 +00:00
parent ca6ecf50f9
commit caacc47ff9
1 changed files with 11 additions and 13 deletions
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24
libavcodec/h263.c
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@ -4717,8 +4717,6 @@ static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
if (cache&0x80000000) {
if (cache&0x40000000) {
int ulevel;
/* third escape */
SKIP_CACHE(re, &s->gb, 2);
last= SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
@ -4744,16 +4742,6 @@ static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
SKIP_COUNTER(re, &s->gb, 1+12+1);
}
if(s->mpeg_quant){
if(intra) ulevel= level*s->qscale*s->intra_matrix[scan_table[1]];
else ulevel= level*s->qscale*s->inter_matrix[scan_table[0]];
}else
ulevel= level*s->qscale*16;
if(ulevel>1030*16 || ulevel<-1030*16){
av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
return -1;
}
#if 0
if(s->error_resilience >= FF_ER_COMPLIANT){
const int abs_level= ABS(level);
@ -4779,6 +4767,16 @@ static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
if (level>0) level= level * qmul + qadd;
else level= level * qmul - qadd;
if((unsigned)(level + 2048) > 4095){
if(s->error_resilience > FF_ER_COMPLIANT){
if(level > 2560 || level<-2560){
av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
return -1;
}
}
level= level<0 ? -2048 : 2047;
}
i+= run + 1;
if(last) i+=192;
} else {
@ -6062,7 +6060,7 @@ int flv_h263_decode_picture_header(MpegEncContext *s)
s->dropable= s->pict_type > P_TYPE;
if (s->dropable)
s->pict_type = P_TYPE;
skip_bits1(&s->gb); /* deblocking flag */
s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);