generic-library/ffmpeg
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fix decoding with quant matrixes which contain elements <16

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Originally committed as revision 3069 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2004-04-25 19:03:35 +00:00
parent 49f3806dd8
commit 3c0da30c01
1 changed files with 9 additions and 1 deletions
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10
libavcodec/h263.c
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@ -4722,6 +4722,8 @@ 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);
@ -4747,10 +4749,16 @@ static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
SKIP_COUNTER(re, &s->gb, 1+12+1);
}
if(level*s->qscale>1024 || level*s->qscale<-1024){
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);