From 3c0da30c01194ad123b6fd998fc4f4184ebd25cb Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 25 Apr 2004 19:03:35 +0000 Subject: fix decoding with quant matrixes which contain elements <16 Originally committed as revision 3069 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/h263.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'libavcodec') diff --git a/libavcodec/h263.c b/libavcodec/h263.c index 28707b2d59..2e9cadd88e 100644 --- a/libavcodec/h263.c +++ b/libavcodec/h263.c @@ -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); -- cgit v1.2.3