From 02fb0d7c7247d1dd04e5df0ac8c2be6b64762bbe Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 11 Jul 2005 22:15:03 +0000 Subject: [PATCH] fix decoding of (broken) files with f_code=0 fix segfault if the first P frames header is damaged Originally committed as revision 4432 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/mpeg12.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c index e507a44549..33fc2faa75 100644 --- a/libavcodec/mpeg12.c +++ b/libavcodec/mpeg12.c @@ -2220,7 +2220,7 @@ static int mpeg1_decode_picture(AVCodecContext *avctx, if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) { s->full_pel[0] = get_bits1(&s->gb); f_code = get_bits(&s->gb, 3); - if (f_code == 0) + if (f_code == 0 && avctx->error_resilience >= FF_ER_COMPLIANT) return -1; s->mpeg_f_code[0][0] = f_code; s->mpeg_f_code[0][1] = f_code; @@ -2228,7 +2228,7 @@ static int mpeg1_decode_picture(AVCodecContext *avctx, if (s->pict_type == B_TYPE) { s->full_pel[1] = get_bits1(&s->gb); f_code = get_bits(&s->gb, 3); - if (f_code == 0) + if (f_code == 0 && avctx->error_resilience >= FF_ER_COMPLIANT) return -1; s->mpeg_f_code[1][0] = f_code; s->mpeg_f_code[1][1] = f_code; @@ -3138,8 +3138,12 @@ static int mpeg_decode_frame(AVCodecContext *avctx, start_code <= SLICE_MAX_START_CODE) { int mb_y= start_code - SLICE_MIN_START_CODE; + if(s2->last_picture_ptr==NULL){ /* skip b frames if we dont have reference frames */ - if(s2->last_picture_ptr==NULL && s2->pict_type==B_TYPE) break; + if(s2->pict_type==B_TYPE) break; + /* skip P frames if we dont have reference frame no valid header */ + if(s2->pict_type==P_TYPE && !s2->first_slice) break; + } /* skip b frames if we are in a hurry */ if(avctx->hurry_up && s2->pict_type==B_TYPE) break; /* skip everything if we are in a hurry>=5 */