From 02fb0d7c7247d1dd04e5df0ac8c2be6b64762bbe Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
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 e507a44549b..33fc2faa759 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 */
--
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