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| author | Michael Niedermayer <michaelni@gmx.at> | 2009-11-28 22:51:53 +0000 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2009-11-28 22:51:53 +0000 |
| commit | fc23d843e11b8d7e461127dd4bb25d7525ec5990 (patch) | |
| tree | 36c8f94c7baf86f72489788986e637f206b35ffa /libavcodec/mpeg12.c | |
| parent | bbf266fdb5fab3edc62eeb3ed1535db0d636738e (diff) | |
| download | ffmpeg-fc23d843e11b8d7e461127dd4bb25d7525ec5990.tar.gz | |
Check order of startcodes, ignore some obviously wrong ones.
Fixes issue487.
Originally committed as revision 20643 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/mpeg12.c')
| -rw-r--r-- | libavcodec/mpeg12.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c index 7afc3ba1bb..33ae18f667 100644 --- a/libavcodec/mpeg12.c +++ b/libavcodec/mpeg12.c @@ -2260,6 +2260,7 @@ static int decode_chunks(AVCodecContext *avctx, const uint8_t *buf_ptr = buf; const uint8_t *buf_end = buf + buf_size; int ret, input_size; + int last_code= 0; for(;;) { /* find next start code */ @@ -2296,8 +2297,12 @@ static int decode_chunks(AVCodecContext *avctx, /* prepare data for next start code */ switch(start_code) { case SEQ_START_CODE: + if(last_code == 0){ mpeg1_decode_sequence(avctx, buf_ptr, input_size); + }else{ + av_log(avctx, AV_LOG_ERROR, "ignoring SEQ_START_CODE after %X\n", last_code); + } break; case PICTURE_START_CODE: @@ -2310,13 +2315,18 @@ static int decode_chunks(AVCodecContext *avctx, if(mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0) s2->pict_type=0; + last_code= PICTURE_START_CODE; break; case EXT_START_CODE: init_get_bits(&s2->gb, buf_ptr, input_size*8); switch(get_bits(&s2->gb, 4)) { case 0x1: + if(last_code == 0){ mpeg_decode_sequence_extension(s); + }else{ + av_log(avctx, AV_LOG_ERROR, "ignoring seq ext after %X\n", last_code); + } break; case 0x2: mpeg_decode_sequence_display_extension(s); @@ -2329,6 +2339,7 @@ static int decode_chunks(AVCodecContext *avctx, break; case 0x8: mpeg_decode_picture_coding_extension(s); + last_code= PICTURE_START_CODE; break; } break; @@ -2337,14 +2348,19 @@ static int decode_chunks(AVCodecContext *avctx, buf_ptr, input_size); break; case GOP_START_CODE: + if(last_code == 0){ s2->first_field=0; mpeg_decode_gop(avctx, buf_ptr, input_size); + }else{ + av_log(avctx, AV_LOG_ERROR, "ignoring GOP_START_CODE after %X\n", last_code); + } break; default: if (start_code >= SLICE_MIN_START_CODE && - start_code <= SLICE_MAX_START_CODE) { + start_code <= SLICE_MAX_START_CODE && last_code!=0) { int mb_y= start_code - SLICE_MIN_START_CODE; + last_code= SLICE_MIN_START_CODE; if(s2->last_picture_ptr==NULL){ /* Skip B-frames if we do not have reference frames and gop is not closed */ |