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| author | Michael Niedermayer <michaelni@gmx.at> | 2008-02-20 19:45:38 +0000 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2008-02-20 19:45:38 +0000 |
| commit | 21da962cf1ffcfd975d1d1699450cb59a401b361 (patch) | |
| tree | aebea32f6483fa3329bd0ead3ef9d2054e64a5e7 | |
| parent | 5cbd67ea43d979a0c1bc7c367b63d62d35e104e3 (diff) | |
| download | ffmpeg-21da962cf1ffcfd975d1d1699450cb59a401b361.tar.gz | |
Make find_frame_end() merge 2 mpeg2 field pictures. This should make mpeg2
field pictures much more digestable.
Originally committed as revision 12160 to svn://svn.ffmpeg.org/ffmpeg/trunk
| -rw-r--r-- | libavcodec/mpeg12.c | 46 |
1 files changed, 30 insertions, 16 deletions
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c index 7f3a181952..56b456a078 100644 --- a/libavcodec/mpeg12.c +++ b/libavcodec/mpeg12.c @@ -2182,29 +2182,43 @@ int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size) int i; uint32_t state= pc->state; - i=0; - if(!pc->frame_start_found){ - for(i=0; i<buf_size; i++){ + /* EOF considered as end of frame */ + if (buf_size == 0) + return 0; + +/* + 0 frame start -> 1/4 + 1 first_SEQEXT -> 0/2 + 2 first field start -> 3/0 + 3 second_SEQEXT -> 2/0 + 4 searching end +*/ + + for(i=0; i<buf_size; i++){ + assert(pc->frame_start_found>=0 && pc->frame_start_found<=4); + if(pc->frame_start_found&1){ + if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80) + pc->frame_start_found--; + else if(state == EXT_START_CODE+2){ + if((buf[i]&3) == 3) pc->frame_start_found= 0; + else pc->frame_start_found= (pc->frame_start_found+1)&3; + } + state++; + }else{ i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1; - if(state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){ + if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){ i++; - pc->frame_start_found=1; - break; + pc->frame_start_found=4; } if(state == SEQ_END_CODE){ pc->state=-1; return i+1; } - } - } - - if(pc->frame_start_found){ - /* EOF considered as end of frame */ - if (buf_size == 0) - return 0; - for(; i<buf_size; i++){ - i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1; - if((state&0xFFFFFF00) == 0x100){ + if(pc->frame_start_found==2 && state == SEQ_START_CODE) + pc->frame_start_found= 0; + if(pc->frame_start_found<4 && state == EXT_START_CODE) + pc->frame_start_found++; + if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){ if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){ pc->frame_start_found=0; pc->state=-1; |