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authorMichael Niedermayer <michaelni@gmx.at>2008-02-20 19:45:38 +0000
committerMichael Niedermayer <michaelni@gmx.at>2008-02-20 19:45:38 +0000
commit21da962cf1ffcfd975d1d1699450cb59a401b361 (patch)
treeaebea32f6483fa3329bd0ead3ef9d2054e64a5e7 /libavcodec
parent5cbd67ea43d979a0c1bc7c367b63d62d35e104e3 (diff)
downloadffmpeg-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
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/mpeg12.c46
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;