virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-11-26 19:01:44 +02:00
Code Issues Releases Activity

mjpeg_parser: Rewrite to skip marker segments

Browse Source 
Based on code by Aaron Miller <amiller@atlasdigital.tv>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2011-10-29 23:54:21 +02:00
parent 429b3cd6f5
commit 1af3571e05
1 changed files with 36 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
libavcodec/mjpeg_parser.c
View File

@ -30,6 +30,7 @@
typedef struct MJPEGParserContext{
ParseContext pc;
int size;
}MJPEGParserContext;
/**
@ -39,20 +40,32 @@ typedef struct MJPEGParserContext{
static int find_frame_end(MJPEGParserContext *m, const uint8_t *buf, int buf_size){
ParseContext *pc= &m->pc;
int vop_found, i;
uint16_t state;
uint32_t state;
vop_found= pc->frame_start_found;
state= pc->state;
i=0;
if(!vop_found){
for(i=0; i<buf_size; i++){
for(i=0; i<buf_size;){
state= (state<<8) | buf[i];
if(state == 0xFFD8){
i++;
vop_found=1;
break;
if(state>=0xFFC00000 && state<=0xFFFEFFFF){
if(state>=0xFFD80000 && state<=0xFFD8FFFF){
i++;
vop_found=1;
break;
}else if(state<0xFFD00000 || state>0xFFD9FFFF){
m->size= (state&0xFFFF)-1;
}
}
if(m->size>0){
int size= FFMIN(buf_size-i, m->size);
i+=size;
m->size-=size;
state=0;
continue;
}else
i++;
}
}
@ -60,13 +73,25 @@ static int find_frame_end(MJPEGParserContext *m, const uint8_t *buf, int buf_siz
/* EOF considered as end of frame */
if (buf_size == 0)
return 0;
for(; i<buf_size; i++){
for(; i<buf_size;){
state= (state<<8) | buf[i];
if(state == 0xFFD8){
pc->frame_start_found=0;
pc->state=0;
return i-1;
if(state>=0xFFC00000 && state<=0xFFFEFFFF){
if(state>=0xFFD80000 && state<=0xFFD8FFFF){
pc->frame_start_found=0;
pc->state=0;
return i-3;
} else if(state<0xFFD00000 || state>0xFFD9FFFF){
m->size= (state&0xFFFF)-1;
}
}
if(m->size>0){
int size= FFMIN(buf_size-i, m->size);
i+=size;
m->size-=size;
state=0;
continue;
}else
i++;
}
}
pc->frame_start_found= vop_found;