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h264_probe() 

Originally committed as revision 14186 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2008-07-12 19:50:48 +00:00
parent 55823964dc
commit 010acd8ea1
1 changed files with 45 additions and 1 deletions
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46
libavformat/raw.c
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@ -347,6 +347,50 @@ static int mpeg4video_probe(AVProbeData *probe_packet)
return 0;
}
static int h264_probe(AVProbeData *p)
{
uint32_t code= -1;
int sps=0, pps=0, idr=0, res=0;
int i;
for(i=0; i<p->buf_size; i++){
code = (code<<8) + p->buf[i];
if ((code & 0xffffff00) == 0x100) {
int ref_idc= (code>>5)&3;
int type = code & 0x1F;
static const int8_t ref_zero[32]={
2, 0, 0, 0, 0,-1, 1,-1,
-1, 1, 1, 1, 1,-1, 2, 2,
2, 2, 2, 0, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2
};
if(code & 0x80) //forbidden bit
return 0;
if(ref_zero[type] == 1 && ref_idc)
return 0;
if(ref_zero[type] ==-1 && !ref_idc)
return 0;
if(ref_zero[type] == 2)
res++;
switch(type){
case 5: idr++; break;
case 7:
if(p->buf[i+2]&0x0F)
return 0;
sps++;
break;
case 8: pps++; break;
}
}
}
if(sps && pps && idr && res<(sps+pps+idr))
return AVPROBE_SCORE_MAX/2+1; // +1 for .mpg
return 0;
}
static int h263_probe(AVProbeData *p)
{
int code;
@ -647,7 +691,7 @@ AVInputFormat h264_demuxer = {
"h264",
NULL_IF_CONFIG_SMALL("raw H.264 video format"),
0,
NULL /*mpegvideo_probe*/,
h264_probe,
video_read_header,
raw_read_partial_packet,
.flags= AVFMT_GENERIC_INDEX,