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Code Issues Releases Activity

mpeg probe: check the 2/4-bit synchronization value found after a pack_start_code.

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This commit is contained in:
Alex Converse 2011-09-28 15:43:24 -07:00
parent bf00a73ace
commit fe21f78d2b
1 changed files with 6 additions and 1 deletions
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7
libavformat/mpeg.c
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@ -49,6 +49,10 @@ static int check_pes(uint8_t *p, uint8_t *end){
return pes1||pes2;
}
static int check_pack_header(const uint8_t *buf) {
return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
}
static int mpegps_probe(AVProbeData *p)
{
uint32_t code= -1;
@ -61,9 +65,10 @@ static int mpegps_probe(AVProbeData *p)
if ((code & 0xffffff00) == 0x100) {
int len= p->buf[i+1] << 8 | p->buf[i+2];
int pes= check_pes(p->buf+i, p->buf+p->buf_size);
int pack = check_pack_header(p->buf+i);
if(code == SYSTEM_HEADER_START_CODE) sys++;
else if(code == PACK_START_CODE) pspack++;
else if(code == PACK_START_CODE && pack) pspack++;
else if((code & 0xf0) == VIDEO_ID && pes) vid++;
// skip pes payload to avoid start code emulation for private
// and audio streams