怎样获取MPEG2/TS流的PTS值

 

5个字节总共5*8 = 40bits = 4 + 3 + 1 + 15 + 1 + 15 + 1

'0011'            4 bslbf            
PTS [32..30] 3 bslbf
marker_bit   1 bslbf
PTS [29..15] 15 bslbf
marker_bit   1 bslbf
PTS [14..0]   15 bslbf
marker_bit   1 bslbf

// 注意，get_pts参数值为&buf[payload_start+sizeof(ulong)]

// 前面部分的代码可以不要， uint64就是你系统中的无符号64位整形数

#define MKWORD(h, l) (((h) << 8) | (l)) 

uint64  get_pts(uchar *buf)
{
   uchar ptsflag;
   uchar peshdr_datalen;
   int index = 0;
   ushort pktlen = MKWORD(buf[index], buf[index+1]);
 
   index += sizeof(ushort);
 
   index ++;
   ptsflag = (buf[index] & 0xc0) >> 6;
   index ++;
   peshdr_datalen = buf[index++];
 
   if (ptsflag & 0x2) {
      uint64 pts;
      ushort pts29_15, pts14_0;
      unsigned uint64 pts32_30 = (buf[index] & 0x0e) >> 1;   

      index++;
      pts29_15 = MKWORD(buf[index], buf[index+1] & 0xfe) >> 1;
      index += 2;
      pts14_0  = MAKE_WORD(buf[index], buf[index+1] & 0xfe) >> 1;
      pts = (pts32_30 << 30) | (pts29_15 << 15) | pts14_0;

      return pts;
   }

 return 0;
}