我正在解析Wireshark捕获的RTMP流,并将媒体数据写入.flv文件。我知道如何计算时间戳,但是溢出时如何处理?
最佳答案
所以我这样解决了问题:
1)解析RTMP header (从timestamp的开头读取4个字节)并获取timestamp(u_int 32);
if ( ( _timestamp >> 8 ) == 0xffffff ) /* check if extended timestamp is present */
{
_timestamp = (_timestamp & 0x000000ff) + 0xffffff;
}
else
{
_timestamp >>= 8 ;
}
2)计算.flv文件的时间戳(.flv文件中的时间戳始终为32位,例如0x00000100是简单时间戳,等于1,0xffffff01是扩展时间戳,等于0xffffff + 0x01)
if ( ( timestamp_calc + _timestamp ) >= 0xffffff )
{
unsigned __int8 temp = _timestamp;
unsigned __int8 * ptr;
if ( (timestamp_calc + _timestamp) >= 0xffffffff ){ timestamp_calc = _timestamp; }
else
{
timestamp_calc = 0xffffff;
timestamp_calc <<= 8;
ptr = (unsigned __int8 *)×tamp_calc;
ptr[ 0 ] = _timestamp;
}
}
else
{
timestamp_calc += _timestamp;
}