hi all I'm a newcomer for ffmpeg. I can not understand this function.pls do me a favor. static int check_pack_header(const uint8_t *buf) { return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20; } 1> can this function check the header of mepg ps(0x000001BA)? 2> why use the 0xC0 and 0xF0? thanks in advance Br/York