RTCP & amp; RTP protocol format analysis 6: RTCP Sender report

RTCP & RTP protocol format analysis 6: RTCP Sender report
The sender report consists of three parts, and the fourth part may be extended. Part 1: Header, 8 bytes long, version: 2 bits, RTP version identifier. This version in the RTCP package has the same meaning as that in the RTP package, generally 2 p: fill bit, 1 bit. If set, there are several fill bits at the end of the RTCP package, which is not the control information, but is within the length of the entire message, the last bit indicates the number of bytes to be ignored, including itself. This number should be an integer multiple of 4. RC: Total number of reported blocks received, 5 digits, the total number of received report blocks in this package. The value 0 is valid. PT: the packet type, 8 bits, contains a constant value of 200, indicating that this is an rtcp sr packet. Length: length, 16 bits, the length of the RTCP packet minus 1, the unit is 32 bits, including the header and any padding bytes, SSRC: 32 bits, the sender's synchronization source identifier. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~ The second part is the sender information, which is 20 bytes long and appears in each sender report. This domain has the following meanings: NTP timestamp: 64-bit. The background clock time when the report is sent, this time is combined with the receiver report sent by the receiver to calculate the round-trip RTT, RTP timestamp: 32 bits,