Hi! I think in the constructor of an RTPpacket object from the packet bistream, the Ssrc needs to be built. As I am working on a protocal called GB28181, I need to identify the video stream from different cameras through Ssrc. And I think it can be built from 8th, 9th, 10th, 11th bit in the header[], which is a little bit similiar to building the TimeStamp. Thanks!