Study On H.264 Video Transmission System Based On RTP

With the popularization of broad band Internet, the advancement in processing capability of personal computers, and the development of video compress techniques, the requirement for Internet video services, especially for real-time video stream such as video telephony, video conference and distance education, has been increasing continuously. Therefore, the study of Internet real-time video communication is becoming of great importance, regardless of in scientific research or in application field.RTP/RTCP protocol is a real-time stream transport standard put forward by IETF. It introduces timestamp and increasing sequence number for real-time data stream transport, and uses RTCP to monitor QoS Information. H.264/AVC is a video encoding standard presented jointly by ITU-T and MPEG. Comparing with current video compression standards, H.264 shows higher compression performance, and possesses better network adaptability. H.264 divides CODEC into two layers, NAL and VCL, and presents a lot of new error concealing and recovery techniques.In this paper, a general concept of video communication, as well as its application scenarios and its QoS control methods are firstly introduced. The details of RTP protocol and the formats of several important RTP/RTCP packets are then analyzed, followed by an in-depth discussion of some new features and coded stream format of H.264. On the basis of the above, a H.264 NALU structure which adapts for RTP transport and the use of VCL's error recovery tools are studied thoroughly. A real-time H.264 video stream transport system scheme is presented in the end, which combines NAL based RTP payload control, VCL's error concealing (recovery) tools, rate control and application layer (RTP) FEC.