Research On Internet-based Real-time Transmission System In MPEG-4 Video Streams

With the help of popular Internet, powerful processing ability of personal computers, and the development of video compression technology, the demand of Internet- based real-time video service is increasing rapidly, such as video telephone, video conference, and long-distance multimedia education. Therefore, the research of real-time video communications plays an important role in our daily life.Research on Internet-based Real-time Transmission System in MPEG-4 Video Streams is introduced in this paper, which is based on Real-time Transport Protocol (RTP) and Real-time Transport Control Protocol (RTCP). The application of MPEG-4 encoding is presented in this paper. The system can be used not only in LANs but also in Internets. The first characteristic of this system is packetization algorithm of MPEG-4 bit stream that reduces the effect on video quality because of transmitted data loss. Secondly, the adaptive encoding rate control algorithm, based on RTP/RTCP, is designed for manipulating MPEG-4 Codec encoding rate with the varying of network bandwidth. The algorithm is derived from the loss rate of datagram to avoid network congestion and use the optimal bandwidth.At the beginning of this paper, technologies related to video communications are introduced, and the Qos of Internet-based video communications is analyzed, and then, the characteristics of MPEG-4 are described. At the meanwhile, the motivation for RTP/RTCP is explained by comparing some communication protocols. After the system framework, work environment and work process are illustrated, programming method of buffer, RTP/RTCP and the algorithms are discussed in detail. Finally, it is proved that the system has steady and adaptive properties through system test.