Multimedia Network Transmission

Current situation of multi-media transmission technology is introduced in this paper firstly. Then, the protocol frames of multi-media transmit on network, QoS control and IP multi-cast are studied. At the end of paper, a real time video surveillance system over Internet is also designed and implementedThe main work includes:1. The characteristic of multi-media transmission is analyzed and the technology requirements are studied. Parameters of performance are put forward to scaling QoS. The influencing factors are analyzed and solving methods are proposed.2. RTF and RTCP are introduced. A real time multi-media transmission system is implemented based on RTP and RTCP. Multi-threads technology and buffer storage technology are adopted in this system. Applying this system to experimentation, satisfying result is obtained.3. Protocol frames of multi-media transmission are designed in this paper. Network design and resolution are also studied. An extended protocol over the UDP is proposed for multi-media transmission. A data packet head in eight bytes is designed to communicate information efficiently. This packet head includes sequence number, timestamping and some other information. Transmission is smoothed and the time interval is controlled strictly, so that the delay and dithering of transmission is diminished. In order to guarantee security of transmission, data packet can be encrypted according to the user' s requirements. Consequently, real time multi-media transmission is implemented. Besides, the virtue and shortage of this extended protocol are put forward in this paper.4. A real time video surveillance system over Internet is implemented based on extended UDP. Technology of IP multi-cast is also introduced generally.At last, several difficulties in multi-media transmission are discussed in prospects, such as synchronization technology, congestion control and QoS control. The study value and research direction are proposed based on studying literature.