Research Of Self-adaptive Transmission Technologies In Network Video Monitoring System

With the rapid development of network technology and streaming mediatechnology, Network video monitoring system has become the focus of theresearch of the security and protection industry in the world nowadays. Manystudies have been done on streaming media transmission technologies innetwork video monitoring system because internet can’t provide enough QoS(Quality of Service) supports to meet the demands of streaming media. Tosupport video streaming over the current internet, a self-adaptive transmissiontechnology which relieves the network congestion need to be researched. How toresolve the inconsistency between the QoS architecture of internet and theassurance of real-time has become a dominant area in today research formonitoring system.In the thesis, studies are made mainly on implementing self-adaptive controltechnologies in network video monitoring system. In order to construct the system,we should choose appropriate compress standard and transport protocol. Whileexisting streaming self-adaptive schemes are mainly designed for particularcongestion control algorithms, quality adaptation algorithms and error controlalgorithms, this paper proposes a improved self-adaptive scheme based on ratecontrol algorithm. The algorithm is effective in providing somewhat smooth videoservice for the clients by way of adaptively adjusting the transmission rate ofvideo streams. The thesis puts forward a design plan of network video monitoringsystem which includes self-adaptive transmission control technology.The thesis firstly analysis the main compress standard in video monitoringsystem, such as MJPEG, MPEG-1/2, MPEG-4and H.264. We select H.264compress standard for the video monitoring system of the topic. This articlediscusses the transport protocol and selects RTP, RTCP and RTSP for the transmission of video streams over internet.After that, the thesis provides a threshold-based sending rate congestioncontrol method. The sender sends out RTP packets with sequence number andtime stamp to the receiver. The receiver calculates the QoS statistics such asdelay jitter and packet loss rate according to the RTP packets, and sends RTCPfeedback packets to the sender periodically. The sender compares the feedbackloss rate with the threshold and evaluates the level of network congestion. Byadjusting frame rate, compressibility and resolution to change sending speed, aclosed-loop adaptive congestion control algorithm is achieved. In the meantime, avideo buffer is set up for receiver to improve stability and continuity of videoplaying.In the end, the thesis puts forward a design plan of network video monitoringsystem based on TMS320DM642which includes self-adaptive transmissioncontrol technology. Self-adaptive transmission modules are devised from thefollowing two aspects: network video server and web monitor client (monitoringcenter). The scheme can give satisfactory video quality under various internetconditions while fully utilizing the available network bandwidth. At the end of thearticle, the article summarizes the whole systems to review, combine of the futuregeneration network (IPv6) QoS research, and explains how to realize monitoringsystem with adaptive technique.