Design And Construction Of The VOD Education System Base On Expanded Streaming Media Format

With the rapid progress of Internet technology and multimedia compression coding, multimedia communication systems based on Internet have become more and more important.At the present time, the remote education system with the technology of media streaming is more and more popular.In this paper, our research focused on some key themes in order to construct a remote education system base on expanded streaming media format.The network topology of our system is based on B/S mode including two segments: server and client. The system consists of two modules, the mulitimedia courseware management module and the VOD(Video On Demand) module. In this paper, we complete the design and construction of the vod education system server segment, including web server and multimedia streaming server.The transmission and synchronization of multimedia streams is the key problems in real-time multimedia system. We researched into the transmission protocol.We use the feedback RTP/RTCP protocol group in order to guarantee the transmission quality by dynamic adjustment transmission rate. In order to serve for multi-users simultaneously, the system selected the multithread method dealing with multimedia streaming transmission.The critical buffer of the multithread method is also described. Referencing many multimedia synchronization models and their corresponding synchronization method, we adopt the method which combines the time stamp method and synchronizing point method, which is just available for our system. The flow control is an important factor to guarantee the network transmission quality. In this paper our research focused on the closed loop flow control method based on the feedback mode.In addition, we brought a decision strategy for the QOS of the server.We use the .NET technology which can simplify the system development, make the user interface more friendly and convenient for the client. We divide the system into different module based on their different functions, in order to facilitate the renewal and maintenance of the system.