Research And Design Of P2P Video Conferencing Based On DirectShow

As the development of network technology, multimedia technology and communication technology, text and voice communication can not meet people's requirement any more, so the development and application of video conference have became one hot spot of the network application. Video conference system is a communication system which uses the network to transmit sequential pictures, audio and data to many participants. Through this system, people in different places can communicate with each other freely and effectively.At present, most video conference systems use a video server to receive and transfer video and audio data. Because of the resource limitation of video server in CPU, memory and bandwidth, the quality of video and voice in the system gets worse rapidly as soon as the number of clients increases. So the video sever becomes the bottleneck of video conference's development. Besides, the quality and definition of video and audio are greatly affected by the compression and encoding of data. Integrating software and hardware can solve this problem, but the cost is really high. So it is of great importance to design a new video conference software to suit common consumers.Recently, the developing P2P technology can distribute the function of server to different clients, and If we can apply it to the video conference, it will make a great breakthrough. In this paper, we analyzed the characters of P2P and video conference, then, put forward a structure of P2P video conference, next, designed a prototype of video conference system based on the Visual C++ platform. The server in this system only manages clients and conference rooms, but not the data transmission among different clients. Adopting DirectShow technology, each client can solve the problems of the collection and synchronization of audio and video steam, and then transfer data by ALM(applicant layer multicast).