Design And Implementation Of Video Conferencing Client Data Processing System

Video conference system makes it possible that remote people can join a meeting at the same time,and is getting more and more favored by people for its fast, low-cost. Different from simple text communication, video conferencing includes audio and video information which enhances the authenticity and intelligibility of meetings. Meanwhile, shared whiteboard, shared file and other interactive features could enhance the collaboration between participants.The video conferencing client was divided into two parts: information management system and data processing system. This paper mainly study the design and the implement of video conferencing client data processing system. The data processing system does not only interact with the upper level(Information Management System) but also with conference server.The system designed 4 layers to deal with the processing of video conferencing client data,they are the data interface layer, data processing layer, auxiliary control layer, protocol processing layer. Data interface is designed to do the data interaction with the upper layer, Data processing layer is to solve the different client data types problem; auxiliary is to improve system control;protocol processing layer is to send and receive the data which has been processed. To support the design and implementation of the above functions, this paper analyzed and designed the data type; researched and designed common data communication formats; researched SIP / SDP protocol for session establishment; researched Direct Show technology framework for audio video capture and researched G.729 and H.264 encoding algorithm to complete audio and video compression; researched RTP / RTCP protocol to perform the real-time transmission of audio and video; researched and designed the synchronization algorithm of audio and video to ensure media synchronization.Finally, we tested the validity of this system, verified the correctness of the system design and function, summarized the full text and planed the future work.