Design And Implementation Of Video Conference System Based On Hybrid P2P Architecture

With the development of technology,more and more video conferencing system into the social life,and plays an important role and has extensive application.Currently more famous video conference system for commercial field of WebEx,AVCON and so on,individual application field is more is to realize the instant communication systems incidental function.Although the existing system to achieve the basic functions,there are still many places yet to be improved,such as different user LAN directly establish the connection between users is difficult,requirements of real-time transmission of audio and video data is difficult to achieve,due to the large differences in the user network conditions of cyber source waste etc..These problems can be solved to some extent by the rational use of cyber source user.In order to solve these problems,this paper compared and analyzed by existing methods for video conference related field,select the appropriate method and combine together to form a solution.Using P2P based on Application Layer Multicast(ALM)infrastructure,in order to users and reasonable use of cyber source,and through the NAT traversal technology ICE to achieve user directly connected;application layer multicast algorithm is proposed by MSRA DigiMetro,the solution of multiple data source transmission and each user cyber source allocation problem;in order to reduce the network the amount of data transmission using the current H.264 video compression coding standard highest efficiency etc..In video coding for motion estimation algorithm and improve the corresponding optimization,compared to algorithm reference software and improvement of the algorithm,and a conclusion that the improved algorithm than the reference algorithm in software of video quality and coding time has certain improvement.Then,for H.264 video data encapsulation strategy are comprehensively analyzed,designed by packaging process and strategy of RTP,according to the RTP package H.264 video stream data for error control in transmission process to design a Qos solution.This paper implements a small multi-point video conference system,mainly to complete the audio,multi point between video transmission function implementation conference.The use of open source Google library libjingle to achieve,and the realization of P2P architecture and application layer multicast based on it,the use of the FFMPEG/X264 open source library of the highest efficiency in the implementation of H.264 encoding and decoding,the Windows using the DirectShow implementation of video capture and playback function.System test results show that,the problems of user connectivity,resource utilization,has obtained a better solution,real-time performance is greatly improved.