The Research And Implementation Of TCO/RTMP/WebSocket Protocol Conversion In Video Conference System

Video Conferencing is that people in multiple locations have remote video communication services through the Internet,which not only enrichs means of communication in people's life and work but also improves the quality of people to communicate and exchange,and its scope of applications constantly grow now.Video Conferencing System includes streaming media servers,network and the clients.With the sharp increase of users,the project's original Red5 streaming server emerged a shortage of concurrent processing capability,needing a highly concurrent server to replace it.On the other hand,the clients exist problems and they have new demands.PC client shows stable performance,but it need to install the client-software and its use is very complex.Flash client has been used widely,but it is based on the Flash-plug,which exists security loopholes and poor compatibility issues.In this paper,I design a new HTML5 Client,which is free plug-in,native components and cross-platform,and it is an ideal client.However,when it is integrated into the existing project,needing to solve the protocol conversion in the real-time video and audio communication between it and existing two clients.To solve the problems and to meet the demand above,the Core work of this paper includes:1.Design and implement the related functions of HTML5 Client,including design custom messages to encapsulate the video and audio data,use Web Socket API to handle WebSocket data-frames,use JavaScript technology to assembly and parse custom messages;2.Research the realization of original TCP module,design and add WebSocket protocol processing,and then the new TCP module can handle TCP and WebSocket protocols,to realizes two real-time communications include the video&audio communication between HTML5 Client and PC Client and the audio communication between HTML5 Client and Flash Client;3.Analyze and build Nginx streaming media server,which has been tested with high concurrent processing capability,and it can replace Red5 server;Research the source of Nginx and RTMP modules,design and develop a new RTMP expansion module,and thenNginx server supports multiple Flash Client in real-time video&audio communications,so that it meets multi-users requirements;4.Based on Nginx's Upstream mechanism,design and implement a new HTTP module,which not only supports WebSocket function,but also provides data conversion betwen RTMP packets and custom messages,so that HTML5 Client and Flash Client achieve real-time video communication.In this paper,I test the functions of multi-protocol conversion and application,which are all passed.Performance tests show that the realization of multi-protocol conversion system has high concurrency,low latency and low packet loss rate,thus this paper has good practical value.