Research And Implement On The Streaming Mediaadaptive Transmission Strategy Based On HTTP Streaming

Network convergence has become an inevitable trend as the rapid development of TCP / IP, optical communication, digital and software technology. Therefore, the industry proposed the concept of "Three-Network Convergence", which refers to the integration of telecommunications networks, cable tv networks and the Internet. These three major networks would gradually form a comprehensive multimedia communication network through technical transformation, resources sharing and service integration. As one of the core technologies of video service applications for "Three-Network Convergence", streaming media technology based on HTTP streaming has become attractive among more and more researchers. This paper did in-depth research on the key technologies of streaming media adaptive transmission based on HTTP streaming. The specific work is as follows:Firstly, knowledge of streaming media technology is introduced briefly. According to the features of streaming media transmission over the network convergenced, this paper summarized the key technologies of streaming media adaptive transmission based on HTTP streaming. Compared with traditional streaming media technology, HTTP streaming has different technical requirements for the multi-bit rate of media source and adaptive algorithm. Furthermore, new technical contents have been added to HTTP streaming technology, such as media files segmentation and container format transformation.Secondly, based on the research of the key technologies of HTTP adaptive streaming, and combined with the requirements of school-enterprise cooperation projects "three-screen integration‖, this paper designed and developed a prototype system which provided HTTP adaptive streaming with a variety of container formats. There are three functional modules at the server, and several new media processing technology for HTTP streaming is innovative implemented, such as media container format transformation method based on intermediate forms and server-driven adaptive algorithm of HTTP Streaming.The client used different player strategies according to different streaming media container format. As for ISMV file, the player interface is beautified and a client-driven adaptive algorithm of HTTP streaming is implemented through further development of the Silverlight. As for FLV file, Jw Player is selected. The prototype system was successfully run above 8 hours with stable, continuous, smooth HTTP streaming playback, and adaptive algorithm can work well under different network conditions.Finally, this paper proposed an improved model of the RA algorithm based on the study of HTTP adaptive streaming. This algorithm made reference to the current Microsoft Smooth Streaming adaptive strategy, drew on the advantages of the two RA algorithms, and put forward an accurate method for estimating the current available bandwidth. The simulation results show that, compared with the two RA algorithms, the improved RA algorithm can better adapt to the current status of the network bandwidth, and enhance the user experience to a greater extent.