Research And Design Of An Embedded Vod Terminal To Achieve

With the development of the science and technology, the requirement of information deepening, people having more and more requirement of the interactivity of audio and video programs, they exhibit great interest in the multimedia information especially the service of VOD. And then, at the beginning of the 1990s, with the continuous development of the multimedia and network technology, the VOD (Video On Demand) come out. VOD, briefly speaking is a TV which is controlled by audience, he or she can arbitrarily choose the favorite program, in other words, users are active when selecting and watching programs. At the same time, users can perform the similar VCR manipulations, such as fast-forward, fast-backward and pause etc.VOD provides the services including the video and audio etc for users via network. It covers all aspects of the network multimedia, has the remarkable social and economic benefit, and is in the foreland of the multimedia application. The technology of the compression and storage of the multimedia is mature on the whole; wide band is in rapid progress; all network structures unite at IP protocol; bandwidth of WAN (Wide Area Network) is growing day and day. With the related problems being gradually solved, rapid network connecting into here and there, the foundation project of VOD basically verge on maturity. VOD system can widely apply to the fields such as IPTV, digital library, remote class and electronic commerce etc, and possess the high valuable utility, accordingly, it become one of the hotspots of the recent research.On the basis of the embedded Blackfin561 hardware platform and uClinux operating system platform, this thesis researches on how to achieve a VOD player terminal in the embedded device. The key points of the research in this thesis include: Firstly, how to perform the development of the embedded system, the reduction of the operating system and translation of the bootloader; Secondly, the research of the diversified protocols related with the real-time transferring technology of the streaming multimedia; Thirdly, the research of the diversified compressive coding format of the audio and video data; Fourthly, based on the academic research upon, this thesis exhibits the total and detailed design scheme of the system; Fifthly, the research of the synchronization of the audio and video data and the research of the caching of streaming media.There are two features in this thesis: In one aspect, according to the character of the embedded system, the streaming media VOD technology is introduced into the embedded system, and the real-time transfer and control of the VOD streaming media data is achieved through the RTSP and RTP/RTCP protocols. In the other aspect, the method of the synchronization and caching for the audio and video media data is designed, which provides a certain QoS assurance for the streaming media VOD terminal.