Research On Algorithm Of Video & Audio Variable Speed Playback And Its Applications In IPTV

During the past few decades, traditional television has brought people with lots of happiness of vision and hearing, and it has been a big part of life. But the weakness of low interaction also appears. With the development of multimedia technologies, bandwidth of network, storage technologies and processing capabilities of computer, providing the interactive function can be a possibility. VCR function is one aspect of multimedia interactive function and it includes: play/stop, pause/resume, random access, video fast forward, video fast backward, video slow play, audio fast forward, audio fast backward, audio slow play and so on. In all these functions there are four items: video fast forward, video fast backward, audio fast forward, audio fast backward which are the most difficult to be implemented. Based on these, this paper includes these aspects of research.Firstly, this paper introduces the composing, provided services, features of IPTV and explains the format of video and audio which are used in IPTV. After introducing three kinds of video format (MPEG-4,H.264,AVS), it compares the features of these three things. Then the paper introduces the principles of MPEG-4 video codec. Taking XVID as an example, it gives lots of details about each module in the codec. As for audio aspect, the paper analyzes the principles of the MP3 codec.Secondly, after analyzing and concluding the principles, execution conditions and advantage and disadvantage of the former algorithms, the paper introduces a new algorithm. Then it gives some much more explanation about the background knowledge, basic principles, derivation of conclusion, execution condition, final result and advantage and disadvantage of the new algorithm.Lastly, this paper give the simulation procedure and result of the new algorithm and former algorithm, and also do some discussions and analyses about the result of the simulation.After software simulation and verification, the algorithm which is proposed in this paper can fulfill the requirement and has a good balance between algorithm calculation complexity, storage requirement, channel bandwidth and the quality of picture.