Research And Implementation Of Video-on-Demand System In PS2P Network

In recent years, digital media industry rises rapidly world-wide. By transmitting the digital multimedia content via Internet and mobile phones, it has gradually changed people's entertainment habits. This thesis depends on digital audio and video products integration and distribution platform, and introduces a digital multimedia service system which is based on IP and contains copyright protection. Through this platform, the whole digital multimedia industry can develop ahead more healthy.As an important part of the Digital Media Products Integration and Network Distribution Platform, the Video-on-Demand system will interact with the massive subscribers. Such system manages and plays the digital video and audio contents which have legal copyrights. The Video-on-Demand system is based on Peer to Server & Peer (P2SP) technology, which combines the advantages of Peer to Peer (P2P) and Peer to Server (P2S), and is able to download and playback high-speed audio/video contents smoothly.This thesis first introduces the state-of-the-art in digital multimedia content distribution over network, with detailed discussion and analysis of the traditional C/S model and P2P streaming media framework, particularly BitTorrent (BT), which is the delegate of P2P file sharing technology. By analyzing architecture, protocol, piece selection algorithm, chocking algorithm and incentive mechanism of BT,this paper identifies the difficulty of applying the advantages of the P2P content distribution protocol in video-on-demand system and introduces the existing solutions.Based on previous analysis results, a video-on-demand system framework in P2P and S2P mixed network environment is designed. With the support from the resource server, this thesis proposes a new piece selection strategy based on user behavior to meet the performance demand of the drag-and-drop operation. In order to take into account the fairness of the system, an incentive mechanism based on user nodes'statistics information is introduced.Finally, this thesis gives a detailed description on system implementation, followed by system performance evaluation and analysis. Analysis results show that under the premise of ensuring high-speed transmission of audio/video contents, the system allows users to obtain good audio-visual experience and good quality of service.