导　　师： 任小西;李仁发

学科专业： 081203

授予学位： 硕士

作　　者： ;

机构地区： 湖南大学

摘　　要： 近年来,以互联网为传播介质,以数字化多媒体内容为主体的数字媒体产业在全球范围内快速崛起,并逐渐改变了人们娱乐休闲的方式。本文以数字音像内容集成分发平台为依托,构建一个基于IP网络的、具有版权保护的数字多媒体点播系统,促进数字多媒体产业健康、有序的发展。 数字音像内容集成分发平台是“十一五”国家科技支撑计划重大项目现代服务业共性技术支撑体系与应用示范工程关键课题,旨在建立一套基于Internet网络传输的正版数字音像内容管理发行平台。作为其重要组成部分,视频点播系统直接面向最终用户,下载和播放具有合法版权的数字音像内容。该系统基于Peer and Server to Peer /(PS2P/)技术,融合了Peer to Peer/(P2P/)和Server to Peer/(S2P/)网络分发的优点,实现了音视频内容的高速下载和流畅播放。 本文首先介绍了数字音像内容网络发行的国内外现状,讨论和分析了传统C//S模式与P2P流媒体系统框架。对P2P文件共享技术的代表BitTorrent/(BT/)系统进行了详细的分析,包括BT系统的组成结构、BT协议、BT客户端的片段选择算法、阻塞算法和激励机制。指出了将P2P内容分发优势应用在视频点播系统中的难点,并对现有的解决方案进行了介绍。 其次,本文设计了在P2P与S2P混合网络环境中的视频点播系统框架,在引入了资源服务器的支持的同时,对BT协议的片选策略进行修改,增加了基于用户行为驱动的片断选择策略来满足点播系统的拖放操作。为了兼顾系统的公平性,引入了基于用户积分统计的激励机制。接着本文对系统的实现进行了详细介绍。 最后,本文对视频点播系统的性能进行了测试。分析结果表明,该系统能够保证在音视频内容高速传输的前提下,让用户获得良好的视听体验和服务质量。 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 introduc

关 键 词： 视频点播 片断选择 激励机制

领　　域： [自动化与计算机技术] [自动化与计算机技术]