【作者】 刘清；

【导师】 刘泉；

【作者基本信息】 武汉理工大学 ， 通信与信息系统， 2006， 硕士

【摘要】 近年来,Intemet有了蓬勃的发展。一方面,主干网和接入网速率不断提高,为各种宽带应用提供了必需的硬件基础设施;另一方面,随着文本、图像和语音视频信号己经可以数字化,并可通过网络存储、传送和再现。越来越多的人选择了网络,并愿意在网络上享受这种自由的交互式地观看语音视频节目方式,这一切都为视频点播技术的发展创造了良好的条件。 面对现在宽带网络上提供的高质海量多媒体内容,如何保证用户观看高质量多媒体视频,如何进行分发与管理,是现在研究的核心问题。针对这一问题,本文通过对视频与压缩技术的主要应用之一的VOD系统进行深入探讨,结合当前国内的网络带宽固定,用户却日益增加的现状,将分布式结构应用到视频服务系统中。设计了一种可扩展、负载均衡、高可用、高性能的视频服务系统,并力求使这种新的分布式系统能满足宽带用户和电信级网络对宽带信息服务的需求。 VOD即视频点播是利用视频服务器存储视频节目和其他多媒体信息,通过传输网络和客户端设备向用户提供交互式视频服务的系统。 本文首先简单比较了集中式与分布式视频服务系统结构的优劣,讨论VOD系统的体系结构,并介绍了VOD系统的几个主要组成部分。 然后对视频服务系统设计中的请求调度、负载均衡和内容存储等关键技术进行了深入的分析,并针对视频服务领域的特点,研究并实现了相对于传统算法的改进方案。在负载均衡方面,本文研究并实现了基于负载预测的平衡算法:在网络存储方面,本文研究了分布式网络存储方式的原理和实现方法。 基于以上研究,本文设计了一个能独立于现有宽带网的大型分布式VOD视频服务系统框架,并针对其多服务器并行、客户流大规模并发的特点在上述三个方面加以实现。更多还原

【Abstract】 Recently, with the rapid development of Internet technology, the data rate of bone network and access network is increasing which is provide the enough condition for broadband and services on the hardware part .Because of the signal of text, picture, voice and video to be digital signal that is easy of saving and transmission on the internet, more and more people prefer to watching video interactively on Internet. All of these create excellent condition of the development of VOD technology.How to manage lots of high quality multimedia program on the network is the key point for supplying the perfect service for consumers. According to the researching of VOD system and the fact of the increasing internet consumers, this article use distributed structure into VOD system. This new system is scalability, load balance, high availability and high performance, which could be satisfy broadband consumers and lager scale network.Video on demand (VOD), with the video server storing the video programs and other multimedia information, provides the clients with interactive video service though the transmission network and Consumer Premises Equipment.In this paper, firstly, I compares cluster and distributed video service system, and then I discusses the structure of VOD system and some important components in this system. Moreover, it draws the improved algorithm based on deep reaching request scheduling, load balance, programs storage and video service characteristic. For load balance, a balance algorithm based on load prediction was provided and achieved. For network storage, the paper shows the principle of distributed network storage and the method of implement.According to the deep research and study, the last part of paper supplies a frame of large scale distributed VOD video service system on existing network. and the improvement of request scheduling, load balance and programs storage.更多还原