网络视频监控系统自适应技术的研究

【作者】 张益斌；

【导师】 金心宇；

【作者基本信息】 浙江大学 ， 电路与系统， 2004， 硕士

【摘要】 随着Internet的迅猛发展，流媒体技术逐渐成为网络应用的主流技术。在网络视频监控系统中，流媒体技术更是具有广阔的应用前景和研究价值，但同时面临着监控信息的实时性和IP网络的Qos之间的矛盾。如何有效的为在网络上传输实时传输视频信息提供Qos，成为当前视频监控中研究的一个热点问题。 当前的研究主要集中在对数字音视频压缩标准以及压缩方式的选择的研究上，因为不同的压缩标准及压缩方式对数字音视频产生的结果显而易见，也容易最见成效，然而压缩标准及压缩方式的选择往往受到硬件的制约，并且单单通过视频源编码方案很难为网络视频监控系统提供一个良好的视频质量保证。本文首先对数字音视频的各种压缩标准进行比较和分析，最终选取了MPEG-4作为视频监控系统的视频压缩方案。随后，就本论文的主要内容—如何通过改进传输拥塞控制和选择适合流媒体的传输层协议来保证实时视频监控系统的Qos展开分析研究。Internet是一个“尽力而为”的网络，绝大部分应用都是基于TCP协议之上。为了保证和TCP兼容，文章对TCP的拥塞控制技术AIMD展开讨论，分析了在网络时变的情况下，流媒体传输应用TCP进行传输会造成视频码率的急速波动，从而造成视频质量的下降，无法得到一个令人满意的Qos方案的原因。基于之上的讨论，论文对端对端拥塞控制技术进行讨论，并着重介绍TFRC协议。其后，文章利用基于TFRC拥塞控制的MSTFP(流媒体TCP兼容协议)和缓冲管理提出了流媒体网络传输自适应技术的设计方案及实现，并通过在实验室架构网络测试方案，获得数据完成对自适应技术的论证。在文章的最后，文章对整个系统进行了总结回顾，并结合下一代网络IPv6的Qos研究现状如何对实现监控系统实现自适应技术进行了展望。更多还原

【Abstract】 With the rapid development of Internet, Streaming Media has become the prime newly application. In the video monitoring system of the network, Streaming Media has more broad future and research value. Although, according to the requirement of real-time in the monitor data, how to resolve the inconsistency between the Qos (Quality of Service) architecture of Internet and the assurance of real-time has become a dominant area in today research for monitoring system.Present research to concentrate on mainly is compress standard and compress research of choice of way to digital audio frequency and video, because compression standard compress way is obvious to digital result that audio frequency and video produce, apt to become effective most. Compress standard and compress choice of way often restrict by the hardware, and source code scheme is very difficult to offer a good video quality assurance to video monitoring system of the network through video only. This text compares and analyses various kinds of compression standards of the digital audio and video at first, has chosen MPEG-4 compressed scheme as the video of monitoring system of video finally. Afterwards, the main content of this thesis -how to get a considerate Qos architecture through the improvement of control scheme of the congestion and the choice of the protocol which is suit to Streaming media in the transmission layers of ISO architecture. Internet is the "best-effort" network, it is based on TCP agreement that the majority is used. For guarantee and TCP compatible, this article discusses congested control technology AIMD to TCP organization. Because of the situation that changes in the network , streaming media that use TCP can cause video yards of fluctuation rapidly of rate to transmit to go on to transmit, thus cause decline quality of video, unable to get one satisfactory Qos scheme. On the basis of this discussion, this article introduce TFRC agreement emphatically. Thereafter, the article is utilized on the basis ofcongested MSTFP that based on the congested control of TFRC, with the buffer control we put forward design plan of adaptive technique, and finish the demonstration of the adaptive technique through the test datum that acquired from the scheme that is built up in the lab. At the end of the article, the article summarizes the whole systems to review, combine of the future generation network(IPv6) Qos research ,and explains how is current situation to realize monitoring system with adaptive technique to go on.更多还原