【作者】 李欣；

【导师】 王海婴；

【作者基本信息】 北京邮电大学 ， 通信与信息系统， 2006， 硕士

【摘要】 近年来，随着电子技术、计算机技术、网络技术的发展，基于网络的视频传输得到了广泛的应用，诞生了视频会议、视频监控、远程医疗、网络电视等网络多媒体业务。联合视频专家组(JVT)制定出的H.264标准，在视频编码效率方面比原有视频标准(如H.263和MPEG2)更加高效；同时为了适应不同的传输网络，H.264从设计理念上把视频编码和传输分开，形成两个层次：视频编码层(Video Coding Layer，VCL)和网络提取层(Network Abstraction Layer，NAL)；VCL主要提供核心的高质量的视频压缩，NAL则是针对具体的网络传输环境把压缩数据进行传输封装。由于H.264出色的性能，该项标准对于今后网络视频编码传输、数字电视等领域必将带来深远的影响。 本文设计了一个基于H.264的网络视频传输方案，方案采用C／S结构，服务器端采用多线程技术，用软件实现CIF格式图像序列的实时H.264编码，以RTP协议承载编码后的H.264码流通过网络传输到客户端；客户端接收到H.264码流后将其解码显示，并通过RTCP发送反馈信息，供服务器端进行对网络状况的自适应调整。 按照设计方案，本文在PC机上搭建实验平台，实现了基于H.264的网络视频传输系统的原型，并在实际测试中加以改进，在编解码器端加入对灵活宏块排序(Flexible Macroblock Ordering，FMO)分散(Dispersed)模式的支持。 然后本文对网络视频传输中的两个关键问题：码率控制和差错隐藏进行了研究。提出一种基于滑动窗口的计算简单的码率控制算法和一种基于对象几何形状的差错隐藏算法，并整合到实验平台中，最终实现了一个具有一定实用性的基于H.264的视频传输方案。更多还原

【Abstract】 In recent years, with the development of electronic technology, computer science and network technology, video communication on the network was applied widely. A lot of network multimedia services appeared, such as video conference, video monitoring, long-distance medical treatment and network TV. Joint Video Team (JVT) established H.264 video compression recommendation, which is more efficient than the old video compression recommendation (e.g. H.263 and MPEG-2). H.264 separate video encoding and transmission to two layers: Video Coding Layer (VCL) and Network Abstraction Layer (NAL) in order to fit different network. VCL provide core high qualified video compression. NAL encapsulate compressed video data based on specific network environment. Because of the excellent performance, H.264 will bring far-reaching effect in network video transmission, digital TV and other correlative field.The whole project of network video transmission based on H.264 was designed in article. The project was C/S structure; the server used multithread technology, achieved real time H.264 encoding for CIF format Video stream by software; after encoding, the server used RTP protocol transferring encoded H.264 data to client through network; the client decoded and displayed received H.264 data, and sent feedback information by RTCP, for server using to adapt network.The whole project was implemented on computer, as a prototype of network video transmission based on H.264 for further study. Then the prototype was tested and improved, added support to FMO (Flexible Macroblock Ordering) Dispersed mode.Two key issue of network video transmission: rate control and error concealment was studied in article. A rate control arithmetic based on slip window which has lower更多还原