【作者】 倪修建；

【导师】 傅丰林；

【作者基本信息】 西安电子科技大学 ， 通信与信息系统， 2002， 硕士

【摘要】 随着Internet网络的迅速发展，传统的视频会议系统正向着基于Internet网络实现的方向发展。本文实现了一个简单的视频会议Internet网络传输系统，研究了在现有Internet网络上传输视频会议存在的服务质量问题和同步问题。对于视频会议Internet网络传输的服务质量问题，本文首先分析了Internet网络上的端到端时延，结合时延分析，在传输系统中采用带质量指示反馈的变速率视频传输方案，另外在接收端采用回放缓冲方案以减小Internet网络时延抖动。对于视频会议Internet网络传输时存在的媒体同步问题，本文引进了ISO／IEC的PREMO模型，统一处理基于时间和基于事件的同步方法。结合这个模型，在传输系统中采用一种自适应多媒体同步方法。最后，还结合Internet网络的发展，研究了ATM信元时延对视频会议传输系统实时性的影响。更多还原

【Abstract】 With the rapid development of Internet networks, the traditional video conference is changing toward implementing on Internet networks. This paper studies on the questions of quality of service and synchronization between multimedia in the transmission system of video conference on Internet. On the question of quality of service, the paper analyses the end to end delay on Internet networks, then a variable bit rate scheme based on quality indication feedback is adopted in the transmission system. At the same time, several delay reduction techniques for playout buffering are used at receiver end. On the question of synchronization, the PREMO model is introduced in the paper, which is used to uniformly treat the two synchronization patterns based on time and event separately. With consideration of PREMO model, an adaptive multimedia synchronization scheme is used in the transmission system of video conference. Last, with a view to the development of Internet networks, the paper studies the impact of ATM cell delay on multimedia in the transmission system of video conference.更多还原