MPEG-2传送流传输方法的研究与改进  

Research and Revision on Transmission of MPEG-2 Transport Stream

作　　者：洪飞[1] 吴志美[1] 

机构地区：[1]中国科学院软件研究所多媒体通信与网络研究中心,北京100080

出　　处：《计算机学报》2004年第3期352-356,共5页Chinese Journal of Computers

基　　金：国家自然科学基金 ( 6 0 2 72 0 98);北京市科委项目基金 (H0 11710 0 10 12 3 )资助

摘　　要：高品质视频流媒体的传输在流媒体业务中占有很重要的地位 ,同时带来许多难题 .以传统的恒定速率传输变比特率压缩的视频时 ,播放终端往往需要很大的缓存 .PCR协助的恒定速率传输是一种新的恒定速率传输机制 .这个方法的详细研究表明PCBR方法利用嵌入MPEG 2传送流的程序参考时钟来定期校正传送速率 ,是以较高传输速率为代价减少了缓存需求 .因此对该方法进行了改进 ,通过缩小传输时间尺度来降低传送速率但没有增加额外的缓存需求 ,在NS通信系统仿真软件和实验平台的测试结果都表明 ,改进的方法能够更好服务于流媒体传输与终端回放 .The transmission of high-quality streaming media plays a key role in providing streaming services, which poses great challenges. Transmitting compressed variable bit rate video with traditional constant bit-rate (CBR) service for continuous playback requires a large buffer at the viewer's side. This paper studies one new CBR transmission scheme, called PCR-assist CBR (PCBR), in detail, which employs the Program Clock Reference embedded in the MPEG-2 Transport Streams to reduce the buffer requirement. The PCBR scheme uses PCRs to examine its transmission regularly, which reduces the buffer requirement at the cost of higher transmission rate. Authors present the revised PCBR scheme which reduces the transmission rate by shorting the transmit time scale. Simulation results in NS and authors' broadband testbed both show that this method serves best for the transmission and playback by slowing down the transmission rate without higher buffer requirement.

关 键 词：MPEG-2 视频编码 流媒体 多媒体服务器 流传输 视频传输 

分 类 号：TN919.81[电子电信—通信与信息系统]