一种基于反向复用的MPEG-2数字视频监控系统  

Inverse multiplexing-based MPEG-2 digital video supervision system

作　　者：童胜勤[1] 鲁放[1] 王宏远[1] 

机构地区：[1]华中科技大学电子与信息工程系,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2005年第6期54-57,共4页Journal of Huazhong University of Science and Technology(Natural Science Edition)

摘　　要：介绍了一种新颖的用于SDH光纤传输网络的数字视频监控系统的技术实现方案.该方案中视频图像经过MPEG2标准压缩生成恒定速率(4～8Mbit/s)的数字码流,采用多E1反向复用技术将其传送到视频解码端还原.利用SDH设备具有的VC12级交叉能力,通过视频切换控制台动态改变各网元设备的交叉连接关系,使得监视图像输入路数较多时系统带宽得以复用共享.同时利用SDH设备内提供的分布式数据共线通道实现了视频切换控制台对各摄像机的远程云台控制.论述了实现中的关键技术,包括N×E1反向复用、E1映射时钟同步、分布式视频切换和共线方式云台控制.对本方案中的全程视频延时和切换时间构成的估算表明,本方案中视频延时主要取决于MPEG2的编解码延时.通过初步分析说明,由于在稳定状态下传输引入的处理延时为定值,因而无需进行PCR的调整.进而给出了支持平滑切换的实现思路.多项实际工程应用证明该技术具有良好的实用价值.A new digital video supervision scheme used for SDH-based fiber transport network was proposed. An analog video was compressed to digital stream with constant bit rate (4-8Mbit/s) using MPEG-2 standard. The stream was transported to decompressed side to recovery the original picture by multiple E1 inverse multiplexing. When original video channel numbers are more than the monitor terminal, TU-12′s class cross connection of each relative network equipment should be changed dynamically in order to share the bandwidths. Camera centralized remote control basd on the distributed control bus data channel is adopted. The key techniques, including N×E1 inverse multiplexing, E1 mapping synchronization, distributed video switch and camera remote control based on distributed data bus were discussed. The timing estimation showed that the total delay from original video to recovered video mainly depends on the video compression and decompression processing. It was concluded that no PCR adjustment is needed due to the fixed transport delay in steady status. The smoothly video switching method was also pointed out. The availability was proved by several applications.

关 键 词：视频监控 视频切换 反向复用 

分 类 号：TN919.8[电子电信—通信与信息系统]