VOD系统中基于组播的自适应缓冲策略

The dynamic buffering algorithm based on multicast for VOD system

提出了一种基于组播的视频点播自适应缓存调度算法,它提高了传统视频点播批处理算法的效率,实时响应用户的点播请求,解除了批处理算法中的时间限制,每当新的点播请求与原点播的节目相同时,新的点播请求并入到原点播视频流进行组播处理,并利用动态缓存以节省视频服务器和网络的资源.同时该算法能够根据系统的限制条件动态调整点播方式,在宽带小区视频点播系统中,视频服务器的磁盘速度常常受限,本算法针对该受限条件对系统进行优化,从而最大程度地提高了点播的成功率.图2,参9.

In this paper,we propose a new dynamic buffering algorithm based on multicast communications.Unlike the typical batching schemes,this new method allows every clients that request the same video to share a channel without not delaying the earlier request,so it can supply instantaneous videoondemand services.With the dynamic schemes,the system can adjust the VOD service modes according to the environment parameters.In local widebandwidth VOD systems,the disk I/O performance of video server is constrained,we optimize the system's buffering and other parameters for ondemand data delivery in order to maximum ondemand video number.2figs.,9refs.