支持VBR编码视频的有效平滑算法  

Efficient smoothing algorithm for VBR-encoded videos

作　　者：李凯慧[1] 吴志美[1] 张源海[1] 许长桥[1] 

机构地区：[1]中国科学院软件研究所

出　　处：《通信学报》2008年第1期97-103,共7页Journal on Communications

基　　金：国家重点基础研究发展计划(“973”计划)基金资助项目(2007CB307100,2007CB307106)~~

摘　　要：针对VBR编码视频流传输时造成的资源需求的高可变性和资源利用的不平衡性,提出一个新颖算法BSBS-VBR(buffer sharing and bandwidth smoothing of VBR streams)。通过提前计算并预取最小所需的视频数据量,使服务器以固定码率获取并传输VBR编码视频;使用间隔缓存策略,根据系统当前资源状态为新请求分配资源,并根据当前访问分布以及可用资源对已分配缓存进行动态调整,保持资源平衡分配。该算法可减少服务器资源的峰值需求,平滑资源使用,提高资源利用率,扩大可服务用户数量。通过实验进行了验证。Using VBR encoded media files could obtain better video quality. However, it produced traffic burst and unbalanced resource utilizations. A novel algorithm BSBS-VBR （buffer sharing and bandwidth smoothing of VBR streams） was proposed. Through computing the minimum size of a video prefix to be prefetched in advance and prefetching them on request, it allowed video server to obtain and transmit a VBR-encoded stream at a fixed rate. Through interval caching, it could keep the balance allocation of the resources, as which allocated resources for each request according to the available cache and disk bandwidth, and adjusted buffer size at run-time according to the current request distribution and available resources dynamically. With BSBS-VBR, the peak requirements of the resources can be reduced, the utility of the resources can be improved, and more users can be served. These conclusions are proved by comparing with several existing methods experimentally.

关 键 词：间隔缓存 动态缓存分配 VBR CBR 

分 类 号：TP37[自动化与计算机技术—计算机系统结构]