一种自相似媒体流的分组存储算法  

Packet storage for self-similar media stream

作　　者：向哲[1] 钟玉琢[1] 

机构地区：[1]清华大学计算机科学与技术系,北京100084

出　　处：《清华大学学报（自然科学版）》2002年第1期44-47,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目 ( 6 99730 2 5 );国家"九七三"资助项目 ( G19990 32 70 0 )

摘　　要：在媒体服务器上采用分组存储策略可显著减少生成媒体流的系统开销 ,从而有效提高系统性能。该文提出了两种分组存储策略 :等长分组存储 (ISO- PS)策略和索引分组存储 (Index- PS)策略 ,在分析自相似 MPEG媒体流突发特性对分组存储影响的基础上 ,设计了一种适合自相似媒体流的分组存储算法 I- IPS。该算法引入了对 MPEG媒体流分组时间的评价因子 ,通过该因子决策媒体流采取 ISO- PS或Index- PS策略以提高系统整体性价比。实验证明 :对于自相似特性有显著差异的不同 MPEG1/ 2 (运动图像专家组 )节目 ,I- IPS算法均能有效降低存储浪费率 。Packet storage in media servers can greatly improve system performance by efficiently reducing the cost of media stream creation. Isometric Packet Storage (ISO PS) and Indexed Packet Storage (Index PS), are proposed, and the influence of the self similar MPEG media stream on these schemes is also studied. Then, a new packet storage algorithm called I IPS (Isometric and Indexed Packet Storage) is introduced for self similar media streams. I Ips uses the value of the evaluation factor for media packet granularity to select either the ISO PS or the Indetx PS scheme for the media stream to achieve a better performance/price ratio. Experience indicates that I IPS remarkably reduces the waste rate of packet storage and provides fairly high performance for different MPEG1/2 media streams with various self similar features.

关 键 词：自相似 流式媒体 分组存储 运动图像专家组 多媒体技术 媒体服务器 

分 类 号：TP37[自动化与计算机技术—计算机系统结构]