Video on Demand with VBR Encoded Video

使用 VBR 编码视频的视频点播

• 批准号: 9706495
• 负责人: Magda El Zarki
• 金额: $ 17.5万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-15 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9706495&HistoricalAwards=false
• 关键词: Video; Demand; VBR; Encoded

This research studies how emerging broadband networks can efficiently deliver video on demand. The research assumes that video is variable-bit-rate (VBR) encoded. Particular emphasis will be placed on a design which the P.I.s have recently devised, Join-the-Shortest-Queue (JSQ) Prefetching. Not only does this exciting design give constant-quality playback and almost 100% link utilization, but it also allows for immediate commencement of the video upon user request and near instantaneous response to interactive actions (pause/resume and temporal jumps). This research will examine two distinct end-to-end architectures for video on demand. In the first architecture, there is one video server from which all the videos emanate; the video server is attached to a cable headend or to an ADSL switch. In the second architecture, there are multiple video servers and there is a complex, multi-link network which separates the servers from the clients. The research will study JSQ prefetching for the first architecture; it will study a priority-based scheme which mimics JSQ prefetching for the second architecture. This research shall also develop analytically based call-admission rules for our JSQ prefetching design. It shall investigate how the special structure of MPEG-1 and MPEG-2 encoding can be exploited for designing call admission schemes and selective packet discard schemes at the server. It shall develop an auxiliary payload specification for transporting MPEG 1 and 2 video on demand over real-time protocol (RTP). Finally, an implementation of the JSQ prefetching scheme, which will stream several simultaneous videos to clients, will be developed. The research is described at http://www.seas.upenn.edu/~ross/jsq.html .

这项研究研究新兴的宽带网络如何高效地提供视频点播。该研究假设视频是变比特率(VBR)编码的。重点将放在P.I.最近设计的一种设计上，即加入最短队列(JSQ)预取。这一令人兴奋的设计不仅提供恒定的回放质量和几乎100%的链路利用率，而且还允许在用户请求时立即开始视频，并几乎即时响应交互操作(暂停/恢复和时间跳转)。本研究将研究视频点播的两种截然不同的端到端架构。在第一种体系结构中，有一个视频服务器，所有视频都从该服务器发出；该视频服务器连接到电缆头端或ADSL交换机。在第二种体系结构中，有多个视频服务器，并且有一个将服务器与客户端分开的复杂的多链路网络。本研究将研究第一种体系结构的JSQ预取；它将研究一种基于优先级的方案，该方案模仿第二种体系结构的JSQ预取。这项研究还将为我们的JSQ预取设计开发基于分析的通话准入规则。它将调查如何利用MPEG1和MPEG2编码的特殊结构来设计服务器处的呼叫接纳方案和选择性分组丢弃方案。它应制定用于通过实时协议(RTP)传输MPEG1和2视频点播的辅助有效载荷规范。最后，将开发JSQ预取方案的实施，该方案将向客户同时传输几个视频。这项研究在http://www.seas.upenn.edu/~ross/jsq.html上进行了描述。