Low Latency Live Video Streaming over HTTP 2.0
Low Latency Live Video Streaming over HTTP 2.0
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DOI：
10.1145/2578260.2578277
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发表时间：
2014-03
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影响因子：
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通讯作者：
Sheng Wei;Viswanathan Swaminathan
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文献类型：
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作者：
Sheng Wei;Viswanathan Swaminathan
超文本传输协议 (HTTP) 作为一种可扩展且高效的协议，已被广泛采用，用于通过 Internet 传输视频内容。 HTTP 流媒体客户端接收清单文件，通过 HTTP 下载引用的视频片段，并无缝模拟视频流播放它们。这引入了至少一个分段持续时间延迟，使得 HTTP 流不适合需要低延迟的实时视频流用例。降低实时延迟（减少分段持续时间）的直接解决方案会导致 HTTP 请求数量激增，以及 HTTP 缓存中资产的低效部署。为了解决这个问题，我们开发了一种基于 HTTP 2.0 的低延迟实时视频流技术。特别是，我们采用 HTTP 2.0 中新的服务器推送功能，一旦视频片段可用，就会主动将实时视频从 Web 服务器流式传输到客户端。我们在 MPEG Dynamic Adaptive Streaming over HTTP (DASH) 原型中实现了这种基于服务器推送的低延迟机制。我们的实验结果表明，使用服务器推送方案可以提高实时延迟的性能。更重要的是，通过利用 HTTP 2.0 中的服务器推送功能，我们能够避免请求爆炸问题，同时通过减少分段持续时间来降低延迟。
Hypertext Transfer Protocol (HTTP) has been widely adopted as a scalable and efficient protocol for streaming video content over the Internet. HTTP streaming clients receive a manifest file, download the referred video segments over HTTP, and play them back seamlessly emulating video streaming. This introduces at least one segment duration latency making HTTP streaming unsuitable for live video streaming use cases that require low latencies. The straightforward solution to lower live latency that reduces segment duration leads to an explosion in the number of HTTP requests, as well as inefficient deployment of assets in HTTP caches. To solve this problem, we develop a low latency live video streaming technique over HTTP 2.0. In particular, we employ the new server push feature in HTTP 2.0 to stream the live video actively from the web server to the client, as soon as the video segments become available. We implement this server push based low latency mechanism in a MPEG Dynamic Adaptive Streaming over HTTP (DASH) prototype. Our experimental results indicate performance gains in live latency using the server push scheme. More importantly, by leveraging the server push feature in HTTP 2.0, we are able to avoid the request explosion problem while lowering latency by reducing the segment duration.