Optimized Transcoding For Large Scale Adaptive Streaming Using Playback Statistics

HTTP-based video streaming techniques have now been widely deployed to deliver video streams over communication networks. With these techniques, a video player can dynamically select a stream from a set of pre-encoded representations of the same source based on available bandwidth and viewport size. Since bitrate accounts for most of the cost incurred in these platforms, the problem is to minimize bitrate while maximizing quality. In this paper we use measurements on the actual usage of millions of video clips to create probability distributions of available bandwidth and viewport sizes. These probability distributions inform the optimization process and the resulting scheme demonstrates an overall bandwidth reduction of 9.7% compared with existing techniques without loss of delivered quality.