CloudStream: delivering high-quality streaming video through a content-aware cloud-based H.264/SVC video proxy

Existing media providers such as YouTube and Hulu deliver video by turning it into a progressive download. This can result in frequent video freezes under varying network dynamics. In this paper, we present CloudStream: a cloud-based video proxy that can deliver high-quality streaming videos by (1) first transcoding the original video in real-time to a scalable video codec; and (2) then performing streaming adaptation to mitigate the network dynamics. The key to step (1) is a multilevel transcoding parallelization framework with two mapping options (Hallsh-based Mapping and Lateness-first Mapping) that optimize transcoding speed and reduce the transcoding jitters while preserving the encoded video quality. For step (2), We provide a content-aware streaming adaptation scheme aimed at reducing streaming jitters and providing high and consistent video quality in the presence of network bandwidth variations. We evaluate the performance of CloudStream on our campus cloud testbed and a controlled network environment.