Rate-distortion optimized video peer-to-peer multicast streaming

TLDR: A rate-distortion model which predicts end-to-end video quality in throughput limited environments is presented and used to determine the over-provisioning necessary to avoid self-inflicted congestion.

Abstract: We study peer-to-peer multicast streaming, where a source distributes real-time video to a large population of hosts by making use of their forwarding capacity rather than relying on dedicated media servers. Hosts which may disconnect at any time, therefore a robust control protocol is needed to maintain connectivity among peers. This work presents a new peer-to-peer multicast protocol and analyzes the gains that video coding and prioritized packet scheduling at the application layer can bring to the overall streaming performance. A rate-distortion model which predicts end-to-end video quality in throughput limited environments is presented and used to determine the over-provisioning necessary to avoid self-inflicted congestion. The video stream transmitted by the source contains H.264 SP and SI frames, which are used to adaptively stop error propagation due to packet loss. Distortion-optimized retransmission requests are issued by receiving hosts to recover the most important missing packets while limiting the induced congestion. Experiments for several hundred hosts simulated in NS-2 illustrate the benefits of our system. We achieve typical end-to-end delays of 1 sec, and a stable video quality with less than 2.5% of frames lost to playout interruptions.