Video quality assessment and comparative evaluation of peer-to-peer video streaming systems

We design a test methodology to analyze in detail the video quality received at each peer in a peer-to-peer (P2P) video streaming system. The metrics that we employ at each peer include video PSNR, statistical analysis of frame-freeze events, the amount of time to wait before video playback starts, nature of the data-paths established to serve the peer, protocol overhead and duplicate data received. These metrics are estimated by analyzing the packet reception times at each peer and utilizing information about the original uncompressed video as well as the encoded video. We use this framework to compare the performance of three P2P video streaming systems by deploying them on our controlled traffic-shaped network test-bed. We can emulate the same network conditions and peer behavior for testing different systems and ensure that the experiments are repeatable. These measurements highlight the differences between systems based upon their underlying implementation, overlay architecture, and choice of protocols. This measurement study helps to gauge the performance of currently available P2P video streaming systems and points out desirable performance improvements.