Reducing perceptual discontinuity in peer-to-peer live video streaming based on frame loss visibility information

When a live streaming video is delivered over a peer-to-peer (P2P) network, the chunk delay is always a problem of great concern. A serious chunk delay can produce obvious discontinuity of the streaming video, resulting in low satisfaction of the service. Video on P2P is divided into several chunks and distributed to the peers. Each chunk has its own playback time deadline. The playback time of a delayed chunk is overlapped with that of the next chunk. Traditionally, fast forwarding and uniform frame skipping are the two methods used to deal with the chunk delay problem. However, they may easily produce the effect of perceptual discontinuity and perceived by a viewer. This paper proposes a frame dropping method based on frame loss visibility information in order to maintain visual continuity of the video. The frame with lower loss visibility will be dropped first. In a previous work, the idea of loss visibility was applied by a router to develop a frame dropping strategy when network congestion occurs. In this work, we apply it to the chunk-level playback controller in P2P network. The number of frames to be dropped is dependent on the value of chunk delay. The main difference between the proposed approach and the traditional methods is that different frames could be chosen and dropped. A viewer's satisfaction is evaluated by using the way of subjective video quality assessment. The proposed method produces higher MOS (mean opinion score) than that of the two traditional methods.