Reducing Perceptual Discontinuity P2P Live Video Streaming Using Adaptive Scheme Based on Frame Loss Visibility

Abstract

When a live streaming video is delivered over a peer-to-peer (P2P) network, the video is divided into several chunks and distributed to peers. Each chunk has its own playback time deadline. A chunk delay can be a problem of great concern because a serious chunk delay can produce obvious discontinuity of the streaming video, resulting in low satisfaction for a viewer. 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 the viewer. This study 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. Given a fixed chunk delay, the main difference between the proposed approach and the uniform frame skipping method is the way of choosing frames for dropping (fast forwarding method does not drop any frame but play all the frames at a faster speed). A viewer's satisfaction is evaluated by using the way of subjective video quality assessment. The proposed method can produce higher MOS (mean opinion score) than that of the traditional methods (fast forwarding and uniform frame skipping), demonstrating the effectiveness of the proposed approach.