Rate-Smoothed Encoding for Real-Time Video Streaming Applications

摘要

For real-time video streaming applications over the constant bit rate channels, it is highly desired that video signals can be encoded in not only good average quality but also smooth video quality. However, in the case that the network resource is sufficiently large and the video quality has reached the target quality, the quality smoothing is not necessary and the rate smoothing is desired to avoid overusing the unnecessary network resource but also achieve a smoothed traffic rate. In this paper, we propose a novel real-time rate-smoothed encoding scheme by applying the low pass filtering idea. Both theoretical analysis and experimental results show that the proposed rate-smoothed encoding scheme can achieve a target average quality while significantly reducing the peak rate and the rate variance. We have further proposed a joint quality and rate smoothed encoding scheme, which can provide adaptive smoothing according to different situations. Experimental results show that the proposed joint smoothing scheme can make an optimal balance between the quality fluctuation and the rate fluctuation, and hence improve the overall system performance.