Adaptive intra-refresh for low-delay error-resilient video coding

Low-delay and error-resilient video coding is critical for real-time video communication over wireless networks. Intra-refresh coding, which embeds intra coded regions into inter frames can achieve a relatively smooth bit-rate and terminate the error propagation caused by the transmission loss. In this paper, we proposed a novel linear model for the intra-refresh cycle-size selection adapting to the network packet loss rates and the motions in the video content. We also analyze issues in designing the intra-refresh coding pattern and the refresh order, and propose a strategy which can adapt to different cycle-size and obtain better R–D performance compared with traditional random intra-refresh and vertical-partition intra-refresh. Experimental results show that the linear cycle-size selection model works effectively, where a 3 dB improvement can be achieved compared with a fixed cycle-size. Also, with the proposed intra-refresh order, a 2.0% bitrate reduction is obtained in average compared with the vertical-partition intra-refresh.