Key-frame reference selection for error resilient video coding using low-delay hierarchical coding structure

Low-delay hierarchical coding structure (LD-HCS), as one of the most crucial components in the High Efficiency Video Coding (HEVC) standard, substantially complicates the temporal reference relationship and achieves better compression ratios. There have been lots of research work on increasing the error resilience of HEVC coding. However, most of them neglect the characteristics of LD-HCS and cannot achieve the optimum trade-off between coding efficiency and error robustness. To this end, in this paper, a non-feedback reference picture selection algorithm is proposed to improve the error robustness of HEVC streaming under LD-HCS, by reducing temporal error propagation in case of packet loss. Specifically, the temporal relationship among different frames under LD-HCS is firstly analyzed, and then frames with the lowest temporal layer are considered as the potential key-frame which is capable of preventing error propagation. Secondly, the end-to-end distortions of using two different reference schemes for the potential key-frame are compared based on an overall distortion estimation model, and the reference scheme that has less total distortion is chosen ultimately. Moreover, the potential key-frame will be encoded entirely in intra-mode if the error propagation is severe. Extensive experiment results demonstrate that the proposed reference picture selection method significantly reduces the effect of temporal error propagation. Compared to the state-of-the-art approaches, the proposed method is able to improve the video quality over error-prone networks.