An Efficient Rate-Distortion Optimization Method for Low-Delay Configuration in H.265/HEVC Based on Temporal Layer Rate and Distortion Dependence

Currently, as one of the most important video coding structures, the low-delay (LD) configuration has been widely adopted in the video communication systems, such as video surveillance and video conferencing systems. The rate-distortion optimization (RDO) is also a crucial technique for improving the performance of video coding. The RDO performance of H.265/HEVC with the LD configuration is significantly affected by the temporal dependence. This letter examines the dependence of rate and distortion among temporal layers in H.265/HEVC with the LD configuration. An efficient RDO method is then proposed based on temporal dependence, where the optimized Lagrangian multipliers are estimated by adaptively selecting the scaling factors according to the video motion characteristics pertaining to different temporal layers. The experimental results show that compared with the RDO method adopted in the H.265/HEVC test model (i.e., HM), the proposed RDO method can achieve the average BD-rate reductions of 6.4% and 5.8% for the LD P and LD B configurations, respectively.