Low-Delay Hevc Adaptive Quantization Parameter Selection through Temporal Propagation Length Estimation

Rate Distortion Optimization (RDO) is employed in the contemporary video coding standard, High Efficiency Video Coding (HEVC), to improve its coding efficiency. Due to its high complexity, RDO is generally performed with fixed quantization parameters (QPs). Fixing QPs, however, does not consider the impact of the current frame on the future frames within the temporal propagation chain, leading to suboptimal performance. To address the adaptive QP design, in this paper, we first estimate the propagation length that is defined as the impact length of the current unit on future units. Based on this impact length, we then propose an adaptive frame-level QP selection algorithm for the low-delay (LD) HEVC standard. Compared to the default HEVC, our method performs significantly better by achieving -4.71% and -3.93% BD-rate gains for LDP and LDB configurations of HEVC, respectively, at a negligible increase in time overhead.