SATD-based joint decision algorithm for parallelized intra prediction encoder in H.265/HEVC
Yao‐Jen Chang, Pei-Hsuan Tsat, Chun-Lung Lin · 2016
A Hadamard transformed sum of absolute difference (SATD)-based joint decision algorithm (SJDA) is proposed for intra prediction encoder in High Efficiency Video Coding. The SJDA performs the SATD-only distortion costs in 4×4 prediction units (PUs) to select rough modes of larger PUs. An adaptive block selection scheme is proposed in SJDA to adaptively adjust the PU sizes every 16×16 block by an approximate SATD-based rate distortion cost. To smartly select intra prediction modes that will be enabled for rate-distortion optimization (RDO) calculations, the SJDA proposes a novel evaluation signaled scheme to signal the evaluation results to a decision module by deriving a decision rule. Compared to HM, the SJDA averagely saves 73% encoding time with +3.3% BD-rate, while reducing 60% RDO modules in a parallelized encoder, 80% SATD operations, and 77% RDO operations. Simulations also show the proposed algorithms are superior to classical ones.