A fast inter CU decision algorithm for HEVC

A fast CU decision algorithm is very desirable for High Efficiency Video Coding (HEVC) due to its high encoding complexity. In this paper, a fast inter CU decision algorithm is proposed, with the motion correlations between neighboring CUs discussed. Decision for splitting of collocated CU has a strong impact on current CU, high-motion CUs are early split by means of calculating motion diversity of collocated CUs. On the other hand, SKIP mode indicates a motion sharing relation among neighboring CUs and it can be used to early determine CU termination. A discriminant function minimizing expected risk is defined for both early SKIP mode detection and SKIP mode based termination decision. Experimental results show that the proposed algorithm can reduce computational complexity by 48.2% with only 0.46% BDBR increase for random access configuration. For the low-delay B configuration, it can reduce complexity by 45.9% with 0.55% BDBR increase penalty. The results show our algorithm achieves less BDBR increase compared with other state-of-the-art works.