Fast coding unit decision algorithm for HEVC

HEVC adopts a flexible Coding Unit (CU) quadtree structure. With more flexible CU size selection, the coding efficiency of HEVC increases significantly but its complexity is much higher than that of H.264/MPEG-4 AVC. To reduce computational complexity, we propose a fast algorithm, which consists of splitting decision and termination decision, in constructing the CU quadtree. This scheme is designed to be complementary to the current three fast tools included in HEVC TM5.0. In other words, when it is combined with the existing fast CU tools, it still provides additional time savings. The time reduction of our scheme is most noticeable on HD pictures. In comparison with the original HM5.0, our proposed method averagely saves about 43% encoding time and the BD rate increases by about 2.2% for the HD test sequences.