A Fast Coding Unit Depth Decision Algorithm for HEVC Inter Prediction

High Efficient Video Coding (HEVC) adopts a quad-tree structure to partition the Coding Unit (CU). Each CU can be split into smaller CUs recursively. It achieves high coding efficiency. But it also dramatically increases the computational complexity. This paper proposes a fast coding unit depth decision algorithm for HEVC inter prediction which can provide better coding efficiency. The proposed algorithm introduces early termination methods based on their motion characteristics. The certain threshold is used to decide whether the coding unit (CU) should be split into smaller CUs (or PUs). By this way, many partition operations and rate distortion (RD) cost computations will be skipped to reduce the complexity. Experimental results show that the proposed technique saves 45.76% encoding time on average with negligible loss of coding efficiency.