An Early Termination Algorithm of Prediction Unit (PU) Search for Fast HEVC Encoding

The latest video coding standard, high efficiency video coding (HEVC) achieves high coding efficiency by employing a quadtree-based coding unit (CU) block partitioning structure which allows recursive splitting into four equally sized blocks. At each depth level, each CU is partitioned into variable sized blocks of prediction units (PUs). However, the determination of the best CU partition for each coding tree unit (CTU) and the best PU mode for each CU causes a dramatic increase in computational complexity. To reduce such computational complexity, we propose a fast PU decision algorithm that early terminates PU search based on the best mode and the rate-distortion (RD) cost of the upper depth CU. Experimental results show that the proposed method significantly reduces the encoding run-time by 18.1% with only negligible loss of coding efficiency. Keywords-HEVC, Fast encoding, CU, PU