Fast motion estimation for HEVC with adaptive search range decision on CPU and GPU

In this paper, we propose a fast Motion Estimation (ME) algorithm with Adaptive Search Range (ASR) decision to further accelerate the Graphics Processing Units (GPU)-based ME for High Efficiency Video Coding (HEVC). The proposed approach adaptively decides search ranges on the Central Processing Unit (CPU) and transfers them to the GPU. Then, the GPU performs ME process in parallel. The proposed approach solves the dependency problem in the Motion Vector Predictor (MVP) derivation stage by using only temporal Motion Vectors (MVs). The proposed algorithm yields the total encoding time reduction of 40.3% with negligible Rate Distortion (RD) loss of 1.2%. In terms of ME, the GPU-based ME with ASR decision provides the time reduction of 54.7% and 1446.8× speed-up on average compared to the GPU-based ME without ASR decision and the full-search ME in the reference model, respectively.