*+,-High Efficiency Video Coding (HEVC) GPU (integer-pel) (Motion Estimation)  !"./0. -Motion Vector Difference (MVD)1#23 0. 45, 678MVD19:367; 9?0. #@9?AB 0. R-CPU #STU, CPUG8LMNRGPUOV0. #@GPUGWX>Y0. ./GHIJ-Z[<=\]1.1%8BD-rate ( RO^L_837.9% `a951.2bcdYL_eG0. f, #2gTh-ijWXHIJ\]57.5%8L_`k0.6% BD-rate ( eG0.AbstractIn this paper, we propose a new Adaptive Search Range (ASR) decision algorithm for accelerating GPU-based Integer-pel Motion Estimation (IME) of High Efficiency Video Coding (HEVC). For deciding the ASR, we classify a frame into two models using Motion Vector Differences (MVDs) then adaptively decide the search ranges of each model. In order to apply the proposed algorithm to the GPU-based ME process, starting points of the ME are decided using only temporal Motion Vectors (MVs). The CPU decides the ASR as well as the starting points and transfers them to the GPU. Then, the GPU performs the integer-pel ME. The proposed algorithm reduces the total encoding time by 37.9% with BD-rate increase of 1.1% and yields 951.2 times faster ME against the CPU-based anchor. In addition, the proposed algorithm achieves the time reduction of 57.5% in the ME running time with the negligible coding loss of 0.6%, compared with the simple GPU-based ME without ASR decision.Keyword : HEVC, Fast ME, Adative Search Range, MVD, GPGPU%+,(Regular Paper)!Vlmn+,T.19o.5, 2014p9q(JBE Vol. 19, No. 5, September 2014)http://dx.doi.org/10.5909/JBE.2014.19.5.699ISSN 2287-9137 (Online) ISSN 1226-7953 (Print)