Adaptive Cross-Diamond Search Algorithm for Fast Block Motion Estimation in H.264

Motion estimation plays a key role in the H.264. It is the most computationally intensive module. In this paper, we proposed a novel adaptive cross-diamond search (ACDS) algorithm for fast block motion estimation in H.264. The proposed algorithm adaptively chooses different search pattern according to the seven types of macro block division in H.264 and the motion vector distribution characteristics of video sequence. Experimental results show that the proposed ACDS algorithm is much faster than the UMHexagonS algorithm, whereas similar prediction quality is still maintained.