Fast Inter Mode Selection Algorithm for Motion Estimation in MPEG-4 AVC/JVT/H.264

The newest video coding standard H.264/AVC utilizes flexible block sizes and multiple reference frames to do motion estimation. Totally, there are seven possible types of block sizes to be selected in motion estimation. The exhaustive cost calculation for possible modes is required to find the motion vector. In order to reduce the computational complexity, this paper proposes a fast algorithm to select the block mode. The algorithm uses fuzzy inference with motion vector tightness and the variance of image intensity to determine whether it is necessary to do motion estimation with smaller size block mode. From the simulation result, the proposed fast algorithm can save at least 30% encoding time without sacrificing the picture quality and the bite rate efficiency.