An adaptive motion vector refinement algorithm for video transcoder

An adaptive refinement algorithm for motion vector in video transcoding is presented. Making use of the spatial coherence and amplitude intensity of local motion vectors, a motion activity model is constructed, by using which the search range of the macroblock is adaptively confirmed. Then, a multi-pattern refinement strategy based on the horizontal and vertical search (HAVS) and diamond search (DS) is proposed. Simulation results show that the proposed method reduces the computational complexity significantly without degrading the video quality.