An Efficient Algorithm for Motion Estimation with Multiple Reference Frames in H.264/AVC

Multiple reference frames motion compensation is one of the new features adopted in H.264/AVC to improve the coding efficiency of inter frames. However, the computational complexity of multi-reference frames motion estimation (MRME) is increased in proportion to the number of searched reference frames. This paper presents a novel scheme to reduce the complexity of MRME. In order to speed up the MRME process, the following factors such as frame rate, motion activity and search range are considered. Experiment results verify that the proposed algorithm can reduce the number of reference frame from 5 to 1.6 and save the MRME time by 90.2% on average respectively with little degradation of coding efficiency.