Fast multi-frame motion estimation algorithm with adaptive search strategies in H.264

In the new H.264/AVC video coding standard, motion estimation takes up a significant encoding time, especially when using the straightforward full search algorithm (FS). A fast flexible multi-frame motion estimation algorithm with adaptive search strategies (FMASS) is presented. With special considerations on the multiple reference frames and block modes, several techniques, i.e., adaptive search strategies for single frame and flexible multi-frame selection, have been utilized to improve significantly the speed-up performance in H.264. Extensive simulations show that it can minimize the matching points by more than 1190 times compared with FS. In addition, the output quality of the encoded sequences loses only 0.053 dB in terms of PSNR on average. Fast speed-up performance and unnoticeable quality losses make the proposed algorithm outperform most of the other well-known algorithms proposed recently, such as ARPS3, MVFAST and UMHexagonS, of which the latter two have been already accepted by MPEG-4 and JVT respectively.