Fast motion estimation algorithm for H.264 with multi-references

In H.264 standard,the codec allows seven block types to search the best motion vector in several reference frames to achieve lower bit rate and higher quality.Since the reference code uses the full search scheme to obtain the best performance,it will increase the computational complexity significantly.Synthesis motion vectors were adopted to predict the optimal matching location according to correlation and continuity of motion vectors among adjacent frames.Meanwhile,adaptive criteria related to selected MB's mode were used to determine whether it is necessary to search more reference frames.The simulation results show that the speed of the proposed algorithm is over six times faster than that of the original scheme adopted in JVT reference software with similar video quality and low bit rate.