Local reference with early termination in H.264 motion estimation

Multiple reference frames and variable block sizes improve compression efficiency of H.264, however, they also increase the encoder complexity and motion estimation time. This paper proposes a new algorithm, called Local Reference with Early Termination (LRET) to reduce the H.264 motion estimation time without adding to the encoder complexity. The LERT algorithm rearranges the search order of the reference frames based on the selection probability of the reference frames in the current frame. The experimental results show that the LERT achieves up to 59% reduction in motion estimation time with comparable video quality and negligible increase in bit-rate, as compared to the best algorithm in H.264 reference software.