Rate distortion-based motion estimation search ordering for rate-constrained successive elimination algorithms

In this paper, we propose a new class of search ordering algorithms to reduce the computational cost of motion estimation in video coding. We show that conventional search orderings, such as spiral search, can weaken the filtering criterion of rate-constrained successive elimination algorithms. Based on this new insight, we derive a new search ordering that takes into account the impact of the rate constraint. Our simulation results demonstrate that, on average, the amount of SAD operations required to encode the tested sequences, is reduced by 2.86%, when compared to the H.264 JM reference software´s implementation of spiral search. For sequences with unpredictable motion, this reduction is greater than 5% and can exceed 10% when smaller block partitions are evaluated.