Variable size block motion estimation can improve encoding performance

but increases the computational time.A fast motion estimation algorithm based on multi-search centers prediction and dynamic search range adjustment was proposed to speed up the computation.The multi-search centers prediction analyzes motion vectors of spatial and temporal adjacent blocks and results multiple predictive motion vectors which are used as search centers.Compared with the traditional motion vector prediction

the proposed prediction method can improve up to 14.6% prediction accuracy.According to the count and magnitude of the predictive search centers

the search range is dynamically adjusted to further reduce the computational complexity.Experimental results show that the proposed algorithm can reduce about 96.22%

59.50%

and 39.06% computational time separately compared with the fast full search algorithm

UMHS algorithm

and EPZS algorithm in H.264 reference software

while keeping similar rate-distortion performance.