Dynamic Search Range Control for H.264

This paper proposes an effective mechanism to select the dynamic search range for the H.264 multiple reference frames motion estimation with variable block sizes. Our dynamic search range control mechanism divides the search range into different zones determined by the block mode and reference frame of the target macroblock. In each zone, the search range is set on the basis of the motion vectors of its neighboring macroblocks and the motion vectors of block size 8x8. Experimental results show that our algorithm not only significantly reduces the computational complexity but also maintains the similar video coding quality as full search.