Compared with the previous standard

the compression performance of H.264 has significantly improved because of different block-size motion estimation.However

encoder using above technology becomes extraordinarily complex.Thus

a real-time video encoder based on H.264 faces enormous challenges.Making full use of the spatiotemporal correlation of video and similar motion between the different-size block

according to the central-biased characteristic of motion vector

a fast motion estimation algorithm appropriated for H.264 is proposed in this paper.By effective prediction of search window center point

adaptive selection of search patterns and termination of the search

the speed of the proposed algorithm speedups 95-247 times than full search and 4.1-6.3 times than the fast motion estimation algorithm recommended in H.264 while maintains similar distortion performance.