提出了基于自适应搜索长度的UMHexagonS算法。UMHexagonS算法是H.264标准视频编码中的运动估计算法之一。经过理论和数据的分析后，发现其搜索长度的选择可以改进，于是提出了利用前若干搜索点的信息来选择合适搜索长度的自适应算法，使搜索算法避开了一部分多余的搜索点。实验结果表明,在保证PSNR和码率变化不大的前提下，可以有效地降低大约15%的运动估计时间。

The paper proposes the adaptive search range algorithm of UMHexagonS, which is one of motion estimation algorithms for video encoding system on the H.264 standard. Based on analyzing the search range theoretically and experimentally, its search range algorithm can be improved. Then, the adaptive algorithm, derived from the anterior search points, is created to reduce the redundant search points. The result shows that the adaptive algorithm can reduce the 15% period of motion estimation under the premise of little change on PSNR and Bit Rate.