Abstract: H.264/AVC is the latest video compression standard enacted by ITU-T and ISO/IEC Joint Working Group.Motion estimation，as the most computational complexity component in H.264，has a significant impact on the performance of the entire algorithm.An adaptive fast motion estimation algorithm is presented to improve the efficiency of the search process.Experimental results show that with a slight decrease of PSNR，the proposed algorithm substantially improves the encoding speed，providing a feasible choice for practical application.

摘要： H.264/AVC是ITU-T和ISO/IEC联合制定的最新视频压缩标准。运动估计作为H.264算法中计算最复杂的部分，在很大程度上影响着整个算法的性能。为提高运动估计算法的搜索效率，提出了一种自适应的快速运动估计算法。实验结果表明，该算法可大幅提升编码速度，而PSNR仅略有下降，为工程实现提供了一种可行的选择。