H.264是最新的视频编码标准,它相对于以前的视频编码标准在编码效率上有了巨大的提高。高编码效率得益于采用了一系列新的编码技术,这也导致了较高的计算复杂度。H.264运用了可变块运动估计方法,这也是H.264编码过程中最耗时的模块。提出了一种基于H.264的可变块快速运动估计算法。该算法基于以下3种策略:静止块的预测、非静止块的预测搜索和合并过程中的自适应精细搜索。试验结果证明,该算法能够将计算复杂度降低到快速全搜索运动估计算法的3%,而PSNR和码率几乎与快速全搜索算法得到的结果相当。

H.264,the latest video coding standard,achieves significant improvement in coding efficiency compared with previous standards.The high coding efficiency is based on some new techniques which also lead to high computational-complexity.H.264 uses variable-block-size motion estimation,which is the most time-consuming module.In this paper,we propose a fast variable-block-size motion estimation algorithm for H.264.The algorithm is based on three schemes: stationary block prediction,predictive search for non-stationary blocks and adaptive refinement search in merging process.Experimental results show that our algorithm can reduce the computational-complexity to 3% of fast full search motion estimation algorithm,with negligible PSNR loss and bit rate increase.