H.264/AVC编码器子象素插值快速实现方法

子象素运动估计是H.264/AVC等混合编码标准中普遍使用的用于提高预测精度的技术,使得预测精度达到1/4象素,甚至1/8象素,从而提高编码性能。在做运动估计之前需要对参考图像插值,由于插值算法复杂度较高,计算资源耗费很大,所以如何简化和优化其插值算法,实现一个快速的插值过程,对编码器的实时性极其重要。论文提出了一种H.264/AVC编码器子象素插值的快速实现方法,首先简化运算的复杂度,然后通过优化数据结构来消除数据相关性,最后使用SIMD指令优化算法,从而高效地实现了标准的插值过程。实验证明,使用提出的方法实现的插值过程比H.264/AVC参考软件JM10的插值过程快25倍以上。

Fast Implementation for Fraction PixelInterpolation of H.264/AVC Encoder

The sub-pixel motion estimation is a popular technology,it has been widely used in most current coding standards,such as H.264/AVC,for achieving higher prediction accuracy.It can be 1/4 pixel,and some even to 1/8 pixel precision,to improve the coding effficiency.However,the computation complexity of sub-pixel interpolation is usually very heavy.It costs much time in encoder and result in much lower running speed.In this paper,the performance of fractional pixel interpolation is improved drastically by predigesting arithmetic implimentation,redesigning data structure to reduce data depending,and using SIMD insturction. Experimental results based on AVC/H.264 reference mode JM10 encoder show that the improved interpolation algorithm is 25 times faster than that of the reference software.