改进的H.264帧间模式选择算法

Improved inter frame mode selection algorithm for H.264

针对H.264帧间模式选择算法存在的问题,提出一种帧间模式选择快速算法。算法采用8×8块运动矢量同质性分析对宏块模式进行选择,缩小候选模式范围,降低H.264帧间模式选择算法的计算复杂度;使用模式相关和运动矢量合并对UMHexagonS算法进行优化,减少大量的运动估计搜索点数,取得了较高的编码效率。实验结果表明,与使用UMHexagonS的帧间模式选择算法相比,该算法在峰值信噪比及输出码流码率基本不变的前提下,可以平均减少大约50%的运动估计时间。

Aiming at the problem of H.264 inter frame mode selection algorithm, a fast inter frame mode selection algorithm is proposed in this paper. The algorithm selects the macroblock mode by using homogenous analysis of an 8×8 block motion vector, to narrow the scope of the candidate modes and decrease the computational complexity of the H.264 inter frame mode selection algorithm. Meanwhile, the algorithm uses mode correlation and motion vector merging to optimize the UMHexagonS algorithm, which could reduce a large number of motion estimation search points, and obtain higher coding efficiency. The experimental results show that compared with inter frame mode selection algorithm using UMHexagonS, the proposed algorithm can reduce about 50% motion estimation time with only negligible change of PSNR and output stream bit rate.