光电子  >> Vol. 1 No. 2 (December 2011)

H.264视频编码器中运动估计算法的优化
Optimization of Motion Estimation Algorithm in H.264 Video Encoder

DOI: 10.12677/oe.2011.12004, PDF, HTML, 下载: 2,279  浏览: 7,244  科研立项经费支持

作者: 郭亲弟, 龙长贵

关键词: H.264UMHexagonS运动估计运动复杂度MVFAST
H.264; Umhexagons; Motion Estimation; Motion Complexity; MVFAST

摘要: 运动估计是视频编码的关键技术,H.264编码器中的运动估计采用UMHexagonS算法,具有良好的综合性能,但其运算量仍比较大,难以满足实时编码的要求。本文基于MVFAST算法图像运动复杂度,提出了一种UMHexagonS的改进算法。依据ROS(支撑域),通过在水平垂直的四个方向上分别设置搜索范围,建立了非搜索中心对称的动态窗口,用更小的搜索范围覆盖了最佳匹配点,进一步减小了搜索点数;进一步根据图像运动复杂度,优化了起始搜索模板的选择策略,直接减少了中等和低等运动复杂度视频序列的计算量。实验表明,与UMHexagonS算法相比,改进后的算法在获得几乎同等重建图像质量和码率的同时,运动估计时间平均节省了24.53%;与对照文献相比算法节省了6.24%,有效的提高了编码器的实时性。
Abstract: Structural Motion estimation is the key technology of Video coding, The UMHexagonS algorithm of H.264 encoder has a good overall performance, while its computation is still relatively large to meet the requirement of real-time encoding. In this paper, based on the complexity of image motion in MVFAST algorithm, an improved UMHexagonS algorithm is proposed. Based on ROS (region of support), by setting search range separately in the four directions of horizontal and vertical, a dynamic search window was established to covering the best match point using a smaller search window; Further according to the image motion complexity, the selection strategy of initial search template was optimized , which directly reduce the computation of low and middle complexity of motion video sequence. Experiments show that, compared to UMHexagonS algorithm, our optimized algorithm can save about 24.53% ME time but almost has no change in the reconstructed picture quality and bitrate; and ME time is 6.24% lesser than compared algorithm as well as enhance the real-time performance of the encoder.

文章引用: 郭亲弟, 龙长贵. H.264视频编码器中运动估计算法的优化[J]. 光电子, 2011, 1(2): 16-20. http://dx.doi.org/10.12677/oe.2011.12004

参考文献

[1] T. Wiegand, G. Sullivan, G. Bjontegaard, et al. Overview of the H.264/AVC video coding standard. IEEE Transactions on Cir- cuits and Systems for Video, 2003, 13(7): 560-576.
[2] B. C. Zhi, Z. Peng and H. Yun. Fast integer pel and fractional pel motion estimation for JVT. JVT 6th Meeting, Document JVT- F017, Awaji, 5-13 December 2002.
[3] Y. Cheng, K. Dai and Z. Y. Wang. A new zero block detection method for H.264/AVC. Journal of Computer Research and De- velopment, 2005, 42(10): 1758-1762.
[4] W. Wei, Z. X. Hou. A fast motion estimation algorithm with adaptive threshold. Journal of Optoelectronics•Laser, 2008, 19(9): 1254-1257.
[5] X. Z. Xu, Y. He. Modification of dynamic search range for JVT. JVT-Q088, 17th Meeting on Joint Video Team (JVT) of ISO/IEC MPEG & ITU-T VCEG, 14-21 October 2005, USA.
[6] X. J. Wu, S. J. Bai and W. T. Lu. Optimization on motion esti- mation algorithm based on H.264. Journals of Electronic, 2009, 37(11): 2541-2145.
[7] J.-Y. Nan, J.-S. Seo, et al. New fast search algorithm for block matching motion estimation using temporal and spatial cor- relation or motion vector. IEEE Trans on Consumer Electronics, 2000, 46(4): 934-942.
[8] Y. Q. Zhang, S. Zafar. Predictive block-matching motion estima- tion for TV Coding. IEEE Transactions on Broadcasting, 1991, 37(3): 102-105.
[9] P. I. Hosur, K.-K. Ma. Motion vector field adaptive fast motion estimation. Second International Conference on Information, Communications and Signal Processing (ICICS’99), Singapore, 7-10 December 1999.
[10] A. M. Tourapis, O. C. Au and M. L. Liou. Predictive motion vector field adaptive search technique (PMVFAST). ISO/IEC JTC1/ SC29/WG11 M5866, Noordwijkerhout, March 2000.
[11] I. Ahmad, W. G. Zheng. A fast adaptive motion estimation algorithms. IEEE Trans Circuits and Syst Video Technol, 2006, 16: 420-438.