【作者】 王莉理；

【导师】 陈强；

【作者基本信息】 南京大学 ， 控制科学与工程， 2012， 硕士

【摘要】 H.264视频压缩编码是由ITU-T视频编码专家组和ISO/ICE活动图像专家组组成的联合视频组共同开发的高性能编码,但是编码算法复杂度较高。运动估计是视频编码中的影响复杂度的主要环节。本文首先通过研究运动估计搜索算法的原理,提出了基于运动图像剧烈程度的快速运动估计优化算法。该算法结合图像块的运动相关性,对块的运动区域分为背景区、准背景区和运动区,采用不同的运动估计搜索算法进行视频编码,构造了相应的编码器。其次在TMS320DM6437DSP开发平台上以H.264标准的X264版本开源代码为参考模型,经过对代码进行内联函数优化、C语言级优化、编译器优化、线性汇编优化等优化步骤,实现了运动估计优化算法的功能。最后,运用标准化的测试视频对所提算法进行了数值环境下的模拟和DSP平台上的编码实验,得出了有效的结果。实验结果表明基于H.264的视频编码运动估计优化算法不仅在图像的编码质量方面对各种运动复杂度的视频序列都有较好的适应性,而且较大幅度地提高了编码速度,在DSP平台上可满足视频编码器实时性的需求。更多还原

【Abstract】 The H.264video compression standard is developed by the Joint Video Team of ITU-U Video Coding Experts Group and ISO/ICE Moving Picture Experts Group. The high efficient H.264encoding high efficiency is built on high complexity encoding algorithm. Motion estimation is vital to video compression.In this paper, through the study of motion estimation algorithm, an optimized algorithm based on the different motion complexity of images is proposed. Combined with motion correlation, the images are divided into background area, quasi-background area and sports area. Then motion vector should be searched by the different motion estimation search algorithms in different area. The X264open source code is chosen as a reference model in this paper. Then we realize the video encoder by transplant the X264code to the Integrated Development Environment CCS of TMS320DM6437platform. Some methods such as the inline function optimization, the C language optimization, compiler optimization, linear assembly optimization are applied to the program. Finally, effective results are got through simulation in numerical environment and coding experiment on DSP platform.Experiments results show that, in the PSNR aspects, the optimization algorithm has good adaptability to a variety of motion complexity of image. The great improvements in coding speed can be got from the optimized algorithm. The encoder built on the DSP meets the requirement of the real-time video encoding.更多还原