【作者】 王颖；

【导师】 金炜东；

【作者基本信息】 西南交通大学 ， 电气系统控制与信息技术， 2007， 硕士

【摘要】 视频监控以其方便、信息内容丰富而广泛应用于安保、生产管理等场合。图像编解码技术是视频监控中的关键技术之一。新一代视频编解码标准H.264压缩性能好，但计算复杂度高，限制了H.264标准的应用。Blackfin处理器是ADI公司推出的低功耗、高性能的定点DSP芯片，是H.264标准DSP实现的理想平台。本论文的研究目的是针对视频监控的需要，研究、实现一套基于H.264标准的视频编码系统。探讨H.264软件编码器在BF561上的实现及优化方法。论文主要是H.264和BF561嵌入式系统的应用研究。介绍了H.264标准的基本思想和原理及BF561的开发基础。分析了X264编码器流程，确定软件编码方案。实现了基于uCLinux嵌入式操作系统的X264编码器移植。最后，以ADSP-BF561 EZ-KIT LITE评估板为编码系统，使用各种优化方法和技巧，完成X264编码器的优化。根据BF561的结构特点，论文从项目级和C语言级别初步优化编码器；并着重用汇编优化了H.264的耗时模块，SAD运算、SATD运算和整数DCT变换程序；根据BF561的高速缓存机制，启用CACHE，提高系统编码速度。最后，用不同的测试序列对各阶段优化效果进行测试，确定较优的基于BF561的H.264视频编码器优化方案。本论文设计的软件编码系统具有较高的编码效率，测试结果表明了系统的可行性和稳定性。因此，研究基于BF561的H.264视频编码器具有一定的实用价值。更多还原

【Abstract】 Because of the richness and convenience, video monitoring is used widely by safety guard, product management, and so on. The video codec technology is the key in video monitoring.As the latest video codec standard, H.264 has the advantage of high compression rate. But because of its complex calculation, the application of this standard is limited. Blackifin processor is the pointing device produced by ADI Company, with low-powered consumption and high-powered performance. It is the perfect DSP flat in realizing the H.264 standard.The aim of the paper is to meet the need of video monitoring, research and realize a video encoder system based on H.264 standard, and discuss the realizing of H.264 Video Encoder based on BF561 and how to improve the encoding efficiency.The paper is mainly in the application of H.264 and the embedded system based on BF561. First, the author introduces the basic thought and theory of H.264, and the developing theories of BF561. Second, the author analyzes the flow of X264, and decides the software encodeing scheme. Third, the author realizes the migration of X264 Encoder based on uCLinux embedded operation system. Finally, the ADSP-BF561 EZ-KIT LITE evaluation board is employed as the video coding system. By various methords and skills, the author completes the optimization of X264.According to the characteristic of BF561, first of all, optimize the encoder in project and C language programming primarily. Secondly, optimize the time-consuming module, SAD arithmetic, SATD arithmetic, and DCT transform in assemble language. Thirdly, make use of the mechanism of Cache of the BF561 in order to improve the encoding rate. At last, test the effect of optimizing in every phases by several test sequences, and ascertain the better H.264 Video Encoder optimizing scheme based on BF561.The software encoding system designed in this paper has higher compress ratio. The test results indicates that the system’s feasibility and stability. Therefore, researching the H.264 Video Encoder based on BF561 has a certain practical value.更多还原