Institutional Repository
| H.264视频编码器基于DSP的实现和优化 | |
| Alternative Title | Implementation and Optimization of an H.264 Video Encoder Based on DSP |
| 包晓明 | |
| 2007-06-06 | |
| Degree Grantor | 中国科学院软件研究所 |
| Degree Level | 博士 |
| Place of Degree Grantor | 软件研究所 |
| Keyword | H.264 Dsp Tcp/ip 移植 优化 |
| English Abstract | 视频监控在道路交通、社会治安和安全生产等领域取得了广泛的应用，视频监控产业进入了高速发展的时期。视频监控系统的两个核心技术就是高效稳定的视频编码算法和设备。基于DSP的独立机型嵌入式视频监控前端具有体积小、成本低、开发自由度大和处理能力强等优势，逐渐成为视频监控前端的主流解决方案。目前最新的视频编码国际标准H.264具有压缩比高、容错能力强和网络适应性好等特点，已经被越来越多的嵌入式视频监控前端所采用。 本文以网络视频监控系统为背景，详细阐述了基于PNX1500 DSP的H.264视频编码器的实现方案；针对系统的软硬件平台，提出了多项编码器优化方法，把编码速度提高了数倍，实现了对CIF格式视频流的实时编码。 全文共分五章，第一章分析了选题的应用背景，介绍了目前的视频监控技术和H.264视频编码技术的概况，简述了采用H.264视频编码器的嵌入式视频监控前端系统开发工作。第二章介绍了视频监控前端软件系统基于PNX1500 DSP的详细实现方案，包括软件系统整体结构、H.264算法移植、码率控制、OSD功能实现、报警处理、语音对讲和外围设备控制。第三章介绍了TCP/IP协议栈在视频监控前端软件系统中的实现方案，包括协议栈的移植、增加PPPoE协议和性能测试。第四章针对基于PNX1500 DSP的H.264视频编码器，提出了一系列优化方法，包括使用硬件实现半像素插值、提前判断宏块的跳过模式、简化帧内预测、简化运动估计、SAD值抽样计算、使用DSP定制运算、循环展开和编译优化等，并给出了各种优化方法下的测试结果。第五章对本文进行了总结，并展望了下一步的工作。 |
| Abstract | Video surveillance has been widely applied to many fields, such as road traffic, social security, manufacture security, and so on. Video surveillance industry is in a high-speed developing period. Two key technologies in video surveillance systems are efficient and stable video encoding algorithms and equipments. Embedded front-ends for video surveillance based on DSP have the advantages of small volume, low cost, broad freedom of developing, and high ability of processing, thus they have become the primary resolving scheme for video surveillance. Nowadays the up to date international video encoding standard H.264 has been adopted by more and more embedded front-ends for video surveillance since its high compression rate, error accommodation ability, and nice network adaptability. In the background of a network video surveillance system, this thesis first describes the implementation schemes of an H.264 video encoder based on PNX1500 DSP in detail, and then gives a series of optimization solutions of the video encoder. Test results show that the video encoder increased the encoding speed by several times and performed real-time encoding of video streams in CIF format. This thesis consists of five chapters. The first chapter introduces the application background, including the development status of video surveillance technology and H.264 video encoding technology, and gives an overview of the development of an embedded front-end system for video surveillance based on an H.264 video encoder. The second chapter presents the detailed implementation of the front-end software system based on PNX1500 DSP, including system architecture, H.264 algorithm porting, rate control, OSD function, alarm management, voice interaction, and peripheral equipments control. The third chapter describes TCP/IP protocol stack porting, the implementation of PPPoE protocol, and performance testing results of the protocol stack. The fourth chapter proposes a series of optimization solutions of H.264 video encoder based on PNX1500 DSP, including half-pixel interpolation using hardware, early skip mode decision, intra prediction predigestion, motion estimation predigestion, SAD sample calculation, DSP custom operations, loop unrolling, compilation optimization, and so on. Test results of all the optimization solutions are also included in the fourth chapter. The fifth chapter summarizes this thesis and gives the future work. |
| Pages | 72 |
| Language | 中文 |
| Content Type | 学位论文 |
| URI | http://ir.iscas.ac.cn/handle/311060/7492 |
| Collection | 中科院软件所_中科院软件所 |
| Recommended Citation GB/T 7714 | 包晓明. H.264视频编码器基于DSP的实现和优化[D]. 软件研究所. 中国科学院软件研究所,2007. |
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| File Name/Size | DocType | Version | Access | License | ||
| 10001_20042801502908（1633KB） | 限制开放 | -- | Application Full Text | |||
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