【作者】 汪毅；

【导师】 龚跃玲；

【作者基本信息】 武汉理工大学 ， 电力电子与电力传动， 2007， 硕士

【摘要】 随着社会各方面的快速发展，工业生产、国家安防及日常生活中对网络视频监控系统的要求越来越高，但是目前在网络视频通信的即时性和清晰度等方面都还存在很多技术难点，同时，监控系统的广泛应用对成本问题也提出了更高的要求，将嵌入式系统代替PC机的呼声也越来越高，因此在该方面的研究具有广泛的应用前景和实用价值。H.264是由联合视频组(JVT)制定的新一代视频压缩编码标准。其不仅比H.263和MPEG-4节约了50％的码率，而且对网络传输具有更好的支持功能。这对目前因特网传输多媒体信息具有重要意义。TMS320DM642是TI公司推出的一款针对多媒体处理领域应用的DSP，它在C64x的基础上，增加了很多外围设备和接口，是嵌入式视频系统设计的首选。论文对H.264视频编码技术进行了深入的分析，借鉴国内外优秀算法的经验，提出了一种改进的帧内预测编码算法，以提高H.264的编码效率，改善网络通信即时性问题。同时利用DM642来完成前端视频处理，设计出具有应用前景的视频监控系统。在研究过程中，H.264协议算法的优化是一个技术难点。论文针对帧内预测算法运算量大的特点，提出了一种改进的帧内预测模式选择算法，利用简化的率失真函数判断方法来减小帧内预测复杂度，在不影响原有图像质量的基础上提高编码的运算时间。考虑到部分C语言程序在移植入DSP后会由于数据结构和程序结构上的差别而影响硬件环境的运行效率，因此论文提出了五步优化法，对移植后的程序进行了全面优化，设计了与硬件结合紧密的汇编语言程序，将汇编语言代替部分C语言来实现算法。利用完全针对C6000系列DSP开发的线性汇编算法来优化最终移植入硬件的程序也是论文的关键技术和创新点。线性汇编算法充分的利用了DSP的硬件优势，大大提高了整个程序的运行效率，节约了编码时间。实验表明，优化算法提高了帧内预测模式选择的效率，结合DSP硬件系统的汇编语言改写和线性汇编程序也大大提高了代码效率。更多还原

【Abstract】 Along with the social various aspects fast development, the network video supervisory system is more and more higher in the industrial production, national security and daily life. While there, at present, are many technical difficulties in network video communication instantaneity and definition etc. at the same time, the monitor and control system’s abroad application bring forward to the higher request in the cost, the voice of substitute PC with embedded system become higher and higher, therefore, there has the widespread application prospect and the practical value in this aspect research.H.264 is the new generation of video frequency compression code standard which (JVT) formulates by the union video frequency group. Its not only saved 50% code rate compared to H.263 and MPEG-4, moreover has the better support function to the network transmission. This transmits the multimedia information to the present Internet to have the vital significance.TMS320DM642 is section which TI Corporation promotes in view of multimedia processing domain application DSP, it in the C64x foundation, increased the very many auxiliary equipment and the connection, is embedded video system design the first choice.This thesis has carried on the thorough analysis to the H.264 video code technology, profits from the domestic and foreign outstanding algorithms the experience, proposed in one kind of improvement frame the predictive coding algorithm, enhances H.264 the coding efficiency, the improvement network correspondence instantaneity question. Front meanwhile completes video processing using DM642, this design has the application prospect of the video supervisory system.This research achievements and innovation as follows:The H.264 protocol algorithm optimization is a technical difficulty. In view of the intra prediction algorithm is far calculated characteristic, which proposed in one kind of improvement to the intra prediction pattern choice algorithm, and the use of the simplifies rate distortion optimization function judgment method to reduce the complex in intra prediction. This algorithm does not affect the original picture quality in the foundation but enhance the encoded operation time.Considered the partial C language procedure after transplants into DSP to be able affects the hardware environment as a result of in the construction of data and the procedure structure difference the operating efficiency, therefore this chapter has designed with the hardware union close assembly language procedure, the assembly language will replace the partial C language to realize the algorithm.Using completely aims at C6000 the series DSP development the linear assembly algorithm to optimize finally transplants into the hardware the procedure also is the article innovation spot. The linear assembly algorithm full has used the DSP hardware superiority, greatly enhances the entire procedure operating efficiency, and saves the code time.The experiment indicated that, the optimized algorithm enhanced the intra prediction algorithm efficiency, unified the DSP hardware system assembly rewriting and the linearity assembly program also greatly enhanced the code efficiency.更多还原