【作者】 和艳丽；

【导师】 虞露；

【作者基本信息】 浙江大学 ， 信号与信息处理， 2003， 硕士

【摘要】 随着人们对数字电视，有线／无线可视电话，多媒体应用和视频在介质上存储的广泛关注，过去十年来，视频压缩编码技术有了巨大的发展。目前最成功的技术是基于运动估值，DCT的混合视频编码方案，并导致了ITU-T H．261／3，MPEG-1/2，MPEG-4等国际标准的出现。这些技术的计算密集的特点对其实时实现提出了挑战。专用的基于VLSI的实现是一种解决方案，既可以作为专用的编解码器，又可以作为其中的核心模块。这种方法十分有效，因为设计可以针对专门的算法进行高度优化。其缺点在于其中有大量的专用模块，当算法需要修改时，便无法适应新的算法，只能重新设计。更加灵活的方案是利用可编程DSP。这种方法不仅缩短了开发时间而且具有高度的适应性。而且随着VLSI技术的不断发展，DSP实现与VLSI实现的性能差别也将越来越小。本文首先回顾了DSP处理器结构的演进，然后对视频编码DSP实现的方法进行了探讨。从实时性要求，系统开销的角度分析了如何对算法，程序，以及并行性等进行改进才能满足实时要求，减少系统开销。同时基于DSP系统有限的存储器资源，从改写程序代码的角度，提出了减小存储器占用的策略。本文最后以MPEG-4 Simple Profile编码在TI C6201上的实现为例说明了整个DSP程序开发的流程，对其中采用的各种优化技术进行了一一介绍。更多还原

【Abstract】 Due to the increasing interests in digital TV,wired/wireless video telephony,multimedia applications and storage of video on compact disks,there has been tremendous progress in video compression and coding for the last decade. The most successful techniques so far are the hybrid coding schemes,i.e.,those based on motion estimation(ME) and discrete cosine transformation(DCT).The hybrid coding gives rise to all international standards for moving images,i.e.,ITU-T H.261/3,MPEG-l/2 and MPEG-4. The intensive computation involved in these techniques poses challenges to real-time implementation.Dedicated VLSI-based implementation can be made for such computationally intensive schemes,as either complete codecs or core modules. These approaches are efficient since the design can be highly optimized for particular algorithms. Disadvantages of the approach are the large number of dedicated modules and their limited adaptability for an algorithm to be modified. Adaptation to a new coding scheme can result in a redesign.More flexible implementation is achieved by utilizing programmable DSP. Such an approach not only shorten the time to market but also offers adaptability by reprogramming. With the development of VLSI technique,the performance difference between DSP implementation and VLSI will become very small.This paper is composed of the following parts:Firstly,major video coding techniques and standards and the evolution of DSP architecture is analyzed.Secondly,the methodology of video coding implementation on DSP is given. To meet the real-time requirements and lower the cost some major principles must be adopted during the process of choosing algorithm,writing code and utilizing parallelism.Lastly,as an example of DSP implementation of video coding,the development flow of MPEG-4 video Simple Profile coding on TMS320C6201 DSP is presented. Major techniques are also given.更多还原