导　　师： 杨兆选

学科专业： H1002

授予学位： 硕士

作　　者： ;

机构地区： 天津大学

摘　　要： avs是我国完全具有自主知识产权的第二代音视频标准，其中包括系统、视频、音频、媒体版权管理等四个主要技术标准和一致性测试等支撑标准，为数字音视频产业提供全面的解决方案。其中，avs视频标准是该标准的第二部分。视频基准档次标准基本已经成熟，开始进入产业化进程。更高一级的x-profile也已经进入提案研讨阶段。 本文首先研究了avs视频解码器算法，然后在标准组提供的参考解码器基础上按照通用dsp一般的系统存储器等资源对解码器进行了优化建模。论文对avs解码器中的主要技术模块算法进行了比较详细的算法研究，并对解码流程各个层次进行了比较详细的代码剖析，画出了各个层次解码的程序流程图。在熟知参考解码器的基础上，了解参考解码器与c模型的距离后，进行了解码器的c语言建模工作，对代码整体结构进行了调整，封装；代码内常量表空间的优化；剔除系统相关函数；解码器内部各个环节缓冲存储空间的调整；边带信息的存储拆分；运动矢量，参考索引，参考帧存储空间的片内外划分；为了减少片内外数据交互量对环路滤波机制的调整；以及对各种错误的报告等等一系列的建模工作。 通过上述方法完成建模工作后，对该模型进行了计算复杂度分析和空间复杂度分析。针对特定序列，就解码器中各个模块进行了详细的复杂度分析，统计出了各模块的复杂度和整个解码器在各个环节的存储开销。最后对解码器进行了一致性测试，能够成功解码得到的一致性测试码流。 As the second generation coding standard, AVS /(Audio and Video coding Standard/) is our own independent Intellectual Property. The AVS standard includes four main technical part- system, audio, video and media copyright management, and a support standard-consistency test. It provides a complete solution for digital audio and video industry. AVS video is the second part of AVS standard. Now, the baseline-profile of video has been established and is already on the way of industrialization. And the X-profile is also on the stage of researching and discussing. Firstly, the thesis mainly discusses the main technical modules in the avs video standard. Secondly, according to the configuration of common DSP, a C model is constructed based on the reference video decoder. The core algorithm of avs video decoder are presented and studied in detail. Then, with the research on the reference implementation of avs video decoder, the decoding flow graph is drawn. After farmillar with the code of the decoder and the difference between the reference decoder and the C-model, the C-model construction of the video decoder is on the way. The specific steps include: the adjustment of the decoder structure; the package of some function and the reasonable compression of the memory space of constant tables in the decoder; the removal of some functions related to the special systems; the adjustment of all kinds of buffers in the process of decoding in order to compress the on-chip SRAM space; the split of the huge structure in the decoder; the on-chip and off-chip partition of the memory space of motion-vector, the reference index and the reference frame data. Besides, the mechanism of the deblock filter is fixed so as to reduce the interactivity between the on-chip SRAM and off-chip DRAM, and the mechanism of error report is added in the decoder, etc. Then, the C-model is profiled. A summarization and analysis of the C-model is made from aspects of operation-complexity and memory space complexity.At last, ConformanceTest is made on the C-model, and the result proves that the C-model decoder can process the input coded video stream in the right way.

关 键 词： 视频标准 解码器 环路滤波 图像编码 模型

分 类 号： [TN919.81]

领　　域： [电子电信] [电子电信]