DCT算法分析和结构设计.pdf

Dissertation Submitted to Shanghai Jiao Tong University for the Degree of Master The Analysis And Structure Design Of DCT Algorithm Candidate : Zhang Xiaochen Student ID : 1072109055 Supervisor : Prof MaoZhigang Assistant Supervisor: Prof He Weifeng Academic Degree Applied for : Master of Engineering Speciality : Software Engineering Affiliation : School of Microelectronics Date of Defence : Feb, 2010 Degree-Conferring-Institution : Shanghai Jiao Tong University 第 I 页 DCT 算法分析与结构设计摘要 是 ITU 与 ISO 联合共同开发的新一代视频编码标准,具有很多优点:高编码效率、高压缩质量、自适应的延时特性和容错功能。 具有强大的优势, 的这些强大优势来源于更加复杂精细的算法和更高的硬件支撑平台,它的编解码时间都是之前视频标准的数倍,所以对它的变换编码进行研究有着巨大的现实意义。 标准的DCT 算法, 采用4×4块及 8×8 块的无乘法整数变换编码算法,有效地降低了编解码的运算量,且避免了反变换的误匹配问题。然后采用行列分解法的整体设计来实现二维 DCT,其中运用快速算法、流水线设计等方法来提高算速度,并在这基础上提出一种改进的加法结构--4-2 压缩器和超前进位加法器级联,并将之应用于4×4 及8×8 的整数DCT 编码实现中,降低延迟时间,加快了运算速度。 标准中,为了提高数据压缩的性能,采用分层的二维整数余弦变换。在进行完 DCT 编码后,还要对宏块的直流分量进行 Hadamard 编码, 标准中DCT 编码和Hadamard 编码的矩阵特点,使之可以和Hadamard 编码进行复用,节省面积的作用。通过对加法器结构上的改进,有效的提高了运算速度。 关键字:,DCT,硬件实现第 II 页 THE ANALYSIS AND STRUCTURE DESIGN OF DCT ALGORITHM ABSTRACT is a new generation of vide o coding standard developed by developed by ITU and ISO. The new stan dard has characters such as low bit rate, high quality picture, time-de lay adaptive ability and strong error fix ability. Though is better than the video coding standard before, the advantage of from the more sophisticated algorithm and the higher hardware support, Its time the code and the decode taken is many times of the video coding standa rd before. The research of the critical algorithm and its implementa tion in coder and decoder is very helpful for the application. In , the 4×4 block and 8×8 bl ock integer cosine transform are used. This can help to reduce the complexity in coding and decoding. Avoid the mismatch between th e DCT and this design , researching the DCT