次世代高清音频编解码技术(毕业论文)案例.doc

次世代高清音频编解码技术 Researching of the next generation high definition audio codec technology 专 业： 班 级： 姓 名： 指导教师姓名： 指导教师职称： [摘 要] 近年来以数字音频技术为代表的多媒体技术飞速发展，CD，DVD等早已走进千家万户，高清晰数字节目广播则正在全球范围内逐步开展。AC-3是杜比实验室开发的数字音频编码技术，该技术可以传输和存储多达5个全频带声道和一个低频效果声道，而所占用的存储空间比CD上一路线性PCM编码所占用的空间还要少。由于AC-3系统编码灵活，在消费电子领域，当前大多数的电影制作都使用了该技术，美国等国家的数字电视系统也采用该技术作为音频编码标准。数字化影院系统(DTS)5.1环绕立体声编码格式也便应运而生，为人们提供了高品质的听觉享受，目前广泛应用于影院、DVD、HDTV等消费电子领域。 本文主要介绍了杜比数字音频和DTS数字音频的发展，比较了杜比数字音频和DTS数字音频的优缺点，详细介绍了次世代高清音频的格式，研究了AC-3、DTS的编码及解码技术，详细研究了AC-3编码器核心算法模块：输入滤波、暂稳态判决、MDCT、指数编码、比特分配。推导并实现了用N／4点FFT实现N点MDCT的快速算法，并将短窗MDCT转换为与长窗MDCT一致的计算方式。研究了DTS音频编解码器核心算法模块，包括子带编码、矢量量化、块解码、循环冗余校验、差分脉冲调制解码、联合子带解码和低频效果声道插值。 关键词：AC-3、DTS、解码、算法 [Abstract] Digital audio technology as the representative multimedia technology has developed rapidly recently. CD, DVD and other multimedia devices have already been applied in thousands of families. High-definition digital broadcasting is developing gradually worldwide. AC-3 is a digital audio coding technology developed by Dolby Lab. The technology can transfer or store as many as 5 full frequency band channels and a low frequency effect channel, the memory required is less than one channel linear PCM data in CD. Due to the flexibility of AC-3 system, in the custom electronic domain, most of movies are using this technology now, and the digital TV system of several countries, like America, also make use of this technology as the standard of audio coding. The digital theater system (DTS)5.1 surround sound encoding format came into being, which could provide people with a high quality acoustic enjoyment. Now DTS has been widely used in films, DVD,HDTV and other consumer electronics. Dolby digital and DTS audio was studied in this paper, development and digital audio formats, this paper introduces the AC-3, DTS, encoding and decoding technology. AC-3 encoder