基于AC3的虚拟环绕声实现

Q260046902专业做论文西南科技大学毕业设计（论文）题目名称：基于AC3的虚拟环绕声实现年级：2003级√本科□专科学生学号：20035303学生姓名：黄小宝指导教师：詹曦学生单位：信息工程学院技术职称：助教学生专业：通信工程教师单位：信息工程学院西南科技大学教务处制西南科技大学本科生毕业论文I基于AC3的虚拟环绕声实现摘要：DolbyAC3提供的5.1声道音频模式是当前应用得最广泛、声音质量较高、编码效率最高的一种音频编码模式。基于AC3的虚拟环绕声系统能够满足人们在不允许布置多个扬声器的情况对环绕声音质的要求，而且简化了系统，降低了消费；它特别适用于耳机这类只有两个扬声器的设备。本文论述了用软件实现虚拟环绕声的两种途径，即用Matlab和C语言编程来仿真5.1声道虚拟环绕声重放。用Matlab进行虚拟环绕声的仿真是通过对AC3音频文件解码后得到的六个声道信号进行虚拟环绕声滤波处理。C程序设计将多通道虚拟环绕声处理技术与AC3解码程序相结合，实现基于AC3的5.1声道虚拟环绕声重放系统。Matlab和C语言的实现结果通过标准布置的左、右两个扬声器播放，在正确的听音位置进行试听，能够感觉到声音有明显的空间感和立体感，实现结果良好。关键词：虚拟环绕声；DolbyAC3；HRTF；AC3解码器西南科技大学本科生毕业论文IIVirtualReproductionofSurroundSoundBasedonAC3Abstract:Themodelof5.1channelaudiosuppliedbyDolbyAC3iswidelyused.Thequalityof5.1channelaudioisgood,andthecodingefficiencyofthecodingmodelisthehighestatpresent.TheSystemoftheVirtualReproductionofSurroundSoundbasedonAC3willbeabletomeetpeople’srequirementofthehigherqualityofsurroundsound,whileitisnotallowedtoplacemorespeakersduetothelimitedconditions,anditcouldsimplifythesystemandreducetheconsumption.Itisespeciallyfittotheequipmentsthathaveonlytwospeakers,suchasheadphones.Thispaperdiscussedthetwomethodsofmakingvirtualsurroundsoundcometrue,i.e.,useMatlabandClanguagetosimulatethevirtualreproductionofAC35.1channelsurroundsound.BecauseofprocessingthesixchannelssignalofAC3byusingthevirtualsurroundsoundfilteringtechnology,thesimulationofthevirtualreproductionofsurroundsoundunderMatlabcomestrue.WhileprogrammingbyClanguage,TheSystemoftheVirtualReproductionofSurroundSoundbasedonAC3comestruebycombiningthevirtualsurroundsoundfilteringtechnologyandAC3decoder.WhiletheresultsofMatlabprogramandClanguageprogrambeplayedbytwospeakersthatplacedatthestandardposition,youcouldfeelthefeelingofspaciousnessandthirddimensionobviously.So,theresultoftheimplementationiswell.Keywords:VirtualSurroundSound,DolbyAC3,HRTF,AC3decoder西南科技大学本科生毕业论文III目录第1章绪论..........................................................................................................11.1课题背景、目的及意义.............................................................................11.1.1课题背景..............................................................................................11.1.2课题的目的及意义..............................................................................41.2论文的主要内容和框架.............................................................................4第2章系统总体设计..............................................................................................62.1系统实现原理.............................................................................................62.2MATLAB仿真实现虚拟环绕声的设计....................................................92.3C语言编程实现基于AC3的虚拟环绕声系统........................................92.4本章小结...................................................................................................10第3章主要技术简介............................................................................................113.1DolbyAC3.................................................................................................113.1.1DolbyAC3的特点、配置和应用.....................................................113.1.2DolbyAC3的编码原理.....................................................................123.1.3DolbyAC3的解码原理.....................................................................133.2头相关传输函数.......................................................................................133.2.1HRTF的定义.....................................................................................143.2.2HRTF数据的获取.............................................................................153.3本章小结...................................................................................................17第4章Matlab编程实现虚拟环绕声的设计........................................................184.1Matlab的特点...........................................................................................184.2系统设计...................................................................................................184.2.1从AC3文件中分离出5.1独立声道数据........................................194.2.2程序设计............................................................................................224.3结论分析...................................................................................................234.4本章小结...................................................................................................24第5章C语言编程实现基于AC3的虚拟环绕声系统.......................................255.1VC++6.0软件介绍...................................................................................25西南科技大学本科生毕业论文IV5.2程序设计背景...........................................................................................255.2.1解码原理............................................................................................255.2.2MDCT和IMDCT..............................................................................285.3程序设计...................................................................................................305.3.1子函数IMDCT..................................................................