MP3编码算法分析

:1008-1402(2005)01-0064-04MP3,,(,100081):MPEG-I,123.1,;3,MP3,,MP3,,,.MPEG-I3,MP3,,,.:MP3;MPEG-I;:TN919.81:A0,MP3,,.,MP3CD..MP3,MP3.MP3,MPEG(MovingPicturesExpertsGroup)19921.5Mbit/sMPEG-I.MPEG-I[1](ISO11172),.,,.,123,MP1,MP2,MP3.,,,.MP3CD.,1644.1kHzCD,760kb/s.MP3,,.MP3.MP3MP1,MP2,,,MP3,,FFT,MDCT,,.MP1,MP2,,MP3,,(,),MP3.MP3,MP3.1MP3MP31,,MP3(:2004-11-12:(1977-),,,,.231()Vol.23No.1200501JournalofJiamusiUniversity(NaturalScienceEdition)Jan.2005MDCT),,(),,MP3.MP3,PCM,32,MDCT()18,576.ISO11172,576,.,,.MP3,576,.,MP3,.1MP3232MDCT.,(44.1kHz,16,1644100bit/s,,1.41Mbps,CD)32.32,,.,561:MP3MDCT,;MDCT,18,576,,MDCT,[2].32FIRBPF,BPF512.32512C{Xi}512X,32S.S32SK.:PCM32512X,512X(2[3]);CX,Z,Ci;512Z864Yi,8Y;Y32,3,Mik=cos[(2i+1)(k-16)/64][4].,(MPEG-I),:.,MDCT,[1].3MPEG-I.MPEG-I,,;,.MP3,MPEG-IMP3.,.FFT,();;,.,,[5].,SMR(signal-to-maskra2dio),.4MPEG-I,4,MDCT.4,,,;,,.,.,MPEG-I8191.,,,.,,.,,,,,,,,.,,..66()2005,.MP3,32,..,.5MP3,MP3,,.MP3,MPEG-I,.MP3,MDCT,,[6],.,,,.:[1]ISO/IEC11172-3CodingofMovingPicturesandAssociatedAudioforDigitalStorageMediaatuptoAbout1.5Mbit/sPart3:Audio(1993)[S].[2],,.MPEG-III[J].1998,5,2-5.[3]SeymourShlien.GuidetoMPEG-IAudioStandard[J].Broadcasting.1994,4(4),206-218.[4],.[J]..1999,7,3-6.[5],,.MPEG[J].().1997,37(10),45-48.[6]FarshidGolchin,KuldipK.Paliwal,LosslessCodingofMPEG-ILayerIIIEncodedAudioStreams[J].Speech,andSignalProcessing.2000,2(7),11885-11888.ANALYSISOFMP3CODINGARITHMETICMAChang-ping,SONGDan,MAYou-ming(ElectronicEngineeringDepartment,BeijingInstituteofTechnology,Beijing100081,China)ABSTRACT:TheISOMPEG-1standarddescribestheimplementationofthreecompressionschemescalledlayer1,layer2andlayer3.Thelayer1schemeisthesimplesttoimplementationbutitsefficiencyisnotasgoodastheothertwolayers.Thelayer3scheme,commonlyknownasMP3,providesthebestperformanceatlowbitratesandhasbecomewidelypopularforthetransmissionofencodedaudiofile(MP3s)throughtheInternet.However,itisal2sothemostdifficultonetoimplement.ThispaperisdesignedtointroducethecodingschemefortheMPEG-Ilayer3standard.InthispaperweanalyzethekeytechniquesadoptedbyMP3codingarithmeticsuchassubbandcoding,psy2choacousticmodelsandHuffmancodingparticularlyandfindouttheapproachtoimplementthem.Furthermore,afea2sibleadviceofimprovingtheencodingschemeisproposedtomakethecodemoreefficient.KEYWORDS:MP3;MPEG-I;digitalaudio761:MP3