MP4-3GP-PSP文件格式

2/21/2006CompanyConfidential1MP4/3GP/PSPfileformat2/21/2006CompanyConfidential2TopicsMP4fileGlobalStructureVariousBoxtypeintroductionDetailIntroduceMediaTraksBox3GPfileintroductionPSPfileintroduction2/21/2006CompanyConfidential3MP4GlobalfileStructureIPTVMPEG4文件moov...otherboxestrak(OD)trak(BIFS)trak(video)trak(audio)trak(videohint)trak(audiohint)IODftypmdatInterleaved,time-ordered,BIFS,OD,videoandaudioaccessunits,andhintinstructions2/21/2006CompanyConfidential4Object-StructuredfileformatISObasemediafileformat---globalcontainerThebasicobjectsinfileiscalledBOXBoxcontainatomsThere’slot’skindofatoms,liketrakatoms,mvhdratomsBasicallythere’s3boxesinaMP4file1.ftypbox2.Moovbox3.Mdatbox2/21/2006CompanyConfidential5MoovHeader/TraksMvhdcontainssomeglobalinformationforthefileCreationtime,mofificationtime,timescale,duration,next_trak_idtoallownewtrakstobeaddedorremoveddynamicallyTrakboxhas2functionscontainmediadata(mediatracks)containpacketizationinformationforstreamingprotocols(hinttracks).2/21/2006CompanyConfidential6TraksTraksDescribeastreamofMediaDataOD---(iods)OptionalBIFS---OptionalVideotracksAudiotracksvideohinttracksaudiohinttracks2/21/2006CompanyConfidential7TraksTrakshasfollowingatomsTkhd----Trakheader,containsthetrakIDandinformationsaboutthetrakTref----referencetorelatedtraksMdia---MediaBox,containsinformationaboutthemediadata2/21/2006CompanyConfidential8TipicalMediaTraks2/21/2006CompanyConfidential9Mdhrbox2/21/2006CompanyConfidential10Hdlrbox•declarestheprocessbywhichthemedia-datainthetrackispresented•‘vide’Videotrack•‘soun’Audiotrack•‘hint’Hinttrack2/21/2006CompanyConfidential11MinfboxVmhd:VideoMediaheaderBoxSmhd:SoundMediaheaderBoxHmhd:hintheaderboxNmhd:NullMediaHeaderBox,formediaotherthaVideoandAudio2/21/2006CompanyConfidential12MinfBox--ContinuedDinfBox---DefinesthedataURL,datareferenceStblBox---referencetoMediaMetadatahasstts,ctts,stsd,stsz,stz2,stsc,stssboxes2/21/2006CompanyConfidential13sttsBoxDetailStts---Timetosamplebox,defineseverysampledecodingtimeDT(n+1)=DT(n)+STTS(n)2/21/2006CompanyConfidential14CttsboxdetailCtts-providestheoffsetbetweendecodingtimeandcompositiontime.CT(n)=DT(n)+CTTS(n)2/21/2006CompanyConfidential15StsdboxdetailStsdThesampledescriptiontablegivesdetailedinformationaboutthecodingtypeused,andanyinitializationinformationneededforthatcoding.VisualSampleEntry:width/height,resolutionetcAudioSampleEntry:samplesize,samplerateetcContainsmp4Vandmp4Aboxes,whichcontainesdsboxwhichhasdecoderconfiginformation2/21/2006CompanyConfidential16SampleSizeBoxesStszcontainsthesamplecountandatablegivingthesizeinbytesofeachsample.aentry_sizeofzeroindicatesthateverysamplehasthesample_size2/21/2006CompanyConfidential17MdatboxInterleaved,time-ordered,BIFS,OD,video,andaudioaccessunits,tofindtheAudio/Videodatatobedecoded,usestbl/stscboxtogetthedata2/21/2006CompanyConfidential183GPlimitationstoMP4fileformatAll3GPfileshouldhavea“3GP”suffixnameFtypboxdependingwhichprofilesthe3GPfilestoconformingto,thefiletypeboxshouldhasBrandandcompatiblebrandsbesetaccordingly.ForexampleforaMPEG4compatible3GPfile:Brand:3gp,3gp5CompatibleBrands:3gp5,3gp4,mp42,isom2/21/2006CompanyConfidential193GPextentionstoMP4fileformatStreaming-serverprofileBranded‘3gs6’AddextentionofRTPhinttrackstothefile,definedin3GPPTS26.234Progressive-downloadprofilebranded‘3gr6‘the‘moov’boxshallbeplacedrightafterthe‘ftyp’boxinthebeginningofthefile;-allmediatracks(ifmorethanone)shallbeinterleavedwithaninterleavingdepthofonesecondorless.2/21/2006CompanyConfidential203GPCodecH.263profile0Level45H.263profile3Level45MPEG-4VisualSimpleProfilelevelObH.264(AVC)BaselineProfileLevel1bEnhancedaacPlusExtendedAMR-WBMPEG-4AACLowComplexity(AAC-LC)MPEG4AACLongTermPrediction(AAC-LTP)2/21/2006CompanyConfidential213GPVideoQualityQCIF（176x144）MandatorySQCIF（128x96）OptionalCIF（352x288）OptionalSQCIF（128x96）=15FPSQCIF（176x144）=10FPSCIF（352x288）=3FPS2/21/2006CompanyConfidential22PSPfileformatFtypboxshouldhave“MSNV”brandandcompatiblebrandnameAddedaUUIDboxwhichcontainFPRF,VPRF,APRF,whichcontainscodec_information,average/maxframerate,average/maxbitrate,aspectratioinformationedts/stssisrequiredSomeotherrequiementssuchastimescale,fixedvoprateetc,butseemsnotimportant2/21/2006CompanyConfidential23PSPcodeclimitationsMPEG4SimpleProfileSupportNTSConly,progressiveencoding,onlysupportQVGAresolutionBitrateshouldnotexceed768Kbps2/21/2006CompanyConfidential24ReferencesISO/IEC14496-12:2004(E)ISO/IEC14496-14:2003(E)3GPPStandard26244-6.3.0(2005.03)SONYPSPfile/MemoryStickspecification