基于Linux智能手机多媒体移动学习系统的设计和实现

上海交通大学硕士学位论文基于Linux智能手机多媒体移动学习系统的设计和实现姓名：陈华曦申请学位级别：硕士专业：计算机软件与理论指导教师：申瑞民20090101LinuxILinuxMobileLearningE-LearningSymbiamLinuxWindowsMoblieE-LearningCSMXMontavistaLinuxdaydaymobile.comE-LearningCSMXMontavistaLinux1.MontavistaLinuxLinuxII2.XvidMADQtGUILinuxLinuxIIITheDesignandImplementationofMultimediaM-LearningSystemonLinuxbasedsmartphoneABSTRACTWiththefastdevelopmentofmobilecomputingterminalsandthepopularityofthenetwork,MobileLearningisbecomingoneofthemostpopularresearchanddevelopmentareasintoday’sE-Learning.Throughconvenientandflexiblemobileterminalsandnetwork,researchersanddevelopershopetoprovideuserswithteachingandlearningresourcesandservicesthatcanbeaccessibleanytimeanywhere.Inrecentyears,smartphoneisdevelopingquickly,especiallythesmartphonebasedonSymbian,LinuxandWindowsMobile.Thiscreatesexcellentopportunitiesforthedevelopmentofmoreadvancedmobilelearningsystems.BasedontheMontaVistaLinuxPlatformandtheCSMXcodecwhichisdevelopedbyE-LearningLabofSJTU,theprojectdescribedinthisthesisdesignedandimplementedamultimediamobilelearningsystem.Bydownloadingcoursesfromdaydaymobile.com,usersofthissystemcanlearnlotsofcurriculumsanytimeanywhere.ThisthesismainlydescribestheinnovativeworkintheLinuxIVfollowingareas:Firstly,thecoursewaresfromdaydaymobile.comincludedifferentstreams,teachervideo,audio,lecturevideoandhandwritings.ThesestreamsareplayedordisplayedbythisLinuxbasedsystemsimutanously.Basedonuser’spreferences,theycancustomizethelearningexperience,eitherbeinglecturenotes+smallvideo+audio,orcloseteachervideoandzoomthelecturenotesforpersonalizelearning.Secondly,theopensourcedecodingsystemandtheopensourcearchitectureareadoptedinthissystem,suchasxvid,MADandQt.FollowingthedesignpatternIalsoseparatedthecoremodulewithGUIandcodecwithcoremodule.Thismakesthesystemmodularizedandeasytoporttootherplatform.KeyWords:mobilelearning,multiplestreamsplay,Linux,opensource2009225√“√”20092252009225Linux111.1[1]20081567.119.1%25.7%SymbianLinuxRIMWindowsMobileCPUCNNIC20080722[2]2.537.2%22%200712,5.47286200913G[2]2.537305Canalys2008[3]Symbian46.6%Mac17.3%RIM15.2%WindowsLinux13.6%5.1%45Linux21.21.2.1ClarkQuinn[5]IAInformationApplicationsPalmsWindowsCEChabraFigueiredo[6]PaulHarris[7]e-learningPDAAlexzanderDye[8]MobileEducation-aglanceatthefuturem-learning1.2.2312[11,20]Linux33Email1.3[48]1[14][15]PDA1-11-1Figure1-1MobileLearningManagementSystemLinux42mCLT[16]1-21-2Figure1-2InstanceofSeamlessLearning[17,18]E-mail[23,25]1.4E-LearningM-LearningM-LearningLinux5E-LearningM-LearningE-LearningCSMXE-Learning[22]MPEGMovingPictureExpertsGroupMPEGMPEGMPEG-1MPEG-2MPEG-4MPEG-7MPEG-211988CDISO/IEC1172MPEG-MPEG-XISO(InternationalOrganizationforStandardization)MPEGDCTMPEG-1MPEG-11992ISO/IEC11172VideoCDMPEG-1Layer3MP3MPEG-2Linux9MPEG-2199413818-113818-213818-313818-4MPEG-2MPEG-2(profile)(level)201111MP@ML()SDTVHDTVMP@HL()MPEG4MPEG419957199811ISO/IECISO/IEC1449648006400bits/s176144MPEG4MPEG4DVDMPEG2CDROMDVDMPEG4MPEG-7MPEG-7(1+2+4=7,MPEG-3MPEG-5MPEG-6)199610MPEG7’MPEG-7MPEG-7MPEG-7Linux10MPEG21MPEG199910MPEG“”12MPEGMPEG-21“”“”2.1.1.1MPEG-1Layer3/MP3[40][31]1)MPEG-1Layer320Hz20kHz1kHz-4kHzMPEG-1MPEG2-1-PCM2-1MPEG[40]Figure2-1ArchitectureofMPEGAudioEncoder[40]MPEG-1Layer3(FastFourierTransform)-ModifiedDiscreteCosineTransformM-DCT102/21()2()cos[(1/2)],0,...,/212NiNFufiiuuNNπ−=+=++=−∑(2.1)MPEG-1Layer32-2Linux1132M-DCT1024FFTPCM2-2MPEG-1Layer3[40]Figure2-2ArchitectureofMPEG-1Layer3AudioEncoder[40]2)MPEG-1Layer3[31]MPEGFRAMEFRAMEFRAMEHEADER4BYTE32bitCRCFRAMEHEADER16bit01,2FRAMEHEADERMAIN_DATA2-1FRAMEHEADERCRCfreeMAIN_DATA4BYTES0OR2BYTES2-1MPEG-1Layer3;Table2-1MPEG-1Layer3frameformatFRAMEHEADERAAAAAAAAAAABBCCDEEEEFFGHIIJJKLMM13[31]MAIN_DATAFRAMEHEADERbitrateMP396Kbps96128Kbps192KbpsKbpsKbpsMP3bitrateMP3CBRMP3CBRbitrateMP3VBRFRAMECBRVBR1)CBRCBRFRAMEFrame2-226msMP3Linux12FrameSize=(((MpegVersion==MPEG1?144:72)*Bitrate)/SamplingRate)+PaddingBit(2.2):Bitrate128000,aSamplingRate44100,andPaddingBit1FrameSize=(144*128000)/44100+1=417bytes2)VBRVBRXINGMP3FRAME“XINGMP3FRAMEMP3VBRFRAMEMP3FRAME100100FRAMEINDEX4MP3240S100INDEX2.4SINDEXFRAMEFRAME2.1.1.2MPEG-4AdvancedSimpleProfileMPEG-4part2MPEG-4part21999ISO/IEC14496-2()ProfilesAdvancedSimpleProfile(ASP)[40]MPEG-4ASPMPEG-4ASPMPEG-1MPEG-2Videoobject[39][40]2-3MPEG-4ASP5Video-objectSequence,VSVideoObjectVOVOVideoObjectLayerVOL5MPEG-4ASPVOPVOPI-VOPIntra-VOP,VOPP-VOPPrediction-VOPVOPB-VOPLinux13Bidirection-VOPMPEG-4ASPVOPMPEG-1MPEG-2VOPMPEG-4ASP[40]2-3MPEG-4ASP[45]Figure2-3ArchitectureofMPEG-4ASPVideoLayer[45]2.1.2CSMXCSMX[41]123PPT(Lzw)(JPEG)Linux142-4CSMX/APIMPEG-210/10/1/CSMXTscc[41]2-52-4CSMXFigure2-4thePrincipleoftheCSMXScreenCodec05010015020025030012345676543212321CSMX(Kbyte)Tscc(Kbyte)CSMX