B3 多媒体档案影像内容验证与画面品质分析

23April20061X2009年論Presenter:WilliamWuVideoProductManager23April20062RGBMatrixCompositeEncoder270MHz.1485GHzYR-YB-YSerializerYCRCBITU-RBT.601-2ParallelDigitalComponent27MB/secComponentAnalogVideo(RGB)AnalogCompositeVideo(PAL/NTSC/SECAM)AtoDConvAudioDataColorDifferenceComponentAnalogVideo(Y,B-Y,R-Y)AtoDConvAtoDConv6.75MHz37.125MHzSampleRateforB-YandR-Y13.5MHz74.25MHzSampleRateforYBasebandAnalog/SDISignalBasebandAnalog/SDISignal10BitA/D270mB/SSerialDigitalComponent-SDIITU-RBT.601(SMPTE259M)270Mb/secSD-SDIITU-RBT.709(SMPTE292M)1.485Gb/secHD-SDISMPTE244/2453Gb/sec3G-SDIDTVBroadcastingSystemDTVBroadcastingSystemVideoSourceCodingVideoSourceCodingandMPEG2/H.264andMPEG2/H.264CompressionCompressionAudioSourceCodingAudioSourceCodingandMPEG2andMPEG2CompressionCompressionTransportTransportVideoSubsystemVideoSubsystemAudioSubsystemAudioSubsystemAudioAudioVideoVideoControlDataControlDataAncillaryDataAncillaryDataServiceMultiplexServiceMultiplexServiceMultiplexandTransportServiceMultiplexandTransportITUITU--RDigitalTerrestrialTelevisionRDigitalTerrestrialTelevisionBroadcastingModelBroadcastingModel1.Telcoa.SDHb.ATMc.SONET2.Satellitea.DVB-S(QPSK)3.Cablea.DVB-C(16,32or64QAM)4.Terrestriala.DVB-T(OFDM)b.ATSC(8VSB)5.IPInternet-StreamingVideo23April20064QCfromanMPEGvideoperspectiveQCof‘conventional’ingest(toMPEG-2)DigitisetoSDIEncodetoMPEG-2;storeonvideoserverDecodebacktoSDI(forQConly)Encodedvideo/filesQCpointsWaveformmonitor;oscilloscopeMPEGMonitorOscilloscope;monitorsDigitalVideoAnalogVideoIngestserverNTSCorPALSDI(ASI/IP)MPEG-223April20065WaveformdisplayonAnalogWaveformMonitorQCfromananalogperspectivefStandard“baseband”analogtests:–presenceandlevelofsynchronisationsignals–videogamut,signallegality–audiolevels–lineandframetimingsfStandardsolutions:–waveformmonitors–vectorscopes–picturemonitors–oscilloscopesDirectcorrelationwithanalogsignal‘Arrow-head’display–legalityofcompositevideo‘Diamond’display(RGBgamut)Vectordisplay(PbPrcoloramplitude)WaveformdisplayondigitalWaveformMonitorTekMGBRYCY23April20066QCfromanSDIDigitalperspectivefNodirectcorrelationtoanalogsignal,e.g.–synchronization‘signals’arecode-wordsindatastream–videodataneedstobeextractedtore-construct‘analog’signalfExampleSDIerrors:–signaljitter,–EDHerrors–levelerrors–bitsmis-interpreted–timingerrorsNodirectcorrelationwithanalogsignalSDIsignaljitterdisplayonwaveformmonitorUnitInterval0.8Volts+10%Jitter0.2UIp-p20%to80%RisetimeOvershootRising/FallingEdgelessthan10%23April20067VideoSession23April20068PESpacketsGenerallydefinedlengthRec601VideoElementaryStreamTransportStream188BytesperpacketNottoscaleTransportStreamFormationVideoCodecs:MPEG2/MPEG4/H.26423April20069StructureofMPEG-2TransportStreamsfInsidepacketizationandCRCdataofMPEG-2TS:fVideoandaudiodatacanbetensorhundredsofMbytes–interleavedintimethrough-outtheMPEG-2TSpackets188bytepackets(or204bytes)HeaderPIDCRCVideoElementaryStreamAudioElementaryStreamMeta-dataTransportStreamdata-tables,etc.VideoAudioTablesMeta-data23April200610TransportStream/MPEGtestingfE.g.errorsin:–PATs,PIDs,–PMTs,PCRs,–Transportstreamwrappers–Videowrappersf(MPEG2,h.264,VC1)–Audiowrappersf(MPEG2,AC3,AAC)23April200611ElementaryStreamsfVideoandaudiocompressionseparatefromTS–complexfandincreasinglysowithMPEG-4/AVC–generatetheirowntypesoferrorsfLegalTScanhaveincorrect/illegalESwithin188bytepackets(or204bytes)PIDCRCVideoElementaryStreambiterrorsduringencoding23April200612Lookingatarealpieceofvideo…fAsinglebiterrorinasingleblockinasingleframefNOTspottedinplay-outcentre–despitea‘full’QCbeingdonei.e.fbase-bandtestsfTStestsfvisuallywatchedbyQCpersonnelfErrorsmoothedoverbytheadvanceddecoderinplay-outcentrefButcausedcustomer’sset-topboxtocrash–broadcasterthoughtend-customerswerehaving‘fingertrouble’23April200613GoodbutstillnogoodfLegalandsyntacticallycorrect-butnotcorrectforthebroadcaster:–broadcasterwants720x480NTSCbutthevideohasbeensupplied/encodedat704x480–Englishaudioisrequiredtobeonchannels1&2(Spanishon3&4)butthesehavebeenswapped–thepeakbit-rateshouldbe4.5MBits/sec,butactuallygoesto4.6MBits/sec–ingestedvideoisexpectedtohavefblackscreenforthefirst3secondsfaudiotoneforthefirst2secondsbutthetimesforeachhavebeeninadvertentlyswappedf…andmanymorebroadcasterconstraints23April200614Goodbutreallybad(quality)f‘Good’videoi.e.fully–legal(videoandaudioconstraints)–syntacticallycorrect–andcomplianttobroadcaster’ssystemparametersf…butjustpoorqualityvideo23April200615TransportStream/Containerfile01File-basederrors(fromdistribution)VideoAudioMeta-dataTransportStream/Containerfile02VideoAudioMeta-dataTransportStream/Containerfile03VideoAudioMeta-dataTransportStream/Containerfile04VideoAudioMeta-dataTransportStream/Containerfile05VideoAudioMeta-dataTransportStream/Containerfile06VideoAudioMeta-dataTransportStream/Containerfile97VideoAudioMeta-dataMultipleProgramTransportStream23April200616File-basederrors–de-muxandstoreTransportStream/Containerfile06VideoAudioMeta-dataTransportStream/Containerfile97VideoAudioMeta-dataVideoingestserverVideoAudioMeta-dataMultipleProgramTranspo