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TV基础知识介绍王江Aug,2013TV系统组成TVSystemArchitectureTVSystemArchitectureTunerDemodulatorDecoderScalerDisplayModulatorEncoderTransmitterVideoAudioAudioTVsetsystemTVsetsystemTvSTvSystemystemFrequencyRangeFrequencyRangeVHFLowVHFHighUHFf40MHz140MHz141MHz425MHz426MHz870MHzCCIR48.25~855.25MHzChina44.25~863.25MHzFrance47.75~216.25MHzUS55~991.25MHzJapan91.25~765.25MHzUK471~855.255MHZFMradio176~90MHzFMradio288~108MHzDVB-T55~860MHzAnalogTVBroadcastingSystem(1)AnalogTVBroadcastingSystem(1)Source:NeilPickford(AustralianCommsLab),Displaybank,KDC2003SummerNTSCPALSECAMPAL/SECAMUnknownNTSCPALSECAMPAL/SECAMAnalogTVBroadcastingSystem(2)AnalogTVBroadcastingSystem(2)•PAL(systemB/G,D/K,I)–CCIRHyperChannel,Germany,NorthEurope(IF38.9MHz,systemB/G)–CHINAChannel(IF38.0MHz,systemD/K)•NTSC(systemM/N)–US(IF45.75MHz)–JAPAN(IF58.75MHz)•SECAM(systemB/G,D/K,L/L’)–FranceVHFLow(IF33.4MHz,systemL’)–FranceVHFHigh,UHF(IF38.9MHzsystemL)–Russia(IF38.9MHz,systemD/K)•Others–Brazil(PAL,systemM,BTSC,525line,SIF4.5MHz)–Argentina(PAL,systemN,625line,SIF4.5MHz)DigitalTVWorldwideDigitalTVWorldwideISDB-TDTMBTVFTVFunctionBlockunctionBlockTVtunerVideodemodulatorDigitaldemodulator(COFDM/QAM)Mpeg2decoder(Embedded32bitRISC)VideodecoderScalerAnalogVideo,AudioMPEG2TSCCIR601/656AnalogtunerDigitaltunerDVB-T/ATSCDigitalComboseriesOpenCable(US)DVB-T/AnalogDisplayIFTunerIntroductionTunerIntroductionTunerOnlyIFIQDemodulatorTunerOnlyNIMModuleCVBSAudioTS44.25MHzto863.25Mhz,TunerIntroductionTunerIntroductionTunerVHFVHF-L40MHz~140MhzVHF-H141MHz~425MHzUHF426MHz~870MHzIFUS45.75MHzJP58.75MHzEUP38.9MHzCHN38.0MHzTuner-CANComboTunerBlockDiagram(DVBComboTunerBlockDiagram(DVB--T)T)BalumTunerIC4MHzX’talSAW1.2GHzI2CLo1Lo2RFAGCDemodulatorAntennaDigitalREF[9][3][4][36][2]AFTADSSDASCL[5]5V[6]AGCD0D7MPEG2TransportStreamSAWSAWNTSCCVBSAudio[10][8][7]SIFAnalogTunerArchitectureTunerArchitecture频率转换频率转换•CH10193.25MHz,IF=45.75MHz193.25MHzLOff45.75MHzLO=RF+45.75=193.25+45.75=239MHzOSCILLATORPLLOSCILLATORPLLOSC1OSC1OSC1BANDSWITCHFrequencyDivisionFrequencyDivision4MVCO4M/80=50K4M/64=62.5KN14toN0R2,R1,R0AFT(AutoFineTuning)AFT(AutoFineTuning)193.25MHzLO45.75MHz239MHzIFLoShiftÆIFShiftIF193.25MHzLOVAFTDetectionfLOÊVAFTÊPLLÊfLOÌChannelAutoScanChannelAutoScanSolution1TunerRFVideodecodeMicronI2CSync.SignalRFMicronI2CSolution2TunerCVBSSYNCDetectorVideoSyncSeparateCircuitVideoSyncSeparateCircuitTuner-SiliconSiliconSiliconTDA18273HNDemodulator-AnalogAFCcharacteristicDemodulator-Digital以以DVBDVB--TT为代表为代表利用IFFT运算实现OFDM调制框图OFDM信号解调器原理框图Decoder&Scaler模拟信号波形模拟信号波形YCompositeCYCbCrAnalogvideowaveform(75%colorbarsignal)onoscilloscopeVideoDecorderVideoDecorderVBIVBIVBITheTelevisionVerticalBlankingInterval(VBI),alsoknowasFieldBlankingInterval(FBI)consistsofTVLines6to22infieldone&318to335infieldtwo.VerticalBlankingIntervalVerticalBlankingIntervalVBIStandardsVBIStandards•WideScreenSignaling(WSS)•Teletext•ClosedCaptionClosedCaptionClosedCaptionClosedCaptioncontinuedClosedCaptioncontinued……•StandardsEIA-608:USACC&EDS(CGMS-A,V-Chip)•SampleRate0.5035MHz•DataRate0.5035Mb/sec•ValidVBIDataLine21,284forNTSC18,281forPAL-M22,235forPALB,D,G,H,I,N,CNWideScreenSignalingWideScreenSignaling•StandardsITU.BT.1119:WSSInformationforNTSCandPALvideosignals.IEC61880:Video&accompaniedVBIDataforProgressiveScanSystemsEIA-JCPR-1204:WSSInformationforNTSCvideosignals.ETSIEN300294:WSSInformationforPALvideosignals.EIA-805:VBIDataonComponentInterfaces.•ClockFrequency5MHz(Ts=200nS)WideScreenSignalingcontinuedWideScreenSignalingcontinued……•ClockFrequency5MHz(Ts=200nS)•SignalAmplitude0.5V+/-5%(700mV)•ModulationCodingBi-Phase(Td=6Ts)•Preamble•DataBits14Bits•OddParityBits1outof14Bits数字解码数字解码•略pictureColorSpacePropertiesColorSpaceProperties•Differentrepresentationsofsamedata•Mathematicalconversionformulas•Choosemostconvenientforapplication亮度方程亮度方程给出彩色光的亮度Y与三基色（R、G、B）的关系式Y＝1.0000R十4.5907G十0．06015B在不同的彩色电视制式中，由于所选的标准白光和显像三基色不同，导致亮度方程也互有差异。以C白光为标准白光源的NTSC制彩色电视制式的亮度方程为Y＝0.229RN十0.587GN十0.114BN以D65光为标准白光源的PAL制彩色电视制式的亮度方程式为Y＝0.222RP十0.707GP十0.071BP由于NTSC制彩色电视广播发展较早，大量的电视设备都是按它设计的，所以PAL制中没有采用自己的亮度方程，而是延用了NTSC的亮度方程式，使用了与NTSC制彩色电视相同的显像三基色。为了书写方便，一般应用中，略去显像三基色系数下标，并被近似地写为Y＝0.30R十0.59G十0.11B。VideoColorSpacesVideoColorSpaces•Thereallyimportantpartforvideo–GetB&WseparatedfromColor!!•AllowsmassivecompressionofcolorinformationY=0.30R+0.59G+0.11BR-Y=R-（0.30R+0.59G+0.11B）=0.70R-0.59G-0.11BG-Y=G-（0.30R+0.59G+0.11B）=-0.30R+0.41G-0.11BB-Y=B-（0.30R+0.59G+0.11B）=-0.30R-0.59G+0.89BAdaptiveContrastandColor(ACC)AdaptiveContrastandColor(ACC)Purpose:ToboostthepicturecontrastandblacklevelMethod:TheACCcircuitmodifiestheluminanceusingatransferfunctionbasedontheaverageluminancehistogramoftheinputimageAdaptiveContrastandColor(ACC)AdaptiveContrastandColor(ACC)HistogramGeneration:theimageisdividedinto3separate,programmable(andoverlapping)luminancerangesor“bins”PixelCountLowBinMidBinHighBinLuminanceValue(Y)0255W1W2W3AdaptiveContrastandColor(ACC)AdaptiveContrastandColor(ACC)MediumBrightImageandit’shistogramLowBrightImageandit’shistogramLuminancePixelCount0255HistogramLuminancePixelCount2550Hist