Ts流结构PSISI表格课件.ppt

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1、Ts流基本结构，Psi/Si表格，290测量主要参考文献ISO/IEC13818-1TR101211EN300468TR101290TransportStreamStructureTheTransportStreamcombinesoneormoreprogramswithoneormoreindependenttimebasesintoasinglestream.TheTransportStreamisdesignedforuseinenvironmentswhereerrorsarelikely,suchasstorageortransmissioninlossyorn

2、oisymedia.TransportStreampacketsare188bytesinlength.TransportStreamStructuresync_byte--Thesync_byteisafixed8bitfieldwhosevalueis'01000111'(0x47).Sync_byteemulationinthechoiceofvaluesforotherregularlyoccuringfields,suchasPID,shouldbeavoided.transport_error_indicator--Thetransport_error_indi

3、catorisa1bitflag.Whensetto'1'itindicatesthatatleast1uncorrectablebiterrorexistsintheassociatedTransportStreampacket.Thisbitmaybesetto'1'byentitiesexternaltothetransportlayer.Whensetto'1'thisbitshallnotberesetto'0'unlessthebitvalue(s)inerrorhavebeencorrected.PID--ThePIDisa13bitfield,indicat

4、ingthetypeofthedatastoredinthepacketpayload.PIDvalue0x0000isreservedfortheProgramAssociationTable.PIDvalue0x0001isreservedfortheConditionalAccessTable.PIDvalues0x0002-0x000Farereserved.PIDvalue0x1FFFisreservedfornullpackets.transport_scrambling_control--This2bitfieldindicatesthescramblingm

5、odeoftheTransportStreampacketpayload.TheTransportStreampacketheader,andtheadaptationfieldwhenpresent,shallnotbescrambled.Inthecaseofanullpacketthevalueofthetransport_scrambling_controlfieldshallbesetto'00'.continuity_counter--Thecontinuity_counterisa4bitfieldincrementingwitheachTransportSt

6、reampacketwiththesamePID.Thecontinuity_counterwrapsaroundto0afteritsmaximumvalue.Thecontinuity_countershallnotbeincrementedwhentheadaptation_field_controlofthepacketequals'00'or'10'.data_byte--DatabytesshallbecontiguousbytesofdatafromthePESpackets,PSIsections,packetstuffingbytesafterPSIsec

7、tions,orprivatedatanotinthesestructuresasindicatedbythePID.InthecaseofnullpacketswithPIDvalue0x1FFF,data_bytesmaybeassignedanyvalue.Thenumberofdata_bytes,N,isspecifiedby184minusthenumberofbytesintheadaptation_field().PSITableProgramSpecificInformation(PSI)incl