TVequipment
Built-inTVcard
Thebuilt-inTVcardcanreceiveTVandvideosignalsofmultipleformats.Whenusingit,firstinstallitonthePCIslotofthemotherboard,andinserttheTVsignalcableintoitsTVsignalinputinterface,andtheninstallthedriverintheoperatingsystem,aswellasTVreceivingandvideocapturesoftware,andyoucanwatchTVshow.Thebuilt-inTVcardtakesupcertainsystemresourceswheninuse.
UsingthemultitaskingfeaturesoftheWindowsoperatingsystem,youcanopenawindowtowatchTVprogramswhileopeningotherprogramstowork.Inaddition,theTVcardcangenerallyuseitsownsoftwaretorecordTVprograms.Thedisadvantageofthebuilt-inTVcardisthatitissusceptibletoelectromagneticinterferencefromtheinternalcomponentsofthecomputer,whichcausesitsplaybackqualitytodecline.Inaddition,thebuilt-inTVcardcanonlywatchTVprogramswhenthecomputeristurnedon.
ExternalTVBox
ThemostcommonexternalTVboxisaTVboxwithaVGAinterface.ThiskindofTVboxcandirectlypasstheVGAinterface.MostoftheexternalTVreceiverboxescanwatchTVprogramswithoutturningonthecomputer.YouonlyneedtoturnontheswitchoftheTVboxandthemonitor,andtheexternalTVboxesaregenerallyequippedwithsimilarordinaryTVboxes.TheremotecontrolusedbytheTVcangreatlyimprovetheconvenienceofoperation.Inthepast,theexternalTVboxcouldnotrecordTVprograms,norcoulditperformvideocompression,butitwasequivalenttosimplyaddingthefunctionofwatchingTVonthecomputer.Later,manufacturersintroducedanexternalTVboxwithaUSBinterface.ThisTVboxcombinesthecharacteristicsoftheabovetwoproducts.Althoughitisanexternalproduct,itmustinstallthedriverandplaybacksoftwareintheoperatingsystemandturnonthecomputer.Canbeused.Duetotheexternaldevice,itsreceivingeffectisbetterthanthebuilt-inPCITVcard.TheTVboxwiththeUSBinterfacecanperformvideocaptureandcompression,andmostoftheTVboxeswiththeUSBinterfaceprovideexcellentvideocompressionfunctions.
Videocapturecard
Thevideocapturecardcaninputvideodataormixedaudioandvideodataoutputfromcameras,videorecorders,videodiscplayers,televisions,etc.intothecomputer,andconvertthemintoacomputerthatcanbediscernedThedataisstoredinthecomputer.Thevideocapturecardcanreceivetheanalogvideosignalfromtheinputterminal,collectthesignal,quantizeandencodeittoformadigitalsignal,andthencompressandencodeitintoadigitalvideo.Mostvideocapturecardshavehardwarecompressioncapabilities.Accordingtotheirpurposes,videocapturecardscanbedividedintobroadcast-levelvideocapturecards,professional-levelvideocapturecards,andcivilian-levelvideocapturecards.Theirgradesaremainlydifferentfromthequalityofthecollectedimages,andtheircharacteristicsareasfollows.
1.Theadvantageofabroadcast-gradevideocapturecardisthatthecapturedimageshavehighresolutionandhighvideosignal-to-noiseratio.Thedisadvantageisthatthegeneratedvideofilesrequirelargeharddiskspace.Thedatavolumeperminuteconsumesatleast200MB,anditismostlyusedtorecordprogramsproducedbyTVstations.
2.Thegradeofprofessional-gradevideocapturecardisslightlylowerthanthatofbroadcast-grade.Theresolutionofthetwoisthesame,butthecompressionratioisslightlylarger.Theminimumcompressionratioisgenerallywithin6:1.TheinputandoutputinterfacesareAVcompositeterminalandSterminal.Thistypeofproductissuitableforadvertisingcompaniesandmultimediacompaniestoproduceprograms.
3.Thedynamicresolutionofcivilian-gradevideocapturecardsisgenerallylow,andmostofthemdonothavevideooutputfunctions.