Txawm tias muaj kev taw qhia thiab lees txais cov TV digital thiab HDTV tshaj tawm thiab cov khoom siv (xws li Blu-duab tshav Disc players thiab media streaming), cov teeb meem qub rau cov qauv video thoob ntiaj teb tsis tau muab tshem tawm. Kab lus no piav qhia vim li cas NTSC thiab PAL cov qauv tseem tseem ceeb.
Cov ntaub ntawv no siv rau TVs los ntawm ntau lub tuam txhab, suav nrog, tab sis tsis txwv rau, LG, Samsung, Panasonic, Sony, thiab Vizio.
kab hauv qab
Txawm hais tias cov yeeb yaj kiab tam sim no feem ntau yog digital, tus ncej tus nqi siv hauv analog video systems tau muab tso rau hauv cov TV digital thiab HDTV cov qauv. Hauv kev yees duab (analog, HD, thiab 4K Ultra HD), xws li hauv zaj duab xis, cov duab pom ntawm lub vijtsam zoo li ua tiav thav duab. Txawm li cas los xij, muaj qhov sib txawv ntawm txoj kev sib kis los ntawm cov neeg tshaj tawm xov xwm, hloov mus los ntawm kev tshaj tawm lossis cov khoom siv hauv lub cev, thiab tso tawm rau ntawm lub vijtsam.
Kab thiab Pixels
Cov duab yeeb yaj kiab uas tshaj tawm nyob lossis kaw yog tsim los ntawm cov kab scan lossis pixel kab. Hauv zaj duab xis, tag nrho cov duab qhia ib zaug. Nyob rau hauv sib piv, cov kab los yog pixel kab nyob rau hauv ib tug video duab tso saib nyob rau hauv lub screen, pib nyob rau hauv lub sab saum toj ntawm lub screen thiab tsiv mus rau hauv qab. Cov kab no tso rau hauv ib qho kev sib cuam tshuam los yog kev ua tiav.
Interlacing lossis interlaced scan faib cov kab rau hauv ob daim teb. Cov kab khib nyiab lossis pixel kab tso saib ua ntej, thiab cov kab zauv lossis pixel kab tso saib tom ntej, ua kom tiav thav duab.
Kev soj ntsuam qib zuj zus qhia cov kab sib txuas ua ke es tsis txhob kis kab ua ob thaj chaw sib txawv. Qhov no txhais tau hais tias ob qho tib si khib thiab txawm-tus lej lossis pixel kab tso rau hauv cov lej ua ntu zus.
Tus naj npawb ntawm kab ntsug lossis kab pixel qhia cov duab nthuav dav. Qhov ntau kab hauv ib daim duab, qhov nthuav dav. Tus naj npawb ntawm kab yog kho nyob rau hauv ib qho system.
NTSC and PAL
Ob lub ntsiab analog video yog NTSC thiab PAL.
NTSC yog 525-kab lossis pixel kab, 60 daim teb nrog 30 ntas-ib-ob, ntawm 60 Hz system rau kev sib kis thiab tso saib cov duab video. Txhua lub thav duab raug xa mus rau hauv ob qhov chaw ntawm 262 kab lossis pixel kab uas tso saib ua ke (interlaced). Ob daim teb tau ua ke, yog li txhua tus ncej qhia nrog 525 kab lossis pixel kab. NTSC yog tus qauv analog video hauv Teb Chaws Asmeskas, Canada, Mexico, qee qhov chaw ntawm Central thiab South America, Nyiv, Taiwan, thiab Kauslim Teb.
PAL yog hom tseem ceeb hauv ntiaj teb rau kev tshaj tawm TV analog thiab cov yeeb yaj kiab analog. Nws yog 625 kab lossis pixel kab, 50 teb nrog 25 ntas ib ob, 50Hz system. Zoo li NTSC, lub teeb liab yog interlaced rau hauv ob lub teb, muaj li ntawm 312 kab lossis pixel kab txhua. Txij li thaum tsawg dua ntas (25) tso saib ib ob, me ntsis flicker nyob rau hauv daim duab yog tej zaum pom, zoo li lub flicker ntawm projected zaj duab xis. Txawm li cas los xij, PAL muaj kev daws teeb meem me ntsis thiab cov xim zoo dua li NTSC. Lub teb chaws uas muaj cov hauv paus hauv PAL muaj xws li UK, Lub Tebchaws Yelemees, Spain, Portugal, Ltalis, Tuam Tshoj, Is Nrias teb, Australia, feem ntau ntawm Africa, thiab Middle East.
DigitalTV/HDTV and NTSC/PAL Frame Rate
Txawm hais tias qhov kev daws teeb meem ntau ntxiv ntawm cov digital thiab cov ntsiab lus siab tshaj tawm thiab cov ntsiab lus video software yog ib qib zuj zus thaum piv HDTV rau analog NTSC thiab PAL cov qauv, tus ncej tus nqi yog lub hauv paus ntawm ob lub tshuab.
Nyob hauv NTSC-raws li lub teb chaws, 30 cais thav ntawv tso saib txhua ob (ib qho ua tiav txhua 1/30th ntawm ib thib ob). Hauv PAL-raws li lub teb chaws, 25 cov duab sib cais tso tawm txhua thib ob (ib qho tag nrho qhia txhua 1/25th ntawm ib thib ob). Cov thav duab no tso tawm siv ob txoj kev sib cuam tshuam scan (480i lossis 1080i) lossis txoj kev ntsuas kev nce qib (480p, 720p, lossis 1080p).
Qhov twg digital thiab HDTV hloov zuj zus los ntawm NTSC yog tias cov thav ntawv xa tawm raws li cov duab sib cuam tshuam (1080i), txhua tus ncej yog tsim los ntawm ob daim teb, txhua qhov qhia txhua 60th ntawm ib thib ob, thiab cov ncej ua tiav qhia txhua 30th ntawm ib thib ob., siv NTSC-raws li 30 ntas-ib-second ncej tus nqi. Yog hais tias tus ncej yog kis nyob rau hauv cov kev vam meej scan hom (720p los yog 1080p), nws qhia ob zaug txhua txhua 30th ntawm ib tug thib ob.
PAL-raws li Digital TV thiab HDTV Ncej tus nqi
Qhov twg digital thiab HDTV hloov zuj zus los ntawm PAL yog tias cov thav ntawv xa tawm raws li cov duab sib cuam tshuam (1080i), txhua tus ncej yog tsim los ntawm ob daim teb, txhua qhov qhia txhua 50th ntawm ib thib ob, thiab cov kab lus ua tiav qhia txhua 25th ntawm ib thib ob., siv PAL-raws li 25 ntas-ib-thib ob tus ncej tus nqi.
Yog hais tias lub thav duab xa mus nyob rau hauv cov kev vam meej scan hom (720p lossis 1080p), nws qhia ob zaug txhua 25th ntawm ib ob.
Txoj kab hauv qab
Digital TV, HDTV, thiab Ultra HD, txawm hais tias muaj kev dhia loj rau hauv qhov koj pom ntawm lub TV lossis qhov screen, tseem muaj cov hauv paus hauv cov qauv yees duab analog uas muaj hnub nyoog tshaj 65 xyoo.
Vim li ntawd, muaj qhov sib txawv ntawm cov qauv digital thiab HDTV siv thoob plaws ntiaj teb, txhawb kev cuam tshuam rau tus qauv video thoob ntiaj teb.
Tsis tas li, raws li kev hloov pauv txuas ntxiv mus rau digital thiab HD-tsuas kis tau tus mob, ntau tus tseem muaj NTSC thiab PAL-based video playback li, xws li VCRs, analog camcorders, thiab tsis yog-HDMI nruab DVD players ntsaws rau hauv HDTVs (thiab 4K. Ultra HD TVs).
Txawm tias muaj hom ntawv xws li Blu-duab tshav, muaj cov xwm txheej uas cov yeeb yaj kiab lossis cov yeeb yaj kiab tseem ceeb yuav nyob hauv HD, thiab qee qhov ntawm cov yeeb yaj kiab ntxiv yuav nyob hauv cov qauv daws teeb meem NTSC lossis PAL hom.
DVDs tseem ua rau hauv NTSC lossis PAL hom.
Txawm hais tias 4K cov ntsiab lus tam sim no dav dav ntawm kev tshaj tawm thiab Ultra HD Blu-duab tshav Disc, 4K TV tshaj tawm cov qauv yog nyob rau theem pib ntawm kev siv. TVs uas yog 4K-raws li yuav tsum txhawb analog video tawm tswv yim ntev npaum li analog video playback li siv.
8K daws teeb meem streaming thiab tshaj tawm tam sim no yog ib yam zoo, txawm hais tias nws tus nqi siab tuav nws rov qab los ntawm kev saws me nyuam.
Thaum kawg, koj yuav tsis siv cov khoom siv yees duab analog ntxiv lawm, tab sis hnub ntawd tseem tsis tau muaj.
