Txheeb tawm lub xeev ntawm Digital TV broadcasting
Kev siv DTV thiab HDTV tshaj tawm ntawm DTV Transition uas tau tshwm sim rau lub Rau Hli 12, 2009, yog ib qho keeb kwm loj heev, raws li nws tau hloov txoj kev ntawm TV ntsiab lus tau tshaj tawm thiab nkag los ntawm cov neeg tau txais kev pab nyob rau hauv Tebchaws Asmeskas Txawm li cas los, muaj qee tus tsis meej pem li cov ntsiab lus DTV thiab HDTV txhais tau li cas.
Txhua HDTV tshaj tawm digital, tab sis tsis yog txhua Digital TV broadcasting yog HDTV. Hauv lwm cov lus, tib qhov chaw faib tawm rau digital TV broadcasting tuaj yeem siv los muab cov teeb liab video (lossis ob peb) thiab lwm yam kev pab, lossis siv tau los xa tawm ib lub teeb liab HDTV.
Txawm hais tias muaj 18 txoj kev daws teeb meem tau muaj rau digital TV broadcasting, tau tso cai los ntawm Cov Txheej Txheem Kev Tshaj Tawm Hauv TV (ATSC) , thiab tag nrho Digital TV tuners yuav tsum tau txiav txim siab tag nrho 18 hom ntawv, daim ntawv thov DTV tshaj tawm tau tuaj rau 3 kev daws teeb meem tawm tswv yim: 480p, 720p, thiab 1080i.
480p
Yog hais tias koj muaj cov luam tawm theej duab DVD player thiab TV , koj paub txog 480p (480 kab ntawm kev daws teeb meem, luam tawm progressively). 480p zoo ib yam nkaus rau tib txoj kev daws teeb meem ntawm analog TV, tiam sis kis tau los ntawm dig muag (DTV). Nws yog hu ua SDTV (Standard Definition Television), tab sis cov duab yog luam kom raws li qhov ua tau, tsis yog nyob hauv lwm thaj tsam xws li hauv kev sib txuas lus TV analog.
480p muab ib daim duab zoo (tshwj xeeb tshaj yog rau cov duab 19-29 "tshwj xeeb tshaj plaws) Nws yog ntau dua cov yeeb yaj kiab uas zoo tshaj tus qauv kab los yog tus txheem DVD tso tawm, tiam sis nws tsuas muab ib nrab ntawm cov duab video hauv HDTV, yog poob ntawm cov vijtsam loj dua (piv txwv li, Cov TV nrog qhov ntau thiab tsawg dua 32 inches thiab).
Txawm li cas los xij, 480p yog ib feem ntawm qhov pom zoo DTV broadcasting scheme, nws tsis yog HDTV. Cov txheej txheem no yog tso raws li DTV Broadcasting Standards los muab cov kev tshaj tawm ntawm ntau txoj hauv kev ntawm qhov programming hauv tib lub bandwidth raws li ib qho teeb meem HDTV. Hauv ua ke, 480p tsuas yog qhov ntau ntawm koj xav pom hauv lub teeb liab analog TV, nrog me ntsis nce hauv daim duab zoo.
720p
720p (720 txoj kab ntawm kev daws teeb meem ntawm kev sib tw ua ke) kuj yog digital TV hom, tab sis nws kuj yog ib qho ntawm HDTV tawm suab.
Xws li, ABC thiab FOX siv 720p ua lawv cov standard HDTV tshaj tawm. Tsis tsuas yog 720p muab ib tug duab zoo nkauj, zoo li zaj duab xis vim nws qhov kev siv scan loj hlob, tab sis duab qhia yog tsawg kawg 30% sharper tshaj 480p. Yog li ntawd, 720p muab kev txhim kho duab ntxiv uas pom tau ntawm ob qho tib si nruab nrab (32 "- 39") raws li cov npo loj dua. Kuj, txawm tias 720p yog qhov txhais tau tias, txhais tau tias tsawg dua bandwidth dua 1080i , uas yog them ntxiv tom ntej.
1080i
1080i (1.080 cov kab ntawm kev daws teeb meem ntawm lwm cov teb uas muaj 540 kab txhua) yog hom siv tau ntau tshaj li HDTV siv rau tshaj tawm hauv TV. Cov hom ntawv no tau raug pom los ntawm PBS, NBC, CBS, thiab CW (nrog rau cov kws tshaj lij uas muaj txuj ci HDNet, TNT, Showtime, HBO, thiab lwm yam kev them nqi) raws li lawv cov txheej txheem HDTV. Txawm hais tias tseem tshuav ib qho kev sib cav hais txog tias nws yog qhov zoo tshaj li 720p hauv qhov kev xam pom ntawm tus neeg saib xyuas, technically, 1080i muab cov duab kom ntxaws tshaj plaws ntawm tag nrho cov 18 kev pom zoo DTV broadcast qauv. Ntawm qhov one hand, qhov pom tau qhov ntawm 1080i yog poob rau ntawm cov vijtsam me me (hauv 32 ").
Txawm li cas los xij, qhov teeb meem ntawm 1080i yog:
- 1080i yuav siv ntau qhov bandwidth ntawm tag nrho cov DTV tawm suab.
- 1080i yog ib lub teeb liab interlaced, uas txhais tau hais tias cov duab tso tawm yog ua los ntawm cov kab lossis pixel kab uas tau luam tawm / tso tawm kom pom zoo dua tsis ua raws li hauv 480p thiab 720p.
- 1080i tuaj yeem tsis pom tshwm nyob rau hauv nws daim ntawv sau txog LCD, OLED, Plasma, lossis DLP TV . Yuav kom pom cov duab xa hauv 1080i, cov hom kev teeb tsa yuav tsum hloov cov teeb liab 1080i rau 720p lossis 1080p thiaj li tso saib tau cov duab hauv TV.
Ua lwm yam lus, yog tias koj muaj 1080p LCD los yog TV OLED, (los yog tseem muaj Plasma lossis DLP TV) nws yuav deinterlace lub teeb liab 1080i thiab tso tawm nws li duab 1080p . Cov txheej txheem no, yog tias ua tiav zoo, tshem tawm cov kab uas pom pom muaj nyob hauv cov duab 1080i interlaced, ua rau cov npoo tawv heev. Los ntawm tib qhov token, yog tias koj muaj 720p HDTV, koj lub TV yuav ua rau lub koos pis tawj thiab nqes cov duab 1080i rau 720p rau cov npo.
Yuav ua li cas txog 1080p?
Txawm hais tias 1080p yog siv rau Blu-Ray, Cable, thiab Internet streaming, nws tsis yog siv nyob rau hauv tshaj tawm-huab cua TV broadcasting. Yog vim li cas rau qhov no yog tias thaum Digital TV broadcast standards raug pom zoo, 1080p tsis yog ib feem ntawm qhov kev ua zauv. Raws li qhov tshwm sim TV broadcasters tsis tshaj tawm cov xov tooj cua tshaj tawm hauv 1080p.
Ntau Ntxiv - 4K thiab 8K
Txawm hais tias DTV tshaj tawm txoj kab ke tam sim no, tsis txhob cia li so tsis tau, vim cov txheej txheem txuas ntxiv yuav tsum muaj cov kev daws teeb meem 4K , thiab, ntxiv mus kev, 8K .
Pib, nws xav tias kev tshaj tawm 4K thiab 8K kev daws teeb meem tshaj-cua-tsis yuav ua tau vim yog txoj cai loj tshaj plaws. Txawm li cas los xij, muaj kev tshuaj ntsuam uas ua rau muaj peev xwm ua kom haum txhua yam xov xwm hauv kev siv hluav taws xob hauv kev siv tam sim no uas siv cov yees tshiab yees duab yees uas khaws cia qhov zoo tshaj qhov tsim nyog rau TV saib kawg. Yog li ntawd, nws muaj kev mob siab rau kev daws teeb meem 4K hauv TV tshaj tawm los ntawm kev siv ATSC 3.0 .
Raws li TV noj ua cov cuab yeej tsim nyog thiab kev hloov kho dua tshiab, thiab TV ua lag luam pib siv ATSC tuners rau hauv TVs thiab ntsaws rau saum txheej thawv, cov neeg tau txais kev pab yuav nkag mus rau 4K TV transmissions, tab sis, tsis zoo li hnub nyuab uas yuav tsum tau hloov los ntawm analog rau digital / HDTV broadcasting, qhov kev hloov mus rau 4K yuav qeeb thiab tam sim no yog kev yeem.
Qhov kev siv ntawm 4K TV broadcasting yog twv yuav raug hu tom qab lwm txoj kev nkag mus rau 4K cov ntsiab lus, xws li hauv internet streaming cov kev pab cuam, xws li Netflix thiab Vudu , nrog rau ntawm lub cev Ultra HD Blu-Ray Disc hom . Tseem, DirecTV tseem muaj kev txwv 4K satellite txau .
Meanwhile, txawm hais tias qhov kev siv zog loj yog coj 4K rau TV broadcasting, Nyiv kuj tseem thawb ua ntej nrog nws 8K Super Hi-Vision TV Broadcasting hom uas kuj muaj txog 22.2 channel suab. Super Hi-Vision tau soj ntsuam kom zoo dua kaum lub xyoo thiab npaj siab yuav npaj siab rau kev siv dav ntau dua los ntawm 2020, tab sis yuav tsum tau tso cai kawg tso cai.
Txawm li cas los, thaum 8K TV broadcasts yuav muaj nyob rau ntau yam yog txhua tus neeg twv, raws li nyob rau hauv 2020, 4K TV broadcasting tseem tsis tau ua kom tiav - yog li ua lwm dhia mus 8K yuav zaum tau lwm xyoo caum tawm, tshwj xeeb tshaj yog thaum xav tias cov TV makers haven tsis tau 8K TVs lossis cov ntsiab lus muaj rau cov neeg siv tau - thiab txawm tias los ntawm 2020, cov TV zoo li no yuav tsawg. Tau kawg, yuav tsum tau 8K cov ntsiab lus saib - TV broadcasters yuav tsum ua kom lwm qhov cuab yeej loj.