Pavel Jelic Yog tias koj yog ib tus ntawm cov neeg siv uas nyiam teeb tsa lawv cov khoom ntawm lawv tus kheej kev txiav txim siab kom haum lawv ntau li ntau tau, ces tej zaum koj tau tuaj hla Apple TV nqis seem. Video thiab suab nrog yam khoom Chrome. Nrog rau qhov kev xaiv no, lawv muaj nyob rau ntawm Apple TV ob txoj kev xaiv, uas koj tuaj yeem xaiv los ntawm. Txawm li cas los xij, qhov tseeb yog tias cov neeg siv zoo tib yam uas tsis cuam tshuam nrog cov ntaub ntawv thiab, tej zaum, tso saib cov thev naus laus zis, tej zaum tsis paub tias qhov kev xaiv Chroma txhais li cas thiab qhov chaw lawv yuav tsum xaiv. Hauv kab lus no, cia peb saib ua ke ntawm chroma txhais tau li cas thiab qhov twg nws tuaj yeem teeb tsa hauv tvOS.
Nws yuav yog txaus siab rau koj
Flying thoob ntiaj teb nrog Apple Chroma yog dab tsi?
Chroma sampling Kuv yog ib tug txiv neej compression, nrog kev pab ntawm uas lub txo qhov loj ntawm cov ntaub ntawv xim. Cov teeb liab video tau muab faib ua classical ob yam tseem ceeb - ntaub ntawv hais txog qhov kaj (luma) thiab cov ntaub ntawv hais txog xim (chroma). Cov ntaub ntawv hais txog qhov kaj (luminance, abbreviated luma), txhais qib brightness ntawm cov duab kis, thiab yog li ntawd kuv sib piv. Luma txhais qhov loj ntawm tag nrho cov duab, thiab yog li ntawd cov duab dub-thiab-dawb tsis zoo saib tsawg dua cov xim ib. Cov ntaub ntawv hais txog xim (chrominance, abbreviated chroma), kuj yog siv rau cov duab xa mus tseem ceeb, tab sis tsis ntau li luma - muab tso yooj yim, chroma tsis tshua muaj kev cuam tshuam rau tag nrho cov tsos ntawm daim duab. Yog li ntawd, thaum lub sij hawm daim duab kis tau tus mob, lub thiaj li hu subsampling, yog li ntawd txo qhov kis ntawm cov ntaub ntawv xim. Ua tsaug rau qhov tseeb tias qhov loj ntawm cov ntaub ntawv xa tawm xim raug txo, nws muaj peev xwm xa cov ntaub ntawv ntau ntxiv txog qhov ci, thiab cov duab tshwm sim tuaj yeem ci dua nyob rau hauv cov nqe lus ntawm zoo dua thiab muaj tseeb dua. Nyob rau tib lub sijhawm, nws yuav khaws cia duab clarity thiab tib lub sijhawm koj tuaj yeem txo qhov loj ntawm tag nrho cov ntaub ntawv video mus txog o 50%.
Chroma qhia li cas?
Kev teeb tsa muaj nyob hauv tvOS 4:2:2 los yog 4:2:0, XNUMX:XNUMX:XNUMX Txawm li cas los xij, nws yuav tsum raug sau tseg tias peb tuaj yeem ntsib teeb tsa 4 :4:4. Thawj tus lej ib txwm qhia hauv cov lej no qauv loj. Tom ntej no ob tug lej ces muaj feem xyuam ceg tawv. Ob tus lej no cuam tshuam thiab txhais thawj tus lej kab rov tav a ntsug sampling. Qhov no zoo dua piav nrog ib qho piv txwv. Chaw 4:4:4 tsis siv tsis muaj compression, Yog li ntawd tsis muaj qhov tsis txaus ntseeg - qhov no muaj kev thauj mus los cov ntaub ntawv tiav hais txog qhov ci thiab xim. Chaw 4:2:2 ces kis ib nrab cov ntaub ntawv hais txog xim - nws los txog kab rov tav subsampling. 4 :2:0 xa ib quarter cov ntaub ntawv hais txog xim, yog li se ib row xim ntaub ntawv kiag li nco tawm. Yuav kom nkag siab lub ntsiab lus no zoo dua, gallery hauv qab kab lus no koj yuav pom cov duab ntsig txog chroma sampling settings.
Cov duab thaij duab
Kev lag luam zaj duab xis thiab chroma
Txij li thaum peb feem ntau siv Apple TV feem ntau los saib cov yeeb yaj kiab, peb yuav ua tib zoo saib seb chroma sampling cuam tshuam li cas rau cov yeeb yaj kiab, yeeb yaj kiab, thiab lwm yam yeeb yaj kiab. Kev siv chroma sampling yog heev muaj nyob rau hauv kev lag luam yeeb yaj kiab tam sim no 4: 2: 0. Qhov laj thawj tseem ceeb yog qhov tseeb tias tib neeg lub qhov muag tau xyaum tsis muaj lub sijhawm los paub qhov txawv ntawm qhov sib txawv ntawm 4: 2: 0 thiab 4: 4: 4, uas tsis siv cov compression. Thaum twg 4:2:0 txawm tias muaj qhov tseeb poob ntawm cov ntaub ntawv xim, tab sis nws yeej tsis yog hais txog tsis muaj dab tsi hnyav. Hom ntawv 4:2:0 kuj feem ntau siv rau Blu-duab tshav discs thiab lwm yam thaum koj xav kom muaj cov yeeb yaj kiab hauv qhov "zoo tshaj" ua tau zoo. Qhov sib txawv ntawm chroma sampling nqis yog qhov pom tau tshaj plaws thaum nws nyob ntawm qhov screen ntawv me me. Nyob rau hauv cov ntaub ntawv ntawm subsampling, lub thiaj li hu cov khoom qub. Koj tuaj yeem pom hauv qab no gallery, nyob rau hauv uas koj tuaj yeem saib cov artifacts cais rau txhua hom ntawv.
Cov duab thaij duab
Yuav teeb Chroma hauv tvOS li cas?
Hauv Apple TV, peb muaj Chroma teeb tsa muaj nyob hauv hom 4:2:0 lossis 4:2:2, XNUMX:XNUMX:XNUMX thaum nws raug xaiv los ntawm lub neej ntawd 4: 2: 0. Raws li koj tuaj yeem tau nyeem los ntawm cov kab uas tau teev tseg saum toj no, 4: 2: 0 hom yog qhov zoo tshaj plaws hauv qhov no, txij li hauv nws cov ntaub ntawv "tsuas yog" ib feem peb ntawm cov ntaub ntawv xim raug xa mus. Qhov kev teeb tsa no tau xaiv tsuas yog vim tib neeg feem ntau siv tag nrho HDMI cables zoo tib yam, uas tsuas yog tsis tuaj yeem tswj hwm kev sib kis ntawm 4: 2: 2 hom. Yog li ntawd, hom 4: 2: 2 yuav tsum tau teeb tsa los ntawm cov neeg zoo li no uas tau muab pov tseg high-speed thiab high-zoo HDMI kab. Yog tias koj xav hloov Chroma nqis hauv tvOS, mus rau Chaw -> Video & Suab -> Chroma. Yog koj sim teem lub hom ntawv 4:2:2, XNUMX:XNUMX:XNUMX yog li Apple TV yuav ceeb toom koj thiab tom qab ntawd khiav qhov kev sim ntawm koj cov cables. Yog tias koj cov cables dhau mus, cov ntawv yuav yog li ntawd 4: 2: 2, txwv tsis pub yuav muaj restores qhov qub chaw, yog li ntawd rau 4: 2: 0.
Cov duab thaij duab
