Tomas Chlebek Ua ntej ob peb hnub Netflix thaum kawg tau qhib rub tawm cov ntsiab lus rau kev saib offline. Ib qho ntawm cov laj thawj tseem ceeb vim li cas qhov kev xaiv no tsuas yog tam sim no tau hais tias yog teeb meem nrog kev nrhiav cov qauv tsim nyog thiab zoo.
Ob qib zoo yog muab rau rub tawm - "Standard" thiab "siab dua". Nws tsis paub tias qhov kev daws teeb meem tshwj xeeb thiab cov bitrates lawv muaj dab tsi, uas yog vim lawv txawv raws li cov ntsiab lus. Netflix xav muab qhov ua tau zoo tshaj plaws ntawm qhov zoo thiab qhov loj ntawm cov ntaub ntawv rub tawm.
Qhov tshwm sim yog qhov zoo dua ntawm qhov me me
Nws tau siv cov ntaub ntawv sib txawv ntawm cov streaming rau lub sijhawm ntev, tab sis nws xav los nrog kev daws teeb meem ntau dua rau kev rub tawm. Yog li, thaum streaming kom deb li deb tau siv H.264 / AVC Main profile (AVCmain) codec (cov ntaub ntawv compression hom), Netflix rau txawb tau qhia txog kev txhawb nqa rau ob qho tib si - H.264 / AVC High profile (AVCHi) thiab VP9, yav dhau los siv los ntawm iOS pab kiag li lawm thiab ib tug thib ob Android ntaus ntawv.
VP9 yog qhov zoo dua ntawm qhov sib piv ntawm qhov zoo thiab cov ntaub ntawv tus nqi; tab sis thaum nws muaj pub dawb, Apple tsis txhawb Google-tsim codec no, thiab nws tsis zoo li qhov ntawd yuav hloov txhua lub sijhawm sai sai. Yog vim li cas Netflix xaiv AVChi. Nws txiav txim siab siv ib txoj kev tshiab rau cov ntaub ntawv compression. Qhov no muaj nyob rau hauv kev tshuaj xyuas ib tug neeg scenes thiab txiav txim siab lawv cov duab complexity (piv txwv li ib tug calm scene nrog ib tug tsawg kawg nkaus ntawm kev txav mus los ntawm ib qho kev ua yeeb yam nrog ntau yam khoom txav).
Raws li nws, tag nrho cov yeeb yaj kiab / series yog tom qab ntawd "sliced" rau hauv qhov nruab nrab ntawm ib thiab peb feeb ntev, thiab rau txhua qhov kev daws teeb meem thiab cov ntaub ntawv ntws yuav tsum ua kom tau raws li qhov yuav tsum tau ua yog xam tus kheej. Txoj hauv kev no kuj tau siv rau VP9 codec, thiab Netflix npaj siv nws rau nws lub tsev qiv ntawv tiav thiab siv nws tsis yog rau rub tawm xwb, tab sis kuj rau streaming.
Kev sib txawv codecs thiab compression txoj kev muaj ob lub txim: txo cov ntaub ntawv ntws thaum tswj cov khoom qub, lossis nce qhov zoo thaum tswj cov ntaub ntawv tib yam. Tshwj xeeb, cov ntaub ntawv nrog lub hom phiaj ntawm tib cov duab zoo tuaj yeem xav tau 19% tsawg qhov chaw nrog AVChi codec thiab mus txog 35,9% tsawg qhov chaw nrog VP9 codec. Video zoo nrog tib cov ntaub ntawv kwj (post ntawm Netflix blog muab piv txwv rau 1 Mb/s) piv rau AVCMain nce 7 ntsiab lus rau AVChi raws li tus qauv xeem VMAF, nrog VP9 ces los ntawm 10 ntsiab lus. "Cov kev nce qib no muab cov duab zoo dua rau cov streaming mobile," blog hais.
