Tomas Chlebek Ngaphambili izinsuku ezimbalwa I-Netflix igcine ivumele ukulanda okuqukethwe ukuze kubukwe ungaxhunyiwe ku-inthanethi. Esinye sezizathu eziyinhloko zokuthi kungani le nketho ifika manje kuphela kwathiwa izinkinga ngokuthola ifomethi nekhwalithi efanele.
Amaleveli ekhwalithi amabili anikeziwe ukuze alandwe - "Okujwayelekile" kanye "Kuphezulu". Akwaziwa ukuthi yiziphi izinqumo ezithile nama-bitrate abanazo, okubangelwa ukuthi zihluka ngokuya ngokuqukethwe. I-Netflix ibifuna ukunikeza isilinganiso esingcono kakhulu phakathi kwekhwalithi nosayizi wefayela elilandiwe.
Umphumela uba ikhwalithi engcono ngosayizi omncane
Usenesikhathi eside esebenzisa ukugeleza kwedatha okuguquguqukayo ukuze asakaze, kodwa ubefuna ukuqhamuka nesixazululo esiyonga kakhulu sokulanda. Ngakho-ke, nakuba ukusakaza kuze kube manje sekusebenzisa i-codec ye-H.264/AVC Main (AVCMain) (uhlobo lokucindezelwa kwedatha), i-Netflix yeselula yethule ukusekelwa kwabanye ababili - H.264/AVC High profile (AVCHi) kanye ne-VP9, eyangaphambili isetshenziswa amadivayisi we-iOS kanye nedivayisi yesibili ye-Android.
I-VP9 ingcono ngokwesilinganiso phakathi kwekhwalithi nenani ledatha; kodwa ngenkathi itholakala mahhala, i-Apple ayisekeli le codec edalwe yi-Google, futhi akubukeki sengathi lokho kuzoshintsha noma nini maduze. Kungakho iNetflix ikhethe i-AVHi. Unqume ukusebenzisa indlela entsha yokucindezela idatha. Lokhu kuhlanganisa ukuhlaziya izigcawu ezingazodwana nokuthola ubunkimbinkimbi bezithombe zazo (isb. indawo epholile enokunyakaza okuncane uma kuqhathaniswa nesigcawu sesenzo esinezinto eziningi ezihambayo).
Ngokusho kwakhe, lonke ifilimu/uchungechunge lube "lusikwa" lube izingxenye eziphakathi komzuzu owodwa nemithathu ubude, futhi engxenyeni ngayinye ukulungiswa nokugeleza kwedatha okudingekayo ukuze kuzuzwe ikhwalithi edingekayo kubalwa ngakunye. Le ndlela yabe isisetshenziselwa i-codec ye-VP9, futhi i-Netflix ihlela ukuyisebenzisa emtatsheni wezincwadi wayo ophelele futhi ingayisebenziseli ukulanda kuphela, kodwa futhi nokusakaza.
Ama-codec ahlukene nezindlela zokucindezela zinemiphumela emibili: ukunciphisa ukugeleza kwedatha ngenkathi kugcinwa ikhwalithi yangempela, noma ukwandisa ikhwalithi ngenkathi kugcinwa ukugeleza kwedatha okufanayo. Ngokucacile, amafayela anekhwalithi yesithombe efanayo angadinga isikhala esincane esingu-19% nge-codec ye-AVHi kanye nesikhala esifika ku-35,9% esingaphansi nge-codec ye-VP9. Ikhwalithi yevidiyo enokusakazwa kwedatha okufanayo (okuthunyelwe ku-Netflix blog inikeza isibonelo se-1 Mb/s) uma kuqhathaniswa ne-AVCMain ikhuphuke ngamaphoyinti angu-7 ku-AVHi ngokwezinga lokuhlola I-VMAF, nge-VP9 bese ngamaphuzu ayi-10. "Lokhu kwanda kunikeza ikhwalithi yesithombe engcono kakhulu yokusakaza ngeselula," kusho ibhulogi.
