MP4 → WebP

Yambitsani mu wosewera, peza nthawiyo ndi kumbukirani nthawi yoyenera, chifukwa MP4 siyimagwiritsa ntchito nthawi yoyenera yolemba nkhani. Pezani nthawi yoyamba, wonjezerani nthawi yoti mugwiritse ntchito, ndipo wosinthayo adzafuna nthawiyo ndi kuchotsa nthawi yomwe mwafunsira. Kufuna kwa nthawiyo ndi koyenera kwa frame, koma kumatha kukhala koyenera ngati inali ndi mndandanda woyenera — onetsetsani kuti ndi woyenera panthawiyo musanayambe kujambula kanema. MP4 amathandiza okha imodzi yotchuka subtitle mtundu (mov_text), ndi multi-traka audio ndi osati olimba m'mphepete mwa desiki osewera.

Kuyambira pakupanga. A MP4 ndi fayilo ya media ya ISO, ndipo magulu a banja amalemba kuzungulira ngati chiwonetsero chazithunzi m'chipindacho, osati posintha ma pixels - chifukwa chake clip yojambula yokhala ndi foni imatha kuwona bwino m'modzi mwa osewera ndikukhala pambali pamodzi. Animation imapangidwa kuchokera ku pixels yosinthidwa, kuti chiwonetserocho chiyenera kuvomerezedwa pambuyo polemba chiwonetsero choyamba; ngati chithunzicho chimabwerera kumbuyo, sinthanitsani chiyambi ndikusinthanso. Zonse zina za kamera kapena wolemba wolemba ndi nkhani yothandiza: kanema wa kanema, mzere wokhazikika wa ma frame. Zikuoneka kuti pafupifupi aliyense MP4 m'munda ndi H.264 kanema ndi AAC audio; chidebenso mwalamulo ali HEVC, AV1 ndi VP9.

Yai, pamene muli ndi fayiloyo. A MP4 ndi zomwe webusaitiyi imagwiritsa ntchito kwa kanema wa inline chifukwa mabrowser amasewera popanda plugin, kotero clip yomwe imasewera mu tabu nthawi zambiri ndi MP4 yokhayo yomwe imasunga ndi kutsitsa pano monga fayilo ina iliyonse. Chiwopsezo ndi wosewera wosewera yemwe amapatsa ma segments ochepa omwe ali ndi masamba ochepa kuposa fayilo imodzi - omwe ayenera kusinthidwanso pambuyo poti chilichonse chitha kusinthidwa. Malamulo ndi chinthu china chomwe chimafunikira kuwunikira: kukhala ndi mwayi wotsitsa kanema sichifanana ndi kukhala ndi ufulu wosindikizanso animation yomwe idapangidwa kuchokera ku izo. MP4 ndi otetezeka zotheka kutumiza zolinga - aliyense foni, browser, console, wolemba ndi Smart TV anamanga mu zaka zapitazi amasewera izo popanda mapulogalamu zowonjezera.

Lossy, kwa chilichonse chomwe chimayamba ngati kanema. Animated WebP ingakongoletse ma frame ake mosiyana: mode ya lossless imasunga ma pixel onse ndipo imagwirizana ndi zithunzi zopanda malire ndi mawu a pazenera, pomwe mode ya lossy imagwiritsa ntchito kuyembekezera kwa block-based monga momwe video codec imagwiritsa ntchito ndipo imagwirizana ndi zithunzi zachilendo. Frames za kamera ndi zokhala ndi ma granules ndi ma gradients omwe lossless compression sapeza mzere, choncho animation ya lossless ya kanemayo imatha kuyendetsa nthawi zambiri kuposa ya lossy yomwe imawoneka ngati yofanana. Ikani ya lossy ngati kuti chiyambi chake chinali kujambula kwa skrini kwa mawu owoneka bwino. WebP ndibe yachiwiri-mtundu kunja kwa browser — kusindikiza workflows, zaka zakale Office zomanga ndi ena foni galleries sakuvomereza izo.

Animated WebP imagwira ntchito bwino kwambiri pazolemba pansi pa 10 masekondi. Kuwonjezera pa zomwe mafayilo amapanga (GIF ndizomwe zimapangidwa ndi frame). Kwa ma animations ochepa, amagwiritsa ntchito WebP kapena APNG, omwe amagwiritsa ntchito kutsitsa kwa video-codec-grade ndi kukula bwino.

GIF yokhala ndi ma animations: 2 mpaka 8 MB pa 480p malinga ndi kuvuta kwa kuyendetsa. WebP yokhala ndi ma animations: 200 KB mpaka 1 MB pamodzi ndi kuwonekera / kudalirika. WebP yokhala ndi ma animations ndi 5 mpaka 10x yothandiza kuposa GIF pokhala ndi kuwala kofanana. WebP amapatsa modes lossy ndi lossless, ndi alpha kuwala ndi animation alipo m'modzi kapena m'modzi.

Mwachidule timalowetsa mpaka 15 fps kwa GIF yoanima (yokhala ndi mavuto owoneka bwino kuposa 25 fps) ndi 24 fps kwa WebP / APNG yoanima (yoyang'anira bwino kwambiri). Chotsani mwa kusankha kwa frame-rate ngati woyang'anira wanu amathandizira kuchuluka kwa chiyambi.

Sichoncho — mavidiyo a WebP (GIF, WebP, APNG) sasunga mawu. Ngati mukufuna mawu, yesani kujambula kanema (MP4, WebM) m'malo mwa kujambula zithunzi zosaoneka.

Yes - njira yowerengera loop-count imawongolera ngati WebP imayenda mopanda malire (default), imasewera nthawi N, kapena imasewera nthawi imodzi. Kuwerengera kwa loop kusungidwira mu metadata ya WebP yonyamula ndipo imalemekeza aliyense woonera wamakono.

Zifukwa ziwiri zofala. Choyamba, kuchepetsa kuchuluka kwa ma frame: 15 fps WebP kuchokera ku 60 fps MP4 kumachepetsa 75% ya ma frame; kuchotsa ndi slider ya kuchuluka kwa ma frame. Chachiwiri, kuchepetsa kwa palette: GIF imathamanga mpaka ku 256 colors ndi gradient-heavy MP4 dithers.

Ndio — njira yosintha kukula imachepetsa MP4 pambuyo pochotsa ma frame, zomwe zimachepetsa kwambiri kukula kwa fayilo ya WebP. 480p WebP kuchokera ku 4K MP4 ndi pafupifupi 16x yaying'ono kuposa 4K WebP.