Kodi vidiyo ya codec imagwira ntchito bwanji? Gawo 1: Zoyambira

Gawo lachiwiri: Momwe vidiyo ya codec imagwirira ntchito

raster iliyonse chithunzi akhoza kuyimiridwa mu mawonekedwe matrix awiri-dimensional. Pankhani ya mitundu, lingaliro likhoza kupangidwa poyang'ana chithunzi ngati matrix atatu-dimensional, momwe miyeso yowonjezera imagwiritsidwa ntchito kusunga deta pamtundu uliwonse.

Ngati tilingalira mtundu womaliza monga kuphatikiza kwa otchedwa. mitundu yoyambirira (yofiira, yobiriwira ndi yabuluu), mu matrix athu amitundu itatu timatanthauzira ndege zitatu: yoyamba yofiira, yachiwiri yobiriwira ndi yotsiriza ya buluu.

Titcha mfundo iliyonse mu matrix awa pixel (chithunzi chazithunzi). Pixel iliyonse imakhala ndi zambiri za kukula kwake (nthawi zambiri ngati nambala) yamtundu uliwonse. Mwachitsanzo, pixel yofiira zikutanthauza kuti muli 0 wobiriwira, 0 buluu ndi pazipita wofiira. Pixel ya pinki akhoza kupangidwa pogwiritsa ntchito mitundu itatu. Pogwiritsa ntchito manambala kuyambira 0 mpaka 255, pixel ya pinki imatanthauzidwa ngati Red = 255, Green = 192 и Buluu = 203.

Nkhaniyi idasindikizidwa mothandizidwa ndi EDISON.

Tikukula ntchito zowunikira makanema, kutsitsa makanema, komanso tili pachibwenzi kujambula kanema m'chipinda chopangira opaleshoni.

Njira zina zolembera chithunzi chamtundu

Pali zitsanzo zina zambiri zoyimira mitundu yomwe imapanga chithunzi. Mwachitsanzo, mutha kugwiritsa ntchito phale yolondolera, yomwe imafunikira baiti imodzi yokha kuyimira pixel iliyonse, m'malo mwa atatu ofunikira mukamagwiritsa ntchito mtundu wa RGB. Muchitsanzo chotere, ndizotheka kugwiritsa ntchito matrix a 2D m'malo mwa 3D matrix kuyimira mtundu uliwonse. Izi zimapulumutsa kukumbukira, koma zimapereka mtundu wocheperako wa gamut.

RGB

Mwachitsanzo, yang'anani chithunzichi pansipa. Nkhope yoyamba idapakidwa utoto. Zina ndi ndege zofiira, zobiriwira ndi zabuluu (kulimba kwa mitundu yofananira kumawonetsedwa mu grayscale).

Timawona kuti mithunzi yofiira mu choyambirira idzakhala m'malo omwewo pomwe mbali zowala kwambiri za nkhope yachiwiri zikuwonekera. Ngakhale kuti chopereka cha buluu chikhoza kuwonedwa makamaka m'maso a Mario (nkhope yomaliza) ndi zinthu za zovala zake. Zindikirani komwe ndege zonse zamitundu itatu zimapereka zochepa (mbali zakuda kwambiri pazithunzi) - masharubu a Mario.

Kuti musunge kukula kwa mtundu uliwonse, kuchuluka kwa ma bits kumafunika - kuchuluka uku kumatchedwa kuzama pang'ono. Tinene kuti ma bits 8 agwiritsidwa ntchito (kutengera mtengo kuchokera pa 0 mpaka 255) pamtundu uliwonse. Ndiye tili ndi kuya kwa mtundu wa 24 bits (8 bits * 3 R/G/B ndege).

Katundu wina wa fano ndi chilolezo, chomwe ndi chiwerengero cha ma pixel mu muyeso umodzi. Nthawi zambiri imatchedwa m'lifupi × kutalika, monga chithunzi cha 4 ndi 4 pansipa.


Katundu wina womwe timachita nawo tikamagwira ntchito ndi zithunzi / makanema ndi Chiŵerengero cha mawonekedwe, kufotokoza ubale wabwinobwino pakati pa m'lifupi ndi kutalika kwa chithunzi kapena pixel.

Akamanena kuti filimu kapena chithunzi chinachake ndi 16 ndi 9 mu kukula, nthawi zambiri amatanthauza chiwonetsero cha mawonekedwe (DAR - kuchokera Onetsani Aspect Ration). Komabe, nthawi zina pakhoza kukhala mawonekedwe osiyana a pixels payekha - mu nkhani iyi tikukamba chiwerengero cha pixel (NDI - kuchokera Pixel Aspect Ration).

Chidziwitso kwa wolandira alendo: DVD zimayenderana DAR 4 mpaka 3

Ngakhale mawonekedwe enieni a DVD ndi 704x480, amakhalabe ndi 4: 3 mawonekedwe chifukwa PAR ndi 10:11 (704x10 / 480x11).

Ndipo potsiriza, tikhoza kudziwa видео monga ndandanda wa n mafelemu a nthawiyo nthawi, yomwe ingaganizidwe ngati gawo lowonjezera. A n ndiye kuchuluka kwa mafelemu kapena kuchuluka kwa mafelemu pamphindikati (FPS - kuchokera Mafelemu pa Chachiwiri).

Chiwerengero cha ma bits pa sekondi imodzi yofunika kuti muwonetse kanema ndi yake liwiro kufala - bitrate.

bitrate = m'lifupi * kutalika * kuzama pang'ono * mafelemu pamphindikati

Mwachitsanzo, kanema wa 30 fps, 24 bps, 480x240 angafune 82,944,000 bps kapena 82,944 Mbps (30x480x240x24) - koma ngati palibe njira yopondereza yomwe ikugwiritsidwa ntchito.

Ngati kutengerapo liwiro pafupifupi mosalekeza, ndiye imatchedwa liwiro kufala kosalekeza (CBR - kuchokera mlingo wokhazikika pang'ono). Koma imathanso kusiyanasiyana, pankhaniyi imatchedwa mtengo wamtengo wapatali (Chithunzi cha VBR - kuchokera variable bit rate).

Chithunzichi chikuwonetsa VBR yocheperako, pomwe ma bits ambiri samawonongeka pakakhala chimango chakuda kwathunthu.

Mainjiniya poyambilira adapanga njira yowonjezerera kuwirikiza kwachiwonetsero kwa kanema popanda kugwiritsa ntchito bandwidth yowonjezera. Njirayi imadziwika kuti vidiyo yolumikizidwa; Kwenikweni, imatumiza theka la chinsalu mu "chimango" choyamba ndi theka lina mu "chimango" chotsatira.

Masiku ano, mawonekedwe amagwiritsidwa ntchito kwambiri matekinoloje opitilira apo. Ndi njira yowonetsera, kusunga kapena kutumiza zithunzi zosuntha zomwe mizere yonse ya chimango chilichonse imakokedwa motsatizana.

Chabwino! Tsopano tikudziwa momwe chithunzi chimayimiridwa ndi digito, momwe mitundu yake imakonzedwera, ndi ma bits angati pamphindikati yomwe timathera kuti tiwonetse kanema, ngati bit rate ndi nthawi zonse (CBR) kapena variable (VBR). Timadziwa za chigamulo chomwe chinaperekedwa pogwiritsa ntchito mlingo woperekedwa, timadziwa mawu ena ambiri, monga mavidiyo osakanikirana, PAR ndi ena.

Kuchotsa redundancy

Amadziwika kuti kanema popanda psinjika sangathe ntchito bwinobwino. Kanema wa ola limodzi pakusintha kwa 720p ndi mafelemu 30 pamphindikati zitha kutenga 278 GB. Timafika pamtengowu pochulukitsa 1280 x 720 x 24 x 30 x 3600 (m'lifupi, kutalika, bits pa pixel, FPS ndi nthawi mumasekondi).

Gwiritsani ntchito ma aligorivimu ophatikizika opanda kutaya, monga DEFLATE (yogwiritsidwa ntchito mu PKZIP, Gzip ndi PNG), sizingachepetse bandwidth yofunikira mokwanira. Tiyenera kuyang'ana njira zina compress kanema.

Kuti muchite izi, mutha kugwiritsa ntchito mawonekedwe a masomphenya athu. Ndife bwino kusiyanitsa kuwala kuposa mtundu. Kanema ndi mndandanda wazithunzi zotsatizana zomwe zimabwerezedwa pakapita nthawi. Pali kusiyana pang'ono pakati pa mafelemu oyandikana a zochitika zomwezo. Kuphatikiza apo, chimango chilichonse chimakhala ndi madera ambiri omwe amagwiritsa ntchito mtundu womwewo (kapena wofanana).

Mtundu, kuwala ndi maso athu

Maso athu amazindikira kwambiri kuwala kuposa mtundu. Mutha kudziwonera nokha izi poyang'ana chithunzichi.

Ngati simukuwona kuti kumanzere kwa chithunzicho mitundu ya mabwalo A и B ndizofanana, ndiye kuti ndizabwinobwino. Ubongo wathu umatikakamiza kulabadira kwambiri kuwala ndi mthunzi osati mtundu. Kumanja pakati pa mabwalo osankhidwa pali jumper ya mtundu womwewo - kotero ife (ie ubongo wathu) timadziwa mosavuta kuti, kwenikweni, ndi mtundu womwewo.

Tiyeni tione (m’njira yophweka) mmene maso athu amagwirira ntchito. Diso ndi chiwalo chovuta kumvetsa chomwe chili ndi ziwalo zambiri. Komabe, timakonda kwambiri ma cones ndi ndodo. Diso lili ndi ndodo pafupifupi 120 miliyoni ndi ma cones 6 miliyoni.

Tiyeni tiganizire kawonedwe ka mtundu ndi kuwala ngati ntchito zosiyana za mbali zina za diso (kwenikweni, zonse zimakhala zovuta kwambiri, koma tidzazichepetsa). Maselo a ndodo ndi omwe amachititsa kuwala, pamene ma cone cell ndi omwe amachititsa mtundu. Ma cones amagawidwa m'mitundu itatu, kutengera mtundu womwe ali nawo: S-cones (buluu), M-cones (wobiriwira), ndi L-cones (wofiira).

Popeza tili ndi ndodo zambiri (zowala) kuposa ma cones (mtundu), tikhoza kunena kuti ndife okhoza kusiyanitsa kusintha pakati pa mdima ndi kuwala kusiyana ndi mitundu.

Kusiyanitsa Kumvetsetsa Mawonekedwe

Ofufuza mu psychology yoyesera ndi magawo ena ambiri apanga malingaliro ambiri a masomphenya aumunthu. Ndipo mmodzi wa iwo amatchedwa ntchito zosiyana sensitivity. Zimagwirizana ndi kuwunikira kwakanthawi komanso kwanthawi. Mwachidule, ndi za kuchuluka kwa masinthidwe omwe amafunikira wowonera asanawazindikire. Onani kuchuluka kwa mawu oti "ntchito". Izi ndichifukwa choti titha kuyeza magwiridwe antchito osiyanitsa osati pazithunzi zakuda ndi zoyera, komanso zamitundu. Zotsatira za mayeserowa zimasonyeza kuti nthawi zambiri maso athu amamva kuwala kusiyana ndi mtundu.

Popeza tikudziwa kuti timakhudzidwa kwambiri ndi kuwala kwazithunzi, titha kuyesa kugwiritsa ntchito mfundoyi.

Mtundu wamitundu

Tinaganizira pang'ono momwe tingagwiritsire ntchito zithunzi zamitundu pogwiritsa ntchito dongosolo la RGB. Palinso zitsanzo zinanso. Pali chitsanzo chomwe chimalekanitsa kuwala ndi chroma ndipo chimadziwika kuti YCbCr. Mwa njira, pali zitsanzo zina zomwe zimapanga magawano ofanana, koma tidzangoganizira izi.

Muchitsanzo chamtundu uwu Y ndi chiwonetsero cha kuwala, komanso amagwiritsa ntchito njira ziwiri zamitundu: Cb (blue blue) ndi Cr (wofiira wolemera). YCbCr ikhoza kutengedwa ku RGB, ndipo kutembenuka kobwereranso kumatheka. Pogwiritsa ntchito chitsanzochi tikhoza kupanga zithunzi zamitundu yonse monga momwe tikuonera pansipa:

Sinthani pakati pa YCbCr ndi RGB

Wina angatsutse: zingatheke bwanji kupeza mitundu yonse ngati zobiriwira sizikugwiritsidwa ntchito?

Kuti tiyankhe funsoli, tiyeni tisinthe RGB kukhala YCbCr. Tiyeni tigwiritse ntchito ma coefficients omwe adatengera muyeso BT. 601, zomwe zidalimbikitsidwa ndi gululo ITU-R. Gawoli limakhazikitsa miyezo yamakanema a digito. Mwachitsanzo: 4K ndi chiyani? Kodi mtengo wa chimango uyenera kukhala wotani, kusintha, mtundu wamtundu?

Choyamba tiyeni tiwerengere kuwala. Tiyeni tigwiritse ntchito zokhazikika zomwe ITU ikufuna ndikusinthira ma RGB.

Y = 0.299R + 0.587G + 0.114B

Tikakhala ndi kuwala, tidzalekanitsa mitundu ya buluu ndi yofiira:

Cb = 0.564 (B - Y)

Cr = 0.713 (R - Y)

Ndipo titha kutembenuzanso ndikukhalanso wobiriwira pogwiritsa ntchito YCbCr:

R = Y + 1.402Cr

B = Y + 1.772Cb

G = Y - 0.344Cb - 0.714Cr

Kawirikawiri, zowonetsera (zowunikira, ma TV, zowonetsera, ndi zina zotero) zimagwiritsa ntchito chitsanzo cha RGB chokha. Koma chitsanzo ichi chikhoza kukonzedwa m'njira zosiyanasiyana:

Mtundu wa subsampling

Ndi chithunzi chomwe chikuyimiridwa ngati kuphatikiza kwa kuwala ndi chrominance, titha kugwiritsa ntchito chidwi chachikulu cha mawonekedwe amunthu pakuwona kuwala kuposa chrominance pochotsa zomwe mwasankha. Chroma subsampling ndi njira yosungira zithunzi pogwiritsa ntchito kusanja kocheperako kwa chroma kuposa kuwunikira.

Ndi ndalama zingati zomwe zimaloledwa kuchepetsa kusintha kwa mtundu?! Zikuoneka kuti pali kale zithunzi zomwe zimafotokoza momwe mungagwirire chigamulo ndi kuphatikiza (Resulting Color = Y + Cb + Cr).

Mapulani awa amadziwika kuti downsampling systems ndipo amawonetsedwa ngati 3-fold ratio - a:x:y, yomwe imatsimikizira kuchuluka kwa zitsanzo za kuwala ndi zizindikiro za kusiyana kwa mitundu.

a - sampuli yopingasa (nthawi zambiri imakhala yofanana ndi 4)
x - chiwerengero cha zitsanzo za chroma mumzere woyamba wa ma pixel (kusintha kopingasa kofanana ndi a)
y - kuchuluka kwa kusintha kwa zitsanzo za chroma pakati pa mizere yoyamba ndi yachiwiri ya ma pixel.

Kupatulapo ndi 4:1:0, kupereka chitsanzo chimodzi cha chroma mu chipika chilichonse cha 4-by-4 luminance resolution.

Njira zodziwika bwino zomwe zimagwiritsidwa ntchito mu ma codec amakono:

• 4:4:4 (palibe kutsitsa)
• 4:2:2
• 4:1:1
• 4:2:0
• 4:1:0
• 3:1:1

YCbCr 4:2:0 - fusion chitsanzo

Nachi chithunzi chophatikizidwa pogwiritsa ntchito YCbCr 4:2:0. Dziwani kuti tikungowononga ma bits 12 pa pixel imodzi.

Izi ndi momwe chithunzi chomwechi chikuwonekera, chojambulidwa ndi mitundu ikuluikulu yamitundu yayikulu. Mzere woyamba ndi YCbCr yomaliza, mzere wapansi ukuwonetsa kusintha kwa chroma. Zotsatira zabwino kwambiri, poganizira za kutaya pang'ono kwa khalidwe.

Kumbukirani pamene tidawerengera 278 GB malo osungira kuti tisunge fayilo ya kanema ya ola limodzi pa 720p resolution ndi mafelemu 30 pamphindikati? Ngati tigwiritsa ntchito YCbCr 4:2:0, ndiye kukula uku kuchepetsedwa ndi theka - 139 GB. Mpaka pano, akadali kutali ndi zotsatira zovomerezeka.

Mutha kupeza histogram ya YCbCr nokha pogwiritsa ntchito FFmpeg. M'chithunzichi, buluu amalamulira zofiira, zomwe zimawoneka bwino mu histogram yokha.

Mtundu, kuwala, mtundu wa gamut - ndemanga ya kanema

Tikukulimbikitsani kuti muwone kanema wodabwitsa uyu. Imalongosola chowala chomwe chili, ndipo nthawi zambiri madontho onse ali ndi madontho ё za kuwala ndi mtundu.

Mitundu ya chimango

Tiyeni tipitirire. Tiyeni tiyese kuthetsa redundancy nthawi. Koma choyamba, tiyeni titanthauze mawu ena ofunikira. Tiyerekeze kuti tili ndi kanema wokhala ndi mafelemu 30 pa sekondi imodzi, nawa mafelemu ake anayi oyamba:

Timatha kuona kubwerezabwereza kochuluka mu mafelemu: mwachitsanzo, maziko a buluu omwe samasintha kuchoka pa chimango kupita ku chimango. Kuti tithane ndi vutoli, titha kuwagawa m'mitundu itatu ya mafelemu.

I-frame (Intro Frame)

I-frame (chithunzi chofotokozera, chimango chachinsinsi, chimango chamkati) chimakhala chokhazikika. Mosasamala zomwe mukufuna kuwona, I-frame kwenikweni ndi chithunzi chokhazikika. Feremu yoyamba nthawi zambiri imakhala I-frame, koma timawona mafelemu a I nthawi zonse ngakhale pakati pa mafelemu oyamba.

P-frame (Pmawonekedwe osinthika)

P-frame (chithunzi cholosera) imatengera mwayi kuti pafupifupi nthawi zonse chithunzi chomwe chilipo chikhoza kupangidwanso pogwiritsa ntchito chimango chapitacho. Mwachitsanzo, mu chimango chachiwiri kusintha kokha ndi mpira kupita patsogolo. Titha kupeza chimango 2 mwa kungosintha pang'ono chimango 1, kugwiritsa ntchito kusiyana pakati pa mafelemu awa. Kuti tipange chimango 2, timayang'ana chithunzi choyambirira 1.

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B-frame (Bi-predictive Frame)

Nanga maulalo osati zakale zokha, komanso mafelemu amtsogolo kuti apereke kuponderezedwa kwabwinoko?! Izi kwenikweni ndi B-frame (bidirectional frame).

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Kuchotsa kwapakatikati

Mitundu yamafelemuyi imagwiritsidwa ntchito kuti ipereke kupanikizana kwabwino kwambiri. Tiwona momwe izi zimachitikira mu gawo lotsatira. Pakalipano, tiyeni tiwone kuti "zokwera mtengo" kwambiri pokumbukira zomwe zimagwiritsidwa ntchito ndi I-frame, P-frame ndiyotsika mtengo kwambiri, koma njira yopindulitsa kwambiri pavidiyo ndi B-frame.

Kuchepetsa kwakanthawi (kulosera kwapakati pa mafelemu)

Tiyeni tiwone zomwe tingasankhe kuti tichepetse kubwereza nthawi. Titha kuthetsa kuperewera kwamtunduwu pogwiritsa ntchito njira zolosera.

Tidzayesa kugwiritsa ntchito ma bits ochepa momwe tingathere kuti tisindikize mafelemu 0 ndi 1.

Tikhoza kupanga kuchotsa, timangochotsa chimango 1 kuchokera ku chimango 0. Timapeza chimango 1, timangogwiritsa ntchito kusiyana pakati pa icho ndi chimango chapitacho, kwenikweni timangoyika zotsalirazo.

Koma bwanji ndikakuuzani kuti pali njira yabwinoko yomwe imagwiritsa ntchito tizidutswa tating'ono?! Choyamba, tiyeni tiphwanye chimango 0 kukhala gulu lomveka bwino lomwe lili ndi midadada. Ndiyeno tidzayesa kufananitsa midadada kuchokera ku chimango 0 ndi chimango 1. Mwa kuyankhula kwina, tidzayesa kusuntha pakati pa mafelemu.

Kuchokera ku Wikipedia - kubweza chiwongola dzanja

Kulipiridwa kwa block motion kumagawa chimango chapano kukhala midadada yosadumphana ndipo vesi yolipira yolipirira imafotokoza za komwe midadadayo idachokera (malingaliro olakwika wamba ndikuti m'mbuyomu chimangocho chimagawidwa m'zigawo zosadukizana, ndipo zoyendetsa zolipirira zimauza komwe midadadayo imapita. Koma kwenikweni, ndi njira ina yozungulira - si chimango cham'mbuyo chomwe chimawunikidwa, koma chotsatira; sizikudziwika bwino komwe midadada ikusunthira, koma komwe idachokera). Nthawi zambiri, midadada yoyambira imadutsana mumtundu woyambira. Ma algorithms ena ophatikizira makanema amasonkhanitsa chimango chapano kuchokera pagawo lililonse, koma mafelemu angapo omwe adafalitsidwa kale.

Pakuwunika, tikuwona kuti mpira wachoka (x= 0, y=25) pa (x= 6, y= 26), makhalidwe x и y dziwani vekitala yoyenda. Chinthu chinanso chomwe tingachite kuti tisunge ma bits ndikusindikiza kokha kusiyana kwa ma vectors oyenda pakati pa malo omaliza ndi omwe adanenedweratu, kotero kuti vekitala yomaliza idzakhala (x=6-0=6, y=26-25=1). ).

Muzochitika zenizeni, mpira uwu ukhoza kugawidwa n blocks, koma izi sizisintha tanthauzo la nkhaniyi.

Zinthu zomwe zili mu chimango zimayenda m'miyeso itatu, kotero mpirawo ukasuntha, ukhoza kukhala wocheperako (kapena wokulirapo ngati ukupita kwa wowonera). Ndizomveka kuti sipadzakhala machesi abwino pakati pa midadada. Nawa mawonedwe ophatikizidwa a kuyerekezera kwathu ndi chithunzi chenicheni.

Koma timawona kuti tikamagwiritsa ntchito kuyerekezera koyenda, pali data yocheperako yokhotakhota kuposa kugwiritsa ntchito njira yosavuta yowerengera delta pakati pa mafelemu.

Kodi chipukuta misozi chenicheni chingakhale bwanji

Njirayi imagwiritsidwa ntchito pazitsulo zonse mwakamodzi. Nthawi zambiri mpira wathu wosunthika wokhazikika umagawidwa m'magulu angapo nthawi imodzi.

Mutha kumva malingaliro awa nokha pogwiritsa ntchito jupyter.

Kuti muwone ma vector oyenda, mutha kupanga kanema wolosera zakunja pogwiritsa ntchito ffmpeg.

Mukhozanso kugwiritsa ntchito Intel Video Pro Analyzer (yalipidwa, koma pali kuyesa kwaulere komwe kumangokhala mafelemu khumi oyambirira okha).

Kuchepa kwa malo (zoneneratu zamkati)

Ngati tisanthula chimango chilichonse muvidiyo, tipeza malo ambiri olumikizana.

Tiyeni tidutse chitsanzo ichi. Chowoneka ichi makamaka chimakhala ndi mitundu ya buluu ndi yoyera.

Ichi ndi chimango cha I. Sitingathe kutenga mafelemu am'mbuyomu kuti anenedweratu, koma titha kukakamiza. Tiyeni encode kusankha red chipika. Tikayang'ana oyandikana nawo, timawona kuti pali mitundu ina yozungulira.

Timaganiza kuti mitundu imafalikira molunjika mu chimango. Zomwe zikutanthauza kuti mtundu wa ma pixel osadziwika udzakhala ndi zokonda za oyandikana nawo.

Kuneneratu koteroko kungakhale kolakwika. Ndicho chifukwa chake muyenera kugwiritsa ntchito njirayi (mawonekedwe amkati), ndikuchotsani zenizeni zenizeni. Izi zidzatipatsa chipika chotsalira, chomwe chidzabweretsa matrix opanikizika kwambiri poyerekeza ndi oyambirira.

Ngati mukufuna kuchita zolosera zamkati, mutha kupanga kanema wa macroblocks ndi maulosi awo pogwiritsa ntchito ffmpeg. Kuti mumvetse tanthauzo la mtundu uliwonse wa block, muyenera kuwerenga zolemba za ffmpeg.

Kapena mutha kugwiritsa ntchito Intel Video Pro Analyzer (monga ndatchulira pamwambapa, mtundu waulere waulere umangokhala mafelemu 10 oyamba, koma izi zitha kukukwanirani poyamba).

Gawo lachiwiri: Momwe vidiyo ya codec imagwirira ntchito

Source: www.habr.com