Codecs: Chii Chiri MuVhidhiyo?

by kim Updated: June 27, 2022

Codecs chikamu chakakosha chemaitiro ekugadzira vhidhiyo. Codecs seti yealgorithms inoshandiswa kuita compress uye decompress vhidhiyo uye maodhiyo mafaera. A codec yakakosha kudzikisa saizi yemafaira, ichikubvumidza iwe kutamisa uye nekuachengeta nekukurumidza.

Muchikamu chino, tichave tichisuma kuti macodecs chii, vanoshanda sei, uye yavo kukosha mukugadzira vhidhiyo.

Tsanangudzo yeCodec

A codec itekinoroji inokodha vhidhiyo, odhiyo uye data hova mudhijitari fomu. MaCodecs anodzvanya iyo data kuti itore nzvimbo shoma mukuchengetedza kana kutapurirana, uye zvakare inonatsiridza mhando yevhidhiyo kana odhiyo rwizi nekuvandudza zviratidziro zvayo kana ruzha.

Macodecs anoshandiswa zvakanyanya mukuparadzirwa kwepamhepo kwefirimu, TV uye mimhanzi. Online yekufambisa masevhisi akadai Netflix, Amazon Prime Vhidhiyo uye Spotify shandisa macodecs kudzvanya zvirimo pasina kukanganisa pamhando. Encoding mavhidhiyo ane epamberi macodecs anogona kuvaita madiki muhukuru vachiri kuchengetedza mhando yeyakatanga sosi zvinhu. Izvi zvinobvumira masevhisi ekutepfenyura kugovera zviri nyore mavhidhiyo kune vatengi pasina kuisa hombe bandwidth mutengo pamanetiweki avo kana zvivakwa.

Pamusoro pekugonesa kuchengetedza kwakanaka uye kutapurirana, macodecs anogona kupa akati wandei mabhenefiti kune online kutenderera vanopa senge:

• Kurumidza kurodha nguva
• Kuvandudzwa kwesimba rekushandisa
• Zvirinani scalability
• Kuwedzera kuenderana kwemidziyo

Macodecs anogona zvakare kushandiswa kune kuchengetedza zvinangwa ne encrypting content files kuitira kuti vashandisi vane mvumo chete vakwanise kuzviwana.

Basa reCodecs muVhidhiyo

Codecs, chidimbu che "coder-decoder", maalgorithms ane basa rekudzvanya nekudzikisa mavhidhiyo nemaodhiyo mafaira. Nekushandisa hunyanzvi hwekutsikirira matekiniki, macodecs anokwanisa kudzikisa saizi yemavhidhiyo nemaodhiyo mafaira pasina kurasikirwa zvakanyanya. Izvi zvinogonesa kukurumidza kurodha uye kurodha kumhanya - ungave uri kufambisa bhaisikopo kana kutamba mutambo pamhepo- pamwe nekutora nzvimbo shoma pane yako hard drive.

Pamusoro pezvo, macodecs anoshandiswawo pakurekodha uye mushure mekugadzirisa vhidhiyo data kugadzira iyo yepamusoro-soro mifananidzo inogoneka neinosiyana furemu mitengo, bitrate, kudzika kwemavara etc. Macodecs anoona kuti ndeupi rudzi rwekodhadhi tekinoroji ichashandiswa - semuenzaniso, 4K resolution kana HD - kuitira kukwidziridza ruzivo rwekuona. Zvichienderana nezvinodiwa zvechishandiso chega chega, kune akati wandei akasiyana macodecs aripo akadai se:

• H264/AVC
• .265/HEVC
• VC-1/WMV9
• MPEG4
• VP8/VP9

Kodeki inoshanda nekudzvanya rwizi rwekupinda (kureva, vhidhiyo kana odhiyo) kuita diki faira resaizi inogona kudzorwa zvakanyanya pamanetiweki kana kuchengetwa pamadhiraivha emuno; izvi zvinozivikanwa se encoding. Zvakasiyana pakutamba (semuenzaniso kana uchifambisa mavhidhiyo pamhepo), mafaera akadzvanywa anofanirwa kushandurwa kuti adzokere mumhando yavo yekutanga yemhando yepamusoro iyo inowanikwa ne. decoding iyo encoded ruzivo kubva kare; nzira iyi inozivikanwa se decoding. Nerubatsiro rwehardware yakakodzera (senge makadhi emifananidzo nezvimwewo), hardware yakabatsira encoding inogona kuvandudza encoding kumhanya zvakanyanya pakurasikirwa kushoma mumhando - izvo zvinoita kuti ive yakakodzera kune maapplication ane yakakwirira frame rate zvinodiwa senge chaiyo-nguva yekufambisa masevhisi kana mutambo wegore.

Mhando dzeCodecs

Codecs ndiwo hupenyu hwemukati wevhidhiyo - ivo vanosarudza kuti mavhidhiyo anomanikidzwa sei, akaderedzwa uye anofambiswa. Vanotigonesa kuona mavhidhiyo ehukuru hwakasiyana uye zvigadziriso pane chero mudziyo. Kune akawanda akasiyana macodecs aripo, rimwe nerimwe richitamba rakasiyana mukuita kwekuona vhidhiyo yezvinhu.

Muchikamu chino, tichatarisa zvakadzama pane mhando dzakawanda dzemacodecs:

Kurasika Codecs

Kurasika macodecs ndiwo maitiro ekumanikidza anoderedza kunaka kwevhidhiyo yepakutanga, kupa mhando yemifananidzo uye data nekuda kwesaizi yefaira. Chinangwa ndechekuita kuti vhidhiyo iite diki zvakakwana kuti ionekwe kana kudhawunirodha nekukurumidza uye nemazvo. Kana ichienzaniswa nemakodhidhi asina kurasikirwa, macodecs anorasikirwa anowanzo gadzira mafaira madiki ane data shoma, asi izvi zvinouya pamutengo weacuity uye kutendeka kwese.

Mhando mbiri dzakajairika dzekurasikirwa macodecs ndeaya intraframe or nguva dzose bitrate (CBR) uye interframe or variable bitrate (VBR). Intraframe coding inorekodha yakazara yemukati furemu sechikamu chimwe mukati mega rega rakamanikidzwa faira; izvi zvinoguma nemafaira makuru asi mashoma ekugadzira pakati pega ega furemu uye yemhando yepamusoro mifananidzo yakazara. Interframe coding inokamura mafuremu emukati kuita zvikamu kuti zvibvumire zvimwe zvikamu zvakamanikidzwa pasina shanduko inooneka pakati pemafuremu; mhedzisiro mafaera anowanzo kuve nehukuru diki pane intraframes asiwo artifacts akawanda pakati pemafuremu.

Mienzaniso yakakurumbira yekurasikirwa macodecs inosanganisira MPEG-4 AVC / H.264, MPEG-2 uye H.265 / HEVC, Windows Media Vhidhiyo 9 (WMV9), RealVideo 9 (RV9), DivX, Xvid uye VP8/VP9. Izvi zvave kuwedzera mukurumbira mumavhidhiyo ekutepfenyura maapplication akadai seYouTube nekuda kwekugona kwavo kudzvanya data rakawanda nekukurumidza pasina kuzvipira kwakakosha mumhando yemifananidzo - vashanyi vanogona kuona mavhidhiyo marefu ane yakaderera bandwidth yekubatanidza asi vachichengeta zvine musoro kujeka kwekuona.

Yakarasika Codecs

Vhidhiyo macodecs imhando yemakombuta software inoshandiswa kudhijitari vhidhiyo yedata data, kana encoding. Iyi nzira inodiwa kana uchishanda nemafaira makuru edhijitari kuitira kuti uderedze saizi yefaira uye uwedzere kuti faira inotorwa sei, inotamiswa kana kufambiswa nekukurumidza. Codecs dzakakamurwa kuita mapoka maviri akasiyana: kurasikirwa uye lossless codecs.

Macodecs asina kurasikirwa anopa iyo chaiyo yedhijitari replica yefaira mushure mekukodha nekupa yakazara data kurongeka, iyo inobvumira chaiyo dhijitari kudhindwa panguva yekudonha. Zvinotora nzvimbo yakawanda kupfuura kurasikirwa kwekumanikidza asi zvakare hazvibatanidzi kukanganisa kwayo pamwe nekubvumidza zviri nyore odhiyo / mufananidzo kugadziridzwa pasina kukanganisa mumhando. Macodecs asina kurasikirwa anosanganisira algorithms akadai se:

• LZW
• JPEG LS
• FLAC
• ALAC
• MPEG-4 ALS

Hardware Codecs

Hardware codecs macodecs anoshandisa zviwanikwa zvehardware zvakatsaurirwa kuodha uye kudhirodha masaini evhidhiyo. Mamwe masystem matsva emakombuta, senge laptops, anosanganisira hardware-based video encoder unit iyo inogona kushandiswa kukurumidzira encoding process. Aya mauniti anoshanda zvakanyanya uye anogona kupa zvakakosha mabhenefiti pamusoro pesoftware-based codecs. Uye zvakare, mamwe akamira ehardware macodecs aripo anopa nyanzvi mhando mhedzisiro yekutepfenyura/kutepfenyura maapplication.

Iwo maviri makuru marudzi ehardware codecs ndeaya Compression/Encoding uye Decoding Codecs:

• Compression/Encoding Codecs: Zvishandiso izvi zvinowanzouya neazvo evaridzi software, kunyangwe dzimwe sarudzo dzingavepo zvakare. Ivo vanoshandisa zvinhu zvine hunyanzvi kuita vhidhiyo encoding nekumhanya kwakanyanya pasina kushandisa simba rakawanda kana CPU simba zvine chekuita nesoftware encoders. Kufanana nesoftware encoders, ivo vanowanzo gadzira akasiyana siyana ekubuda mafomati senge H.264 kana MPEG-2/4 mafomu.
• Decoding Codecs: Iyo inozivikanwawo semakadhi ekudhirodha kana decoding accelerators, zvishandiso izvi zvinoratidzira zvine simba zvakatsaurirwa machipi akagadzirirwa kududzira akadzvanywa masaini evhidhiyo munguva chaiyo pasina kushandisa yakawandisa sisitimu zviwanikwa.CPU simba) Makadhi edecoding akatsaurirwa akajairika munzvimbo dzehunyanzvi umo nhamba huru dzemavhidhiyo dzinoda kusamisikidzwa nekukurumidza nekukanganisa kushoma pakuita kwehurongwa uye kugadzikana.

Popular Codecs

Codecs zvakakosha kune chero munhu anoshanda nevhidhiyo media. Ndidzo zvinongedzo zvefaira rako revhidhiyo, zvinongedzo zvinoita kuti vhidhiyo inoridza ione pakati pevhidhiyo neodhiyo, uye nzira dzekumanikidza data kuti zvive nyore kuchengeta uye kuyerera. Kune akasiyana macodecs aripo, uye akakodzera epurojekiti yako inoda kusarudzwa.

Muchikamu chino, tichave tichikurukura nezve inonyanya kufarirwa macodecs:

H.264

H.264 (Aizivikanwawo MPEG-4 AVC) ndeimwe yeanonyanya kufarirwa macodecs ekukodha edhijitari mavhidhiyo mafaira kuti ashandiswe mune zvakasiyana-siyana zvekushandisa - kubva pakushambadzira masevhisi kuenda kuBlu-ray vatambi kune smartphones. Kugona kwayo kudzvanya vhidhiyo yemhando yepamusoro kuita diki faira saizi inoita kuti ive imwe yeanonyanya kushandiswa uye akasiyana macodecs pamusika nhasi.

H.264 inoshanda nekupwanya mafuremu edhijitari kuita 8 × 8 mapikisi mabhuroko uye nekuadzvanya nemhando dzakasiyana dzealgorithms. Nemhaka yokuti H.264 inoshanda zvikuru, inokwanisa kugadzira mavhidhiyo edhijitari emhando yepamusoro zvikuru kunyange pa-bitrate yakaderera, zvichiita kuti ive yakakodzera kune zvakasiyana-siyana zvemaapplication kubva kuHDTV kutepfenyura kune vatengi midhiya vatambi uye smartphone/tableti yekutepfenyura masevhisi.

H.264 inopa rubatsiro kune zvose zviri mberi scan (apo mitsara yose yemufananidzo inotanga kuongorora zvose panguva imwe chete) uye mavhidhiyo ekuongorora akabatanidzwa, kunyange zvazvo macodec akawanda emazuva ano achitsigira chete kufambira mberi kwekuongorora nokuti inoshanda zvakanyanya maererano nehukuru hwefaira uye kushandiswa kwebandwidth. H.264 inokwanisawo kubata sarudzo kusvika 4K (4096×2160 pixels), kuve nechokwadi kuti inoramba iine basa sezvo vagadziri vezvemukati vanoenda kune zvigadziriso zvakakura nekufamba kwenguva.

Pamwe chete nekubudirira kwayo, chimwe cheH.264 chinonyanya kukosha ndechokuti yakagamuchirwa nevakawanda vanogadzira zvigadzirwa kare izvo zvinoita kuti zvive nyore kune vashandisi kutumira zvinyorwa pakati pezvigadziro pasina kunetseka pamusoro pekuenderana kwezvinhu kana zvisingaenderane software / hardware configurations. Nokuda kwechikonzero ichi, H.264 inoramba iine codec inokosha kune zvakasiyana-siyana zvemichina uye mapurogiramu nhasi, pasinei nesarudzo itsva dziripo dzakadai se. HEVC (Yakanyanya Kubudirira Vhidhiyo Kukodha).

H.265

H.265, inozivikanwawo se Yakanyanya Kushanda Vhidhiyo Coding (HEVC), ndeye vhidhiyo yekumanikidza mwero inopa yakanyatso kodha kupfuura yakatangira, H.264/MPEG-4 AVC (Pamusoro Vhidhiyo Coding). Inotsigira 8K resolution uye inogona kumanikidza vhidhiyo mafaera kusvika zvakapetwa kaviri zvinobudirira seyakapfuura mwero - nekusvika 40 muzana yakawanda kuchengetedza kupfuura akautangira.

H.265 ndiye mutsivi wechisikigo weH.264/MPEG-4 AVC, ichipa hukuru hwekutsikirira hune matambudziko madiki uye kutamba kwakapfava pamidziyo yekutamba yakadai sematerevhizheni, nharembozha, malaptop uye mahwendefa. Iyo yakavhurika-sosi fomati inokodzera marudzi ese ezvinyorwa - kubva panhepfenyuro yeTV kuenda kumavhidhiyo ekutepfenyura pamusoro peinternet uye Blu-ray discs - inobvumira vanogadzira zvemukati kuti vaunze yakanyanya kunaka yevhidhiyo uku vachideredza bandwidth mutengo.

Kuchinja kweH.265 kunoita kuti ishandiswe mumhando dzakasiyana-siyana dzakadai se:

• Nhepfenyuro terevhizheni (inosanganisira 4K kana kunyange 8K)
• Kutepfenyura uye masevhisi ekutaurirana anosanganisira ayo emafoni uye setiraiti zvishandiso
• Virtual chaiyo zviitiko
• Healthcare applications
• Iyo itsva HEIF mufananidzo fomati - zvichiita kuti zvive nyore kuti mifananidzo yakatorwa kubva kudhijitari ichiri makamera kana nhare dzekamera kuti dzitsikidzwe kupfuura nakare kose pasina kurasikirwa kwemifananidzo.

VP9

VP9 ikodhi yakavhurika uye yemahara-yemahara vhidhiyo codec yakagadzirwa neGoogle. Yakagadziridzwa kuti ishandiswe mumawebhu maapplication, inopa tekinoroji-ye-the-art ine yakagadziridzwa compression yekutepfenyura uye kurodha pasi pakadzika bitrates.

VP9 zvakare inoratidzira akasiyana maficha anobatsira kune vhidhiyo maapplication:

• yakakwirira simba renji uye nzvimbo dzemavara,
• isina kurasikirwa encoding mode,
• adaptive kutenderera uye encoder scalability.

Inotsigira mapixels asiri-square, anopindirana masikweya emavara akasiyana kana kukosha kwechiedza, nzira dzekufanotaura dzenguva pfupi (semubhadharo wekufamba) pamwe nemaitiro ekufungidzira emukati (senge discrete cosine inoshandura). VP9 zvakare ine kugona kuvharidzira mifananidzo inosvika 8 mabhiti ekudzika kwemavara papixel. Iyo fomati inogonesa zvirinani kunaka kwemifananidzo kuburikidza nezvinooneka senge kuderedzwa mazinga eruzha uye mipendero yakapinza pamusoro pemamwe macodecs epamberi.

Kana uchidhinda rwizi rweVP9, mudziyo wemushandisi unoita basa rese kuti uudzorere muchikamu chimwe chete chevhidhiyo. Izvi zvinoita kuti ikurumidze kuwana uye inobvumira kukurumidza kutamba kupfuura nemamwe macodecs nekuda kwayo yakaderera ndangariro zvinodiwa. Izvi zvinonyanya kushanda kana vashandisi vepamhepo vachiwana nzizi dzakawanda kamwechete kubva kwakawanda; vanokwanisa kuzviita pasina kuita kuti zviwanikwa zvavo zvese zvekombuyuta zvisungirirwe mukutsikisa chimwe nechimwe chakaparadzana. Pamusoro pezvo, kuendesa uchishandisa yakajairwa faira fomati senge MP4 inobatsira kugonesa kuenderana pakati pemidziyo kana mapuratifomu angangotadza kuona zvirimo zvakavharwa mune mamwe mafomati seWebM kana MKV.

Codecs uye Vhidhiyo Hunhu

Codecs chikamu chakakosha che encoding uye decoding vhidhiyo, iyo inogona kukanganisa iyo kunaka kwevhidhiyo. MaCodecs anoshandiswa kudzvanya uye decompress vhidhiyo mafaera, uye mhando yecodec yaunosarudza inogona kukanganisa saizi uye mhando yevhidhiyo.

Muchikamu chino, tichakurukura marudzi akasiyana-siyana ecodecs uye maitiro avanogona kukanganisa kunaka kwevhidhiyo:

Bitrate

Bitrate chiyero chemashoko akawanda anodiwa necodec kumiririra vhidhiyo yakapihwa. Yakayerwa mumabhiti pasekondi, iyo bitrate inogona kukanganisa ese ari maviri kunaka kwevhidhiyo uye yakakura sei saizi yefaira rayo.

Iyo yakakwirira bitrate, iyo zvimwe zvakawanda zvinogona kuverengerwa muiyo encoding (kana compression) maitiro uye nokudaro mufananidzo uri nani wauchawana. Nekudaro, zvinoreva zvakare kuti mafaera akakura anozoda kuchengetwa kana kutapurirana. Kana iwe uchitumira vhidhiyo yako pamusoro pemhando ipi neipi yedhijitari network (seinternet), unogona kuona kuti ma bitrate akakwira anokonzera kuwedzera kunooneka kwekunonoka kana nguva yekubhafa.

Chimwe chinhu chinokanganisa bitrate kugadzirisa - sezvo zvigadziriso zvichiwedzera, ndizvo zvinoita saizi yefaira - asi izvi zvinoenderana nemamwe maitiro akafanana macodecs anoshandiswa, furemu chiyero uye saizi yefuremu. Kazhinji, yakaderera bitrate inowanzopa hurombo mavhidhiyo emhando yepamusoro kunyangwe zvimwe zvinhu zvakaita sekugadzirisa zvakakwirira.

MaCodecs ese ane yavo yakasarudzika yakaringana renji yakanakisa mhando yemifananidzo uye kushoma kushandiswa kwedata saka ita chokwadi chekutarisa mune ako aunofarira encoder panguva yekumanikidza.

Resolution

Resolution ndiyo chiyero cheruzivo rwevhidhiyo maererano nemapikseli, uye ndicho chimwe chezvinhu zvekutanga zvinotarisa kunaka kwevhidhiyo. Zvakakosha kunzwisisa izvozvo zvigadziriso zvepamusoro zvinogara zvichiburitsa mavhidhiyo ari nani nekuti kune mapikseli akawanda akatsikirirwa mune yega furemu. Magadzirirwo anonyanya kushandiswa mukutepfenyura online ndeaya 1920 × 1080 (Yakazara HD) uye 1280 × 720 (HD).

Vhidhiyo yepamusoro yekugadzirisa inoda simba rakawanda rekugadzirisa, izvo zvinogona kukonzera nyaya dzekuenderana kana sisitimu yemushandisi isiri kusvika parizvino. Mavhidhiyo epamusoro-soro anorevawo mafaera akakura anoda kodeki iri nani kuti ikwanise kutamba nemazvo pamidziyo yese. Yakajairika indasitiri macodecs anoshandiswa kutenderera online anosanganisira H.264 kana AVC, VP8, VP9 neHLS kana Apple HLS (HTTP Live Streaming).

Zvichienderana nekushandisa kwako uye rudzi rwechishandiso chauri kuronga kuendesa zvirimo kuti uone kuti ndeipi codec yakakunakira.

Pakupedzisira, kana iwe uine yakakodzera encoding setup inoratidzira iyo yakanakisa codec iripo saka haufanirwe kuve nedambudziko rekutumira mavhidhiyo emhando yepamusoro pane chero sarudzo izvo hazvizotamburi nebuffering kana dzimwe nyaya dzekutamba uchiri kuchengetedza yakanaka mwero wekuona kutendeka.

Frame Rate

Frame rate chinhu chakakosha kana zvasvika pamhando yevhidhiyo uye macodecs. Ndiwo chiyero chekuti mangani mafuremu anotorwa musekondi imwe, anowanzo kuyerwa mukati mafuremu pasekondi (FPS). Iyo yakakwirira iyo furemu chiyero, iyo inotsvedzerera iyo tsoka ichaonekwa. Yakaderera furemu mitengo inokonzeresa kune choppy vhidhiyo, nepo mafuremu epamusoro ari kushanda zvakanyanya mukupa mufananidzo wemvura.

Semuenzaniso, pakurekodha ne8 FPS kamera vs 30 FPS kamera, 8 FPS kamera inoburitsa choppier footage nekuda kwehuwandu hwayo hwemafuremu pasekondi. Kune rimwe divi, 30 FPS kamera inogadzira yakatsetseka tsoka ine zvakawanda zvinofamba blur pakati payo kupfuura iyo 8 FPS kamera inoita sezvo paizove nekatatu zvakapetwa mafuremu akatorwa.

Pamusoro peizvozvo, macodecs akasiyana anoda akasiyana mashoma kana epamusoro furemu mareti kuti awane mhedzisiro. Kana ikashandiswa zvisizvo kana usingazive zvinodiwa necodec yako kuti ienderane nereti, vhidhiyo yako inogona kutadza. Iwo akajairika akajairwa mafuremu mareti eazvino mavhidhiyo mafomati uye kuona zviitiko ndezvi 24 fps (mafirimu) uye makumi matatu fps (TV inoratidza). Nekudaro, mamwe macodecs anogona kutsigira epamusoro zvakare - senge 48 fps kana kunyange 60 fps - uku uchipa zviratidziro zvepamusoro uye kutsvedzerera zvichienzaniswa nevashoma vavo.

mhedziso

Mukupedzisa, kunzwisisa macodecs chikamu chakakosha chekugadzira uye kuona mavhidhiyo pamidziyo yedu yedhijitari. Kuziva izvo zvekutanga zvemaodhiyo nemavhidhiyo macodecs, tsananguro dzadzo, uye mutsauko wakakura pakati pawo zvinogona kutibatsira kuita sarudzo ine ruzivo rwakanaka pakusarudza nekuona dhijitari media. Uyezve, kuve nekutarisa kwakazara kweiyo anonyanya kushandiswa mavhidhiyo codecs inogonawo kutipa kunzwisisa kwakawanda kwekuti akasiyana macodecs anogona sei kushandura chitarisiko uye ruzha rwevhidhiyo.

Pakupedzisira, zvinobatsira kuyeuka izvozvo haasi ese evhidhiyo macodecs anopindirana-zvichireva kuti mamwe mavhidhiyo anoda imwe codec anogona kusaridza zvakanaka pane imwe mudziyo kana isingazive rudzi irworwo. Sezvineiwo, isu tave nesarudzo dzakawanda kupfuura nakare kose kana zvasvika pakuona zvatinoda zvedhijitari — zvinosanganisira kuenderana kurinani pamapuratifomu akawanda. Saka tora nguva yako uchitsvaga iyo fomati yakakukodzera uye uone kuti ndeipi inoshanda zvakanyanya kune zvaunoda!

Mhoroi, ndini Kim, amai uye munhu anofarira zvekumira-famba ane ruzivo mukugadzira midhiya nekuvandudzwa kwewebhu. Ndine chido chikuru chekudhirowa uye mifananidzo, uye ikozvino ndiri kunyura nemusoro munyika yekumira-kufamba. Neblog rangu, ndiri kugovera zvandinodzidza nemi varume.