Codecs: Kodi Iwo Mu Video?

pa kim Zasinthidwa: June 27, 2022

Codecs ndi gawo lofunikira pakupanga makanema. Codecs ndi gulu la ma algorithms omwe amagwiritsidwa ntchito compress ndi decompress mavidiyo ndi zomvetsera. Codec ndiyofunikira kuti muchepetse kukula kwa mafayilo, kukulolani kuti musamuke ndikusunga mwachangu.

Munkhaniyi, tikuwonetsa zomwe ma codecs ndi, momwe amagwirira ntchito, ndi zawo kufunikira pakupanga makanema.

Tanthauzo la Codec

A kodi ndiukadaulo womwe umasunga makanema, ma audio ndi ma data mumtundu wa digito. Ma codecs amapondereza deta kotero kuti imatenga malo ochepa posungira kapena kufalitsa, komanso imapangitsa kuti kanema kapena mawu omvera aziwoneka bwino pokonza zowoneka kapena phokoso.

Ma codec amagwiritsidwa ntchito kwambiri pogawa mafilimu, TV ndi nyimbo pa intaneti. Intaneti kusonkhana misonkhano monga Netflix, Amazon Prime Video ndi Spotify gwiritsani ntchito ma codec kuti mutsike zomwe zili popanda kusokoneza khalidwe. Kuyika makanema okhala ndi ma codec apamwamba kumatha kuwapangitsa kukhala ang'onoang'ono kukula ndikusungabe mtundu wazinthu zoyambira. Izi zimalola ntchito zotsatsira kuti zigawitse makanema mosavuta kwa makasitomala popanda kuyika ndalama zazikulu za bandwidth pamanetiweki kapena zomangamanga.

Kuphatikiza pakuthandizira kusungirako bwino komanso kutumiza, ma codec atha kupereka maubwino ena angapo kwa omwe amapereka pa intaneti monga:

• Nthawi zotsegula mwachangu
• Kupititsa patsogolo mphamvu zamagetsi
• Kukhazikika bwino
• Kuwonjezeka kwa chipangizo

Ma codecs angagwiritsidwenso ntchito pazifukwa zachitetezo ndi kubisa mafayilo okhutira kotero kuti ogwiritsa ntchito ovomerezeka okha angathe kuwapeza.

Udindo wa Codecs mu Video

Codecs, chidule cha "coder-decoder", ndi ma aligorivimu omwe ali ndi udindo wopondereza ndi kutsitsa mafayilo amakanema ndi ma audio. Pogwiritsa ntchito njira zapadera zophatikizira, ma codec amatha kuchepetsa kukula kwa mafayilo amakanema ndi ma audio popanda kutaya kwambiri. Izi zimathandizira kutsitsa ndikutsitsa mwachangu - kaya mukusewera kanema kapena kusewera masewera pa intaneti- komanso kutenga malo ochepa pa hard drive yanu.

Kuonjezera apo, ma codec amagwiritsidwanso ntchito pojambula ndi kukonzanso deta ya kanema kuti apange zithunzi zopambana kwambiri zomwe zingatheke ndi mafelemu osiyanasiyana, bitrate, kuya kwa mitundu etc. 4K resolution kapena HD - kuti muwongolere zowonera. Kutengera zofunikira pakugwiritsa ntchito kulikonse, pali mitundu ingapo ya ma codec omwe amapezeka monga:

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

Codec imagwira ntchito pokanikizira mtsinje wolowetsa (ie, kanema kapena mawu) kukhala ma fayilo ang'onoang'ono omwe amatha kuyang'aniridwa bwino pamanetiweki kapena kusungidwa pama drive akomweko; izi zimadziwika kuti Kukododometsa. Mosiyana ndi kusewerera (mwachitsanzo mukamasewera makanema pa intaneti), mafayilo ophatikizika amayenera kusinthidwa kukhala mawonekedwe awo apamwamba kwambiri omwe amakwaniritsidwa ndi kukumbukira zambiri zosungidwa zakale; ndondomekoyi imadziwika kuti kukumbukira. Mothandizidwa ndi zida zoyenera (monga makadi ojambula etc.), hardware yothandizira encoding imatha kupititsa patsogolo liwiro la encoding kwambiri pakutayika pang'ono mumtundu - zomwe zimawapangitsa kukhala oyenera kugwiritsa ntchito ndipamwamba mlingo wamtengo zofunikira monga ntchito zotsatsira nthawi yeniyeni kapena masewera amtambo.

Mitundu ya ma Codecs

Codecs ndizomwe zimatengera makanema - amazindikira momwe makanema amapanikizidwa, kuchepetsedwa komanso kufalikira. Amatithandizira kuwonera makanema amitundu yosiyanasiyana ndi makulidwe pafupifupi pazida zilizonse. Pali mitundu yosiyanasiyana ya ma codec yomwe ilipo, iliyonse imagwira ntchito yosiyana pakuwonera makanema.

M'nkhaniyi, tiona mozama za mitundu yodziwika bwino ya ma codec:

Ma Codecs Otayika

Ma codec otayika ndi miyeso yopondereza yomwe imachepetsa mtundu wa kanema woyambirira, kusiya mtundu wazithunzi ndi data chifukwa cha kukula kwa fayilo. Cholinga chake ndikupangitsa kuti kanema kanema akhale kakang'ono kokwanira kuti kawonedwe kapena kutsitsa mwachangu komanso moyenera. Poyerekeza ndi ma codec osatayika, ma codec otayika nthawi zambiri amatulutsa mafayilo ang'onoang'ono omwe ali ndi deta yochepa, koma izi zimabwera chifukwa cha kutayika komanso kukhulupirika kwathunthu.

Mitundu iwiri yodziwika kwambiri ya ma codec otayika ndi intraframe or Nthawi zonse bitrate (CBR) ndi interframe or variable bitrate (VBR). Intraframe coding imalemba zonse zomwe zili ngati gawo limodzi mkati mwa fayilo iliyonse yophatikizika; izi zimabweretsa mafayilo akulu koma zopangira zochepa pakati pa chimango chilichonse ndi zithunzi zapamwamba kwambiri. Interframe coding imagawaniza mafelemu m'magawo kuti alole magawo ophatikizika popanda kusintha kowonekera pakati pa mafelemu; Mafayilo otsatiridwawo amakhala ndi makulidwe ang'onoang'ono kuposa ma intraframes komanso zinthu zambiri zakale pakati pa mafelemu.

Zitsanzo zodziwika bwino za ma codec otayika akuphatikizapo MPEG-4 AVC / H.264, MPEG-2 ndi H.265 / HEVC, Windows Media Video 9 (WMV9), RealVideo 9 (RV9), DivX, Xvid ndi VP8/VP9. Izi zakhala zodziwika kwambiri pamapulogalamu osinthira makanema monga YouTube chifukwa chakutha kuphatikizira zambiri mwachangu popanda kudzipereka kwambiri pazithunzi - alendo amatha kuwonera makanema ataliatali okhala ndi kulumikizana kocheperako kwinaku akusunga zomveka bwino zowonekera.

Ma Codecs Osataya

Ma codec amakanema ndi mtundu wa mapulogalamu apakompyuta omwe amagwiritsidwa ntchito potsikiza data ya digito, kapena kubisa. Njirayi ndi yofunikira pogwira ntchito ndi mafayilo akuluakulu a digito kuti muchepetse kukula kwa fayilo ndikuwonjezera momwe fayilo imatsitsidwa, kusamutsidwa kapena kusamutsidwa mwachangu. Ma codecs agawidwa m'magulu awiri: chotayika ndi lossless kodi.

Ma codec osatayika amapereka chifaniziro chenicheni cha digito cha fayilo pambuyo pa encoding popereka kulondola kwathunthu kwa data, zomwe zimalola kubwereza kwadijito panthawi ya decompression. Zimatengera malo ochulukirapo kuposa kupsinjika kwamphamvu komanso siziphatikiza kupotoza kwake komanso kulola zosintha zamawu / zithunzi mosavuta popanda kunyengerera pamtundu uliwonse. Ma codec osatayika amaphatikiza ma aligorivimu monga:

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

Hardware Codecs

Ma codecs a Hardware ndi ma codec omwe amagwiritsa ntchito zida zodzipatulira za Hardware kusindikiza ndikuzindikira ma siginecha amakanema. Makina ena atsopano apakompyuta, monga ma laputopu, ali ndi makina ojambulira makanema ozikidwa pa Hardware omwe angagwiritsidwe ntchito kufulumizitsa kabisidwe. Mayunitsiwa ndi ochita bwino kwambiri ndipo amatha kupereka phindu lalikulu pamapulogalamu opangira ma codec. Kuphatikiza apo, ma codec ena amtundu wa standalone alipo omwe amapereka zotsatira zaukadaulo zamapulogalamu owulutsa / kutsitsa.

Mitundu iwiri ikuluikulu ya ma codec a hardware ndi Compress/Encoding ndi Decoding Codecs:

• Compress/Encoding Codecs: Zidazi nthawi zambiri zimabwera ndi pulogalamu yawoyawo, ngakhale zosankha zina zitha kupezekanso. Amagwiritsa ntchito zida zapadera kuti apangitse ma encoding a kanema mwachangu kwambiri popanda kugwiritsa ntchito mphamvu zambiri kapena CPU mphamvu zokhudzana ndi mapulogalamu encoders. Monga encoders mapulogalamu, iwo nthawi zambiri kutulutsa zosiyanasiyana linanena bungwe akamagwiritsa monga H.264 kapena MPEG-2/4 mawonekedwe.
• Decoding Codecs: Zomwe zimadziwikanso kuti makhadi opangira ma decoding kapena ma accelerators, zidazi zimakhala ndi tchipisi tamphamvu zodzipatulira zomwe zimapangidwira kuti zizitha kusindikiza ma siginecha amakanema munthawi yeniyeni osagwiritsa ntchito zida zambiri zamakina (CPU mphamvu). Makhadi odzipatulira odzipatulira amakhala ofala m'malo akadaulo pomwe makanema ambiri amafunikira kusakanizidwa mwachangu osakhudza magwiridwe antchito ndi kukhazikika kwadongosolo.

Ma Codecs Odziwika

Codecs ndizofunikira kwa aliyense amene amagwira ntchito ndi makanema apakanema. Iwo ndi zosakaniza wanu kanema wapamwamba, zosakaniza kuti amalola kanema wosewera mpira kuzindikira pakati kanema ndi zomvetsera, ndi njira compressing deta kuti zikhale zosavuta kusunga ndi akukhamukira. Pali mitundu yosiyanasiyana ya ma codec omwe alipo, ndipo yoyenera pulojekiti yanu iyenera kusankhidwa.

Mu gawo ili, tikambirana za ma codec otchuka kwambiri:

H.264

H.264 (Amatchedwanso MPEG-4 AVC) ndi imodzi mwa ma codec odziwika kwambiri osungira mafayilo amakanema a digito kuti agwiritsidwe ntchito m'mapulogalamu osiyanasiyana - kuchokera kumagulu osakanikirana kupita ku Blu-ray osewera kupita ku mafoni a m'manja. Kuthekera kwake compress mkulu khalidwe kanema mu kukula ndi ang'onoang'ono wapamwamba kumapangitsa kukhala mmodzi wa anthu ambiri ntchito ndi zosunthika codecs pa msika lero.

H.264 imagwira ntchito pophwanya mafelemu a digito kukhala midadada ya ma pixel 8 × 8 ndiyeno kuwapanikiza ndi ma aligorivimu osiyanasiyana. Chifukwa H.264 ndi yothandiza kwambiri, imatha kupanga makanema apamwamba kwambiri a digito ngakhale pama bitrate otsika kwambiri, ndikupangitsa kuti ikhale yabwino kwa mapulogalamu osiyanasiyana kuchokera ku HDTV kuwulutsa kwa ogula media osewera ndi mafoni / piritsi kukhamukira ntchito.

H.264 imapereka chithandizo pazithunzi zonse ziwirizi (kumene mizere yonse ya chithunzi imayamba kusanthula nthawi imodzi) ndi kanema wosakanikirana, ngakhale ma codec ambiri amakono amangothandizira jambulani pang'onopang'ono chifukwa amagwira ntchito bwino potengera kukula kwa fayilo ndi kugwiritsa ntchito bandwidth. H.264 imathanso kuthana ndi zigamulo mpaka 4K (4096×2160 mapikiselo), kuwonetsetsa kuti ikukhalabe yofunikira pomwe opanga zambiri amasunthira kumalingaliro akulu pakapita nthawi.

Pamodzi ndi mphamvu zake, chimodzi mwa ubwino waukulu wa H.264 ndi chakuti wakhala akugwiritsidwa ntchito ndi ambiri opanga zipangizo kale zomwe zimapangitsa kuti zikhale zosavuta kwa ogwiritsa ntchito kutumiza zomwe zili pakati pa zipangizo popanda kudandaula za zovuta zogwirizana kapena zosagwirizana ndi mapulogalamu / hardware kasinthidwe. Pachifukwa ichi, H.264 ikupitirizabe kukhala codec yofunikira pazida zosiyanasiyana ndi ntchito masiku ano, ngakhale zosankha zatsopano zomwe zilipo monga HEVC (Kujambula Kanema Mwachangu Kwambiri).

H.265

H.265, wotchedwanso Kanema Wochita Bwino Kwambiri (HEVC), ndi mulingo wapakanema wamakanema womwe umapereka zolembera bwino kuposa zomwe zidalipo kale, H.264/MPEG-4 AVC (Kukhoditsa Makanema Apamwamba). Imathandizira kusamvana kwa 8K ndipo imatha kupondereza mafayilo amakanema mpaka kawiri mogwira mtima monga muyezo wakale - mpaka 40 peresenti yowonjezereka yosungira bwino kuposa woyamba wake.

H.265 ndiye wolowa m'malo mwachilengedwe wa H.264/MPEG-4 AVC, wopatsa mphamvu zopondereza zazikulu zokhala ndi zovuta zochepa komanso kusewerera kosavuta pazida zosewerera monga ma TV, mafoni am'manja, laputopu ndi mapiritsi. Ndi mawonekedwe otseguka omwe ali oyenera mitundu yonse yazinthu - kuchokera pawayilesi pawailesi yakanema mpaka kutsitsa makanema pa intaneti ndi ma Blu-ray discs - kulola opanga zinthu kuti apereke mavidiyo apamwamba kwambiri pomwe akuchepetsa mtengo wa bandwidth.

Kusinthasintha kwa H.265 kumathandizira kuti igwiritsidwe ntchito pazinthu zosiyanasiyana monga:

• TV yowulutsa (kuphatikiza 4K kapena 8K)
• Ntchito zotsatsira komanso zoyankhulirana kuphatikiza zida zam'manja ndi satellite
• Zochitika zenizeni zenizeni
• Ntchito zamankhwala
• Mtundu watsopano wa zithunzi za HEIF - zomwe zimapangitsa kuti zithunzi zojambulidwa kuchokera ku makamera a digito kapena mafoni a kamera azikanikizidwa kuposa kale lonse popanda kutaya zambiri.

VP9

VP9 ndi makanema otseguka komanso opanda malipiro opangidwa ndi Google. Wopangidwa kuti agwiritsidwe ntchito pamapulogalamu apaintaneti, amapereka ukadaulo wapamwamba kwambiri wokhala ndi kaphatikizidwe kabwino kakutsitsa ndikutsitsa pama bitrate otsika.

VP9 ilinso ndi mawonekedwe osiyanasiyana omwe ali othandiza pamapulogalamu amakanema:

• ma dynamic osiyanasiyana ndi malo amitundu,
• ma encoding mode osataya,
• kusinthasintha kosinthira ndi encoder scalability.

Imathandizira ma pixel osakhala masikweya, mabwalo odutsana amitundu yosiyanasiyana kapena makulidwe owunikira, njira zolosera kwakanthawi (monga chipukuta misozi) komanso njira zolosera zam'tsogolo (monga masinthidwe a discrete cosine). VP9 ilinso ndi kuthekera kosunga zithunzi mpaka 8 bits zakuya kwamtundu pa pixel iliyonse. Mawonekedwewa amathandizira kuti chithunzicho chikhale chabwinoko kudzera m'mawonekedwe ocheperako monga maphokoso ocheperako komanso m'mbali zakuthwa kuposa ma codec ena am'mbuyomu.

Posankha mtsinje wa VP9, ​​chipangizo cha wogwiritsa ntchito chimagwira ntchito zonse kuti chiziyikenso muvidiyo imodzi. Izi zimapangitsa kuti mwachangu kuti mupeze ndipo amalola kusewera mwachangu kuposa ma codec ena chifukwa chake zofunika kukumbukira zochepa. Izi zimagwira ntchito makamaka pamene ogwiritsa ntchito pa intaneti akupeza mitsinje ingapo nthawi imodzi kuchokera kumagwero angapo; atha kutero popanda kukhala ndi zida zawo zonse zamakompyuta zolumikizidwa polemba chilichonse padera. Kuphatikiza apo, kutumiza pogwiritsa ntchito fayilo wamba monga MP4 zimathandiza kuti zigwirizane pakati pa zida kapena nsanja zomwe mwina sizingathe kuwona zomwe zili mumitundu ina monga WebM kapena MKV.

Ma Codecs ndi Ubwino Wamavidiyo

Codecs ndi gawo lofunikira la encoding ndi decoding video, zomwe zingakhudze khalidwe la kanema. Ma codecs amagwiritsidwa ntchito kufinya ndikutsitsa mafayilo amakanema, ndipo mtundu wa codec womwe mungasankhe ungakhudze kukula ndi mtundu wa kanemayo.

M'nkhaniyi, tikambirana mitundu yosiyanasiyana ya codecs ndi momwe angakhudzire khalidwe la kanema:

Bitrate

Bitrate ndi muyeso wa kuchuluka kwa chidziwitso chomwe codec imafunikira kuyimira kanema woperekedwa. Kuyesedwa mu bits pa sekondi iliyonse, bitrate imatha kukhudza zonse ziwiri khalidwe la kanema ndi kukula kwake kwa fayilo kudzakhala kwakukulu bwanji.

Kukwera kwa bitrate, ndi zambiri zitha kuphatikizidwira mu encoding (kapena compression). motero chithunzithunzi chabwinoko chomwe mungapeze. Komabe, zimatanthauzanso kuti mafayilo akuluakulu adzafunika kusungidwa kapena kutumizidwa. Ngati mukutumiza kanema wanu pamtundu uliwonse wapaintaneti (monga intaneti), mutha kupeza kuti ma bitrate apamwamba amayambitsa kuchulukira kwa nthawi yochedwa kapena kusungitsa nthawi.

Chinthu chinanso chomwe chimakhudza bitrate ndikuwongolera - momwe zisankho zikuchulukira, momwemonso kukula kwa fayilo - koma izi zimatengera mawonekedwe ena monga ma codec ogwiritsidwa ntchito, kuchuluka kwa chimango ndi kukula kwake. Nthawi zambiri, ma bitrate otsika amapatsa mavidiyo abwino kwambiri ngakhale zinthu zina monga kusamvana ndipamwamba.

Ma codec onse ali ndi mitundu yawoyawo yoyenera chithunzi chabwino kwambiri komanso kugwiritsa ntchito data pang'ono chifukwa chake onetsetsani kuti mwayang'ana ma encoder omwe mumakonda panthawi yophatikizira.

Chigamulo

Resolution ndiye muyeso wa chidziwitso cha kanema malinga ndi ma pixel, ndipo ndichimodzi mwazinthu zomwe zimatsimikizira mtundu wa kanema. Ndikofunika kumvetsetsa zimenezo Zosankha zapamwamba nthawi zonse zimatulutsa mavidiyo owoneka bwino chifukwa pali ma pixel ochulukira mu chimango chilichonse. Zosankha zomwe zimagwiritsidwa ntchito kwambiri pakusaka pa intaneti ndi 1920 × 1080 (HD Yathunthu) ndi 1280 × 720 (HD).

Kanema wapamwamba kwambiri amafunikira mphamvu yochulukirapo, zomwe zingayambitse zovuta zofananira ngati makina a wogwiritsa ntchito sali pakali pano. Mavidiyo apamwamba kwambiri amatanthauzanso mafayilo akuluakulu omwe amafunikira codec yabwino kuti athe kusewera bwino pazida zonse. Ma codec wamba omwe amagwiritsidwa ntchito potsatsa pa intaneti akuphatikizapo H.264 kapena AVC, VP8, VP9 ndi HLS kapena Apple HLS (HTTP Live Streaming).

Kutengera ndi pulogalamu yanu komanso mtundu wa chipangizo chomwe mukukonzekera kutumiza zomwe mwalemba ziwona kuti ndi codec iti yomwe ili yabwino kwa inu.

Pamapeto pake, ngati muli ndi khwekhwe loyenera la encoding lomwe limaphatikizapo codec yabwino kwambiri yomwe ilipo ndiye simuyenera kukhala ndi vuto popereka mavidiyo apamwamba pa chisankho chilichonse zomwe sizingavutike ndi buffering kapena zovuta zina zosewerera ndikusungabe mawonekedwe abwino a kukhulupirika.

Makhalidwe Okhazikika

Pangidwe la maziko ndichinthu chofunikira kwambiri pankhani yaukadaulo wamakanema ndi ma codec. Ndilo muyeso wa kuchuluka kwa mafelemu omwe amajambulidwa mu sekondi imodzi, nthawi zambiri amayezedwa mkati mafelemu pamphindikati (FPS). Kukwera kwa mafelemu, m'pamenenso chithunzicho chidzawoneka bwino. Mitengo yotsika ya chimango imabweretsa vidiyo yovuta, pamene mitengo yapamwamba ya chimango imakhala yothandiza kwambiri popereka chithunzi chamadzimadzi.

Mwachitsanzo, pojambula ndi kamera ya 8 FPS vs kamera ya 30 FPS, kamera ya 8 FPS idzatulutsa zojambula za choppier chifukwa cha kuchepa kwa mafelemu pamphindikati. Kumbali ina, kamera ya 30 FPS imapanga zithunzi zowoneka bwino zoyenda bwino pakati pawo kuposa kamera ya 8 FPS popeza pangakhale mafelemu ojambulidwa katatu.

Pamwamba pa izi, ma codec osiyanasiyana amafunikira mitengo yocheperako kapena yopitilira muyeso kuti mupeze zotsatira zabwino. Mukagwiritsidwa ntchito molakwika kapena mosadziwa zomwe codec yanu ikufuna kuti zigwirizane ndi mtengo wazithunzi, kanema wanu akhoza kusokonekera. Miyezo yodziwika bwino yamafelemu pamawonekedwe ambiri amakono komanso zowonera ndi 24 fps (mafilimu) ndi 30 fps (ma TV). Komabe, ma codec ena amatha kuthandizira apamwamba - monga 48fps kapena 60fps - popereka zowoneka bwino komanso zosalala poyerekeza ndi anzawo apansi.

Kutsiliza

Pomaliza, kumvetsetsa ma codec ndi gawo lofunikira popanga ndikuwonera makanema pazida zathu zama digito. Kudziwa zofunikira za ma codec omvera ndi mavidiyo, matanthauzo ake, ndi kusiyana kwakukulu pakati pawo kungatithandize kupanga chisankho chodziwa bwino posankha ndi kuonera TV. Kuphatikiza apo, kukhala ndi chiwongolero chonse cha Ma codecs otchuka kwambiri amakanema Atha kutipatsanso kumvetsetsa kwamitundu yosiyanasiyana ya ma codec omwe angasinthire mawonekedwe ndi mawu a kanema.

Pomaliza, ndi bwino kukumbukira zimenezo si onse kanema codecs ndi mtanda n'zogwirizana—kutanthauza kuti mavidiyo ena omwe amafunikira codec imodzi sangasewere bwino pachipangizo china ngati sichizindikira mtunduwo. Mwamwayi, tsopano tili ndi zosankha zambiri kuposa kale pankhani yowonera zomwe timakonda pa digito-kuphatikiza kuyanjana kwabwinoko pamapulatifomu angapo. Chifukwa chake tengani nthawi yanu mukufufuza mtundu woyenera kwa inu ndikupeza yomwe imagwira ntchito bwino pazosowa zanu!

Moni, ndine Kim, mayi komanso wokonda kuyimitsa zoyenda komanso wodziwa zambiri pakupanga media komanso kakulidwe ka intaneti. Ndili ndi chikhumbo chachikulu chojambula ndi makanema ojambula, ndipo tsopano ndikudumphira molunjika kudziko loyimitsa. Ndi blog yanga, ndikugawana zomwe ndaphunzira ndi inu anyamata.