Uxinzelelo olulahlekileyo: Yintoni kwaye uyisebenzisa njani

ngo kim Ukuhlaziywa: Juni 28, 2022

Uxinzelelo olulahlekileyo yindlela esetyenziselwa ukunciphisa ubungakanani beefayile zedatha ngaphandle kokuphazamisa ingqibelelo yedatha yokuqala.

Ikuvumela ukuba uthathe iifayile ezinkulu eziqulethe idatha eninzi kwaye unciphise ubungakanani bazo ukususa enye yedatha kodwa ayichaphazeli umgangatho uwonke. Oku kunokuba luncedo ngakumbi xa usebenzisana nevidiyo enkulu okanye iifayile zemifanekiso.

Intsalela yeli nqaku iya kuchaza imigaqo yokunyanzeliswa kwelahleko kunye indlela yokufaka isicelo kunye nokuyisebenzisa ngokufanelekileyo:

Inkcazo yeLossy Compression

Uxinzelelo olulahlekileyo luhlobo lobuchule bokucinezela idatha obusebenzisa iindlela zokunciphisa ubungakanani befayile okanye umsinga wedatha ngaphandle kokulahlekelwa yimali ebalulekileyo yomxholo wayo wolwazi. Olu hlobo loxinzelelo luvelisa iifayile ezincinci kuneenguqulelo zazo zangaphambili ngelixa ziqinisekisa ukuba umgangatho, ukucaca, kunye nokunyaniseka kwedatha zigcinwe. Isebenza ngokucima ngokukhetha iinxalenye zedatha yemidiya (ezinje ngesandi okanye imizobo) ehlala ingabonakali kwiimvakalelo zomntu. Uxinzelelo olulahlekileyo sele lukhona iminyaka emininzi kwaye ukusetyenziswa kwayo kuye kwanda kakhulu ngenxa yenkqubela phambili yetekhnoloji.

Olu hlobo loxinzelelo lunenzuzo kwiimeko apho i-bandwidth okanye indawo yokugcina inomda, iyenza ibe luncedo ngakumbi:

• Ukusasaza izicelo ezifana ividiyo-kwimfuno (VoD),
• Usasazo lwesathelayithi,
• Umfanekiso wezonyango,
• Iifomati zomsindo wedijithali.

Obu buchule bukwasetyenziswa kakhulu ngaphakathi kwezicelo zeaudio kunye nomhleli wemifanekiso ukugcina umgangatho kunye neesayizi ezisezantsi zefayile xa ugcina ifayile yeprojekthi ehleliweyo. Ukunyanzeliswa kwe-Lossy kungasetyenziswa kwezinye iindidi zedatha ezifana neefayile ezibhaliweyo nje kuphela akukho mxholo obalulekileyo olahlekileyo ngexesha lenkqubo.

Okuchasene ne ilahleko yokuqonda, Nantsi lapho uxinzelelo olungenakulahlekelwa ezama ukunciphisa ukugqwetheka phakathi kwegalelo kunye nemveliso yemithombo yedatha ngaphandle kokunciphisa ukucaca kwengqiqo ngokusebenzisa ulwazi olungafunekiyo oluvela ngaphakathi kwemithombo yomthombo ngokwayo endaweni yokucima naluphi na ulwazi kuyo.

IiNzuzo zokuLahleka koxinzelelo

Uxinzelelo olulahlekileyo yindlela esebenzayo yokunciphisa ubungakanani befayile ngelixa ugcina umgangatho womfanekiso ngokubanzi. Ngokungafaniyo nemveli ngakumbi iindlela zokucinezela idatha engalahlekiyo, ekhetha kwaye ilahle ukukhutshwa kwedatha ekunciphiseni ubungakanani kunye nokunyusa isantya sokuhambisa, ukunyanzeliswa kwelahleko kusebenza ngokukhetha ukulahla ulwazi olungabalulekanga kunye nolunyanzeliswayo kwifayile. Olu hlobo loxinzelelo lusebenzisa i-algorithms ukuhlalutya idatha ngaphakathi kwefayile yedijithali kunye nokuphelisa izahlulo ezingeyomfuneko ngaphandle kokuchaphazela kakhulu umgangatho jikelele okanye umphumo wokuphela.

Xa isetyenziswe ngokuchanekileyo, ukunyanzeliswa kwelahleko kunokubonelela ngeenzuzo ezininzi, ezifana:

• Iimfuno zokugcina ezincitshisiweyo: Ngokususa iinkcukacha ezingabalulekanga kwifayile yedijithali, ubungakanani bomfanekiso obangelwayo bunokuba buncinci kakhulu kunomlingani wayo wokuqala, ukubonelela ngokugcinwa okukhulu kokugcinwa kwe-webmasters.
• Izantya zothumelo eziphuculweyo: I-Lossy compression algorithms isebenzisa idatha encinci ngokususa ulwazi olungeyomfuneko kumfanekiso ongabonakaliyo kwiliso lomntu. Oku kuthetha ukuba iifayile ezithunyelwa kuwo wonke uthungelwano zinokukhawuleza kakhulu kuneenguqulelo zazo zoqobo ngaphandle kokuncama umgangatho.
• Amava okubukela awomeleziwe: Ngokunciphisa okubalulekileyo kwisayizi yefayile kuza amava aphuculweyo okujonga ngelixa ukhangela kwi-intanethi okanye ujonga imifanekiso kwizixhobo eziphathwayo. Ilahleko yemifanekiso ecinezelekileyo ithatha inkumbulo encinci kwisixhobo sehard drive esinceda ngokusebenza komfanekiso xa ulayisha iifoto okanye ubrawuza amaphepha ewebhu.

Iintlobo zokuNxinzelela iLossy

Uxinzelelo olulahlekileyo bubuchule bocinezelo lwedatha olwehlisa ubungakanani befayile ngokulahla iindawo zedata zayo ezithathwa njengengafunekiyo. Kuyanceda uku lungisa ubungakanani befayile kwaye inokunceda ukugcina indawo yokugcina. Olu hlobo lobuchule bokucinezela lunokusetyenziswa kwizicelo ezahlukeneyo ezinje ngomfanekiso, iaudio, kunye neefayile zevidiyo.

Kweli nqaku, siza kuxoxa ezine iintlobo zoxinzelelo lwelahleko, izibonelelo zabo, kunye nokungalunganga:

JPEG

JPEG (Iqela leengcaphephe zeFoto eziDityanisiweyo) ngumgangatho we uxinzelelo olulahlekileyo lwemifanekiso yedijithali. IJPEG ixhasa i-8-bit, imifanekiso engwevu kunye nemifanekiso yemibala engamasuntswana angama-24. IJPG isebenza kakhulu kwiifoto, ngakumbi ezo zineenkcukacha ezininzi.

Xa iJPG yenziwe, umfanekiso uyahlulwa ube ziibhloko ezincinci ezibizwa ngokuba '.ii-macroblocks'. Ifomyula yemathematika inciphisa inani lemibala ekhoyo okanye iithowuni kwibhloko nganye kwaye isusa ukungafezeki okubonakala ngathi, kodwa hayi kwiikhompyuter. Irekhoda zonke iinguqu ezenziwe kwezi bloko ukuze zibuyele phezu kwazo kwaye zirekhode amazwe azo okuqala ukuze kuncitshiswe ubungakanani bazo. Xa ifoto igcinwe njengeJPG, iya kubonakala yahluke kancinane kuxhomekeke ekubeni lungakanani ucinezelo olusetyenzisiweyo ukunciphisa ubungakanani bayo. Umgangatho womfanekiso uyancipha xa izixa eziphezulu zoxinzelelo zisetyenziswa kwaye izinto zakudala zinokuqala ukuvela - kunye nengxolo kunye ne-pixelation. Ekugcineni umfanekiso njengeJPG unokukhetha ukuba kungakanani ukucaca ekufuneka kunikelwe ngenqanaba lokunciphisa ubungakanani befayile-ebizwa ngokuba "uphawu“. Olu seto luchaphazela ubungakanani be uxinzelelo olulahlekileyo isetyenziswe kwifayile yakho.

MPEG

MPEG (Iqela leengcaphephe zeMifanekiso eshukumayo) luhlobo lwe uxinzelelo olulahlekileyo esetyenziswa ikakhulu kwiifayile zeaudio kunye nevidiyo. Yayilwa njengomgangatho wokucinezela iifayile zemultimedia kwaye iye yanda kakhulu ukutyhubela iminyaka. Ingcamango ephambili emva koxinzelelo lwe-MPEG kukunciphisa ubungakanani befayile ngaphandle kokunciphisa umgangatho - oku kwenziwa ngokulahla izinto ezithile zefayile ezingabalulekanga ngokubonakalayo kumbonisi.

Ucinezelo lweMPEG lusebenza ngokuhlalutya ividiyo, iyahlulahlulwe ibe ziziqwengana, kunye nokwenza izigqibo malunga nokuba zeziphi iindawo ezinokulahlwa ngokukhuselekileyo, ngelixa ugcina umgangatho owamkelekileyo womgangatho. IMPEG igxile kwi amacandelo entshukumo kwifayile yevidiyo; Izinto ezingashukumiyo kwindawo zilula kakhulu ukuzicinezela kunezinto ezihambayo okanye ezinotshintsho olukhawulezayo kumbala okanye ukukhanya. Isebenzisa ii-algorithms eziphambili, iMPEG inokudala iinguqulelo ezisebenzayo zesakhelo ngasinye ngaphakathi kwefayile kwaye emva koko isebenzise ezo zakhelo ukumela iinxalenye ezinkulu zomboniso.

Ubungakanani bomgangatho olahlekileyo ngenxa yoxinzelelo lweMPEG kuxhomekeke kuzo zombini ialgorithm ekhethiweyo kunye nezicwangciso ezisetyenzisiweyo. Urhwebo apha luphakathi kobukhulu kunye nomgangatho; izicwangciso eziphezulu ziya kunika iziphumo ezingcono kodwa ngexabiso elikhulu ngokwemiqathango yendawo; ngokuchaseneyo, izicwangciso ezisezantsi ziyakuvelisa iifayile ezincinci ezinelahleko ephawuleka ngakumbi yobulunga, ngakumbi xa isiza iividiyo ezinkulu ezinje ngefilim ezinobude okanye iividiyo ezinokulungiswa okuphezulu ezifanelekileyo kwi-HDTVs.

MP3

MP3, okanye IiNgcali zeMifanekiso eshukumayo yeQela le-Audio Layer 3, yifomati yomsindo ecinezelweyo esebenzisa uluhlu lweealgorithms ezithile ukunciphisa ubungakanani boqobo beefayile zeaudio. Ithathwa njengenye yeefomati ezidumileyo ngenxa yokusebenza kwayo kakuhle ekucinezeleni iingoma zedijithali kwiisayizi ezincinci kunezinye ukulahleka iifomathi. IMP3 isebenzisa indlela “elahlekileyo” yocinezelo esusa enye yedatha yoshicilelo yoqobo kwaye yenza kube lula kwizixhobo ezifana nezidlali zomculo eziphathwayo ukugcina nokusasaza isixa esikhulu somculo wedijithali.

IMP3 inokucinezela naluphi na uhlobo lomxube wedijithali ukusuka i-mono, i-mono ephindwe kabini, i-stereo, itshaneli ephindwe kabini kunye ne-joint stereo. Umgangatho weMP3 uxhasa i-8-320Kbps bit-rate (iikhilobhithi ngesekhondi) icinezela idatha yelizwi kwi-8kbps elungele iinjongo zokusasaza. Ibonelela ngokuqhubekayo amanqanaba aphezulu omgangatho wesandi ukuya kuthi ga kwi-320Kbps ngokuthembeka kwesandi esiphakamileyo kunye ne-bitrate ephezulu enika umgangatho wesandi esifana nesokuphila kubungakanani befayile eyonyusiweyo ekhokelela kumaxesha okhuphelo olucothayo. Xa usebenzisa le ndlela yoxinzelelo, iya kuba yinto eqhelekileyo kubasebenzisi ukuphumeza umndilili I-75% yokunciphisa ubungakanani befayile ngaphandle kwelahleko ekunandipheni ukuphulaphula okanye ukucaca ngenxa yenkqubo yayo yokurekhoda ehambisa ngokufanelekileyo amanani amakhulu edatha ngelixa igcina umgangatho wesandi ofanelekileyo.

Indlela yokusebenzisa i-Lossy Compression

Uxinzelelo olulahlekileyo luhlobo loxinzelelo lwedatha olunciphisa ifayile nge ukususa enye yedatha yayo. Oku kuya kubangela ubungakanani befayile encinci kwaye ngenxa yoko, ukhuphelo olukhawulezayo lwezantya. Uxinzelelo olulahlekileyo sisixhobo esihle sokusebenzisa xa ufuna ukucinezela iifayile ezinkulu ngokukhawuleza.

Kweli nqaku, siza kuxoxa:

• Kusetyenziswa kwanjani uxinzelelo olulahlekileyo
• Ziziphi iingenelo
• Kwenziwa kanjani lungisa iifayile ozicinezelayo

Isikhokelo samanyathelo ngamanyathelo

Ukusetyenziswa koxinzelelo lwelahleko kufuna la manyathelo alandelayo:

1. Khetha uhlobo lwefayile okanye idatha onqwenela ukuyicinezela - Ngokuxhomekeke kwisiphumo esifunwayo sobungakanani befayile kunye nenqanaba lomgangatho, uhlobo lwefomathi ecinezelweyo lunokwahluka. Iifomati eziqhelekileyo zibandakanya JPEG, MPEG, kwaye MP3.
2. Khetha isixhobo sokucinezela - Izixhobo ezahlukeneyo zokucinezela zisebenzisa ii-algorithms ezahlukeneyo ukwenza amanqanaba ahlukeneyo oxinzelelo lwefayile. Ezinye izixhobo ezidumileyo zi WinZip, zipX, 7-Zip kwaye Winrar kubasebenzisi beWindows; Izinto X kubasebenzisi beMac; kwaye iZarc kubasebenzisi beeplatform ezininzi.
3. Lungisa izicwangciso zokuxinzelela - Ukudala isiphumo esilungelelanisiweyo, yenza uhlengahlengiso olufana nokutshintsha inqanaba loxinzelelo, isisombululo somfanekiso okanye ezinye iisetingi ezifakwe ngaphakathi kwefomathi ecinezelweyo ngaphambi kokucinezela idatha. Kwakhona jonga kwiisetingi ezikhulisa imifanekiso yokujongwa kwiwebhu ukuba ikhona.
4. Cofa ifayile okanye idatha-Qalisa inkqubo yoxinzelelo ngokucofa ukuqala okanye "Kulungile" kwisicelo sakho xa ugqibile ngohlengahlengiso lwakho lwesetingi. Kuxhomekeke kubungakanani beefayile ezicinezelweyo, kunokuthatha imizuzu emininzi ukugqiba le nkqubo ngokuxhomekeke kwisantya seprosesa kunye nesicelo sesoftware esisetyenzisiweyo.
5. Susa ifayile okanye idatha-Inkqubo yokukhupha iya kukuvumela ukuba ufikelele kwiifayile zakho ezisanda kutshatyalaliswa xa zigqityiwe ukuze uqalise ukuzisebenzisa ngokukhawuleza kodwa zifaneleke kakhulu kwiprojekthi yakho. Fikelela iifayile ezinqwenelekayo kwiifolda ezicinezelweyo iintlobo ngokwesiqhelo ziyahluka ukusuka .zip .rar .7z .tar .iso njl WinZip , 7Zip , IZarc njl.

Iindlela eziPhambili

Xa usebenzisa uxinzelelo olulahlekileyo, kubalulekile ukusebenzisa ifomathi eyiyo kwisicelo esilungileyo. Umzekelo, ukuba ufuna ukwabelana ngefayile yeprezenteyishini nabanye abantu, kufuneka usebenzise i Ifomati yomfanekiso olahlekileyo kuba unikezelo ludla ngokuboniswa kwisisombululo esisezantsi kunye nobukhulu obuncinci.

Kukho iindlela ezininzi zokwandisa ukusebenza koxinzelelo lwelahleko. Nazi ezinye zeendlela ezilungileyo:

• Khetha ifomathi yocinezelo efanelekileyo ngokwemeko yakho yosetyenziso (jpeg yemifanekiso, mp3 yomsindo, njl).
• Cwangcisa umgangatho womgangatho ofanelekileyo ngokuxhomekeke kubungakanani bedatha ofuna ukuyilahla.
• Lungisa iiparamitha ngokweemfuno zakho; hlalutya urhwebo phakathi kobungakanani befayile kunye nomgangatho.
• Qaphela ukuba ukusebenzisa ilahleko yoxinzelelo ngamaxesha amaninzi ingenza izinto ezibonakalayo kwiifayile zakho zemidiya kunye ukuthoba umgangatho wabo ngokubaluleka ngakumbi kunokuba ipasi enye yoxinzelelo iqhele ukwenza.
• Qinisekisa ukuba i-metadata ehambelana neefayile ezicinezelweyo zigcinwe ngokufanelekileyo ukuze lonke ulwazi olubalulekileyo luhlale lufumaneka xa uhambisa okanye ubonisa izinto eziqulethwe zefayile.

isiphelo

Ukuququmbela, uxinzelelo olulahlekileyo yindlela enhle yokunciphisa ubungakanani beefayile kunye nokunciphisa ixesha lokulayisha kwiiwebhusayithi ngelixa ugcina i umgangatho ophezulu womgangatho. Ikuvumela ukuba unciphise ubungakanani befayile yomfanekiso okanye ifayile yomsindo ngaphandle kokuba nempembelelo enkulu kumgangatho wefayile. Kubalulekile ukukhumbula, nangona kunjalo, ukuba uxinzelelo olulahlekileyo iyakuchaphazela umgangatho wefayile kwaye kufuneka isetyenziswe ngononophelo.

Isishwankathelo seLossy Compression

Uxinzelelo olulahlekileyo luhlobo loxinzelelo lwedatha olunciphisa ubungakanani befayile ngokususa ezinye iinkcukacha eziqulethwe kwifayile yokuqala. Le nkqubo idla ngokukhokelela kwiifayile ezincinci kuneefayile zoqobo kwaye zicinezelwe kusetyenziswa i-algorithms efana ne JPEG, MP3 kunye ne-H.264 ukubalula ezimbalwa. Iindlela zokucinezela ezilahlekileyo zikholisa ukurhweba ngomgangatho othile wobungakanani kodwa i-algorithms ephuculweyo inokuvelisa iifayile ezinomahluko omncinci obonakalayo ukusuka kweyokuqala engaxinzelelwanga.

Xa usebenzisa ucinezelo lwelahleko, kubalulekile ukuqwalasela ukuba ungakanani umgangatho oya kwamkeleka kwinjongo yokunciphisa ubungakanani befayile. Olunye ucinezelo lwelahleko lunokunciphisa ubungakanani beefayile ngokumangalisayo ngelixa unikezela ngelahleko ekumgangatho omncinci ngelixa abanye benokuvelisa iifayile ezincinci kakhulu kodwa ngokugqwetha okungamkelekanga okanye izinto zakudala. Ngokubanzi, ukuba kufunwa ukuncitshiswa kobukhulu obukhulu, kuya kulindeleka ukuba ilahleko enkulu yomgangatho ilindeleke kwaye ngokuchaseneyo.

Ngokubanzi, ukunyanzeliswa kwelahleko kunika indlela esebenzayo yokunciphisa ubungakanani beefayile ngaphandle kokuncama ukusebenza okuninzi xa kuthelekiswa neefomathi ezinganyanzeliswanga kwiimeko ezininzi; nangona kunjalo, ezi ngxaki kufuneka zivandlakanywe kwimeko nganye-nge-case phambi kokwenza isigqibo malunga nokuba okanye hayi isisombululo esifanelekileyo kwiseti yengxaki enikiweyo.

Izinto eziluncedo zokuSebenzisa iLossy Compression

Uxinzelelo olulahlekileyo lubonelela ngeenzuzo ezininzi kwiifayile zemidiya yedijithali. Eyona nzuzo icacileyo kukuba ukunyanzeliswa kwelahleko kunika iqondo elikhulu ukunciphisa ubungakanani befayile ngaphezu kwesiko i-algorithms yoxinzelelo olungenakulahleka. Oku kunceda ukugcina ugcino kunye neemfuno zokusetyenziswa kwe-bandwidth ubuncinci xa uhambisa iifayile ezinkulu zeendaba kwi-intanethi, okanye ukuzicinezela ukugcinwa kwendawo.

Ukongeza ekunikezeni ubungakanani bokunciphisa ubungakanani befayile obungcono kuneendlela zendabuko ezingalahlekiyo, ukusetyenziswa koxinzelelo lwelahleko kwenza kube lula ukunciphisa ubungakanani beefayile ngakumbi ngelixa ugcina umgangatho owamkelekileyo womgangatho (kuxhomekeke kuhlobo lweendaba ezixinzelelweyo). Ukongeza, ukusebenzisa ii-algorithms ezilahlekileyo kuvumela abasebenzisi ukuba benze Lungisa umfanekiso kunye nomgangatho wesandi ekuhlaleni njengoko kufuneka ngaphandle kokuphinda kufakwe ikhowudi yonke ifayile - oku kwenza ukugcina iifayile zeprojekthi kube lula kwaye ngokukhawuleza kuba iinxalenye zefayile yemidiya kufuneka ziguqulwe.

Ekugqibeleni, ukusebenzisa ii-algorithms ezilahlekileyo kunokubonelela ngokhuseleko olongezelelweyo kwezinye iimeko; Ukusukela ukuba isandi esisezantsi sebitrate ayihlukanga kakhulu kwaye kunzima ukuyitolika ngokufanayo xa ithelekiswa neenguqulelo eziphezulu zebitrate, inokubonelela ngomaleko ongezelelweyo wokhuseleko ukuba iiseti zedatha ezinkulu zifuna ukhuseleko kukuphulaphula okungagunyaziswanga okanye ukujongwa. Uxinzelelo olulahlekileyo luluhlu olubanzi lweenzuzo yenza ukuba idume phakathi kwabasebenzisi bemidiya yedijithali abafuna iifayile ezincinci ezinomzamo omncinci.

Molo, ndinguKim, umama kunye nomthandi we-stop-motion onemvelaphi kwindalo yemidiya kunye nophuhliso lwewebhu. Ndinothando olukhulu lokuzoba kunye noopopayi, kwaye ngoku ndintywila kuqala kwihlabathi le-stop-motion. Ngebhlog yam, ndabelana nawe ngokufunda kwam.