I-codec iyi-algorithm (Kulungile ivumela ukuthi kube lula - uhlobo lwenqubo!), Isikhathi esiningi efakwe njengesofthiwe kuseva noma efakwe ngaphakathi kwezingxenye zehadiwe ( ATA , IP eliphezulu njll), esetshenziselwa ukuguqula Izwi (esimweni se-VoIP) isignali yedatha yedijithali ukuze idluliselwe phezu kwe-Inthanethi noma kunoma iyiphi inethiwekhi ngesikhathi socingo lweVoIP.
Igama le-codec livela kumagama abhalwe phansi i-coder-decoder noma i-compressor-decompressor. Ama-codecs avame ukufeza imisebenzi emithathu elandelayo (okumbalwa kakhulu okugcina):
- Ukuqhafaza - ukucacisa
- Ukucindezela - ukucindezeleka
- Ukubethela - Decryption
Ukuqhafaza - ukucacisa
Uma ukhuluma ngefoni ejwayelekile ye-PSTN, izwi lakho lihanjiswa ngendlela ye-analog phezu komugqa wefoni. Kodwa nge-VoIP, izwi lakho liguqulwa libe yizibonakaliso zedijithali. Lokhu kuguqulwa kubizwa nge-encoding, futhi kutholakala nge-codec. Uma izwi elithambile lifinyelela endaweni yalo, kufanele lihlehliselwe esimweni sayo sangaphambili sokudala ukuze omunye umlobi angalizwa futhi aluqonde.
Ukucindezela - ukucindezeleka
Ububanzi bomkhawulo buyinto elula. Ngakho-ke, uma idatha ithunyelwa yenziwa ilula, ungathumela okuningi ngesikhathi esithile, futhi ngaleyo ndlela uthuthukise ukusebenza. Ukuze wenze izwi elithambileyo likhulu kancane, liyancipha. Ukucindezela kuyinkimbinkimbi lapho idatha egcinwe khona kodwa isebenzisa isikhala esincane (izingqikithi zedijithali). Ngesikhathi sokucindezela, idatha ivalwe kwisakhiwo (ipakethe) efanele ku-algorithm yokucindezela. Idatha ecindezelwe ithunyelwe phezu kwenethiwekhi futhi uma ifinyelela endaweni yayo, idonswa emuva kwayo isimo sangempela ngaphambi kokuba ihlelwe kabusha. Nokho, ezimweni eziningi, akudingekile ukuba udidezele idatha emuva, ngoba idatha ecindezelekile isivele isesimweni esithengiwe.
Izinhlobo zokucindezela
Uma idatha icindezelekile, iba lula futhi ngakho ukusebenza kuthuthukiswa. Kodwa-ke, kuvame ukuba ukuthi ukulungiswa okuhle kokucindezela kunciphisa izinga lemininingwane ecindezelweyo. Kunezinhlobo ezimbili zokucindezela: ukulahlekelwa nokulahlekelwa. Ngokucindezeleka okungalahleki, awulahlekelwa lutho, kodwa awukwazi ukucindezela okuningi. Ngokucindezeleka okulahlekile, ufezekisa ukunciphisa okukhulu, kodwa ulahlekelwa ngekhwalithi. Ngokuvamile uthola idatha ecindezelweyo emuva esimweni sayo sokuqala ngokucindezeleka okulahlekile, ngoba ikhwalithi yayihlatshelwe ubukhulu. Kodwa lokhu isikhathi esiningi akudingekile.
Isibonelo esihle sokucindezeleka okulahlekile yi-MP3 yokulalelwayo. Uma ucindezela umsindo, awukwazi ukucindezela emuva, wena umsindo we-MP3 usuvele ulungile kakhulu ukuwulalela, uma uqhathaniswa namafayela amaningi alalelwayo ahlanzekile.
Ukubethela - ukuchithwa kwemfihlo
Ukubethela kungenye yamathuluzi angcono kakhulu ekufezeni ukuphepha. Kuyinkqubo yokushintsha idatha esimweni esinjalo sokuthi akekho owaziyo ukuyiqonda. Ngale ndlela, ngisho noma idatha encrypted isamukelwa abantu abangagunyaziwe, idatha isalokhu iyimfihlo. Uma idatha efihliwe ifinyelela endaweni, iyabhaliswa emuva kwifomu layo langempela. Ngokuvamile, uma idatha igxiliwe, isivele ibhalwa ngezinga elithile, njengoba ishintshiwe esimweni sayo sokuqala.
Iya kulesi sixhumanisi ohlwini lwamakhodi ejwayelekile avame ukusetshenziswa ngeVoIP .