I-codec i-algorithm (i-OK yenza ukuba kube lula-uhlobo lwenkqubo!), Ininzi yexesha elifakwe njengesoftware kwiservisi okanye efakwe ngaphakathi kwinqununu ye-hardware ( ATA , IP yefoni njl.)), Esetyenziswa ukuguqula Izwi (kwimeko yeVoIP) iimpawu kwidijithali yedatha ukuba idluliselwe kwi-intanethi okanye nayiphina inethiwekhi ngexesha lekholi yeVoIP.
Igama le-codec livela kumagama aqhotyoshelweyo-coder-decoder okanye compressor-decompressor. IiCodec ngokuqhelekileyo zifezekisa le mi sebenzi emithathu ((bambalwa kakhulu okugqibela):
- Ukucwangcisa - ukucacisa
- Ukunyanzeliswa - ukunciphisa
- Ukubhaliweyo - UkuCacisa
Ukucwangcisa - ukucacisa
Xa uthetha ngefowuni eqhelekileyo ye-PSTN, ilizwi lakho lithathwa ngendlela ye-analog phezu komgca wefowuni. Kodwa ngeVoIP, ilizwi lakho liguqulwa libe yimpawu zedijithali. Olu guqulo lubizwa ngokuba yi-encoding, kwaye lufezekiswe yi-codec. Xa ilizwi eligciniweyo lifikelela kwindawo yalo, lifuneka lihlaziywe kwi-analog yalo yangaphambili ukuze omnye umyalezo angayiva aze ayiqonde.
Ukunyanzeliswa - ukunciphisa
I-Bandwidth yintengiso encinane. Ngoko ke, ukuba idatha ithunyelwe yenziwe ilula, ungathumela ngaphezulu kwixesha elithile, kwaye ngoko uphucule ukusebenza. Ukwenza i-vocitized voice iyancipha, iyancipha. Ukunyanzeliswa yinkqubo eyinkimbinkimbi apho idatha efanayo igcinwa kodwa isebenzisa indawo encinci (ibitshi yedijithali). Ngexesha loxinzelelo, idatha idityaniswe kwisakhiwo (ipakethe) ngokufanelekileyo kwi-algorithm yoxinzelelo. Idatha enxininiswe ithunyelwe phezu kwenethiwekhi kwaye emva kokuba ifike kwindawo yayo, iya kugqithiselwa kwakhona kwimoya yasekuqaleni ngaphambi kokuba ihlaziywe. Kwiimeko ezininzi, kunjalo, akudingekile ukuba udibanise idatha kwakhona, kuba idatha edityanisiweyo sele isesigxina.
Iintlobo zoxinzelelo
Xa idatha igxininiswe, iya kuba lula kwaye ngoko ukusebenza kuphuculwe. Nangona kunjalo, kudla ukuba kukuba i-algorithms ye-compression ephezulu iyanciphisa umgangatho wedatha ecinezelekileyo. Kukho iintlobo ezimbini zokuxinzezela: ukulahlekelwa yintlawulo kunye nokulahlekelwa. Ngenxa yokunciphisa ukulahlekelwa, awulahlekelwa yinto, kodwa awuyikuphelisa loo nto. Xa ulahlekelwa yintlungu, ufezekisa kakhulu, kodwa ulahlekelwa ngumgangatho. Ngokuqhelekileyo awufuni ukufumana idatha exilisiweyo kwi-original state kunye nokunyanzeliswa kokulahlekelwa, kuba ubuncinane babedluliselwe ubungakanani. Kodwa le nto ininzi yexesha ayimfuneko.
Umzekelo omhle wokunyanzeliswa kokulahlekelwa yi-MP3 yomsindo. Xa uxinezela kwi-audio, awukwazi ukucindezela emva, i-MP3 audio isele ilungile kakhulu ukuphulaphula, xa kuthelekiswa neifayile ezinkulu ezilalelwayo.
Ukubhaliweyo - ukuchithwa
Ukubhaliweyo ngenye yezixhobo ezifanelekileyo zokufumana ukhuseleko. Yinkqubo yokutshintsha idatha kwimeko enjalo ukuba akukho mntu uyayiqonda. Ngaloo ndlela, nangona idatha ye-encrypted ilandelwa ngabantu abangagunyaziswanga, idatha isasiyimfihlo. Emva kokuba idatha efihliweyo ifinyelela kwindawo leyo, ichithwa kwakhona kwifomu yayo yasekuqaleni. Ngokuqhelekileyo, xa idatha idityanisiwe, sele i-encrypted kwinqanaba elithile, ekubeni iguqulelwe kwimeko yayo yasekuqaleni.
Yiya kule khowudi kuluhlu lwee- codec eziqhelekileyo ezisetyenziselwa iVoIP .