Mene ne AAC-format?

Don kwanan wata, AAC-format har yanzu bai kai da taro rarraba sauti dako, duk da haka, da dama daga sigogi shi ne mafifici a kan duk halin yanzu iri audio matsawa, sabili da haka ya cancanci mu da hankali.

Mene ne wannan?

Mun fara da definition: audio format AAC ne mallakar tajirai (jadadda mallaka) daya matsawa audio fayil. A lokaci guda yana da wani karami asarar quality a lokacin coding fiye da MP3 a cikin wannan bit kudi yanayi. Har ila yau, AAC-format ne mai wideband audio coding algorithm cewa yana amfani da biyu main tsarinsa manufa significantly rage yawan data bukata ga watsa daga high quality-dijital audio. Wannan bayani yana dauke su daya daga cikin mafi ingancin, sayar a wata asarar matsawa da fasaha. The format goyon bayan mafi kayayyakin zamani, ko da šaukuwa. Ya kamata a lura da cewa zobe sautunan a AAC format za a iya saya daga iTunes Store, kuma a cikin wannan shagon ne music, matsa kawai ta wajen yanke shawara. Ya kamata kuma a ce cewa AAC-format asali halitta a matsayin magaji zuwa MP3, wanda zai iya samar da ingantattun quality coding. A shawarar da aka buga a 1997 a matsayin wani sabon, 7th, wani ɓangare na wani iyali na MPEG-2.

manufa na aiki

Lokacin shigar a cikin wannan format, wadannan matakai: imperceptible aka gyara na da sigina suna cire, tsabtace na rikidadde audio sigina redundancy. Bayan nan, cikin bayanai da aka sarrafa a cikin daidai da hanyar bisa ga MDCT su mawuyaci. A na gaba mataki da lambobin suna kara da cewa gyara daban-daban ciki kurakurai. A karshe, siginar da aka daukar kwayar cutar ko ceto.

All bayani

Sha'awa, da AAC-format yana da wani Samfur mita tsakanin 8-96 kHz da kuma yawan tashoshi a cikin tazara 1-48. MP3 Hybrid yana amfani da wani sa na tacewa. Yana nufin wani modified mai hankali cosine canza, bi da bi AAC a wani ƙara kudi na "windows", wanda ya kai 2048 da maki.

Saboda haka, AAC yafi dace wa encode audio rafi da ciwon da hadaddun bugun jini da kuma square-kalaman sakonni, idan aka kwatanta da MP3. Format tsiwirwirinsu da ikon da kuzari canzawa a cikin MDCT block tsawo a cikin kewayon 2048-256 maki. Idan akwai wani gajere ko guda motsi, yi amfani da karamin "taga" for 256 da maki domin ya cimma mafi ƙuduri. A wannan yanayin, tsoho ne 2048-ma'ana manyan "taga" to kara da coding yadda ya dace. AAC yana da yawan abũbuwan amfãni idan aka kwatanta da yadda ya saba MP3. Daga cikin su ya kamata mu ambaci: ganin babban adadin audio tashoshi (har zuwa 48), gagarumin coding yadda ya dace a karkashin yanayi na m da m bit kudi da kuma daukan samfur mita a cikin kewayon daga 8 Hz zuwa 96 kHz (for MP3, wannan adadi ne daga 8 Hz zuwa 48 kHz) kuma a mafi m musamman yanayin kira hadin gwiwa sitiriyo. Amma ga mafita, "AAC +" - a Codec cewa an mayar da hankali a kan yin aiki tare da low bit kudi. Ne mai hade da SBR kuma AAC LC, game da shi, da cimma kyau sauti riga a cikin kewayon 32-48 kbit / s.