Gabatarwa ga HE-AAC
HE-AAC (abin da ake kira aacPlus ) shi ne tsarin haɓakaccen haɓaka don dijital sauti kuma yana takaice don Ƙararren Ƙarƙashin Maɗaukaki na Girma. An gyara don amfani tare da aikace-aikacen aikace-aikacen raɗaɗa inda ake buƙatar ana buƙatar ƙananan rates kamar Radio, Rigaɗa ayyukan kiɗa, da dai sauransu. Akwai nau'i nau'i biyu na wannan maɓallin motsa jiki wanda ake kira kamar HE-AAC da HE-AAC V2. Bita na biyu yana amfani da ƙarin fasali da aka inganta kuma mafi daidaituwa fiye da na farko (HE-AAC).
Taimako ga tsarin HE-AAC
A cikin kiɗa na dijital, akwai alamun misalai na yadda ake tallafawa tsarin HE-AAC da amfani. Wadannan sun haɗa da:
- Mai watsa shirye-shirye na Mai jarida - Akwai bambancin yadda daban-daban takardun kayan aiki na kwakwalwa suna tallafawa tsarin HE-AAC. Alal misali, iTunes (version 9 da mafi girma) da Winamp (pro version) suna goyan bayan HE-AAC da ke tsarawa da kuma tsarawa. Duk da haka, wasu shirye-shirye masu yawa kamar Foobar2000, VLC Media Player, da dai sauransu, kawai suna goyon bayan sake kunnawa na fayilolin mai kunnawa HE-AAC.
- Gidaran ayyukan kiɗa - Ayyukan kiɗa na layi kamar Pandora Radio da Rhapsody amfani da tsarin matsalolin HE-AAC don ingantaccen sauti ga masu amfani da shi. Yin amfani da HE-AAC, buƙatar rubutun da ake bukata don gudanawa yana da yawa fiye da sauran tsarin codec - ana iya karɓar sauti mai jiwuwa kamar low 32 Kbps a mafi yawan lokuta.
- Rediyo na Intanit - Tun da HE-AAC yana da matukar tasiri a cikin ƙananan rates, wannan tsarin matsawa yana da kyau domin gidajen rediyo don watsa labarun watsa labarai a ainihin lokaci.
Harshen farko na HE-AAC
Masu ci gaba da HE-AAC, Coding Technologies , sun fara yin amfani da Spectral Band Replication (SBR) a cikin AAC-LC (ƙananan hadaddun AAC) - sunan kasuwancin kamfanin yana amfani da CT-aacPlus. SBR (wanda Coding Technologies ya ci gaba) ana amfani dashi don bunkasa sauti ta hanyar ingantaccen ƙayyadadden ƙananan ƙwararru. Wannan fasahar inganta kayan haɓaka, wadda ke da kyau don sauko da muryar murya, tana aiki ta hanyar haɓaka ƙananan ƙananan hanyoyi ta hanyar juyawa ƙananan - waɗannan ana adana a 1.5 Kbps.
A shekara ta 2003 kungiyar MPEG ta amince da HE-AAC V1 kuma an haɗa su a cikin takardun MPEG-4 na su kamar yadda aka saba (ISO / IEC 14496-3: 2001 / Amd 1: 2003).
Hali na biyu na HE-AAC
HE-AAC V2 wanda Coding Technologies ya haɓaka shi ne ingantaccen sashi na HE-AAC da aka saki a baya kuma kamfanin ya lasafta shi kamar yadda aka haɓaka AAC +. Wannan bita na biyu ya haɗa da haɓakawa da ake kira Parametric Stereo.
Baya ga haɗin AAC-LC da SBR don ingantaccen rubutun murya kamar yadda aka yi a cikin shirin farko na HE-AAC, wannan version na biyu yana da kayan aiki wanda aka kira, Siffar tace-tsaye - wannan yana mayar da hankali kan ƙwanƙwasa sigina na sigina. Maimakon aiki a cikin mitar bakan kamar yadda yake a cikin SBR, kayan aiki na Intanit yana aiki ta hanyar samar da bayanan gefe game da bambancin tsakanin tashar hagu da dama. Za a iya amfani da wannan bayani na gefe don bayyana tsarin gyare-gyare na hoton sitiriyo a cikin fayil na audio HE-AAC V2. Lokacin da mai amfani da bayanan ya yi amfani da wannan bayanan bayanan, zane na iya kasancewa da aminci (da kuma yadda ya dace) a yayin sake kunnawa yayin kiyaye bitar na waƙoƙin yawo zuwa ƙarami.
HE-AAC V2 yana da wasu kayan haɓɓakaccen kayan aiki a cikin kayan aiki irin su ɓangaren sitiriyo don maye gurbin, ɓoyewar ɓoye, da kuma layi na resine. Tun da amincewa da daidaituwa ta kungiyar MPEG a shekara ta 2006 (kamar yadda ISO / IEC 14496-3: 2005 / Amd 2: 2006), ya zama sananne kamar HE-AAC V2, aacPlus v2, da eAAC +.
Har ila yau an san shi kamar: aac, CT-HE-AAC, eAAC
Karin Magana: CT-aacPlus