He aha te mea AAC-hōputu?

Ki te rā, tonu kore kua tae AAC-hōputu te tohatoha papatipu o kawe tangi, Heoi, he maha o ngā tawhā he reira pai ki ngā momo o nāianei katoa o kōpeketanga oro, me reira e tika o to tatou aro.

He aha te mea te reira?

timata tatou ki te tatararaa: hōputu audio AAC he kamupene kōnae ororongo (arai) kotahi kōpeketanga. I te wa ano kua reira he mate iti o te kounga i roto i Tapa atu MP3 i te tikanga auau moka taua. Ano, AAC-hōputu ko te hātepe waehere audio WideBand e whakamahi ana e rua parau tumu whakawaehere matua ki tino whakaiti i te maha o ngā raraunga e hiahiatia ana mō te tuku o te ororongo mamati-kounga teitei. whakaaro ana tēnei otinga te ki kia kotahi o te kounga teitei, hokona i te mate o te hangarau kōpeketanga. tautoko te hōputu taputapu tino hou, ara kawe. Me kï reira e taea te hokona nga pepe mowhiti i roto i te hōputu AAC i te Store iTunes, a i roto i tenei taonga he waiata, kōpeke anake i te tikanga o te whakatau. kia hoki kia mea te reira e tuatahi hanga te AAC-hōputu rite te mono ki MP3, e taea whakarato ake waehere kounga. whakaputaina te whakatau i roto i te 1997 rite te hou, 7, wahi o te hapu o MPEG-2.

parau tumu o te mahi

A, no te whakawaehere i roto i tenei hōputu, te tukanga e whai ake nei: wāhanga äta o te tohu e nekehia, horoia o te whakawaeheretia hapanga tohu oro. I muri iho, tukatuka te raraunga i roto i runga i te tikanga rite ki te MDCT ratou whīwhiwhi. I te wā i muri e tapiritia nga waehere ki fakatonutonu ngā hapa ā-roto. I te pae hopea, tuku te tohu kei te ranei ora.

kōrero katoa

Te mea faahiahia, e te auau tīpako o waenganui i 8-96 kHz me te maha o takere i roto i te wā 1-48 te AAC-hōputu. whakamahi MP3 ranu te huinga o whiriwhiringa. E pā ana te reira ki te whenu motuhake whakarerekētia taui, i roto i te tahuri AAC i te nui haere tere o "matapihi", e tae 2048 ngā.

Ko te kupu, AAC nui atu oreore ki te whakawaehere te awa audio he te ngātere me tapawha-poipoi tohu matatini, whakaritea ki te MP3. Hōputu riro te kaha ki te hihiri whakawhiti i roto i te roa poraka MDCT i roto i te whānuitanga 2048-256 ngā. Ki te reira te mea he wā-poto he neke kotahi ranei, e whakamahia ana he "matapihi" iti mō te 256 ngā i roto i te tikanga ki te whakatutuki i pai taumira. I roto i tenei take, te taunoa he nui 2048-ira "matapihi" ki te whakanui i te tōtika waehere. he maha o painga whakaritea ki te MP3 mua AAC kua. I roto ia ratou e whakahua tatou: te whakatutukitanga o te maha nui o takere ororongo (ki runga, ki te 48), nui tōtika Tapa i raro i ngā āhuatanga o te auau moka tamau me te tāupe, me te tīpako auau i roto i te whānui i te 8 Hz ki 96 kHz (mo te MP3, ko tenei ahua i 8 Hz ki 48 kHz) me te aratau motuhake atu ngāwari i huaina tīwharawhara ngātahi. Ko rongoā, "AAC +" - he kōtēke arotahi e te i runga i te mahi ki te auau moka iti. He he huinga o te SBR me AAC LC, reira whakatutuki tangi pai kē i roto i te whānuitanga o te 32-48 kbit / s.