Hauv cov suab digital, cov ntawv AMR yog luv luv rau A daptive M ulti- R noj thiab hais txog AMR suab hom ntawv. Lub suab ua hom ntawv no, uas tau tso tawm ua ntej xyoo 1999, yog qhov tshwj xeeb tshaj plaws ntawm kev sib sau thiab khaws cov suab kaw tseg rau cov qauv hom ntawv xws li MP3 , WMA , thiab AAC piv txwv. Nws yog ib hom ntawv sau los ntawm cov ntaub ntawv uas feem ntau tau txheeb xyuas nrog .amr extension - kev zam rau txoj cai no yog tias 3GP thawv hom tuaj yeem siv tau los khaws AMR ntws nrog kev yees duab. Incidentally, hom lub suab coding txheej txheem no qee zaum hu ua vocoding.
AMR Narrowband thiab Wideband versions
Muaj ob qho zoo li AMR hom qauv uas yog AMR-NB thiab AMR-WB. Tus thawj (AMR-NB), yog ib tus qauv narrowband uas nquag siv rau qhov xwm txheej uas muaj qhov tsawg kawg nkaus yog txaus - xws li lub suab sau ntawv yooj yim uas koj muaj rau ntawm koj tus neeg ua si MP3 . Qhov ntau yam siv rau AMR-NB yog 300-3400 Hz uas muaj peev xwm ua tau lub suab zoo uas yog piv rau xov tooj. Qhov no narrowband siv cov nram qab no ntawm cov khoom noj khoom haus:
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Qhov thib ob ntawm AMR yog lub hom lag luam uas yog sawv cev los ntawm acronym, AMR-WB. Raws li lub npe yuav qhia, qhov no yog ib qho kev txawj ntse uas siv ntau tshaj bandwidth dua AMR-NB kom khaws lub suab ntawm ntau dua - qhov siv ntau zaus yog rau qhov no yog 50 -7000 Hz. Cov bitrates siv rau qhov wideband version of AMR yog:
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Vim nws qhov ntau dua thiab cov lus hais zoo tshaj plaws, AMR-WB yog siv kom siv tau hauv GSM (Global System for Mobile Communications) thiab UMTS (Universal Mobile Telecommunications System) technologies - txhais tau tias yog 2G thiab 3G mobile networks feem.
AMR Vs. MP3 rau Cov Xov Tooj
Txawm hais tias hom ntawv MP3 feem ntau yog qhov nrov tshaj suab hom hauv hav zoov, nws tsis yog tshwj xeeb npaum (piv rau AMR) thaum nws tuaj cuag kev hais lus. AMR hom ntawv, ntawm qhov tod tes, zoo heev ntawm kev ua haujlwm thiab yog hom ntawv tshaj xij txawm tias nws tsis yog dav dav txhawb kev kho vajtse thiab software.
Feem ntau cov ntawv thov rau AMR uas koj yuav tau tuaj nyob hauv cov suab paj nruag yog siv lub tshuab ntaus ntawv (xws li MP3 player lossis smartphone) los tuav lub suab; ntau MP3 players hnub no tau ob npaug li cov suab paj nruag siv lub tshuab built-in condenser microphone. Thiaj li yuav ua rau cov neeg siv MP3 players siv tsawg - tshwj xeeb tshaj yog yog flash raws li - cov chaw tsim hluav taws xob tau xaiv los siv AMR hom ntawv. Cov ntaub ntawv nyob rau hauv cov ntawv AMR yog qhov me me me hauv nruab nrab tshaj li cov qauv nrov dua siv los khaws cov suab paj nruag - xws li MP3, AAC, WAV, thiab WMA piv txwv.