Sawubona Habr.
Eminyakeni yamuva nje, ukwethulwa kwezinga lomsakazo wedijithali i-DAB+ kuxoxwe ngakho eRussia, Ukraine naseBelarus. Futhi uma eRussia inqubo ingakathuthuki, khona-ke e-Ukraine naseBelarus kubonakala sengathi sebevele bashintshele ekuhloleni ukusakaza.
Isebenza kanjani, yiziphi izinzuzo nezingozi, futhi ingabe iyadingeka nhlobo? Imininingwane ngaphansi kokusikwa.
Ubuchwepheshe
Umqondo womsakazo wedijithali waqala ukuvela ngasekupheleni kweminyaka yama-80s, lapho sekucaca ukuthi “isikhala” asisekho esanele ebhendini evamile ye-FM yawo wonke umuntu - emadolobheni amakhulu i-spectrum yamahhala ebangeni le-88-108 MHz sebephelelwe amandla. Mayelana nalokhu, i-DAB ibhekwe njengenye indlela enhle - iyindinganiso yedijithali lapho, ngenxa yokubhala amakhodi okuphumelelayo, iziteshi eziningi zingamukelwa. Inguqulo yokuqala ye-DAB isebenzise i-codec ye-MP2, inguqulo yesibili (DAB+) yasebenzisa i-HE-AAC entsha. Izinga ngokwalo lidala ngokwezindinganiso zesimanje - isiteshi sokuqala se-DAB esathulwa ngo-1995, kanye nesiteshi se-DAB+ ngo-2007. Ngaphezu kwalokho, "iminyaka" yezinga elijwayelekile kuleli cala lingaphezulu kakhulu kune-minus - manje ayikho inkinga yokuthenga isamukeli somsakazo kukho konke ukunambitheka nesabelomali.
Kunomehluko omncane phakathi kwe-DAB ne-FM evamile. Futhi iphuzu akukhona ukuthi enye "idijithali" kanti enye "i-analog". Umgomo wokudlulisa okuqukethwe ngokwawo uhlukile. Ku-FM, isiteshi ngasinye sisakaza ngokuzimela, futhi ku-DAB+, zonke iziteshi zihlanganiswa zibe “i-multiplex”, ngasinye esingaba neziteshi ezifika kweziyi-16. Amashaneli amafrikhwensi ahlukene ahlinzekwa ukuze amazwe ahlukene akwazi ukukhetha lawo amahhala kwezinye izinkonzo.
Ngokombono webhizinisi, lo mehluko udala izingxabano eziningi phakathi kwabasakazi mayelana nendlela yokusakaza nge-multiplex. Ngaphambilini, abasakazi ngokwabo bathola ilayisensi ye-frequency, bathenga i-antenna kanye ne-transmitter, manje ilayisense izokhishwa ku-opharetha we-multiplex, futhi uzoqashisa iziteshi eziteshini zomsakazo. Kunzima ukusho ukuthi kungcono noma kubi kakhulu, kwabanye kulula kakhulu ukuba nakho konke okwabo, kwabanye kulula kakhulu ukuqasha.
Ngendlela, mayelana nalokhu, i-DAB inobunzima obukhulu futhi obunesibindi kumlaleli - intengo yokuqashwa kwe-multiplex incike ku-bitrate. Futhi uma ukhetha phakathi kuka-192 no-64kbps... Ngicabanga ukuthi wonke umuntu uyakuqonda okuzokhethwa. Uma ku-FM kunzima kakhulu ukusakaza ngekhwalithi ephansi, khona-ke ku-DAB lokhu kuyakhuthazwa ngisho nangokwezomnotho (kuyacaca ukuthi lokhu akulona iphutha labathuthukisi bezinga, kodwa namanje). Amanani aseRussia, yiqiniso, awakaziwa, kodwa amanani esiNgisi, njengesibonelo, angatholakala .
Ngokombono wezobuchwepheshe, i-DAB+ multiplex iyisiginali ye-broadband enobubanzi be-spectrum obungaba ngu-1.5 MHz, ebonakala ngokucacile kusetshenziswa isamukeli se-RTL-SDR.
Incazelo enemininingwane eyengeziwe ku-PDF ingatholakala .
Amazinga aqhudelanayo
Ngokuvamile, azikho eziningi zazo. I-DAB+ isetshenziswa eYurophu, izinga lidumile e-USA , eNdiya bahlola izinga , kodwa kunzima ukusho ukuthi baphetha kanjani.
Ikhadi liphelelwe yisikhathi kancane (i-DRM nayo yahlolwa eRussia, kodwa yashiywa), kodwa umqondo ojwayelekile ungaqondwa:
(umthombo )
Ngokungafani ne-DAB, abadali bezinga le-HD Radio bathathe indlela ehlukile - isignali yedijithali ibekwe eduze kwesiginali ye-analogue, ivumela abasakazi ukuthi basebenzise izinti zabo nama-mass.
Kodwa-ke, lokhu akuxazululi inkinga eyaqala konke - inkinga yokuntuleka kwezikhala zamahhala ku-spectrum. Futhi ngokwendawo (futhi mhlawumbe nezombusazwe), emazweni angaphambili e-CIS, ukwamukelwa kwezinga laseYurophu kubukeka kunengqondo kunokusetshenziswa kwezinga laseMelika - kusekhona ukukhetha okukhulu kwezimpahla zaseYurophu futhi kulula ukuthenga abamukeli. Kwakusakhulunywa ngakho ngo-2011 , kodwa yonke into yafa (futhi sibonga uNkulunkulu, ngoba izinga layo ledijithali, elingahambisani nanoma yini, liyinto embi kakhulu engase isungulwe abalaleli bomsakazo).
Ukuhlola
Ake ekugcineni siqhubekele engxenyeni ephathekayo, i.e. ekuhlolweni. I-DAB ayisebenzi e-Russia okwamanje, ngakho-ke sizosebenzisa okurekhodiwe kwe-SDR okuvela ku-multiplex yesi-Dutch. Labo abasuka kwamanye amazwe nabo bangajoyina futhi bangithumele amarekhodi ngefomethi ye-IQ, ngizowacubungula futhi ngenze ithebula lesifinyezo.
Ungalalela kanjani i-DAB? Ngoba okujwayelekile kuyidijithali, ungakwazi ukuyikhipha usebenzisa ikhompuyutha kanye nomamukeli we-rtl-sdr. Kunezinhlelo ezimbili - и , bobabili bangasebenza nge-rtl-sdr.
kubukeka sengathi umsebenzi wesifundo somfundi, futhi umbhali ngokusobala akazange azihluphe ngokuklama - amafonti awahambisani nezilawuli, amafasitela awalingani. Kodwa into ebaluleke kakhulu kithi ukuthi ikuvumela ukuthi ufunde futhi ubhale amafayela e-IQ.
Iseku-beta, kodwa isebenza kangcono kakhulu futhi iqopha kangcono. Kungenzeka futhi ukukhipha imininingwane eminingi yokulungisa iphutha:
Kodwa i-welle.io ayikakwazi ukusebenza ngamafayela e-iq, ngakho-ke sizosebenzisa i-Qt-dab.
Ukuze kuhlolwe, ngilayishe amafayela angu-3 ku-cloud.mail.ru, ngalinye liqukethe ukurekhodwa okuthatha iminithi eside kwe-multiplex ye-DAB, usayizi wefayela cishe u-500 MB (lokhu usayizi wokurekhodwa kwe-IQ ye-SDR enomkhawulokudonsa ongu-2.4 MHz). Ungavula amafayela ku-Qt-dab, isixhumanisi sokulanda esinikezwe ngenhla.
Ifayela-1: DAB-8A.sdr — . I-Multiplex 8A isebenza ngemvamisa ye-195.136 MHz futhi iqukethe iziteshi eziyi-16. I-bitrate yazo zonke iziteshi ngu-64Kbps.
Ifayela-2: DAB-11A.sdr — . I-Multiplex 11A imvamisa engu-216.928 MHz. Iqukethe iziteshi ezingu-6, ezinama-bitrate angu-48, 48, 48, 48, 64 kanye no-48KBps ngokulandelanayo.
Ifayela-3: DAB-11C.sdr — . I-Multiplex 11C imvamisa engu-220.352 MHz nayo iqukethe iziteshi eziyi-16. Ama-bitrate azo zonke iziteshi ngokulandelana kwawo: 80, 80, 80, 80, 56, 96, 80, 64, 56, 48, 64, 64, 64, 96, 80 kanye no-64Kbps.
Njengoba ubona, azikho izinkinga ngenani leziteshi, kodwa inkinga enkulu yi-bitrate ephansi. Mayelana nokuqukethwe ngokwako, okuthandwayo kuyehluka futhi ngeke ngikuxoxe; abafisayo bangadawuniloda amafayela bazilalele bona. Akuwona wonke ama-multiplex abalwe kokufakiwe, kodwa ngithemba ukuthi umbono ojwayelekile ucacile.
okutholakele
Uma sikhuluma ngamathemba okusakazwa komsakazo wedijithali, maye, adabukisa kakhulu. Inzuzo enkulu ye-DAB ukusetshenziswa ngempumelelo kwe-spectrum, okuvumela iziteshi eziningi ukuba zifakwe emoyeni. Mayelana nalokhu, i-DAB+ yenza umqondo kulawo madolobha lapho singasenasikhala samahhala ku-FM. ERussia, lokhu cishe iMoscow neSt. Petersburg kuphela; kuwo wonke amanye amadolobha azikho izinkinga ezinjalo.
Mayelana nekhwalithi yomsindo, ngokobuchwepheshe, i-DAB+ inganikeza ama-bitrate afika ku-192Kbps, azonikeza cishe umsindo we-HiFi. Empeleni, njengoba sibona ngenhla, abasakazi bonga imali futhi abaweli ngisho nebha engu-100Kbit/s. Kuma-multiplex amathathu, bekunesiteshi esisodwa kuphela (!) esisakaza ngo-96Kbps (futhi angikwazi ukubiza umculo osakazayo ngo-48kbps nganoma yini ngaphandle kokuhlambalaza - abasakazi abanjalo kufanele baphucwe ilayisense yabo;). Ngakho-ke, maye, singasho ngokuzethemba okungu-99% ukuthi uma usuka ku-FM uye ku-DAB, ikhwalithi yomsindo izoba kubi kakhulu kunalokho okwakuyikho. Yebo, mhlawumbe kwamanye amazwe isimo singcono, kodwa isibonelo, nansi isibuyekezo sesiNgisi ku-YouTube esinesihloko esicacile. . Ngobuchwepheshe, i-DAB yinhle futhi azikho izikhalo ngayo, kodwa ngokwezomnotho, “imali inqobe ububi.”
Ukubuyela eRussia, ingabe kufanelekile ukukhathazeka futhi uqale ukusakaza ku-DAB? Ngokombono wokuhlonishwa kwamazwe ngamazwe, mhlawumbe yebo, ukuze kungabonakali njengezwe lesithathu elibuyela emuva emehlweni omakhelwane balo, futhi njengebhonasi, ukuze izimoto nemisakazo ethengwe eYurophu ikwazi ukuthola ngokugcwele zonke iziteshi. Kodwa ngokombono wabalaleli kanye nekhwalithi yomsindo, cishe, abasebenzisi ngeke bathole noma yiziphi izinzuzo kungaba ngekhwalithi yomsindo noma ikhwalithi yokuqukethwe.
Uma sicabanga ngamathemba esikhathi eside, khona-ke mhlawumbe esikhathini esizayo umamukeli womsakazo uzoba idivayisi enekhadi le-e-sim elididiyelwe kanye nokubhalisela umculo we-Yandex Spotify noma i-Apple Music lapho uthenga. Ngokusobala ikusasa ngelamasevisi okusakaza-bukhoma nokuqukethwe komuntu siqu. Ukuthi lokhu kuzokwenzeka ngokushesha kangakanani, sizobona, isikhathi sizosho.
Source: www.habr.com