Mhoro Habr.
Mumakore achangopfuura, kuunzwa kweDAB + dhijitari redhiyo standard yakakurukurwa muRussia, Ukraine neBelarus. Uye kana iyo nzira isati yafambira mberi muRussia, zvino muUkraine neBelarus zvinoratidzika kuti vakatoshandura kuedza kutepfenyura.
Inoshanda sei, ndezvipi zvakanakira nezvayakaipira, uye zvinotodiwa here? Tsanangudzo pasi pekucheka.
Technology
Pfungwa yeredhiyo yedhijitari yakatanga kubuda mukupera kwema80s, pazvakava pachena kuti pakanga pasina "nzvimbo" dzakakwana mubhendi reFM remunhu wese - mumaguta makuru, yemahara spectrum mu88-108 MHz renji yaive. kupera simba. Panyaya iyi, DAB yaionekwa seimwe yakanaka imwe nzira - idhijitari chiyero umo, nekuda kwekunyanya kushanda kwekodha, zvimwe zviteshi zvinogona kuiswa. Yekutanga vhezheni yeDAB yakashandisa iyo MP2 codec, yechipiri vhezheni (DAB+) yakashandisa itsva HE-AAC. Iyo chiyero pachayo ndeyekare zvakanyanya nemaitiro emazuva ano - yekutanga chiteshi cheDAB chakatangwa muna 1995, uye chiteshi cheDAB + muna 2007. Uyezve, "zera" rechiyero mune iyi kesi rakatonyanya kuwedzera pane minus - ikozvino hapana dambudziko kutenga redhiyo inogamuchira kune yega kuravira uye bhajeti.
Pane misiyano yakati wandei pakati peDAB neyakajairwa FM. Uye iyo pfungwa haisi kunyange iyo imwe i "digit", uye imwe i "analog". Nheyo yekufambisa zvirimo inosiyana. MuFM, chiteshi chega chega chinotepfenyura chakazvimirira, nepo muDAB+, zviteshi zvese zvinosanganiswa kuita "multiplex", imwe neimwe inogona kuva nenhepfenyuro gumi nenhanhatu. Yakasiyana ma frequency chiteshi anopihwa, kuitira kuti nyika dzakasiyana dzisarudze idzo dzisina mamwe masevhisi.
Kubva pamaonero ebhizinesi, musiyano uyu unokonzeresa makakatanwa akati wandei pakati pevatepfenyuro maererano nemafambisirwo ekushambadzira mumultiplex. Pakutanga, vatepfenyuro ivo pachavo vakawana rezinesi re frequency, vakatenga antenna uye transmitter, ikozvino rezinesi richapihwa kune multiplex opareta, uye atove kuhaya zviteshi kunhepfenyuro. Zvakaoma kutaura kuti zviri nani here kana kuti zvakaipisisa, zviri nyore kuti mumwe munhu ave nezvose zvake, kune mumwe munhu zviri nyore kuroja.
Nenzira, mune izvi, DAB ine hombe uye mafuta minus kune muteereri - multiplex mutengo wekurenda zvinoenderana nebitrate. Uye kana ukasarudza pakati pe192 ne64kbps ... Ndinofunga kuti munhu wese anonzwisisa zvichasarudzwa. Kana zvakanyanya kuoma kutepfenyura nemhando yakashata muFM, saka muDAB inotokurudzirwa hupfumi (zviri pachena kuti iyi haisi mhosva yevagadziri vakajairwa, asi zvakadaro). Mitengo yeRussia, hongu, haisati yazivikanwa, asi semuenzaniso, unogona kuona mitengo yeChirungu .
Kubva pakuona kwehunyanzvi, iyo DAB + multiplex chiratidzo chakakura chine hupamhi hwehupamhi hunosvika 1.5 MHz, iyo inonyatso kuoneka ine RTL-SDR inogamuchira.
Tsananguro yakadzama muPDF inogona kuwanikwa .
Kukwikwidzana kwemitemo
Kazhinji, hakuna akawanda acho. DAB + inoshandiswa muEurope, chiyero chakakurumbira muUSA , muIndia kuedza kwakaitwa nechiyero asi kuti dzakapera sei zvakaoma kutaura.
Iro kadhi rakapera zvishoma (DRM yakaedzwawo muRussia, asi yakasiiwa), asi pfungwa huru inogona kunzwisiswa:
(tsime )
Kusiyana neDAB, vagadziri veHD Radio standard vatora imwe nzira nekuisa chiratidzo chedhijitari padivi pechiratidzo cheanalogi, zvichibvumira vatepfenyuri kuti vashandise maantenna avo nemasts.
Zvisinei, izvi hazvigadzirisi dambudziko rakatanga zvose - dambudziko rekushayikwa kwezvigaro zvepachena mumagetsi. Hongu, uye nemamiriro ekunze (uye pamwe nezvematongerwo enyika), munyika dzekare dzeCIS, kugamuchirwa kweEuropean standard kunoratidzika kune musoro kupfuura kushandiswa kweAmerican standard - kusarudzwa kwezvinhu zveEurope kuchiri kukuru uye zviri nyore kutenga vanogamuchira. . Muna 2011 pakanga pachiri kutaurwa , asi zvinhu zvose zvakapera (uye tenda Mwari, nokuti chiyero chayo chedhijitari hachienderani nechinhu chipi nechipi, ichi ndicho chinhu chakaipisisa chinogona kugadzirwa kune vateereri veredhiyo).
Kuedza
Pakupedzisira, ngatiendei kune chikamu chinoshanda, i.e. ku test. DAB haisati yave kushanda muRussia, saka tichashandisa SDR zvinyorwa kubva kuDutch multiplex. Vanoshuvira kubva kune dzimwe nyika vanogonawo kujoina uye kunditumira marekodhi muIQ fomati, ini ndichaagadzirisa uye kugadzira tafura yepivot.
Ungateerera sei kuDAB? Nokuti digital standard, saka inogona kudhindwa uchishandisa komputa uye rtl-sdr inogamuchira. Pane mapurogiramu maviri - ΠΈ , vese vanogona kushanda nertl-sdr.
inoita senge bepa remudzidzi wetemu, uye munyori zviri pachena haana kunetseka nedhizaini - mafonti haakwane mukutonga, mahwindo haakure. Asi kwatiri, chinhu chinonyanya kukosha ndechekuti inokubvumira kuverenga nekunyora mafaira eIQ.
ichiri mu beta, asi inoshanda zvirinani uye inosarudza zvirinani. Izvo zvakare zvinogoneka kuburitsa yakawanda yakawanda yekuwedzera debugging ruzivo:
Asi welle.io haisati yaziva kushanda neiq mafaera, saka tichashandisa Qt-dab.
Kuti ndiedze, ndakaisa mafaira matatu kucloud.mail.ru, imwe neimwe ine miniti imwe yeDAB multiplex rekodhi, saizi yefaira inenge 3MB (iyi ndiyo saizi yeIQ marekodhi eSDR ane bandwidth ye500MHz). Unogona kuvhura mafaera muQt-dab, chinongedzo chekurodha chakapihwa pamusoro.
Faira-1:DAB-8A.sdr- . Multiplex 8A inoshanda pane frequency ye195.136 MHz uye ine 16 zviteshi. Iyo bitrate yezviteshi zvese ndeye 64Kbps.
Faira-2:DAB-11A.sdr- . Multiplex 11A pamwero we 216.928 MHz. Iine zviteshi zvitanhatu, zvine bitrate zve6, 48, 48, 48, 48 uye 64KBps zvakateerana.
Faira-3: DAB-11C.sdr - . Multiplex 11C pa frequency ye 220.352 MHz, inewo 16 zviteshi. Iwo bit mitengo yezviteshi zvese zvakateerana: 80, 80, 80, 80, 56, 96, 80, 64, 56, 48, 64, 64, 64, 96, 80 uye 64Kbps.
Sezvauri kuona, hapana matambudziko nehuwandu hwezviteshi, asi dambudziko guru ndiro yakaderera bitrate. Kana zviri zvemukati pachazvo, kuravira kwakasiyana uye ini handisi kuzokurukura nezvazvo, avo vanoshuvira vanogona kudhawunirodha mafaera uye vateerere vega. Haasi ese ma multiplex akanyorwa muzvinyorwa, asi pfungwa huru ndeyekuti, ndinovimba, yakajeka.
zvakawanikwa
Kana tikataura nezve tarisiro yekutepfenyura kwedhijitari, saka, maiwe, ivo vanosuwa. Kubatsira kukuru kweDAB ndiko kushandiswa kwakanyanya kweiyo spectrum, iyo inobvumira zvimwe zviteshi kuti zvive pamhepo. Panyaya iyi, DAB + ine musoro chete kune iwo maguta pasina nzvimbo yemahara muFM. KuRussia, izvi zvichida chete Moscow neSt. Petersburg, mune mamwe maguta ose hapana matambudziko akadaro.
Nezve mhando yeruzha, DAB+ inogona kupa nehunyanzvi mareti anosvika 192Kbps, ayo anokupa kanenge HiFi ruzha. Mukuita, sezvatinoona pamusoro, vatepfenyuri vanochengetedza mari uye havapfuuri nebhawa kunyangwe pa100Kbps. Pama multiplexes matatu, imwe chete (!) nhepfenyuro yakawanikwa ichitepfenyura pa96Kbps (uye handikwanise kudaidza mimhanzi yekutepfenyura kubva pa48kbps chero chinhu kunze kwekumhura - vatepfenyuri vakadaro vanofanira kunyimwa marezinesi avo;). Saka, maiwe, tinogona kutaura tiine 99% chokwadi kuti kana uchichinja kubva kuFM kuenda kuDAB, mhando yekurira ichave. zvakaipa kupfuura zvazvaive. Ehe, mamiriro angave ari nani kune dzimwe nyika, asi semuenzaniso, wongororo yechirungu paYouTube ine zita rakanaka. . Nehunyanzvi, DAB yakanaka uye hapana zvichemo nezvazvo, asi mune zvehupfumi, "kupambwa kwakakunda zvakaipa."
Kudzokera kuRussia, zvine basa here kutanga kutepfenyura muDAB zvachose? Kubva pakuona kwekuremekedzwa kwenyika dzakawanda, zvichida hongu, kuitira kuti urege kutaridzika senyika yechitatu yakadzokera shure mumaziso evavakidzani, uye sebhonasi, kuitira kuti motokari neredhiyo dzakatengwa muEurope dzigone kugamuchira zvizere zviteshi. Asi kubva pamaonero evateereri uye mhando yeruzha, kazhinji, vashandisi havagamuchire chero mabhenefiti angave mumhando yeruzha kana mumhando yezvinyorwa.
Kana iwe uchifunga nezve tarisiro yenguva refu, saka pamwe mune ramangwana redhiyo ichava chishandiso chine yakasanganiswa e-sim kadhi uye kunyorera kuYandex mumhanzi Spotify kana Apple Music paunotenga. Ramangwana rakajeka mumasevhisi ekutepfenyura uye zvemukati zvemunhu. Izvi zvichaitika nokukurumidza sei, tichaona, nguva ichataura.
Source: www.habr.com