數(shù)字電視外文翻譯文獻(xiàn)

數(shù)字電視外文翻譯文獻(xiàn)數(shù)字電視外文翻譯文獻(xiàn)(文檔含中英文對(duì)照即英文原文和中文翻譯)原文：GingaMiddlewareandDigitalTVinLatinAmericaGabrielBaum,UniversidadNacionaldeLaPlataLuizFernandoG.Soares,PontificalCatholicUniversityofRiodeJaneiroIn2005,BrazillauncheditsdigitalTV(DTV)agenda.Itsmainpremisewastoreducethedigitaldividepresentinthecountry,givingthelowersocialclassestherighttoaccess,produce,anddistributeinformation.Asanaturalconsequence,asecondpremisestressedthegenerationoflocalITjobsandcompaniestosupporttheentireeffort.TobringthebenefitsofDTVtothemasses,BrazildevisedtheJapanese-BrazilianterrestrialDTV(ISDB-T—theInternationalStandardforDigitalBroadcasting),takingtheearlierISDBJapanesestandardasabase(withsomevideoandaudiocodingupdates)andintroducingtheinnovativeBrazilianmiddlewaresystem,calledGinga.ArgentinaadoptedISDB-Tin2009withsimilarobjectivestothoseofBrazil.Sincethen,Gingahasbeenadoptedin12Latin-Americancountries.SeveralothercountriesinCentralAmericaandAfricaaretestingitaswell.GingaMiddlewareThemiddlewareliesbetweentheapplicationcodeandruntimeinfrastructuretoenablefastandeasydevelopmentofTVapplications.In2007,theBrazilianterrestrialDTVstandard2adoptedtheNestedContextLanguage3asitsdeclarativelanguage.Inthebeginningof2009,NCLanditsuseragent,Ginga-NCL,becamepartofISDB-TstandardsandoftheInternationalTelecommunicationUnion(ITU-R)BT1699Recommendation.Alsoin2009,NCLandGinga-NCLbecameanITU-TRecommendationforIPTVservices.4GingawasthefirstfreeDTVmiddleware.Ginga-NCLandNCLspecificationsareopensourceandroyaltyfree,independentofthedistributionnetworkused.NCLandGinga-NCLwereconceivedattheTeleMediaLabatPontificalCatholicUniversityofRiodeJaneiro(PUC-Rio)/Brazilandhavebeendesignedasajointeffort,includingLIFIALabatNationalUniversityofLaPlata(UNLP)/Argentina.RequirementsAimingatsocialinclusion,amiddlewaremustsupportTV(“T”)applicationssuchasT-learning,T-government,andT-health.However,socialinclusionisreachednotonlybyofferingaccesstoinformationbutalsobyprovidingknowledgeabouthowtogenerateinformation.Therefore,aDTVsystemshouldofferauser-friendlylanguagefordesigningapplicationsandservices.Thislanguageshouldbesimpleenoughtobeunderstoodandlearnedbynonexperts.Moreover,itshouldbelightweight,becauseitsinterpretermustruninlow-costreceiverswithlimitedresources.However,itshouldalsobepowerfulenoughtosupportcreativity.Thisneedforasimple,lightweight,andexpressivelanguageledtoadeclarativedomain-specificlanguage(DSL)forTVapplicationdesign,inwhichthecomplexalgorithmicstepstoaccomplishataskarelefttothemachineandaren’tunderuserresponsibility.Thefocusonmediasynchronization(initsgeneralaspect—havinginteractivityasaparticularcase),contentandpresentationadaptability,supportformultipledeviceexhibitions,andsupportthatwouldalsoallowforgeneratingliveDTVapplications,weretherequirementsthatguidedtheNCLdesign.ArchitectureGingawasinitiallyproposedforterrestrialtems,butthesamearchitectureandfacilitieswerelaterappliedtoIPTV.Figure1.TheGingaarchitecture:(a)thegeneralarchitectureand(b)optionalextensions.Furthermore,themodulararchitectureofGingaalsoallowsforitsusewithothertransportsystems(suchassatelliteandcableTV),dependingonlyonitsGingaCommonCore(Ginga-CC)subsystem.Figure1adepictstheGingacomponentsandhowtheyrelatewithothercomponentsofageneralDTVarchitecture.TheGinga-CCsubsystemdeliversapplicationstoGinga-NCL.TheGinga-NCLpresentationengineisthelogicalsubsystemresponsibleforrunningNCLapplications.TheGingaarchitecturealsooffersoptionalextensions(seeFigure1b).Forexample,forterrestrialDTVsystems,theGinga-Jexecutionengine(requiredforfixedreceiversandoptionalforportablereceiversinBrazil;andoptionalforallkindofreceiversinArgentina)isresponsibleforrunningJavaDTVapplications.ConnectedorBroadbandTVmightalsodefinesomeextensionstoimplementservices,suchasElectronicProgramGuidesandwidgets.IPTVspecificservices,suchasvideoondemand,datacasting,andsoon,areexamplesofotherpossibleextensions.GingaoffersNCLservicestoallextensionsthroughawell-definedAPI.Ginga-NCLhasanopensourceGPLreferenceimplementation(www.sof.br)recognizedbyITU-T.Someopensourceproductshavebeenderivedfromthisimplementation,includingLIFIAmiddleware(ginga.ar)forset-topboxes(http://.ar/ginga.ar)andNokiamiddlewareformobilephones(/content/48850?clickSource=search&pos=2).TherearealsosomeotherproprietaryGingaimplementations.AlthoughtherearemanyGingaimplementations,somestillworrythatamonopolycouldbecreatedforthemarketofGinga,mainlyresultingfromitspossibleextensions.Thisshouldbestronglyopposed.ImpactGingahashelpedcreatemanyjobsandITcompaniesinBrazil—atleast13smallandmedium-sizesoftwarecompaniesand60serviceproviders.TVmanufacturershavebeenmerelyassemblersofmultinationalcompaniesinthecountry,butnowthey’reobligedtoestablishlocaldevelopmentsectionstoincorporatethetechnologicalinnovationsbeingcreated.AsforBrazilianprivate(commercial)broadcasters,they’renotcommittedtosocialinclusion.Ofcourse,thisscenariocausessometensions,whichcanonlybeovercomewithastrongandresponsiblegovernmentpolicyandstrongtechnicalsupportfromacademia.InArgentina,aroundadozencompanieshaveshowninterestindevelopingapplicationsorservicesbasedonGinga,andsomehavedevelopedproducts.Inaddition,someacademiclaboratories—mainlyLIFIAandtheUniversityof3deFebrero,withthesupportoftheMinistryofFederalPlanning—havedevelopedtechnologicalinnovationsandinteractiveapplicationsbasedonGinga.IfArgentinacanturnLIFIA’s“ginga.ar”freeimplementation(basedonthePUC-Rio’sreferenceimplementation)intoadefactoproduct,thenitcanprovideaplatformonwhichITcompaniescoulddevelopnewproductsandservices.ContentDistributionTherighttodistributecontentisanimportantcomponentofsocialinclusion,yetprivate(commercial)broadcasterswon’ttransmitsocialthird-partycontentforfree.Perhapsstateandfederalgovernmentscouldpayforsometransmissionsoflarge-scaleinterest,butindependentproducers,suchascommunityTVprogrammers,can’taffordtodistributetheircontent.Publicbroadcastingcouldbeasolution.AlthoughtheprocessofdigitalizationforpublicbroadcastersinBrazilisbehindschedule,theprocesshascurrentlystarted,sothere’shope.TheArgentinianprogramisheavilybasedonpublicmedia,suchasPublicTVandotherchannelslike“Encuentro”and“INCAATV.”Althoughseveralprivatebroadcastershavejoinedtheinitiative,theproductionofcontentisbeingledbythefederalgovernment,promotingtheproductionofcontenttostrengthenanddemocratizecommunication.Nevertheless,anotheralternativefordemocratizingcontentdistributioncomesfromIPnetworks—inparticular,theInternet(seewww.iptv.brinitiative).GingaisaninternationalstandardnotonlyforterrestrialDTVbutalsoforIPTVservicesandthusforhybridDTV.Ginga-NCLcanembedlanguageplayersbutcanalsobeembeddedinotherlanguageplayers—forexample,actingasaplug-inforHTML-5browsers.AnNCLapplicationcanbeembeddedinanHTMLapplicationand,atthesametime,itcanembedanotherHTMLapplication.AworkinthisdirectionhasjustbeenfinishedforFirefoxandChrome;andhasalreadybeenstartedforHBBTV(HybridBroadcastBroadbandTV)andLIME/BML(LightweightInteractiveMultimediaEnvironment).SeveralissuesareunderconsiderationforthenextgenerationoftheNCLlanguage,suchashigh-levelabstractionsfordefiningrelationships,bettersupportforcontext-awareapplications,andsupportformultimodalinteractionsand3Dobjects.NovelissuesforGinga-CCarealsobeingconsideredtokeepGingaasacompetitiveDTVmiddlewareintheworldmarket.References1.L.F.G.Soares,R.F.Rodrigues,andM.F.Moreno,“Ginga-NCL:TheDeclarativeEnvironmentoftheBrazilianDigitalTVSystem,”J.BrazilianComputerSoc.,vol.12,no.4,2007,pp.37–46.2.ABNTNBR15606-2,Ginga-NCLforFixedandMobileReceivers—XMLApplicationLanguageforApplicationCoding,2nded.,BrazilianNat’lStandardsOrganization,2011.3.L.F.G.Soaresetal.,“Ginga-NCL:DeclarativeMiddlewareforMultimediaIPTVServices,”IEEEComm.Magazine,vol.48,no.6,2010,pp.74–81.4.NestedContextLanguage(NCL)andGinga-NCLforIPTVServices,ITU-TRecommendationH.761,Apr.2009.GabrielBaumisaprofessorofinformaticsattheUniversidadNacionaldeLaPlata.Contacthimatgbaum@sol..ar.LuizFernandoGomesSoaresisafullprofessoratthePontificalCatholicUniversityofRiodeJaneiro.He’salsothemainarchitectofGinga,co-editoroftheITU-TH.761RecommendationforIPTVServices,andchairoftheBrazilian譯文：銀河中間件和在拉美地區(qū)的數(shù)字電視Gabriel鮑姆大學(xué)國立deLaPlataLuizFernandoG.Soares，教廷天主教大學(xué)的里約熱內(nèi)盧2005年，巴西推出數(shù)字電視（DTV）議程。其主要的前提是減少數(shù)字鴻溝存在于該國，給有權(quán)訪問，生產(chǎn)，和分發(fā)信息的更低的社會(huì)階層。作為一個(gè)自然的后果，第二個(gè)前提強(qiáng)調(diào)代當(dāng)?shù)鼐蜆I(yè)機(jī)會(huì)和公司支持的整個(gè)努力。為了給群眾帶來數(shù)字電視的好處，巴西制定日本巴西地面數(shù)字電視(ISDB-T——國際標(biāo)準(zhǔn)針對(duì)數(shù)字廣播）、以早些時(shí)候ISDB日本標(biāo)準(zhǔn)作為基礎(chǔ)（與某些視頻和音頻的編碼更新）和引進(jìn)創(chuàng)新的巴西中間件系統(tǒng)，稱為銀河。阿根廷通過與目標(biāo)類似于那些巴西ISDB-T2009年。從那時(shí)起，銀河已在12個(gè)拉丁美洲國家。幾個(gè)中美洲和非洲其他國家以及正在測(cè)試它。銀河中間件中間件介于應(yīng)用程序代碼和運(yùn)行時(shí)基礎(chǔ)結(jié)構(gòu)，使電視應(yīng)用程序快速、簡單地開發(fā)。2007年，巴西的地面數(shù)字電視standard2通過嵌套上下文Language3作為其聲明性語言。在2009年年初，NCL和它的用戶代理，銀河NCL，成為一部分ISDB-T標(biāo)準(zhǔn)和國際電信聯(lián)盟（國際電聯(lián)）的BT1699建議。此外在2009年，NCL和銀河NCL成為了ITU-T建議為IPTV服務(wù)。銀河是第一次的免費(fèi)數(shù)字電視中間件。銀河NCL和NCL規(guī)格是開放源碼和自由、獨(dú)立使用的配電網(wǎng)絡(luò)的專營權(quán)費(fèi)。NCL和銀河NCL被設(shè)想在遠(yuǎn)程媒體實(shí)驗(yàn)室在教廷天主教大學(xué)的仁之（市局-里約）/巴西作為共同的努力，包括LIFIA實(shí)驗(yàn)室在國家的拉普拉塔大學(xué)（通行證）設(shè)計(jì)了/阿根廷。要求針對(duì)社會(huì)包容，中間件必須支持電視（"T"）應(yīng)用程序（如T-學(xué)習(xí)，T-政府、和不健康。然而，社會(huì)包容被達(dá)到不僅是通過提供對(duì)信息的訪問，通過提供有關(guān)如何生成信息的知識(shí)。因此，數(shù)字電視系統(tǒng)應(yīng)提供人性化的語言設(shè)計(jì)應(yīng)用砂服務(wù)。這種語言應(yīng)該是足夠簡單，理解和學(xué)到的咨詢。此外，它應(yīng)涂漆的重量，因?yàn)槠渥g員必須運(yùn)行在低成本接收機(jī)以有限的資源中。然而，它也應(yīng)該是強(qiáng)大到足以支持創(chuàng)造力。這種對(duì)簡單、重量輕、需要和富有表現(xiàn)力的語言導(dǎo)致聲明式域特定語言(DSL)電視應(yīng)用程序設(shè)計(jì)，其中復(fù)雜的算法步驟，以完成一項(xiàng)任務(wù)都留給這臺(tái)機(jī)器并不是根據(jù)用戶的責(zé)任。將重點(diǎn)放在媒體同步（在其一般的方面——具有交互性作為特定的情況下），內(nèi)容和演示文稿的適應(yīng)性、支持多個(gè)設(shè)備展覽、和支持，這也將允許用于生成應(yīng)用程序數(shù)字電視直播了指導(dǎo)NCL設(shè)計(jì)的要求。體系結(jié)構(gòu)銀河是最初提議的forterrestrialtems，但相同的體系結(jié)構(gòu)和facilitieswere后即應(yīng)用于IPTV。圖1。銀河的體系結(jié)構(gòu)：(a)的總體結(jié)構(gòu)和(b)可選的擴(kuò)展。此外，銀河的模塊化體系結(jié)構(gòu)還允許用其他運(yùn)輸系統(tǒng)（例如衛(wèi)星和有線電視），只取決于其銀河共同核心(銀河CC)子系統(tǒng)。圖1a描繪銀河組件以及它們是如何與通用的數(shù)字電視體系結(jié)構(gòu)的其他組件。銀河-CC子系統(tǒng)提供了銀河NCL中的應(yīng)用。銀河NCL演示文稿引擎是邏輯子系統(tǒng)負(fù)責(zé)運(yùn)行NCL應(yīng)用程序。銀河體系結(jié)構(gòu)還提供了可選的擴(kuò)展（見圖1b）。例如，對(duì)于地面數(shù)字電視系統(tǒng)，銀河J執(zhí)行引擎（需要固定接收機(jī)和可選的便攜式接收器在巴西；和可選的各種接收機(jī)在阿根廷）是負(fù)責(zé)運(yùn)行Java數(shù)字電視應(yīng)用程序。連接或?qū)拵щ娨曔€可以定義一些擴(kuò)展，實(shí)現(xiàn)服務(wù)，例如電子節(jié)目指南和小部件。IPTV特定的服務(wù)，如視頻點(diǎn)播、數(shù)據(jù)廣播和等等，都是其他可能的擴(kuò)展的例子。銀河NCL為提供服務(wù)通過定義良好的API的所有擴(kuò)展。銀河NCL已被國際電聯(lián)T.開源GPL參考實(shí)現(xiàn)（www.sof.br）一些開放源代碼產(chǎn)品，推導(dǎo)出此實(shí)現(xiàn)中，包括LIFIA中間件（ginga.ar）的機(jī)頂盒(http://.ar/ginga.ar)和諾基亞手機(jī)的中間件（/content/48850?clickSource=搜索&pos=2）。有還有些其他生產(chǎn)線ietary銀河的實(shí)現(xiàn)。雖然有許多的銀河實(shí)現(xiàn)，但有人仍擔(dān)心壟斷能為市場(chǎng)的銀河，主要因其可能的擴(kuò)展創(chuàng)建。這應(yīng)該是強(qiáng)烈反對(duì)。影響銀河已經(jīng)幫助創(chuàng)造很多就業(yè)機(jī)會(huì)，IT公司在巴西——至少13家小型和中等規(guī)模的軟件公司和60的服務(wù)提供商。電視制造商已經(jīng)不僅僅是匯編器的跨國公司在該國，但現(xiàn)在他們有義務(wù)建立地方發(fā)展部分納入正在創(chuàng)建的技術(shù)革新。巴西私人電臺(tái)和電視臺(tái)（商業(yè)），他們不是致力于社會(huì)包容。當(dāng)然，這種情況下會(huì)導(dǎo)致一些緊張，只可以與一個(gè)強(qiáng)大和負(fù)責(zé)的政府政策和強(qiáng)有力的技術(shù)支持，從學(xué)術(shù)界克服。在阿根廷，周圍十幾家企業(yè)都表示出的興趣開發(fā)的應(yīng)用程序或服務(wù)基于銀河，和一些已經(jīng)開發(fā)出產(chǎn)品。此外，一些學(xué)術(shù)實(shí)驗(yàn)室——