ITU-T G.Imp728 (04 2006) (英) Implementors’ Guide f

INTERNATIONALTELECOMMUNICATIONUNIONITU-TG.728Implementors’GuideTELECOMMUNICATIONSTANDARDIZATIONSECTOROFITU(13April2006)SERIESG:TRANSMISSIONSYSTEMSANDMEDIA,DIGITALSYSTEMSANDNETWORKSDigitalterminalequipments–CodingofanaloguesignalsbymethodsotherthanPCMImplementors’GuideforITU-TRecommendationG.728(“Codingofspeechat16kbit/susinglow-delaycodeexcitedlinearprediction”)Implementors'GuideforITU-TG.728(2004-06)iSummaryThisdocumentisanImplementors'GuidefortheITU-TRecommendationofG.728addressingissuesfoundinparticularinitsAnnexI“FrameorpacketlossconcealmentfortheLD-CELPdecoder”ThisrevisioncontainsallupdatessubmitteduptoandincludingthoseatStudyGroup16meetinginApril2006andsupersedestheG.728Implementors’Guideapproved2004-01.ThisdocumentwasapprovedbyITU-TStudyGroup16on13April2006.Implementors'GuideforITU-TG.728(2004-06)iiChangeLogRevisionDateDescription1.030January2004ApprovedbyITU-TStudyGroup16(TD57/PLEN)2.013April2006ApprovedbyITU-TStudyGroup16(TD255/PLEN)ContactinformationQuestion10/16RapporteurMsClaudeLamblinFranceTelecomR&D/DIHTechnopoleAnticipa2avenuePierreMarzin22307LANNIONCedexFranceTel:[phone]Fax:[phone]E-mail:[e-mail]'GuideforITU-TG.728(2004-06)iiiTableofContents1SCOPE.......................................................................................................................................................................12INTRODUCTION....................................................................................................................................................13DEFECTRESOLUTIONPROCEDURE..............................................................................................................14REFERENCES.........................................................................................................................................................25NOMENCLATURE.................................................................................................................................................26TECHNICALANDEDITORIALCORRECTIONS............................................................................................26.1ERRORINFIXED-POINTPSEUDOCODEFORBLOCK97FEOFG.728ANNEXI.......................................................26.2CORRECTIONTOTABLE2/G.728.........................................................................................................................36.316-BITSLIMITATIONOFADAPTIVEPOSTFILTEROUTPUT......................................................................................36.4CHECKWHETHERM2OUTOFRANGE..................................................................................................................46.5CORRECTIONOFTHEREFERENCEDEFINITIONFORMAXANDMINVALUES.......................................................47IMPLEMENTATIONCLARIFICATIONS..........................................................................................................4ANNEX:G.728DEFECTREPORTFORM..................................................................................................................5Implementors'GuideforITU-TG.728(2004-06)1IMPLEMENTORS’GUIDEFORITU-TG.728:“CODINGOFSPEECHAT16KBIT/SUSINGLD-CELP”1ScopeThisguideresolvesdefectsinG.728andaddressesthefollowingcategories:•editorialerrors•technicalerrors,suchasomissionsandinconsistencies•ambiguitiesInaddition,theImplementors'Guidemayincludeexplanatorytextfoundnecessaryasaresultofinterpretationdifficultiesapparentfromthedefectreports.ThisGuidewillnotaddressproposedadditions,deletions,ormodificationstotheRecommendationsthatarenotstrictlyrelatedtoimplementationdifficultiesintheabovecategories.ProposalsfornewfeaturesshouldbemadethroughcontributionstotheITU-T.ThisImplementors’GuidesupersedestheG.728Implementors’Guideapproved2004-01.2IntroductionITU-TRecommendationG.728definescodingofspeechat16kbit/susinglow-delaycodeexcitedlinearprediction(LD-CELP)andcomprisesthefollowingparts:−G.728(09/92)-Codingofspeechat16kbit/susinglow-delaycodeexcitedlinearprediction−G.728AnnexG(11/94)plusCorrigendum1(02/00)-16kbit/sfixedpointspecification−G.728AnnexH(05/99)-VariablebitrateLD-CELPoperationmainlyforDCMEatrateslessthan16kbit/s−G.728AnnexI(05/99)-FrameorpacketlossconcealmentfortheLD-CELPdecoderInforce−G.728AnnexJ(09/99)-Variablebit-rateoperationofLD-CELPmainlyforvoiceband-dataapplicationsinDCME−G.728AppendixI(07/95)-ProgramsandtestsequencesforimplementationverificationofthealgorithmoftheG.72816kbit/sLD-CELPspeechcoder−G.728AppendixII(11/95)-SpeechperformanceThisImplementors’GuideisacompilationofreporteddefectsforallversionsoftheITU-TG.728.InthiseditionoftheGuide,reporteddefectsidentifiedasof2004-01aregivenfor:−AnnexI-FrameorpacketlossconcealmentfortheLD-CELPdecoderTheGuidemustbereadinconjunctionwiththeRecommendationG.728,toserveasanadditionalsourceofinformationforimplementors.Thechanges,clarificationsandcorrectionsdefinedhereinareexpectedtobeincludedinfutureversionsoftheaffectedRecommendations.3DefectResolutionProcedureUpondiscoveringtechnicaldefectswithanycom