SIST EN 301 712 V7.4.1:2003

• Abstract:

  CR @ TSG#7

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.070.50 - Global System for Mobile Communication (GSM)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Mandate: T-172
• Ref Project: ETSI EN 301 712 V7.4.1 (2000-09) - Digital cellular telecommunications system (Phase 2+) (GSM); Adaptive Multi Rate (AMR) speech; ANSI-C code for the AMR speech codec (GSM 06.73 version 7.4.1 Release 1998)

Overview

SIST EN 301 712 V7.4.1:2003 is a Slovenian adaptation of the European standard EN 301 712, which specifies the ANSI-C source code for the Adaptive Multi-Rate (AMR) speech codec used in the Global System for Mobile Communications (GSM) Phase 2+ digital cellular telecommunications system. Published by the Slovenski inštitut za standardizacijo (SIST), this standard ensures a bit-exact, reference implementation of the AMR codec for reliable speech processing within GSM networks. It follows the technical specification outlined in GSM 06.73 version 7.4.1 (Release 1998).

This standard is vital for developers, manufacturers, and test laboratories that require a trusted, portable, and verifiable implementation of the AMR speech coding algorithm to guarantee interoperability and performance in GSM systems.

Key Topics

• AMR Speech Codec: Details the bit-exact ANSI-C implementation of the Adaptive Multi-Rate codec, an essential component for variable bitrate speech encoding in GSM.
• Portability & Verification: The C code adheres to ANSI-C99 for high portability and is verified on multiple platforms including UNIX, Linux, and PC architectures.
• Codec Structure: The specification describes the codec's modular structure including encoder, decoder, and supporting components for Voice Activity Detection (VAD), Discontinuous Transmission (DTX), and Comfort Noise Generation (CNG).
• File and Data Formats: Defines formats for speech files, mode control files, and bitstream files for input and output operations.
• Test and Homing Procedures: References standardized test sequences and homing frames for compliance testing and validation, allowing implementers to verify correct operation.
• Constants and Tables: Lists all global constants, tables, and fixed parameters required for codec operation, supporting accurate and consistent encoding/decoding.

Applications

The ANSI-C reference code provided by SIST EN 301 712 V7.4.1:2003 is primarily used in the following applications:

• GSM Network Equipment: Essential for GSM base stations, mobile switching centers, and network infrastructure to ensure compliant AMR speech transcoding and error handling.
• Mobile Device Development: Mobile device manufacturers use this standard to implement the AMR codec in handsets and chipsets, guaranteeing interoperability within GSM networks.
• Conformance Testing: Test labs and certification bodies employ the reference implementation as a baseline for validating proprietary AMR codec deployments.
• Research and Development: Academic and R&D organizations leverage the standard for developing enhancements, analyzing speech coding algorithms, and prototyping new voice services.
• Speech Quality Optimization: Enables the creation of robust error-resilient speech services with features like VAD, DTX, and CNG, improving speech quality in varying network conditions.

By following SIST EN 301 712, organizations and developers ensure that their AMR implementations are bit-exact and interoperable with international GSM systems, minimizing integration risks and reducing time-to-market for GSM-compliant devices and services.

Related Standards

Several standards are referenced within SIST EN 301 712 V7.4.1:2003 to provide comprehensive coverage of AMR codec application in GSM networks:

• GSM 06.90: Adaptive Multi-Rate speech transcoding specification
• GSM 06.91: Substitution and muting for lost frames in AMR speech channels
• GSM 06.92: Comfort noise generation techniques for AMR speech channels
• GSM 06.93: Discontinuous transmission for AMR speech traffic channels
• GSM 06.94: Voice Activity Detection (VAD) for AMR speech channels
• GSM 06.74: Test sequences relevant to AMR codec implementation validation
• GSM 01.04: Abbreviations and acronyms used across GSM standards

For further advancement and support in GSM and AMR codec development, these associated standards should be consulted in parallel with SIST EN 301 712 V7.4.1:2003.

Keywords: GSM, AMR speech codec, ANSI-C, digital cellular telecommunications, bit-exact implementation, standardization, speech encoding, SIST, ETSI, conformance testing.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digital cellular telecommunications system (Phase 2+) (GSM); Adaptive Multi Rate (AMR) speech; ANSI-C code for the AMR speech codec (GSM 06.73 version 7.4.1 Release 1998)33.070.50Globalni sistem za mobilno telekomunikacijo (GSM)Global System for Mobile Communication (GSM)ICS:Ta slovenski standard je istoveten z:EN 301 712 Version 7.4.1SIST EN 301 712 V7.4.1:2003en01-december-2003SIST EN 301 712 V7.4.1:2003SLOVENSKI
STANDARD
ETSIEN301712V7.4.1(2000-09)EuropeanStandard(Telecommunicationsseries)Digitalcellulartelecommunicationssystem(Phase2+);AdaptiveMultiRate(AMR)speech;ANSI-CcodefortheAMRspeechcodec(GSM06.73version7.4.1Release1998)GLOBALSYSTEMFORMOBILECOMMUNICATIONSRSIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)2(GSM06.73version7.4.1Release1998)ReferenceREN/TSGS-040673Q7R3KeywordsDigitalcellulartelecommunicationssystem,GlobalSystemforMobilecommunications(GSM)AMR,ANSICCodeETSI650RoutedesLuciolesF-06921SophiaAntipolisCedex-FRANCETel.:[phone]Fax:[phone]SiretN°34862356200017-NAF742CAssociationàbutnonlucratifenregistréeàlaSous-PréfecturedeGrasse(06)N°7803/88ImportantnoticeIndividualcopiesofthepresentdocumentcanbedownloadedfrom:http://www.etsi.orgThepresentdocumentmaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingorperceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).Incaseofdispute,thereferenceshallbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.Usersofthepresentdocumentshouldbeawarethatthedocumentmaybesubjecttorevisionorchangeofstatus.InformationonthecurrentstatusofthisandotherETSIdocumentsisavailableathttp://www.etsi.org/tb/status/Ifyoufinderrorsinthepresentdocument,sendyourcommentto:[e-mail]opartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)3(GSM06.73version7.4.1Release1998)ContentsIntellectualPropertyRights.4Foreword.41Scope.52References.53Definitionsandabbreviations.63.1Definitions.63.2Abbreviations.64Ccodestructure.64.1ContentsoftheCsourcecode.64.2Programexecution.74.3Codingstyle.74.4Codehierarchy.74.5Variables,constantsandtables.114.5.1DescriptionofconstantsusedintheC-code.114.5.2DescriptionoffixedtablesusedintheC-code.114.5.3StaticvariablesusedintheC-code.135Homingprocedure.176Fileformats.236.1Speechfile(encoderinput/decoderoutput).236.2Modecontrolfile(encoderinput).236.3Parameterbitstreamfile(encoderoutput/decoderinput).23AnnexA(informative):ChangeRequestHistory.24History.25SIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)4(GSM06.73version7.4.1Release1998)IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.TheinformationpertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefoundinETSISR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIinrespectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWebserver(http://www.etsi.org/ipr).PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.NoguaranteecanbegivenastotheexistenceofotherIPRsnotreferencedinETSISR000314(ortheupdatesontheETSIWebserver)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.ForewordThisEuropeanStandard(Telecommunicationsseries)hasbeenproducedbyETSITechnicalCommitteeSpecialMobileGroup(SMG).ThepresentdocumentprovidesthebitexactdefinitionoftheAdaptiveMultiRate(AMR)speechtrafficcodecforthedigitalcellulartelecommunicationssystem.ThepresentdocumentcontainsanelectroniccopyoftheANSI-CcodefortheGSMAdaptiveMulti-Ratecodec,givenintheassociatedfile"en_301712v070401o0.zip".TheANSI-CcodeisnecessaryforabitexactimplementationoftheAdaptiveMultiRatespeechtranscoder(GSM06.90[3]),VoiceActivityDetection(GSM06.94[7]),comfortnoise(GSM06.92[5]),DiscontinuousTransmission(GSM06.93[6])andexamplesolutionsforsubstitutingandmutingoflostframes(GSM06.91[4]).Theassociatedfile"en_301712v070401o0.zip"containsa"readme.txt"file,whichexplainstheprocedureforinstallationandusageoftheANSI-Ccodefiles.ThecontentsofthepresentdocumentissubjecttocontinuingworkwithinSMGandmaychangefollowingformalSMGapproval.ShouldSMGmodifythecontentsofthepresentdocumentitwillbere-releasedwithanidentifyingchangeofreleasedateandanincreaseinversionnumberasfollows:Version7.x.ywhere:7indicatesRelease1998ofGSMPhase2+.xtheseconddigitisincrementedforallchangesofsubstance,i.e.technicalenhancements,corrections,updates,etc.ythethirddigitisincrementedwheneditorialonlychangeshavebeenincorporatedinthespecification.NationaltranspositiondatesDateofadoptionofthepresentdocument:25August2000Dateoflatestannouncementofthepresentdocument(doa):30November2000DateoflatestpublicationofnewNationalStandardorendorsementofthepresentdocument(dop/e):31May2001DateofwithdrawalofanyconflictingNationalStandard(dow):31May2001SIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)5(GSM06.73version7.4.1Release1998)1ScopeThepresentdocumentcontainsanelectroniccopyoftheANSI-CcodefortheGSMAdaptiveMulti-Ratecodec.TheANSI-CcodeisnecessaryforabitexactimplementationoftheAdaptiveMultiRatespeechtranscoder(GSM06.90[3]),VoiceActivityDetection(GSM06.94[7]),comfortnoise(GSM06.92[5]),DiscontinuousTransmission(GSM06.93[6])andexamplesolutionsforsubstitutingandmutingoflostframes(GSM06.91[4]).2ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.• Referencesareeitherspecific(identifiedbydateofpublication,editionnumber,versionnumber,etc.)ornon-specific.• Foraspecificreference,subsequentrevisionsdonotapply.• Foranon-specificreference,thelatestversionapplies.• Anon-specificreferencetoanETSshallalsobetakentorefertolaterversionspublishedasanENwiththesamenumber.• ForthisRelease1998document,referencestoGSMdocumentsareforRelease1998versions(version7.x.y).[1]GSM01.04:"Digitalcellulartelecommunicationssystem(Phase2+);Abbreviationsandacronyms".[2]GSM06.74:"Digitalcellulartelecommunicationssystem(Phase2+);TestsequencesfortheGSMAdaptiveMulti-Rate(AMR)speechcodec".[3]GSM06.90:"Digitalcellulartelecommunicationssystem(Phase2+);AdaptiveMulti-Rate(AMR)speechtranscoding".[4]GSM06.91:"Digitalcellulartelecommunicationssystem(Phase2+);SubstitutionandmutingoflostframeforAdaptiveMulti-Rate(AMR)speechtrafficchannels".[5]GSM06.92:"Digitalcellulartelecommunicationssystem(Phase2+);ComfortnoiseaspectsforAdaptiveMulti-Rate(AMR)speechtrafficchannels".[6]GSM06.93:"Digitalcellulartelecommunicationssystem(Phase2+);Discontinuoustransmission(DTX)forAdaptiveMulti-Rate(AMR)speechtrafficchannels".[7]GSM06.94:"Digitalcellulartelecommunicationssystem(Phase2+);VoiceActivityDetector(VAD)forAdaptiveMulti-Rate(AMR)speechtrafficchannels".SIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)6(GSM06.73version7.4.1Release1998)3Definitionsandabbreviations3.1DefinitionsDefinitionoftermsusedinthepresentdocument,canbefoundinGSM06.90[3],GSM06.91[4],GSM06.92[5],GSM06.93[6]andGSM06.94[7].3.2AbbreviationsForthepurposesofthepresentdocument,thefollowingabbreviationsapply:ANSIAmericanNationalStandardsInstituteETSEuropeanTelecommunicationStandardGSMGlobalSystemforMobilecommunicationsI/OInput/OutputRAMRandomAccessMemoryROMReadOnlyMemoryForabbreviationsnotgiveninthissubclauseseeGSM01.04[1].4CcodestructureThisclausegivesanoverviewofthestructureofthebit-exactCcodeandprovidesanoverviewofthecontentsandorganizationoftheCcodeattachedtothepresentdocument.TheCcodehasbeenverifiedonthefollowingsystems:-SunMicrosystemsworkstationsandGNUgcccompiler.-DECAlphaworkstationsandGNUgcccompiler.-IBMPC/ATcompatiblecomputerswithLinuxoperatingsystemandGNUgcccompiler.ANSI-C9899wasselectedastheprogramminglanguagebecauseportabilitywasdesirable.4.1ContentsoftheCsourcecodeTheCcodedistributionhasallfilesintherootlevel.Thedistributedfileswithsuffix"c"containthesourcecodeandthefileswithsuffix"h"aretheheaderfiles.TheROMdataiscontainedmostlyinfileswithsuffix"tab".TheCcodedistributionalsocontainsonespeechcoderinstallationverificationdatafile,"spch_dos.inp".Thereferenceencoderoutputfileisnamed"spch_dos.cod",thereferencedecoderinputfileisnamed"spch_dos.dec"andthereferencedecoderoutputfileisnamed"spch_dos.out".ThesefourfilesareformattedsuchthattheyarecorrectforanIBMPC/ATcompatiblecomputer.Thesamefileswithreversedbyteorderofthe16bitwordsarenamed"spch_unx.inp","spch_unx.cod","spch_unx."dec"and"spch_unx.out",respectively.FinalverificationistobeperformedusingtheGSMAdaptiveMulti-RatetestsequencesdescribedinGSM06.74[2].MakefilesareprovidedfortheplatformsinwhichtheCcodehasbeenverified(listedabove).Oncethesoftwareisinstalled,thisdirectorywillhaveacompiledversionofencoderanddecoder(thebit-exactCexecutablesofthespeechcodec)andalltheobjectfiles.SIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)7(GSM06.73version7.4.1Release1998)4.2ProgramexecutionTheGSMAdaptiveMulti-Ratecodecisimplementedintwoprograms:-(encoder)speechencoder;-(decoder)speechdecoder.Theprogramsshouldbecalledlike:-encoder[encoderoptions];-decoder[decoderoptions].Thespeechfilescontain16-bitlinearencodedPCMspeechsamplesandtheparameterfilescontainencodedspeechdataandsomeadditionalflags.Theencoderanddecoderoptionswillbeexplainedbyrunningtheapplicationswithoption–h.Seethefilereadme.txtformoreinformationonhowtoruntheencoderanddecoderprograms.4.3CodingstyleTheCcodeiswrittenaccordingtothefollowingstructuringconventions.Eachfunctionfunc()thatneedsstaticvariablesisconsideredamodule.Amoduleconsistsof:-a'statestructure'(struct)combiningthestaticvariablesofthemodule;-threeauxiliaryfunctionsfunc_init(),func_reset(),andfunc_exit();-theprocessingfunctionfunc()itself.Theinitializationfunctionfunc_init()allocates(fromtheheap)anewstatestructure,callsthefunc_reset()function,storesthepointertothenewlyallocatedstructureinitsfirstfunctionparameter,andreturnswithavalueof0ifcompletedsuccessfuloravalueof1otherwise.Theresetfunctionfunc_reset()takesapointertothestatestructureandresetsallmembersofthestructuretoapredefinedvalue('homing').Theexitfunctionfunc_exit()performsanynecessarycleanupandfreesthestatestructurememory.Theprocessingfunctionfunc()alsotakesapointertothestatestructureaswellasallothernecessaryparametersandperformsitstaskusing(andpossiblymodifying)thevaluesinthestatestructure.Ifamodulecallsothermodules,thehigherlevelstatestructurecontainsapointertothelowerlevelstatestructures,andtheinit,reset,andexitfunctionsrecursivelycallthecorrespondinglowerlevelfunctions.Bythisconvention,thecodebecomes"instantiable"(morethanonecopyofamodulecanbeusedinthesameprogram)andthestaticdatahierarchyisclearlyvisibleinthecode.4.4CodehierarchyFigures1to4arecallgraphsthatshowthefunctionsusedinthespeechcodec,includingthefunctionsofVAD,DTX,andcomfortnoisegeneration.Eachcolumnrepresentsacalllevelandeachcellafunction.Thefunctionscontaincallstothefunctionsinrightwardsneighbouringcells.Thetimeorderinthecallgraphsisfromthetopdownwardsastheprocessingofaframeadvances.AllstandardCfunctions:printf(),fwrite(),etc.havebeenomitted.Also,nobasicoperations(add(),L_add(),mac(),etc.)ordoubleprecisionextendedoperations(e.g.L_Extract())appearinthegraphs.TheinitialisationofthestaticRAM(i.e.callingthe_initfunctions)isalsoomitted.Thebasicoperationsarenotcountedasextendingthedepth,thereforethedeepestlevelinthissoftwareislevel7.Theencodercallgraphisbrokendownintothreeseparatecallgraphs,tables1to3.SIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)8(GSM06.73version7.4.1Release1998)Table1:SpeechencodercallstructureSpeech_Encode_FramePre_Processcod_amrCopyVad11filter_bankfirst_filter_stagefilter5filter3level_calculationvad_decisioncomplex_estimate_adaptcomplex_vadnoise_estimate_updateupdate_cntrlhangover_additionVad21block_normr_fftc_fftfn10Log10Log2Log2_normPow2tx_dtx_handlerlpcAutocorrLag_windowLevinsonlspAz_lspChebpsQ_plsf_5Lsp_lsfLsf_wtVq_subvecVq_subvec_sReorder_lsfLsf_lspInt_lpc_1and3_2Lsp_azGet_lsp_polInt_lpc_1and3Lsp_azGet_lsp_polQ_plsf_3Lsp_lsfLsf_wtCopyVq_subvec3Vq_subvec4Reorder_lsfLsf_lspInt_lpc_1to3_2Lsp_azGet_lsp_polInt_lpc_1to3Lsp_azGet_lsp_polCopydtx_bufferCopyLog2Log2_normdtx_encLsp_lsfReorder_lsfLsf_lspSet_zerolsp_resetCopyQ_plsf_resetcl_ltp_resetPitch_fr_resetcheck_lsppre_bigWeight_AiResiduSyn_filtol_ltpPitch_olvad_tone_detection_update2Lag_maxvad_tone_detection2Inv_sqrtcomp_corr2hp_max2vad_complex_detection_update2Pitch_ol_wghcomp_corr2Lag_max2vad_tone_detection_update2vad_tone_detection2gmed_nhp_max2vad_complex_detection_update2vad_pitch_detectionLTP_flag_update3subframePreProcWeight_AiSyn_filtResiduCopycl_ltpPitch_frgetRangeNorm_CorrConvolveInv_sqrtsearchFracInterpol_3or6Enc_lag3Enc_lag6(continued)1OptiontocalloneortheotherVADoption2SpecifictoVADoption13SpecifictoVADoption2SIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)9(GSM06.73version7.4.1Release1998)Table1(concluded):SpeechencodercallstructurePred_lt_3or6ConvolveG_pitchcheck_gp_clippingq_gain_pitchcbsearchseeTable2gainQuantseeTable3update_gp_clippingCopysubframePostProcSyn_filtPred_lt_3or6ConvolvePrm2bitsInt2binTable2:cbsearchcallstructurecbsearchcode_2i40_9bitscor_h_xset_signcor_hInv_sqrtsearch_2i40build_codecode_2i40_11bitscor_h_xset_signcor_hInv_sqrtsearch_2i40build_codecode_3i40_14bitscor_h_xset_signcor_hInv_sqrtsearch_3i40build_codecode_4i40_17bitscor_h_xset_signcor_hInv_sqrtsearch_4i40build_codecode_8i40_31bitscor_h_xset_sign12k2Inv_sqrtcor_hInv_sqrtsearch_10and8i40build_codecompress_codecompress10code_10i40_35bitscor_h_xset_sign12k2Inv_sqrtcor_hInv_sqrtsearch_10and8i40build_codeq_pTable3:gainQuantcallstructuregainQuantgc_pred_copyCopygc_predLog2Log2_normLog2_normcalc_filt_energiescalc_target_energyMR475_update_unq_predgc_pred_updateMR475_gain_quantMR475_quant_store_resultsLog2Log2_normgc_pred_updategc_predLog2Log2_normLog2_normG_codeq_gain_codePow2MR795_gain_quantq_gain_pitchMR795_gain_code_quant3calc_unfilt_energiesLog2Log2_normgain_adaptgmed_nMR795_gain_code_quant_modsqrt_l_expQua_gainPow2gc_pred_updateSIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)10(GSM06.73version7.4.1Release1998)Table4:SpeechdecodercallstructureSpeech_Decode_FrameBits2prmBin2intDecoder_amrrx_dtx_handlerDecoder_amr_resetlsp_avg_resetD_plsf_resetec_gain_pitch_resetec_gain_code_resetgc_pred_resetBgn_scd_resetSet_zeroph_disp_resetdtx_dec_resetCopySet_zerodtx_decCopyLsf_lspInit_D_plsf_3CopyD_plsf_3Reorder_lsfCopyLsf_lsppseudonoiseLsp_lsfReorder_lsfLsp_AzGet_lsp_polA_ReflLog2Log2_normBuild_CN_codepseudonoiseSyn_filtLsf_lsplsp_avgCopyD_plsf_3Reorder_lsfCopyLsf_lspInt_lpc_1to3Lsp_AzGet_lsp_polD_plsf_5Reorder_lsfCopyLsf_lspInt_lpc_1and3Lsp_AzGet_lsp_polDec_lag3Pred_lt_3or6Dec_lag6decode_2i40_9bitsdecode_2i40_11bitsdecode_3i40_14bitsdecode_4i40_17bitsdecode_8i40_31bitsdecompress_codedecompress10ec_gain_pitchgmed_nd_gain_pitchec_gain_pitch_updatedecode_10i40_35bitsDec_gainLog2Log2_normgc_predLog2Log2_normLog2_normPow2gc_pred_updateec_gain_codegmed_ngc_pred_average_limetedgc_pred_updateec_gain_code_updated_gain_codegc_predLog2Log2_normLog2_normPow2gc_pred_updateInt_lsfCb_gain_averageph_disp_releaseph_disp_lockph_dispsqrt_l_expEx_ctrlgmed_nagc2Inv_sqrtSyn_filtBgn_scdgmed_ndtx_dec_activity_updateCopyLog2Log2_normlsp_avgPost_FilterCopyWeight_AiResiduSet_zeroSyn_filtPreemphasisagcenergy_oldenergy_newenergy_oldInv_sqrtPost_ProcessSIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)11(GSM06.73version7.4.1Release1998)4.5Variables,constantsandtablesThedatatypesofvariablesandtablesusedinthefixedpointimplementationaresignedintegersin2'scomplementrepresentation,definedby:-Word1616bitvariable;-Word3232bitvariable.Furthermoresomeenumtypesareused,allpossibletorepresentwithonebyte,andabooleanFlag.4.5.1DescriptionofconstantsusedintheC-codeThissectioncontainsalistingofallglobalconstantsdefinedincnst.h.Table5:GlobalconstantsConstantValueDescriptionL_TOTAL320totalsizeofspeechbuffer.L_WINDOW240windowsizeinLPanalysisL_FRAME160framesizeL_FRAME_BY280framesizedividedby2L_SUBFR40subframesizeL_CODE40codevectorlengthNB_TRACK5numberoftracksSTEP5codebookstepsizeNB_TRACK_MR1024numberoftracksmodemr102STEP_MR1024codebookstepsizemodemr102M10orderofLPfilterMP1(M+1)orderofLPfilter+1LSF_GAP205minimumdistancebetweenLSFafterquantization;50Hz=205LSP_PRED_FAC_MR12221299MR122LSPpredictionfactor(0.65Q15)AZ_SIZE44sizeofarrayofLPfiltersin4subframes(4*M+4)PIT_MIN_MR12218minimumpitchlag(MR122mode)PIT_MIN20minimumpitchlag(allothermodes)PIT_MAX143maximumpitchlagL_INTERPOL(10+1)lengthoffilterforinterpolationL_INTER_SRCH4lengthoffilterforCLLTPsearchinterpolationMU26214factorfortiltcompensationfilter0.8AGC_FAC29491factorforautomaticgaincontrol0.9L_NEXT40overheadinLPanalysisSHARPMAX13017maximumvalueofpitchsharpeningSHARPMIN0minimumvalueofpitchsharpeningMAX_PRM_SIZE57max.num.ofparamsMAX_SERIAL_SIZE244max.num.ofserialbitsGP_CLIP15565pitchgainclipping=0.95N_FRAME7oldpitchgainsinaveragecalculationEHF_MASK816bitrepresentationofallsamplesintheencoderhomingframe(leftjustification)4.5.2DescriptionoffixedtablesusedintheC-codeThissectioncontainsalistingofallfixedtablessortedbysourcefilenameandtablename.AlltabledataisdeclaredasWord16.SIST EN 301 712 V7.4.1:2003

ETSIETSIEN301712V7.4.1(2000-09)12(GSM06.73version7.4.1Release1998)Table6:FixedtablesFileTablenameLengthDescriptionc2_9pf.ctrackTable4*5tracktableforalgebraiccodebooksearch(MR475,MR515)cod_amr.cgamma110spectralexpansionfactorscod_amr.cgamma1_12k210spectralexpansionfactorscod_amr.cgamma210spectralexpansionfactorsdtx_dec.clsf_hist_mean_scale10initializationvaluesforDTXlsfparametersdtx_dec.cdtx_log_en_adjust9leveladjustmentsforechmodeec_gains.ccdown7attenuationfactorsforcodebookgainec_gains.cpdown7attenuationfactorsforadaptivecodebookgaingc_pred.cpred4algebraiccodebookgainMApredictorcoefficientsgc_pred.cpred_MR1224algebraiccodebookgainMApredictorcoefficients(MR122)pitch_fr.cmode_dep_parm72parametersdefiningtheadaptivecodebooksearchpermodepost_pro.ca3HPfiltercoefficients(denominator)inPost_Processpost_pro.cb3HPfiltercoefficients(numerator)inPost_Processpre_proc.ca3HPfiltercoefficients(denominator)inPre_Processpre_proc.cb3HPfiltercoefficients(numerator)inPre_Processpred_lt.cinter_661interpolationfiltercoefficientspstfilt.cgamma3_MR12210spectralexpansionfactorspstfilt.cgamma310spectralexpansionfactorspstfilt.cgamma4_MR12210spectralexpansionfactorspstfilt.cgamma410spectralexpansionfactorsbitno.tabprmno9numberofbitsforeachmodebitno.tabprmnofsf8numberofparametersforLPCandfirstsubframeforeachmode(usedfordecoderhomingprocedure)bitno.tabbitno9pointerstothebitno_MR.tablesbitno.tabbitno_MR47517numberofbitsperparametertotransmit(MR475)bitno.tabbitno_MR51519numberofbitsperparametertotransmit(MR515)bitno.tabbitno_MR5919numberofbitsperparametertotransmit(MR59)bitno.tabbitno_MR6719numberofbitsperparametertotransmit(MR67)bitno.tabbitno_MR7419numberofbitsperparametertotransmit(MR74)bitno.tabbitno_MR79523numberofbitsperparametertotransmit(MR795)bitno.tabbitno_MR10239numberofbitsperparametertotransmit(MR102)bitno.tabbitno_MR12257numberofbitsperparametertotransmit(MR122)bitno.tabbitno_MRDTX5numberofbitsperparametertotransmit(MRDTX)c2_11pf.tabstartPos12trackstartsearchpositionforfirstpulsec2_11pf.tabstartPos24trackstartsearchpositionforsecondpulsec2_9pf.tabstartPos16trackstartsearchpositioncorrwght.tabcorrweight251weightingofthecorrelationfunctioninopenloopLTPsearch(MR102)d_homing.tabdhf8pointerstothedhf_MR…tablesd_homing.tabdhf_MR47517parametervaluesforthedecoderhomingframe(MR475)d_homing.tabdhf_MR51519parametervaluesforthedecoderhomingframe(MR515)d_homing.tabdhf_MR5919parame
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