SIST EN 301 712 V7.2.1:2003
(Main)Digital cellular telecommunications system (Phase 2+) (GSM); Adaptive Multi Rate (AMR) speech; ANSI-C code for the AMR speech codec (GSM 06.73 version 7.2.1 Release 1998)
- Abstract
Adaptive Multi- Rate (AMR) ANSI C Source code
- Status
- Published
- Publication Date
- 30-Nov-2003
- 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
SIST EN 301 712 V7.2.1:2003 is the Slovenian adoption of ETSI EN 301 712 Version 7.2.1. It provides the ANSI-C source code for the GSM Adaptive Multi-Rate (AMR) speech codec and the bit-exact reference used for codec implementation. Engineers, quality teams and integrators use it when they need the AMR encoder, decoder, VAD, comfort noise, DTX and lost-frame handling to behave exactly as specified.
What does SIST EN 301 712 V7.2.1:2003 specify?
SIST EN 301 712 V7.2.1:2003 specifies an electronic copy of the ANSI-C code for the AMR speech codec. In practice, it is the reference software package for bit-exact GSM AMR speech processing rather than a general description of the codec.
The document is organized into clauses for scope, references, definitions and abbreviations, C code structure, the homing procedure, and file formats. Annex A is informative and records the change request history.
| Annex | What it covers |
|---|---|
| Annex A | Change Request History |
What are the key requirements of SIST EN 301 712 V7.2.1:2003?
Clause 1 makes the ANSI-C code the reference for bit-exact AMR speech processing. That matters because the code is intended to match the defined behaviour of the AMR transcoder, VAD, comfort noise, DTX and lost-frame substitution and muting functions.
Clause 4 defines how the code is organized and how it is expected to run. The software is split into an encoder and a decoder, and the code structure uses a state structure plus init, reset, exit and processing functions for each module. For implementation work, this means the code is designed to be reusable, instantiable and easier to integrate into larger systems.
Clause 4 also states the data model used by the fixed-point implementation. Word16 and Word32 are signed two’s-complement types, and the code uses fixed tables, constants and static state variables to preserve bit-exact behaviour. This matters when porting the code to another platform, because numeric types and state handling affect exact output.
Clause 4.1 and 4.2 describe the software package and execution model. The distributed files include source, header and table files, plus verification files and Makefiles for verified platforms. The encoder and decoder are called as separate programs, with a speech input file and parameter file for encoding, and a parameter file and speech output file for decoding.
Clause 5 defines the homing procedure for the decoder. The document gives detailed decoder homing frames for all eight AMR codec modes, with fixed parameter values in tables 9a to 9h. In practice, this is the reset and validation mechanism used to bring a decoder to a known state.
Clause 6 defines the file formats used by the encoder and decoder. Speech files carry 16-bit words with 13-bit left-aligned samples, and the bitstream format includes FRAME_TYPE, codec bits and MODE_INFO fields. This is the part that helps test tools and host software exchange AMR data correctly.
Clause 2 points to the companion GSM documents needed to understand the code and its test context, including the AMR transcoding, VAD, DTX, comfort noise, lost-frame handling and test sequences.
What terms does SIST EN 301 712 V7.2.1:2003 define?
- Adaptive Multi-Rate (AMR) - the speech codec family covered by the document.
- Voice Activity Detection (VAD) - logic that decides whether speech is present.
- Discontinuous Transmission (DTX) - a mode that stops sending speech frames during silence periods.
- I/O - Input/Output, used for file and program handling.
- RAM - Random Access Memory, the working memory used by the implementation.
- ROM - Read Only Memory, where fixed data tables may be stored.
- GSM - Global System for Mobile communications, the cellular system context for the codec.
Who uses SIST EN 301 712 V7.2.1:2003?
This standard is used by codec software developers, telecom equipment suppliers, interoperability test labs and QA teams working on GSM speech systems. It is also relevant to integrators and technical buyers who need to confirm that an implementation, test set or software library matches the bit-exact AMR reference behaviour.
What changed in SIST EN 301 712 V7.2.1:2003 from the previous edition?
Annex A records the changes leading to this version, including the introduction of code homing procedures and several bit-exact corrections. The history mentions updates to AGC gain calculation, bitstream output file format, Levinson algorithm behaviour, LSP initialisation, DTX and VAD descriptions, decoder static variables, decoder synthesis filter stability protection, input buffer initialisation, algebraic code vector generation and gain quantisation.
Which standards are used with SIST EN 301 712 V7.2.1:2003?
Clause 2 cites the companion GSM documents used with this code package:
- GSM 01.04 - abbreviations and acronyms.
- GSM 06.74 - test sequences for the AMR speech codec.
- GSM 06.90 - AMR speech transcoding.
- GSM 06.91 - substitution and muting of lost frames.
- GSM 06.92 - comfort noise aspects.
- GSM 06.93 - DTX for AMR speech traffic channels.
- GSM 06.94 - VAD for AMR speech traffic channels.
These references provide the algorithmic definitions, test sequences and related functions that the ANSI-C code implements.
What does the SIST EN 301 712 V7.2.1:2003 document contain?
The document contains call graphs for the encoder and decoder, plus tables for constants, fixed tables and static variables. It also includes the file formats for speech files, mode control files and parameter bitstream files, which are the practical interchange formats used in testing and implementation.
For decoder validation, the homing procedure section gives the exact parameter sets for each AMR mode. For software verification, the document points to GSM 06.74 test sequences and to the bundled reference files used to compare encoder and decoder results.
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Frequently Asked Questions
SIST EN 301 712 V7.2.1:2003 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Digital cellular telecommunications system (Phase 2+) (GSM); Adaptive Multi Rate (AMR) speech; ANSI-C code for the AMR speech codec (GSM 06.73 version 7.2.1 Release 1998)". This standard covers: Adaptive Multi- Rate (AMR) ANSI C Source code
Adaptive Multi- Rate (AMR) ANSI C Source code
SIST EN 301 712 V7.2.1:2003 is classified under the following ICS (International Classification for Standards) categories: 33.070.50 - Global System for Mobile Communication (GSM). The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 301 712 V7.2.1:2003 is associated with the following European legislation: Standardization Mandates: T-172. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
SIST EN 301 712 V7.2.1:2003 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
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 7.2.1 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 7.2.1SIST EN 301 712 V7.2.1:2003en01-december-2003SIST EN 301 712 V7.2.1:2003SLOVENSKI
STANDARD
ETSIEN301712V7.2.1(2000-04)EuropeanStandard(Telecommunicationsseries)Digitalcellulartelecommunicationssystem(Phase2+);AdaptiveMultiRate(AMR)speech;ANSI-CcodefortheAMRspeechcodec(GSM06.73version7.2.1Release1998)GLOBALSYSTEMFORMOBILECOMMUNICATIONSRSIST EN 301 712 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)2(GSM06.73version7.2.1Release1998)ReferenceREN/SMG-110673Q7R1KeywordsDigitalcellulartelecommunicationssystem,GlobalSystemforMobilecommunications(GSM)AMR,ANSICCodeETSI650RoutedesLuciolesF-06921SophiaAntipolisCedex-FRANCETel.:+33492944200Fax:+33493654716SiretN°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:editor@etsi.frCopyrightNotificationNopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST EN 301 712 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)3(GSM06.73version7.2.1Release1998)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.124.5.3StaticvariablesusedintheC-code.145Homingprocedure.176Fileformats.236.1Speechfile(encoderinput/decoderoutput).236.2Modecontrolfile(encoderinput).236.3Parameterbitstreamfile(encoderoutput/decoderinput).23AnnexA(informative):ChangeRequestHistory.24History.25SIST EN 301 712 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)4(GSM06.73version7.2.1Release1998)IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.TheinformationpertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefoundinSR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIinrespectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWebserver(http://www.etsi.org/ipr).PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.NoguaranteecanbegivenastotheexistenceofotherIPRsnotreferencedinSR000314(ortheupdatesontheETSIWebserver)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.ForewordThisEuropeanStandard(Telecommunicationsseries)hasbeenproducedbytheSpecialMobileGroup(SMG).ThepresentdocumentprovidesthebitexactdefinitionoftheAdaptiveMultiRate(AMR)speechtrafficcodecforthedigitalcellulartelecommunicationssystem.ThepresentdocumentcontainsanelectroniccopyoftheANSI-CcodefortheGSMAdaptiveMulti-Ratecodec,givenintheassociatedfile"en_301712v070201p0.zip".TheANSI-CcodeisnecessaryforabitexactimplementationoftheAdaptiveMultiRatespeechtranscoder(GSM06.90[3]),VoiceActivityDetection(GSM06.94[7]),comfortnoise(GSM06.92[5]),DiscontinuousTransmission(GSM06.93[6])andexamplesolutionsforsubstitutingandmutingoflostframes(GSM06.91[4]).Theassociatedfile"en_301712v070201p0.zip"containsa"readme.txt"file,whichexplainstheprocedureforinstallationandusageoftheANSI-Ccodefiles.ThecontentsofthepresentdocumentissubjecttocontinuingworkwithinSMGandmaychangefollowingformalSMGapproval.ShouldSMGmodifythecontentsofthepresentdocumentitwillbere-releasedwithanidentifyingchangeofreleasedateandanincreaseinversionnumberasfollows:Version7.x.ywhere:7indicatesRelease1998ofGSMPhase2+.xtheseconddigitisincrementedforallchangesofsubstance,i.e.technicalenhancements,corrections,updates,etc.ythethirddigitisincrementedwheneditorialonlychangeshavebeenincorporatedinthespecification.NationaltranspositiondatesDateofadoptionofthisEN:31March2000DateoflatestannouncementofthisEN(doa):30June2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):31December2000DateofwithdrawalofanyconflictingNationalStandard(dow):31December2000SIST EN 301 712 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)5(GSM06.73version7.2.1Release1998)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 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)6(GSM06.73version7.2.1Release1998)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-exactCcodeandprovidesanoverviewofthecontentsandorganizationoftheCcodeattachedtothisdocument.TheCcodehasbeenverifiedonthefollowingsystems:-SunMicrosystemsworkstationsandGNUgcccompiler;-DECAlphaworkstationsandGNUgcccompiler;-IBMPC/ATcompatiblecomputerswithLinuxoperatingsystemandGNUgcccompiler;ANSI-C9899wasselectedastheprogramminglanguagebecauseportabilitywasdesirable4.1ContentsoftheCsourcecodeTheCcodedistrubutionhasallfilesintherootlevel.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 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)7(GSM06.73version7.2.1Release1998)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()itselfTheinitializationfunctionfunc_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.Thefunctionscontaincallstothefunctionsinrightwardsneighboringcells.Thetimeorderinthecallgraphsisfromthetopdownwardsastheprocessingofaframeadvances.AllstandardCfunctions:printf(),fwrite(),etc.havebeenomitted.Also,nobasicoperations(add(),L_add(),mac(),etc.)ordoubleprecisionextendedoperations(e.g.L_Extract())appearinthegraphs.TheinitializationofthestaticRAM(i.e.callingthe_initfunctions)isalsoomitted.Thebasicoperationsarenotcountedasextendingthedepth,thereforethedeepestlevelinthissoftwareislevel7.Theencodercallgraphisbrokendownintothreeseparatecallgraphs,Table1to3.SIST EN 301 712 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)8(GSM06.73version7.2.1Release1998)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 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)9(GSM06.73version7.2.1Release1998)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 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)10(GSM06.73version7.2.1Release1998)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 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)11(GSM06.73version7.2.1Release1998)4.5Variables,constantsandtablesThedatatypesofvariablesandtablesusedinthefixedpointimplementationaresignedintegersin2’scomplementrepresentation,definedby:Word1616bitvariableWord3232bitvariableFurthermoresomeenumtypesareused,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)SIST EN 301 712 V7.2.1:2003
ETSIETSIEN301712V7.2.1(2000-04)12(GSM06.73version7.2.1Release1998)4.5.2DescriptionoffixedtablesusedintheC-codeThissectioncontainsalistingofallfixedtablessortedbysourcefilenameandtablename.AlltabledataisdeclaredasWord16.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.tabd
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