ETSI TS 126 073 V17.0.0 (2022-05)

Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; 5G; ANSI-C code for the Adaptive Multi Rate (AMR) speech codec (3GPP TS 26.073 version 17.0.0 Release 17)

RTS/TSGS-0426073vh00

General Information

• Status: Not Published
• Technical Committee: 3GPP SA 4 - Codec
• Current Stage: 12 - Completion
• Completion Date: 03-May-2022

Standards Content (Sample)

ETSI TS 126 073 V17.0.0 (2022-05)






TECHNICAL SPECIFICATION
Digital cellular telecommunications system (Phase 2+) (GSM);
Universal Mobile Telecommunications System (UMTS);
LTE;
5G;
ANSI-C code for the Adaptive Multi Rate (AMR) speech codec
(3GPP TS 26.073 version 17.0.0 Release 17)



---------------------- Page: 1 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 1 ETSI TS 126 073 V17.0.0 (2022-05)

Reference
RTS/TSGS-0426073vh00
Keywords
5G,GSM,LTE,UMTS
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - APE 7112B
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° w061004871

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
If you find a security vulnerability in the present document, please report it through our
Coordinated Vulnerability Disclosure Program:
https://www.etsi.org/standards/coordinated-vulnerability-disclosure
Notice of disclaimer & limitation of liability
The information provided in the present deliverable is directed solely to professionals who have the appropriate degree of
experience to understand and interpret its content in accordance with generally accepted engineering or
other professional standard and applicable regulations.
No recommendation as to products and services or vendors is made or should be implied.
No representation or warranty is made that this deliverable is technically accurate or sufficient or conforms to any law
rule and/or regulation and further, no representation or warranty is made of merchantability or fitness
and/or governmental
for any particular purpose or against infringement of intellectual property rights.
In no event shall ETSI be held liable for loss of profits or any other incidental or consequential damages.

Any software contained in this deliverable is provided "AS IS" with no warranties, express or implied, including but not
limited to, the warranties of merchantability, fitness for a particular purpose and non-infringement of intellectual property
rights and ETSI shall not be held liable in any event for any damages whatsoever (including, without limitation, damages
for loss of profits, business interruption, loss of information, or any other pecuniary loss) arising out of or related to the use
of or inability to use the software.
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2022.
All rights reserved.

ETSI

---------------------- Page: 2 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 2 ETSI TS 126 073 V17.0.0 (2022-05)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The declarations
pertaining to these essential IPRs, if any, are publicly available for ETSI members and non-members, and can be
found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to
ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the
ETSI Web server (https://ipr.etsi.org/).
Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,
including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not
referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become,
essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its

Members. 3GPP™ and LTE™ are trademarks of ETSI registered for the benefit of its Members and of the 3GPP
Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of the
®
oneM2M Partners. GSM and the GSM logo are trademarks registered and owned by the GSM Association.
Legal Notice
This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).
The present document may refer to technical specifications or reports using their 3GPP identities. These shall be
interpreted as being references to the corresponding ETSI deliverables.
The cross reference between 3GPP and ETSI identities can be found under http://webapp.etsi.org/key/queryform.asp.
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

---------------------- Page: 3 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 3 ETSI TS 126 073 V17.0.0 (2022-05)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 4
1 Scope . 5
2 References . 5
3 Definitions and abbreviations . 5
3.1 Definitions . 5
3.2 Abbreviations . 5
4 C code structure . 6
4.1 Contents of the C source code . 6
4.2 Program execution . 6
4.3 Coding style. 7
4.4 Code hierarchy . 7
4.5 Variables, constants and tables . 11
4.5.1 Description of constants used in the C-code . 11
4.5.2 Description of fixed tables used in the C-code . 11
4.5.3 Static variables used in the C-code . 13
5 Homing procedure . 18
6 File formats . 24
6.1 Speech file (encoder input / decoder output) . 24
6.2 Mode control file (encoder input) . 24
6.3 Parameter bitstream file (encoder output / decoder input) . 24
Annex A (informative): Change History . 26
History . 27

ETSI

---------------------- Page: 4 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 4 ETSI TS 126 073 V17.0.0 (2022-05)
Foreword
rd
This Technical Specification (TS) has been produced by the 3 Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.

ETSI

---------------------- Page: 5 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 5 ETSI TS 126 073 V17.0.0 (2022-05)
1 Scope
The present document contains an electronic copy of the ANSI-C code for the Adaptive Multi-Rate codec. The ANSI-C
code is necessary for a bit exact implementation of the Adaptive Multi Rate speech transcoder (TS 26.090 [2]), Voice
Activity Detection (TS 26.094 [6]), comfort noise (TS 26.092 [4]), source controlled rate operation (TS 26.093 [5]) and
example solutions for substituting and muting of lost frames (TS 26.091 [3]).
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies.
[1] 3GPP TS 26.074: "AMR Speech Codec; Test sequences".
[2] 3GPP TS 26.090: "AMR Speech Codec; Speech transcoding".
[3] 3GPP TS 26.091: "AMR Speech Codec; Substitution and muting of lost frames".
[4] 3GPP TS 26.092: "AMR Speech Codec; Comfort noise aspects".
[5] 3GPP TS 26.093: "AMR Speech Codec; Source controlled rate operation".
[6] 3GPP TS 26.094: "AMR Speech Codec; Voice Activity Detection".
[7] RFC 3267: "A Real-Time Transport Protocol (RTP) Payload Format and File Storage Format for
Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-WB) Audio Codecs",
June 2002.
3 Definitions and abbreviations
3.1 Definitions
Definition of terms used in the present document, can be found in TS 06.090 [2], TS 06.091 [3], TS 06.092 [4],
TS 06.093 [5] and TS 06.094 [6].
3.2 Abbreviations
For the purpose of the present document, the following abbreviations apply:
ANSI American National Standards Institute
ETS European Telecommunication Standard
GSM Global System for Mobile communications
I/O Input/Output
RAM Random Access Memory
ROM Read Only Memory
ETSI

---------------------- Page: 6 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 6 ETSI TS 126 073 V17.0.0 (2022-05)
4 C code structure
This clause gives an overview of the structure of the bit-exact C code and provides an overview of the contents and
organization of the C code attached to this document.
The C code has been verified on the following systems:
- Sun Microsystems workstations and GNU gcc compiler;
- DEC Alpha workstations and GNU gcc compiler;
- IBM PC/AT compatible computers with Linux operating system and GNU gcc compiler.
ANSI-C 9899 was selected as the programming language because portability was desirable.
4.1 Contents of the C source code
The C code distribution has all files in the root level.
The distributed files with suffix "c" contain the source code and the files with suffix "h" are the header files. The ROM
data is contained mostly in files with suffix "tab".
The C code distribution also contains one speech coder installation verification data file, "spch_dos.inp". The reference
encoder output file is named "spch_dos.cod", the reference decoder input file is named "spch_dos.dec" and the
reference decoder output file is named "spch_dos.out". These four files are formatted such that they are correct for an
IBM PC/AT compatible computer. The same files with reversed byte order of the 16 bit words are named
"spch_unx.inp", "spch_unx.cod", "spch_unx.dec" and "spch_unx.out", respectively.
Final verification is to be performed using the GSM Adaptive Multi-Rate test sequences described in GSM 06.74 [2].
Makefiles are provided for the platforms in which the C code has been verified (listed above). Once the software is
installed, this directory will have a compiled version of encoder and decoder (the bit-exact C executables of the speech
codec) and all the object files.
4.2 Program execution
The GSM Adaptive Multi-Rate codec is implemented in two programs:
- (encoder) speech encoder;
- (decoder) speech decoder.
The programs should be called like:
- encoder [encoder options] ;
- decoder [decoder options] .
The speech files contain 16-bit linear encoded PCM speech samples and the parameter files contain encoded speech
data and some additional flags.
The encoder and decoder options will be explained by running the applications with option –h. See the file readme.txt
for more information on how to run the encoder and decoder programs.
ETSI

---------------------- Page: 7 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 7 ETSI TS 126 073 V17.0.0 (2022-05)
4.3 Coding style
The C code is written according to the following structuring conventions. Each function func() that needs static
variables is considered a module. A module consists of:
- a 'state structure' (struct) combining the static variables of the module;
- three auxiliary functions func_init(), func_reset(), and func_exit();
- the processing function func() itself.
The initialization function func_init() allocates (from the heap) a new state structure, calls the func_reset() function,
stores the pointer to the newly allocated structure in its first function parameter, and returns with a value of 0 if
completed successful or a value of 1 otherwise.
The reset function func_reset() takes a pointer to the state structure and resets all members of the structure to a
predefined value ('homing').
The exit function func_exit() performs any necessary cleanup and frees the state structure memory.
The processing function func() also takes a pointer to the state structure as well as all other necessary parameters and
performs its task using (and possibly modifying) the values in the state structure.
If a module calls other modules, the higher level state structure contains a pointer to the lower level state structures, and
the init, reset, and exit functions recursively call the corresponding lower level functions.
By this convention, the code becomes "instantiable" (more than one copy of a module can be used in the same program)
and the static data hierarchy is clearly visible in the code.
4.4 Code hierarchy
Figures 1 to 4 are call graphs that show the functions used in the speech codec, including the functions of VAD, DTX,
and comfort noise generation.
Each column represents a call level and each cell a function. The functions contain calls to the functions in rightwards
neighbouring cells. The time order in the call graphs is from the top downwards as the processing of a frame advances.
All standard C functions: printf(), fwrite(), etc. have been omitted. Also, no basic operations (add(), L_add(), mac(),
etc.) or double precision extended operations (e.g. L_Extract()) appear in the graphs. The initialization of the static
RAM (i.e. calling the _init functions) is also omitted.
The basic operations are not counted as extending the depth, therefore the deepest level in this software is level 7.
The encoder call graph is broken down into three separate call graphs, Table 1 to 3.
ETSI

---------------------- Page: 8 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 8 ETSI TS 126 073 V17.0.0 (2022-05)
Table 1: Speech encoder call structure
Speech_Encode_Frame Pre_Process
cod_amr Copy
 1 filter_bank first_filter_stage
Vad1
  filter5
  filter3
  level_calculation
  vad_decision complex_estimate_adapt
  complex_vad
  noise_estimate_update update_cntrl
  hangover_addition
 1 block_norm
Vad2
  r_fft c_fft
  fn10Log10 Log2 Log2_norm
  Pow2
 tx_dtx_handler
 lpc Autocorr
  Lag_window
  Levinson
 lsp Az_lsp Chebps
  Q_plsf_5 Lsp_lsf
  Lsf_wt
  Vq_subvec
  Vq_subvec_s
  Reorder_lsf
  Lsf_lsp
  Int_lpc_1and3_2 Lsp_az Get_lsp_pol
  Int_lpc_1and3 Lsp_az Get_lsp_pol
  Q_plsf_3 Lsp_lsf
  Lsf_wt
  Copy
  Vq_subvec3
  Vq_subvec4
  Reorder_lsf
  Lsf_lsp
  Int_lpc_1to3_2 Lsp_az Get_lsp_pol
  Int_lpc_1to3 Lsp_az Get_lsp_pol
  Copy
 dtx_buffer Copy
  Log2 Log2_norm
 dtx_enc Lsp_lsf
  Reorder_lsf
  Lsf_lsp
 Set_zero
 lsp_reset Copy
  Q_plsf_reset
 cl_ltp_reset Pitch_fr_reset
 check_lsp
 pre_big Weight_Ai
  Residu
  Syn_filt
 ol_ltp Pitch_ol 2
vad_tone_detection_update
  Lag_max 2
vad_tone_detection
   Inv_sqrt
  2
comp_corr
  2
hp_max
  2
vad_complex_detection_update
  Pitch_ol_wgh 2
comp_corr
  2 2
Lag_max vad_tone_detection_update
   2
vad_tone_detection
  gmed_n
  2
hp_max
  2
vad_complex_detection_update
 vad_pitch_detection 3
LTP_flag_update
 subframePreProc Weight_Ai
  Syn_filt
  Residu
  Copy
 cl_ltp Pitch_fr getRange
  Norm_Corr Convolve
   Inv_sqrt
  searchFrac Interpol_3or6
  Enc_lag3
  Enc_lag6

(continued)


1 Option to call one or the other VAD option
2 Specific to VAD option 1
3 Specific to VAD option 2
ETSI

---------------------- Page: 9 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 9 ETSI TS 126 073 V17.0.0 (2022-05)
Table 1 (concluded): Speech encoder call structure
  Pred_lt_3or6
  Convolve
  G_pitch
  check_gp_clipping
  q_gain_pitch
 cbsearch see Table 2
 gainQuant see Table 3
 update_gp_clipping Copy
 subframePostProc Syn_filt
 Pred_lt_3or6
 Convolve
Prm2bits Int2bin

Table 2: cbsearch call structure
cbsearch code_2i40_9bits cor_h_x
 set_sign
 cor_h Inv_sqrt
 search_2i40
 build_code
code_2i40_11bits cor_h_x
 set_sign
 cor_h Inv_sqrt
 search_2i40
 build_code
code_3i40_14bits cor_h_x
 set_sign
 cor_h Inv_sqrt
 search_3i40
 build_code
code_4i40_17bits cor_h_x
 set_sign
 cor_h Inv_sqrt
 search_4i40
 build_code
code_8i40_31bits cor_h_x
 set_sign12k2 Inv_sqrt
 cor_h Inv_sqrt
 search_10and8i40
 build_code
 compress_code compress10
code_10i40_35bits cor_h_x
 set_sign12k2 Inv_sqrt
 cor_h Inv_sqrt
 search_10and8i40
 build_code
 q_p

Table 3: gainQuant call structure
gainQuant gc_pred_copy Copy
gc_pred Log2 Log2_norm
 Log2_norm
calc_filt_energies
calc_target_energy
MR475_update_unq_pred gc_pred_update
MR475_gain_quant MR475_quant_store_results Log2 Log2_norm
  gc_pred_update
 gc_pred Log2 Log2_norm
  Log2_norm
G_code
q_gain_code Pow2
MR795_gain_quant q_gain_pitch
 MR795_gain_code_quant3
 calc_unfilt_energies Log2 Log2_norm
 gain_adapt gmed_n
 MR795_gain_code_quant_mod sqrt_l_exp
Qua_gain Pow2
gc_pred_update

ETSI

---------------------- Page: 10 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 10 ETSI TS 126 073 V17.0.0 (2022-05)
Table 4: Speech decoder call structure
Speech_Decode_Frame Bits2prm Bin2int
Decoder_amr rx_dtx_handler
 Decoder_amr_reset lsp_avg_reset
  D_plsf_reset
  ec_gain_pitch_reset
  ec_gain_code_reset
  gc_pred_reset
  Bgn_scd_reset Set_zero
  ph_disp_reset
  dtx_dec_reset Copy
  Set_zero
 dtx_dec Copy
  Lsf_lsp
  Init_D_plsf_3 Copy
  D_plsf_3 Reorder_lsf
  Copy
  Lsf_lsp
  pseudonoise
  Lsp_lsf
  Reorder_lsf
  Lsp_Az Get_lsp_pol
  A_Refl
  Log2 Log2_norm
  Build_CN_code pseudonoise
  Syn_filt
 Lsf_lsp
 lsp_avg
 Copy
 D_plsf_3 Reorder_lsf
  Copy
  Lsf_lsp
 Int_lpc_1to3 Lsp_Az Get_lsp_pol
 D_plsf_5 Reorder_lsf
  Copy
  Lsf_lsp
 Int_lpc_1and3 Lsp_Az Get_lsp_pol
 Dec_lag3
 Pred_lt_3or6
 Dec_lag6
 decode_2i40_9bits
 decode_2i40_11bits
 decode_3i40_14bits
 decode_4i40_17bits
 decode_8i40_31bits decompress_code decompress10
 ec_gain_pitch gmed_n
 d_gain_pitch
 ec_gain_pitch_update
 decode_10i40_35bits
 Dec_gain Log2 Log2_norm
  gc_pred Log2 Log2_norm
  Log2_norm
  Pow2
  gc_pred_update
 ec_gain_code gmed_n
  gc_pred_average_limeted
  gc_pred_update
 ec_gain_code_update
 d_gain_code gc_pred Log2 Log2_norm
  Log2_norm
  Pow2
  gc_pred_update
 Int_lsf
 Cb_gain_average
 ph_disp_release
 ph_disp_lock
 ph_disp
 sqrt_l_exp
 Ex_ctrl gmed_n
 agc2 Inv_sqrt
 Syn_filt
 Bgn_scd gmed_n
 dtx_dec_activity_update Copy
  Log2 Log2_norm
 lsp_avg
Post_Filter Copy
 Weight_Ai
 Residu
 Set_zero
 Syn_filt
 Preemphasis
 agc energy_old
  energy_new energy_old
  Inv_sqrt
Post_Process

ETSI

---------------------- Page: 11 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 11 ETSI TS 126 073 V17.0.0 (2022-05)
4.5 Variables, constants and tables
The data types of variables and tables used in the fixed point implementation are signed integers in 2's complement
representation, defined by:
- Word16 16 bit variable;
- Word32 32 bit variable.
Furthermore some enum types are used, all possible to represent with one byte, and a Boolean Flag.
4.5.1 Description of constants used in the C-code
This subclause contains a listing of all global constants defined in cnst.h.
Table 5: Global constants
Constant Value Description
L_TOTAL 320 total size of speech buffer.
L_WINDOW 240 window size in LP analysis
L_FRAME 160 frame size
L_FRAME_BY2 80 frame size divided by 2
L_SUBFR 40 subframe size
L_CODE 40 codevector length
NB_TRACK 5 number of tracks
STEP 5 codebook step size
NB_TRACK_MR102 4 number of tracks mode mr102
STEP_MR102 4 codebook step size mode mr102
M 10 order of LP filter
MP1 (M+1) order of LP filter + 1
LSF_GAP 205 minimum distance between LSF after quantization; 50 Hz = 205
LSP_PRED_FAC_MR122 21299 MR122 LSP prediction factor (0.65 Q15)
AZ_SIZE 44 size of array of LP filters in 4 subframes (4*M+4)
PIT_MIN_MR122 18 minimum pitch lag (MR122 mode)
PIT_MIN 20 minimum pitch lag (all other modes)
PIT_MAX 143 maximum pitch lag
L_INTERPOL (10+1) length of filter for interpolation
L_INTER_SRCH 4 length of filter for CL LTP search interpolation
MU 26214 factor for tilt compensation filter 0,8
AGC_FAC 29491 factor for automatic gain control 0,9
L_NEXT 40 overhead in LP analysis
SHARPMAX 13017 maximum value of pitch sharpening
SHARPMIN 0 minimum value of pitch sharpening
MAX_PRM_SIZE 57 max. num. of params
MAX_SERIAL_SIZE 244 max. num. of serial bits
GP_CLIP 15565 pitch gain clipping = 0.95
N_FRAME 7 old pitch gains in average calculation
EHF_MASK 8 16 bit representation of all samples in the encoder homing frame (left
justification)

4.5.2 Description of fixed tables used in the C-code
This section contains a listing of all fixed tables sorted by source file name and table name. All table data is declared as
Word16.
ETSI

---------------------- Page: 12 ----------------------
3GPP TS 26.073 version 17.0.0 Release 17 12 ETSI TS 126 073 V17.0.0 (2022-05)
Table 6: Fixed tables
File Table name Length Description
c2_9pf.c trackTable 4*5 track table for algebraic code book search (MR475, MR515)
cod_amr.c gamma1 10 spectral expansion factors
cod_amr.c gamma1_12k2 10 spectral expansion factors
cod_amr.c gamma2 10 spectral expansion factors
dtx_dec.c lsf_hist_mean_scale 10 initialization values for DTX lsf parameters
dtx_dec.c dtx_log_en_adjust 9 level adjustments for ech mode
ec_gains.c cdown 7 attenuation factors for codebook gain
ec_gains.c pdown 7 attenuation factors for adaptive codebook gain
gc_pred.c pred 4 algebraic code book gain MA predictor coefficients
gc_pred.c pred_MR122 4 algebraic code book gain MA predictor coefficients (MR122)
pitch_fr.c mode_dep_parm 72 parameters defining the adaptive codebook search per mode
post_pro.c a 3 HP filter coefficients (denominator) in Post_Process
post_pro.c b 3 HP filter coefficients (numerator) in Post_Process
pre_proc.c a 3 HP filter coefficients (denominator) in Pre_Process
pre_proc.c b 3 HP filter coefficients (numerator) in Pre_Process
pred_lt.c inter_6 61 interpolation filter coefficients
pstfilt.c gamma3_MR122 10 spectral expansion factors
pstfilt.c gamma3 10 spectral expansion factors
pstfilt.c gamma4_MR122 10 spectral expansion factors
pstfilt.c gamma4 10 spectral expansion factors
bitno.tab prmno 9 number of bits for each mode
bitno.tab prmnofsf 8 number of parameters for LPC and first subframe for each mode (used for
decoder homing procedure)
bitno.tab bitno 9 pointers to the bitno_MR. tables
bitno.tab bitno_MR475 17 number of bits per parameter to transmit (MR475)
bitno.tab bitno_MR515 19 number of bits per parameter to transmit (MR515)
bitno.tab bitno_MR59 19 number of bits per parameter to transmit (MR59)
bitno.tab bitno_MR67 19 number of bits per parameter to transmit (MR67)
bitno.tab bitno_MR74 19 number of bits per parameter to transmit (MR74)
bitno.tab bitno_MR795 23 number of bits per parameter to transmit (MR795)
bitno.tab bitno_MR102 39 number of bits per parameter to transmit (MR102)
bitno.tab bitno_MR122 57 number of bits per parameter to transmit (MR122)
bitno.tab bitno_MRDTX 5 number of bits per parameter to transmit (MRDTX)
c2_11pf.tab startPos1 2 track start search position for first pulse
c2_11pf.tab startPos2 4 track start search position for second pulse
c2_9pf.tab startPos 16 track start search position
corrwght.tab corrweight 251 weighting of the correlation function in open loop LTP search (MR102)
d_homing.tab dhf 8 pointers to the dhf_MR… tables
d_homing.tab dhf_MR475 17 parameter values for the decoder homing frame (MR475)
d_homing.tab dhf_MR515 19 parameter values for the decoder homing frame (MR515)
d_homing.tab dhf_MR59 19 parameter values for the decoder homing frame (MR59)
d_homing.tab dhf_MR67 19 parameter values for the decoder homing frame (MR67)
d_homing.tab dhf_MR74 19 parameter values for the decoder homing frame (MR74)
d_homing.tab dhf_MR795 23 parameter values for the decoder homing frame (MR795)
d_homing.tab dhf_MR102 39 parameter val
...