freeswitch/libs/spandsp/spandsp-sim/make_line_models.c

/*
 * SpanDSP - a series of DSP components for telephony
 *
 * make_line_models.c
 *
 * Written by Steve Underwood <steveu@coppice.org>
 *
 * Copyright (C) 2004 Steve Underwood
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*! \page make_line_models_page Telephony line model construction
\section make_line_models_page_sec_1 What does it do?
???.

\section make_line_models_page_sec_2 How does it work?
???.
*/

#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif

#include <stdlib.h>
#include <unistd.h>
#include <inttypes.h>
#include <string.h>
#include <stdio.h>
#if defined(HAVE_FFTW3_H)
#include <fftw3.h>
#else
#include <fftw.h>
#endif
#include <math.h>
#if defined(HAVE_STDBOOL_H)
#include <stdbool.h>
#else
#include "spandsp/stdbool.h"
#endif

#include "spandsp.h"

#if !defined(M_PI)
# define M_PI           3.14159265358979323846  /* pi */
#endif

#define LINE_MODEL_FILE_NAME    "line_models.c"

#define SAMPLE_RATE             8000

#define LINE_FILTER_SIZE        129
#define FFT_SIZE                1024

/* Tabulated medium range telephone line response
   (from p 537, Digital Communication, John G. Proakis */
/*
    amp 1.0 -> 2.15, freq = 3000 Hz -> 3.2, by 0.2 increments
    delay = 4 ms -> 2.2
 */

struct
{
    int frequency;
    float amp;
    float delay;
} proakis[] =
{
    {   0, 0.00,  4.80},
    { 200, 0.90,  3.50},
    { 400, 1.40,  2.20},
    { 600, 1.80,  0.90},
    { 800, 2.00,  0.50},
    {1000, 2.10,  0.25},
    {1200, 2.30,  0.10},
    {1400, 2.30,  0.05},
    {1600, 2.20,  0.00},
    {1800, 2.10,  0.00},
    {2000, 2.00,  0.00},
    {2200, 1.85,  0.05},
    {2400, 1.75,  0.10},
    {2600, 1.55,  0.20},
    {2800, 1.30,  0.40},
    {3000, 1.10,  0.50},
    {3200, 0.80,  0.90},
    {3400, 0.55,  1.20},
    {3600, 0.25,  2.20},
    {3800, 0.05,  3.20},
    {4000, 0.05,  4.20},
    {4200, 0.05,  5.20}
};

#define CPE_TO_CO_ATTENUATION       0       /* In dB */
#define CPE_TO_CO_DELAY             1       /* In us */
#define CPE_TO_CO_IMPEDANCE         2       /* In ohms */
#define CPE_TO_CO_PHASE             3       /* In degrees */
#define CO_TO_CPE_IMPEDANCE         4       /* In ohms */
#define CO_TO_CPE_PHASE             5       /* In degrees */
#define CO_TO_CPE_ATTENUATION       6       /* In dB */
#define CO_TO_CPE_DELAY             7       /* In us */

/* Terms used, for V.56bis:
    AD = attenuation distortion
    EDD = envelope delay distortion */

/* V.56bis EIA LL-1, non-loaded loop */

struct
{
    int freq;
    float ad[8];
} eia_ll1[] =
{
    { 200,    {0.0,    0.4,    767,     -1.4,    767,     -1.4,    0.0,    0.4}},
    { 300,    {0.0,    0.7,    766,     -2.0,    766,     -2.0,    0.0,    0.7}},
    { 400,    {0.0,    0.5,    763,     -2.8,    763,     -2.8,    0.0,    0.5}},
    { 500,    {0.0,    0.6,    765,     -3.4,    765,     -3.4,    0.0,    0.6}},
    { 600,    {0.0,    0.2,    764,     -4.1,    764,     -4.1,    0.0,    0.2}},
    { 700,    {0.0,    0.4,    764,     -4.7,    764,     -4.7,    0.0,    0.4}},
    { 800,    {0.0,    0.4,    762,     -5.4,    762,     -5.4,    0.0,    0.4}},
    { 900,    {0.0,    0.2,    762,     -6.0,    762,     -6.0,    0.0,    0.2}},
    {1000,    {1.2,    0.5,    761,     -6.7,    761,     -6.7,    1.2,    0.5}},
    {1100,    {0.0,    0.6,    759,     -7.4,    759,     -7.4,    0.0,    0.6}},
    {1200,    {0.0,    0.4,    757,     -8.1,    757,     -8.1,    0.0,    0.4}},
    {1300,    {0.0,    0.1,    757,     -8.6,    757,     -8.6,    0.0,    0.1}},
    {1400,    {0.0,    0.3,    755,     -9.3,    755,     -9.3,    0.0,    0.3}},
    {1500,    {0.0,    0.4,    753,    -10.0,    753,    -10.0,    0.0,    0.4}},
    {1600,    {0.0,    0.3,    751,    -10.7,    751,    -10.7,    0.0,    0.3}},
    {1700,    {0.0,    0.1,    748,    -11.3,    748,    -11.3,    0.0,    0.1}},
    {1800,    {0.0,   11.0,    748,    -11.9,    748,    -11.9,    0.0,   11.0}},
    {1900,    {0.1,    0.1,    745,    -12.5,    745,    -12.5,    0.1,    0.1}},
    {2000,    {0.1,    0.3,    743,    -13.9,    743,    -13.9,    0.1,    0.3}},
    {2100,    {0.1,    0.3,    740,    -13.9,    740,    -13.9,    0.1,    0.3}},
    {2200,    {0.1,    0.3,    737,    -14.5,    737,    -14.5,    0.1,    0.3}},
    {2300,    {0.1,    0.3,    734,    -15.2,    734,    -15.2,    0.1,    0.3}},
    {2400,    {0.1,    0.2,    731,    -15.8,    731,    -15.8,    0.1,    0.2}},
    {2500,    {0.1,    0.0,    728,    -16.4,    728,    -16.4,    0.1,    0.0}},
    {2600,    {0.1,    0.0,    729,    -16.8,    729,    -16.8,    0.1,    0.0}},
    {2700,    {0.2,    0.1,    726,    -17.4,    726,    -17.4,    0.2,    0.1}},
    {2800,    {0.2,    0.2,    722,    -18.0,    722,    -18.0,    0.2,    0.2}},
    {2900,    {0.2,    0.3,    719,    -18.6,    719,    -18.6,    0.2,    0.3}},
    {3000,    {0.2,    0.4,    715,    -19.3,    715,    -19.3,    0.2,    0.4}},
    {3100,    {0.2,    0.4,    712,    -19.9,    712,    -19.9,    0.2,    0.4}},
    {3200,    {0.2,    0.5,    708,    -20.5,    708,    -20.5,    0.2,    0.5}},
    {3300,    {0.2,    0.5,    704,    -21.1,    704,    -21.1,    0.2,    0.5}},
    {3400,    {0.2,    0.5,    700,    -21.7,    700,    -21.7,    0.2,    0.5}},
    {3500,    {0.2,    0.5,    696,    -22.3,    696,    -22.3,    0.2,    0.5}},
    {3600,    {0.2,    0.4,    692,    -22.9,    692,    -22.9,    0.2,    0.4}},
    {3700,    {0.2,    0.3,    688,    -23.5,    688,    -23.5,    0.2,    0.3}},
    {3800,    {0.2,    0.2,    684,    -24.1,    684,    -24.1,    0.2,    0.2}},
    {3900,    {0.2,    0.1,    680,    -24.7,    680,    -24.7,    0.2,    0.1}},
    {4000,    {0.2,   -0.1,    676,    -25.2,    676,    -25.2,    0.2,   -0.1}}
};

/* V.56bis EIA LL-2, non-loaded loop */

struct
{
    int freq;
    float ad[8];
} eia_ll2[] =
{
    { 200,   {-0.2,    6.6,   1086,     -4.9,   1085,     -5.6,   -0.2,    6.6}},
    { 300,   {-0.2,    7.7,   1079,     -7.3,   1077,     -8.3,   -0.2,    7.7}},
    { 400,   {-0.2,    6.7,   1062,     -9.9,   1058,    -11.2,   -0.2,    6.7}},
    { 500,   {-0.2,    7.1,   1059,    -12.0,   1053,    -13.6,   -0.2,    7.1}},
    { 600,   {-0.1,    5.2,   1041,    -14.4,   1034,    -16.3,   -0.1,    5.2}},
    { 700,   {-0.1,    5.8,   1030,    -16.5,   1020,    -18.6,   -0.1,    5.8}},
    { 800,   {-0.1,    5.4,   1010,    -18.7,    998,    -21.0,   -0.1,    5.4}},
    { 900,   { 0.0,    4.5,    997,    -20.5,    982,    -23.1,    0.0,    4.5}},
    {1000,   { 3.2,    5.1,    976,    -22.5,    959,    -25.3,    3.2,    5.1}},
    {1100,   { 0.1,    5.0,    954,    -24.5,    934,    -27.4,    0.1,    5.0}},
    {1200,   { 0.1,    4.0,    931,    -26.2,    909,    -29.4,    0.1,    4.0}},
    {1300,   { 0.2,    2.7,    918,    -27.6,    894,    -30.9,    0.2,    2.7}},
    {1400,   { 0.2,    2.8,    897,    -29.2,    871,    -32.6,    0.2,    2.8}},
    {1500,   { 0.3,    2.6,    874,    -30.7,    847,    -34.3,    0.3,    2.6}},
    {1600,   { 0.3,    2.0,    852,    -32.1,    823,    -35.8,    0.3,    2.0}},
    {1700,   { 0.4,    0.9,    831,    -33.4,    800,    -37.2,    0.4,    0.9}},
    {1800,   { 0.5,   40.8,    816,    -34.4,    783,    -38.4,    0.5,   40.8}},
    {1900,   { 0.6,    0.0,    796,    -35.6,    762,    -39.6,    0.6,    0.0}},
    {2000,   { 0.6,   -0.2,    776,    -36.6,    741,    -40.7,    0.6,   -0.2}},
    {2100,   { 0.7,   -0.6,    756,    -37.6,    720,    -41.8,    0.7,   -0.6}},
    {2200,   { 0.8,   -1.1,    737,    -38.6,    700,    -42.9,    0.8,   -1.1}},
    {2300,   { 0.9,   -1.8,    719,    -39.4,    681,    -43.8,    0.9,   -1.8}},
    {2400,   { 1.0,   -2.6,    701,    -40.2,    663,    -44.7,    1.0,   -2.6}},
    {2500,   { 1.0,   -3.7,    684,    -41.0,    646,    -45.5,    1.0,   -3.7}},
    {2600,   { 1.1,   -4.1,    678,    -41.3,    639,    -45.9,    1.1,   -4.1}},
    {2700,   { 1.2,   -4.3,    663,    -42.0,    623,    -46.6,    1.2,   -4.3}},
    {2800,   { 1.3,   -4.5,    647,    -42.6,    607,    -47.3,    1.3,   -4.5}},
    {2900,   { 1.4,   -4.8,    632,    -43.1,    591,    -47.9,    1.4,   -4.8}},
    {3000,   { 1.5,   -5.2,    617,    -43.6,    576,    -48.4,    1.5,   -5.2}},
    {3100,   { 1.6,   -5.6,    603,    -44.1,    562,    -49.0,    1.6,   -5.6}},
    {3200,   { 1.7,   -6.0,    589,    -44.5,    548,    -49.5,    1.7,   -6.0}},
    {3300,   { 1.8,   -6.5,    576,    -44.9,    535,    -49.9,    1.8,   -6.5}},
    {3400,   { 1.9,   -7.1,    563,    -45.3,    522,    -50.3,    1.9,   -7.1}},
    {3500,   { 2.0,   -7.7,    551,    -45.6,    509,    -50.7,    2.0,   -7.7}},
    {3600,   { 2.1,   -8.4,    539,    -45.9,    498,    -51.0,    2.1,   -8.4}},
    {3700,   { 2.2,   -9.1,    528,    -46.2,    486,    -51.3,    2.2,   -9.1}},
    {3800,   { 2.3,   -9.9,    518,    -46.4,    476,    -51.6,    2.3,   -9.9}},
    {3900,   { 2.4,  -10.6,    507,    -46.6,    466,    -51.9,    2.4,  -10.6}},
    {4000,   { 2.5,  -11.5,    498,    -46.8,    456,    -52.1,    2.5,  -11.5}}
};

/* V.56bis EIA LL-3, non-loaded loop */

struct
{
    int freq;
    float ad[8];
} eia_ll3[] =
{
    { 200,   {-0.3,   10.5,   1176,     -5.9,   1173,     -7.4,   -0.3,   10.5}},
    { 300,   {-0.3,   11.5,   1165,     -8.8,   1159,    -11.0,   -0.3,   11.5}},
    { 400,   {-0.3,   10.6,   1140,    -11.8,   1130,    -14.7,   -0.3,   10.6}},
    { 500,   {-0.3,   11.0,   1133,    -14.3,   1117,    -17.8,   -0.3,   11.0}},
    { 600,   {-0.2,    8.5,   1108,    -17.1,   1086,    -21.2,   -0.2,    8.5}},
    { 700,   {-0.2,    8.5,   1090,    -19.4,   1062,    -24.0,   -0.2,    8.5}},
    { 800,   {-0.1,    8.4,   1062,    -21.9,   1029,    -27.0,   -0.1,    8.4}},
    { 900,   { 0.0,    7.1,   1042,    -23.9,   1003,    -29.4,    0.0,    7.1}},
    {1000,   { 3.8,    7.7,   1013,    -23.0,    969,    -31.9,    3.8,    7.7}},
    {1100,   { 0.1,    7.4,    982,    -28.1,    934,    -34.3,    0.1,    7.4}},
    {1200,   { 0.1,    6.0,    953,    -29.9,    900,    -36.5,    0.1,    6.0}},
    {1300,   { 0.2,    4.2,    935,    -31.3,    878,    -38.1,    0.2,    4.2}},
    {1400,   { 0.3,    4.2,    907,    -32.8,    847,    -40.0,    0.3,    4.2}},
    {1500,   { 0.4,    3.7,    880,    -34.3,    817,    -41.7,    0.4,    3.7}},
    {1600,   { 0.5,    2.7,    853,    -35.6,    787,    -43.2,    0.5,    2.7}},
    {1700,   { 0.6,    1.2,    827,    -36.8,    760,    -44.6,    0.6,    1.2}},
    {1800,   { 0.7,   48.7,    809,    -37.8,    739,    -45.8,    0.7,   48.7}},
    {1900,   { 0.8,   -0.2,    785,    -38.8,    715,    -47.0,    0.8,   -0.2}},
    {2000,   { 0.9,   -0.7,    763,    -39.7,    691,    -48.0,    0.9,   -0.7}},
    {2100,   { 1.0,   -1.3,    741,    -40.5,    668,    -49.1,    1.0,   -1.3}},
    {2200,   { 1.1,   -2.1,    719,    -41.3,    647,    -50.0,    1.1,   -2.1}},
    {2300,   { 1.2,   -2.1,    699,    -42.0,    625,    -50.8,    1.2,   -2.1}},
    {2400,   { 1.2,   -4.3,    680,    -42.6,    606,    -51.6,    1.2,   -4.3}},
    {2500,   { 1.3,   -5.6,    663,    -43.2,    588,    -52.3,    1.3,   -5.6}},
    {2600,   { 1.6,   -6.2,    656,    -43.4,    581,    -52.7,    1.6,   -6.2}},
    {2700,   { 1.7,   -6.6,    640,    -43.9,    564,    -53.3,    1.7,   -6.6}},
    {2800,   { 1.8,   -7.0,    624,    -44.3,    548,    -53.9,    1.8,   -7.0}},
    {2900,   { 1.9,   -7.5,    609,    -44.7,    533,    -54.4,    1.9,   -7.5}},
    {3000,   { 2.0,   -8.0,    594,    -45.0,    518,    -54.8,    2.0,   -8.0}},
    {3100,   { 2.2,   -8.6,    580,    -45.3,    504,    -55.3,    2.2,   -8.6}},
    {3200,   { 2.3,   -9.2,    566,    -45.6,    490,    -55.7,    2.3,   -9.2}},
    {3300,   { 2.4,   -9.9,    553,    -45.8,    477,    -56.0,    2.4,   -9.9}},
    {3400,   { 2.6,  -10.7,    540,    -46.0,    465,    -56.3,    2.6,  -10.7}},
    {3500,   { 2.7,  -11.4,    529,    -46.2,    454,    -56.6,    2.7,  -11.4}},
    {3600,   { 2.8,  -12.3,    517,    -46.3,    443,    -56.9,    2.8,  -12.3}},
    {3700,   { 3.0,  -13.1,    507,    -46.4,    432,    -57.1,    3.0,  -13.1}},
    {3800,   { 3.1,  -14.0,    497,    -46.5,    422,    -57.3,    3.1,  -14.0}},
    {3900,   { 3.2,  -14.9,    487,    -46.6,    413,    -57.5,    3.2,  -14.9}},
    {4000,   { 3.3,  -15.9,    478,    -46.6,    404,    -57.7,    3.3,  -15.9}}
};


/* V.56bis EIA LL-4, non-loaded loop */

struct
{
    int freq;
    float ad[8];
} eia_ll4[] =
{
    { 200,   {-0.8,   31.0,   1564,    -10.7,   1564,    -10.7,   -0.8,   31.0}},
    { 300,   {-0.8,   32.6,   1520,    -15.6,   1520,    -15.6,   -0.8,   32.6}},
    { 400,   {-0.8,   29.8,   1447,    -20.5,   1447,    -20.5,   -0.8,   29.8}},
    { 500,   {-0.6,   29.7,   1402,    -24.3,   1402,    -24.3,   -0.6,   29.7}},
    { 600,   {-0.5,   24.9,   1328,    -28.1,   1328,    -28.1,   -0.5,   24.9}},
    { 700,   {-0.4,   24.8,   1270,    -31.2,   1270,    -31.2,   -0.4,   24.8}},
    { 800,   {-0.3,   22.7,   1200,    -34.0,   1200,    -34.0,   -0.3,   22.7}},
    { 900,   {-0.1,   19.8,   1148,    -36.2,   1148,    -36.2,   -0.1,   19.8}},
    {1000,   { 6.1,   19.3,   1086,    -38.3,   1086,    -38.3,    6.1,   19.3}},
    {1100,   { 0.1,   17.5,   1027,    -40.1,   1027,    -40.1,    0.1,   17.5}},
    {1200,   { 0.3,   14.3,    974,    -41.6,    974,    -41.6,    0.3,   14.3}},
    {1300,   { 0.5,   10.9,    941,    -42.6,    941,    -42.6,    0.5,   10.9}},
    {1400,   { 0.7,    9.6,    897,    -43.7,    897,    -43.7,    0.7,    9.6}},
    {1500,   { 0.9,    7.7,    856,    -44.6,    856,    -44.6,    0.9,    7.7}},
    {1600,   { 1.1,    5.3,    818,    -45.3,    818,    -45.3,    1.1,    5.3}},
    {1700,   { 1.3,    2.4,    784,    -45.9,    784,    -45.9,    1.3,    2.4}},
    {1800,   { 1.4,   69.1,    761,    -46.3,    761,    -46.3,    1.4,   69.1}},
    {1900,   { 1.7,   -1.3,    732,    -46.6,    732,    -46.6,    1.7,   -1.3}},
    {2000,   { 1.9,   -2.7,    706,    -46.9,    706,    -46.9,    1.9,   -2.7}},
    {2100,   { 2.1,   -4.3,    682,    -47.1,    682,    -47.1,    2.1,   -4.3}},
    {2200,   { 2.3,   -6.0,    659,    -47.3,    659,    -47.3,    2.3,   -6.0}},
    {2300,   { 2.5,   -7.9,    638,    -47.4,    638,    -47.4,    2.5,   -7.9}},
    {2400,   { 2.7,   -9.9,    619,    -47.4,    619,    -47.4,    2.7,   -9.9}},
    {2500,   { 2.9,  -12.0,    602,    -47.5,    602,    -47.5,    2.9,  -12.0}},
    {2600,   { 3.1,  -13.0,    596,    -47.4,    596,    -47.4,    3.1,  -13.0}},
    {2700,   { 3.3,  -13.9,    580,    -47.4,    580,    -47.4,    3.3,  -13.9}},
    {2800,   { 3.5,  -14.8,    566,    -47.3,    566,    -47.3,    3.5,  -14.8}},
    {2900,   { 3.7,  -15.7,    552,    -47.2,    552,    -47.2,    3.7,  -15.7}},
    {3000,   { 3.9,  -16.7,    539,    -47.1,    539,    -47.1,    3.9,  -16.7}},
    {3100,   { 4.1,  -17.7,    526,    -47.0,    526,    -47.0,    4.1,  -17.7}},
    {3200,   { 4.3,  -18.7,    515,    -46.8,    515,    -46.8,    4.3,  -18.7}},
    {3300,   { 4.5,  -19.8,    504,    -46.7,    504,    -46.7,    4.5,  -19.8}},
    {3400,   { 4.7,  -20.8,    493,    -46.5,    493,    -46.5,    4.7,  -20.8}},
    {3500,   { 4.9,  -21.8,    484,    -46.4,    484,    -46.4,    4.9,  -21.8}},
    {3600,   { 5.1,  -22.9,    475,    -46.2,    475,    -46.2,    5.1,  -22.9}},
    {3700,   { 5.3,  -23.9,    466,    -46.0,    466,    -46.0,    5.3,  -23.9}},
    {3800,   { 5.5,  -25.0,    458,    -45.9,    458,    -45.9,    5.5,  -25.0}},
    {3900,   { 5.6,  -26.1,    451,    -45.7,    451,    -45.7,    5.6,  -26.1}},
    {4000,   { 5.8,  -27.2,    444,    -45.5,    444,    -45.5,    5.8,  -27.2}}
};


/* V.56bis EIA LL-5, non-loaded loop */

struct
{
    int freq;
    float ad[8];
} eia_ll5[] =
{
    { 200,   {-1.4,    55.8,   1607,   -12.7,   1574,    -17.4,   -1.4,   55.8}},
    { 300,   {-1.3,    57.2,   1541,   -18.3,   1478,    -24.8,   -1.3,   57.2}},
    { 400,   {-1.2,    52.2,   1443,   -23.6,   1350,    -31.5,   -1.2,   52.2}},
    { 500,   {-1.0,    51.0,   1379,   -27.5,   1261,    -36.4,   -1.0,   51.0}},
    { 600,   {-0.9,    43.2,   1287,   -31.2,   1150,    -40.7,   -0.9,   43.2}},
    { 700,   {-0.7,    41.8,   1216,   -34.0,   1066,    -44.0,   -0.7,   41.8}},
    { 800,   {-0.5,    37.4,   1137,   -36.5,    979,    -46.9,   -0.5,   37.4}},
    { 900,   {-0.2,    32.4,   1080,   -38.3,    915,    -48.9,   -0.2,   32.4}},
    {1000,   { 7.0,    30.5,   1015,   -39.8,    848,    -50.7,    7.0,   30.5}},
    {1100,   { 0.3,    26.8,    956,   -41.1,    788,    -52.2,    0.3,   26.8}},
    {1200,   { 0.5,    21.5,    904,   -42.1,    736,    -53.3,    0.5,   21.5}},
    {1300,   { 0.8,    16.6,    873,   -42.7,    703,    -54.1,    0.8,   16.6}},
    {1400,   { 1.0,    14.1,    832,   -43.2,    663,    -54.8,    1.0,   14.1}},
    {1500,   { 1.3,    10.9,    795,   -43.7,    627,    -55.3,    1.3,   10.9}},
    {1600,   { 1.6,     7.3,    762,   -44.0,    595,    -55.7,    1.6,    7.3}},
    {1700,   { 1.9,     3.2,    733,   -44.2,    567,    -56.0,    1.9,    3.2}},
    {1800,   { 2.2,    81.5,    713,   -44.3,    547,    -56.2,    2.2,   81.5}},
    {1900,   { 2.4,    -1.9,    689,   -44.4,    524,    -56.4,    2.4,   -1.9}},
    {2000,   { 2.7,    -3.9,    667,   -44.4,    503,    -56.5,    2.7,   -3.9}},
    {2100,   { 3.0,    -6.1,    646,   -44.4,    485,    -56.5,    3.0,   -6.1}},
    {2200,   { 3.3,    -8.3,    628,   -44.4,    466,    -56.5,    3.3,   -8.3}},
    {2300,   { 3.6,   -10.7,    610,   -44.3,    450,    -56.5,    3.6,  -10.7}},
    {2400,   { 3.8,   -13.1,    595,   -44.2,    436,    -56.4,    3.8,  -13.1}},
    {2500,   { 4.1,   -15.5,    581,   -44.1,    422,    -56.3,    4.1,  -15.5}},
    {2600,   { 4.3,   -16.7,    577,   -44.0,    417,    -56.2,    4.3,  -16.7}},
    {2700,   { 4.6,   -17.7,    565,   -43.9,    406,    -56.1,    4.6,  -17.7}},
    {2800,   { 4.8,   -18.8,    553,   -43.8,    395,    -56.0,    4.8,  -18.8}},
    {2900,   { 5.1,   -19.9,    542,   -43.7,    395,    -55.9,    5.1,  -19.9}},
    {3000,   { 5.4,   -21.0,    531,   -43.6,    375,    -55.7,    5.4,  -21.0}},
    {3100,   { 5.6,   -22.1,    521,   -43.5,    366,    -55.6,    5.6,  -22.1}},
    {3200,   { 5.9,   -23.2,    511,   -43.4,    357,    -55.4,    5.9,  -23.2}},
    {3300,   { 6.1,   -24.3,    502,   -43.3,    349,    -55.3,    6.1,  -24.3}},
    {3400,   { 6.4,   -25.4,    494,   -43.2,    341,    -55.1,    6.4,  -25.4}},
    {3500,   { 6.6,   -26.5,    486,   -43.1,    334,    -55.0,    6.6,  -26.5}},
    {3600,   { 6.9,   -27.6,    478,   -43.0,    327,    -54.8,    6.9,  -27.6}},
    {3700,   { 7.1,   -28.7,    471,   -42.9,    321,    -54.7,    7.1,  -28.7}},
    {3800,   { 7.3,   -29.9,    464,   -42.8,    315,    -54.6,    7.3,  -29.9}},
    {3900,   { 7.5,   -31.0,    458,   -42.7,    310,    -54.4,    7.5,  -31.0}},
    {4000,   { 7.8,   -32.1,    452,   -42.7,    304,    -54.3,    7.8,  -32.1}}
};


/* V.56bis EIA LL-6, non-loaded loop */

struct
{
    int freq;
    float ad[8];
} eia_ll6[] =
{
    { 200,   {-0.2,  -39.3,   1756,    -12.0,   1748,    -19.8,   -0.2,  -39.3}},
    { 300,   {-0.2,  -31.7,   1642,    -15.9,   1689,    -26.9,   -0.2,  -31.7}},
    { 400,   {-0.2,  -37.5,   1506,    -18.4,   1427,    -33.4,   -0.2,  -37.5}},
    { 500,   {-0.1,  -34.7,   1442,    -19.5,   1301,    -37.7,   -0.1,  -34.7}},
    { 600,   {-0.1,  -46.0,   1363,    -20.1,   1153,    -40.7,   -0.1,  -46.0}},
    { 700,   { 0.0,  -40.8,   1320,    -20.7,   1045,    -42.2,    0.0,  -40.8}},
    { 800,   { 0.0,  -40.1,   1269,    -21.5,    943,    -42.3,    0.0,  -40.1}},
    { 900,   { 0.0,  -40.6,   1227,    -22.5,    878,    -41.3,    0.0,  -40.6}},
    {1000,   { 6.6,  -28.0,   1161,    -23.4,    825,    -39.3,    6.6,  -28.0}},
    {1100,   { 0.0,  -16.5,   1082,    -23.5,    797,    -36.8,    0.0,  -16.5}},
    {1200,   {-0.1,    0.3,   1000,    -22.2,    798,    -34.4,   -0.1,    0.3}},
    {1300,   { 0.0,   -2.3,    943,    -19.3,    826,    -33.2,    0.0,   -2.3}},
    {1400,   { 0.0,   13.5,    896,    -14.0,    870,    -33.8,    0.0,   13.5}},
    {1500,   { 0.1,   22.6,    890,     -7.2,    916,    -36.8,    0.1,   22.6}},
    {1600,   { 0.3,   30.3,    940,     -0.3,    938,    -42.0,    0.3,   30.3}},
    {1700,   { 0.5,   12.5,   1052,      4.6,    929,    -48.0,    0.5,   12.5}},
    {1800,   { 0.8,  458.6,   1212,      6.9,    880,    -52.8,    0.8,  458.6}},
    {1900,   { 1.1,   -5.1,   1410,      3.5,    814,    -56.5,    1.1,   -5.1}},
    {2000,   { 1.4,   -5.0,   1579,     -3.6,    747,    -58.5,    1.4,   -5.0}},
    {2100,   { 1.5,    6.1,   1618,    -13.2,    688,    -58.8,    1.5,    6.1}},
    {2200,   { 1.5,   33.5,   1491,    -21.5,    646,    -57.7,    1.5,   33.5}},
    {2300,   { 1.4,   80.5,   1275,    -24.9,    625,    -55.6,    1.4,   80.5}},
    {2400,   { 1.3,  142.3,   1078,    -20.8,    633,    -53.8,    1.3,  142.3}},
    {2500,   { 1.4,  196.5,    985,     -9.3,    664,    -54.5,    1.4,  196.5}},
    {2600,   { 1.6,  214.5,   1045,      2.4,    692,    -57.6,    1.6,  214.5}},
    {2700,   { 2.4,  196.8,   1326,     13.7,    684,    -63.5,    2.4,  196.8}},
    {2800,   { 3.4,  150.4,   1887,     14.7,    637,    -68.3,    3.4,  150.4}},
    {2900,   { 4.3,  125.3,   2608,      1.3,    501,    -70.7,    4.3,  125.3}},
    {3000,   { 4.9,  174.6,   2730,    -21.8,    533,    -70.6,    4.9,  174.6}},
    {3100,   { 4.9,  380.0,   2094,    -33.7,    506,    -68.5,    4.9,  380.0}},
    {3200,   { 5.2,  759.3,   1642,    -21.3,    522,    -67.0,    5.2,  759.3}},
    {3300,   { 8.0,  680.1,   2348,      0.5,    531,    -72.9,    8.0,  680.1}},
    {3400,   {13.1,  237.8,   4510,    -20.9,    482,    -77.3,   13.1,  237.8}},
    {3500,   {18.2,  -18.8,   4116,    -59.6,    439,    -78.0,   18.2,  -18.8}},
    {3600,   {22.7, -145.4,   3041,    -74.4,    487,    -77.7,   22.7, -145.4}},
    {3700,   {26.8, -214.5,   2427,    -80.1,    383,    -77.1,   26.8, -214.5}},
    {3800,   {30.4, -257.0,   2054,    -82.7,    364,    -76.4,   30.4, -257.0}},
    {3900,   {33.7, -285.6,   1803,    -84.2,    348,    -75.0,   33.7, -285.6}},
    {4000,   {36.8, -306.2,   1621,    -85.1,    334,    -75.7,   36.8, -306.2}}
};


/* V.56bis EIA LL-7, non-loaded loop */

struct
{
    int freq;
    float ad[8];
} eia_ll7[] =
{
    { 200,   { 0.4,   -81.3,    1848,  -10.5,   1737,    -15.6,    0.4,  -81.3}},
    { 300,   { 0.3,   -68.9,    1785,  -16.2,   1585,    -21.6,    0.3,  -68.9}},
    { 400,   { 0.2,   -68.1,    1646,  -22.0,   1388,    -25.8,    0.2,  -68.1}},
    { 500,   { 0.1,   -57.0,    1528,  -26.2,   1247,    -27.7,    0.1,  -57.0}},
    { 600,   { 0.0,   -59.8,    1349,  -28.9,   1087,    -27.3,    0.0,  -59.8}},
    { 700,   { 0.0,   -45.0,    1205,  -29.1,    975,    -24.8,    0.0,  -45.0}},
    { 800,   {-0.1,   -36.9,    1064,  -26.8,    885,    -19.7,   -0.1,  -36.9}},
    { 900,   {-0.1,   -37.1,     989,  -22.6,    846,    -13.5,   -0.1,  -37.1}},
    {1000,   { 5.9,   -29.2,     944,  -16.6,    847,     -6.1,    5.9,  -29.2}},
    {1100,   { 0.1,   -30.8,     951,  -10.5,    900,      0.3,    0.1,  -30.8}},
    {1200,   { 0.2,   -40.7,    1008,   -5.9,    999,      4.9,    0.2,  -40.7}},
    {1300,   { 0.4,   -53.3,    1897,   -4.0,   1122,      4.6,    0.4,  -53.3}},
    {1400,   { 0.5,   -52.7,    1197,   -4.8,   1253,      1.9,    0.5,  -52.7}},
    {1500,   { 0.6,   -48.3,    1269,   -8.4,   1339,     -3.8,    0.6,  -48.3}},
    {1600,   { 0.6,   -38.0,    1274,  -13.2,   1337,    -10.4,    0.6,  -38.0}},
    {1700,   { 0.5,   -21.6,    1208,  -16.9,   1250,    -15.2,    0.5,  -21.6}},
    {1800,   { 0.4,   539.7,    1119,  -17.8,   1143,    -16.6,    0.4,  539.7}},
    {1900,   { 0.3,    35.4,    1027,  -14.7,   1036,    -13.7,    0.3,   35.4}},
    {2000,   { 0.3,    64.1,     989,   -7.9,    998,     -6.9,    0.3,   64.1}},
    {2100,   { 0.4,    76.1,    1045,    0.1,   1040,      1.0,    0.4,   76.1}},
    {2200,   { 0.6,    69.8,    1210,    5.3,   1197,      6.9,    0.6,   69.8}},
    {2300,   { 1.0,    55.9,    1460,    4.6,   1430,      5.4,    1.0,   55.9}},
    {2400,   { 1.2,    51.3,    1692,   -2.8,   1640,     -1.7,    1.2,   51.3}},
    {2500,   { 1.3,    72.6,    1730,  -13.4,   1666,    -11.5,    1.3,   72.6}},
    {2600,   { 1.3,   117.1,    1613,  -49.6,   1556,    -16.9,    1.3,  117.1}},
    {2700,   { 1.1,   222.5,    1371,  -19.5,   1334,    -16.1,    1.1,  222.5}},
    {2800,   { 1.1,   332.3,    1258,   -8.9,   1243,     -5.1,    1.1,  332.3}},
    {2900,   { 1.7,   356.1,    1474,    4.8,   1480,      8.4,    1.7,  356.1}},
    {3000,   { 2.8,   299.9,    2128,    6.6,   2143,      9.8,    2.8,  299.9}},
    {3100,   { 3.9,   309.4,    2813,  -10.5,   2882,     -7.1,    3.9,  309.4}},
    {3200,   { 4.4,   576.4,    2490,  -27.7,   2487,    -22.2,    4.4,  576.4}},
    {3300,   { 5.6,  1030.6,    2237,  -17.4,   2385,     -9.0,    5.6, 1030.6}},
    {3400,   {10.7,   570.2,    3882,  -19.2,   4855,    -14.9,   10.7,  570.2}},
    {3500,   {17.3,    83.5,    4116,  -57.4,   4649,    -63.5,   17.3,   83.5}},
    {3600,   {23.2,  -130.6,    3057,  -74.0,   3175,    -78.6,   23.2, -130.6}},
    {3700,   {28.3,  -153.9,    2432,  -80.0,   2471,    -83.1,   28.3, -153.9}},
    {3800,   {32.8,  -292.4,    2055,  -82.8,   2072,    -85.1,   32.8, -292.4}},
    {3900,   {36.9,  -249.9,    1803,  -84.2,   1811,    -86.1,   36.9, -249.9}},
    {4000,   {40.7,  -356.2,    1621,  -85.1,   1625,    -86.7,   40.7, -356.2}}
};


/* V.56bis ETSI LL-1, non-loaded loop */

struct
{
    int freq;
    float ad[8];
} etsi_ll1[] =
{
    { 200,  {-0.78,   14.0, 1248.5,     -9.7, 1248.5,     -9.7,  -0.78,   14.0}},
    { 300,  {-0.74,   10.0, 1220.9,    -14.3, 1220.9,    -14.3,  -0.74,   10.0}},
    { 400,  {-0.68,    8.0, 1185.2,    -18.6, 1185.2,    -18.6,  -0.68,    8.0}},
    { 500,  {-0.60,    7.0, 1143.9,    -22.6, 1143.9,    -22.6,  -0.60,    7.0}},
    { 600,  {-0.51,    6.0, 1099.0,    -26.2, 1099.0,    -26.2,  -0.51,    6.0}},
    { 700,  {-0.40,    5.6, 1052.5,    -29.5, 1052.5,    -29.5,  -0.40,    5.6}},
    { 800,  {-0.28,    5.3, 1005.9,    -32.4, 1005.9,    -32.4,  -0.28,    5.3}},
    { 900,  {-0.14,    5.0,  960.3,    -35.0,  960.3,    -35.0,  -0.14,    5.0}},
    {1000,  { 4.7,     4.6,  916.4,    -37.3,  916.4,    -37.3,   4.7,     4.6}},
    {1100,  { 0.16,    4.3,  874.6,    -39.3,  874.6,    -39.3,   0.16,    4.3}},
    {1200,  { 0.33,    3.6,  835.3,    -41.1,  835.3,    -41.1,   0.33,    3.6}},
    {1300,  { 0.49,    2.6,  798.5,    -42.6,  798.5,    -42.6,   0.49,    2.6}},
    {1400,  { 0.67,    2.0,  764.2,    -43.9,  764.2,    -43.9,   0.67,    2.0}},
    {1500,  { 0.85,    1.0,  732.3,    -45.1,  732.3,    -45.1,   0.85,    1.0}},
    {1600,  { 1.04,    0.6,  702.7,    -46.1,  702.7,    -46.1,   1.04,    0.6}},
    {1700,  { 1.23,    0.3,  675.3,    -47.0,  675.3,    -47.0,   1.23,    0.3}},
    {1800,  { 1.43,   40.0,  649.8,    -47.7,  649.8,    -47.7,   1.43,   40.0}},
    {1900,  { 1.63,   -1.0,  626.2,    -48.4,  626.2,    -48.4,   1.63,   -1.0}},
    {2000,  { 1.83,   -2.0,  604.3,    -48.9,  604.3,    -48.9,   1.83,   -2.0}},
    {2100,  { 2.03,   -3.3,  584.0,    -49.4,  584.0,    -49.4,   2.03,   -3.3}},
    {2200,  { 2.23,   -3.6,  565.1,    -49.8,  565.1,    -49.8,   2.23,   -3.6}},
    {2300,  { 2.44,   -4.3,  547.5,    -50.1,  547.5,    -50.1,   2.44,   -4.3}},
    {2400,  { 2.64,   -5.0,  531.1,    -50.4,  531.1,    -50.4,   2.64,   -5.0}},
    {2500,  { 2.84,   -6.1,  515.9,    -50.6,  515.9,    -50.6,   2.84,   -6.1}},
    {2600,  { 3.05,   -6.6,  501.6,    -50.8,  501.6,    -50.8,   3.05,   -6.6}},
    {2700,  { 3.25,   -7.3,  488.2,    -51.0,  488.2,    -51.0,   3.25,   -7.3}},
    {2800,  { 3.45,   -7.6,  475.7,    -51.1,  475.7,    -51.1,   3.45,   -7.6}},
    {2900,  { 3.65,   -8.3,  464.0,    -51.1,  464.0,    -51.1,   3.65,   -8.3}},
    {3000,  { 3.85,   -8.6,  453.0,    -51.2,  453.0,    -51.2,   3.85,   -8.6}},
    {3100,  { 4.04,   -9.3,  442.6,    -51.2,  442.6,    -51.2,   4.04,   -9.3}},
    {3200,  { 4.24,  -10.3,  432.9,    -51.2,  432.9,    -51.2,   4.24,  -10.3}},
    {3300,  { 4.43,  -10.6,  423.7,    -51.2,  423.7,    -51.2,   4.43,  -10.6}},
    {3400,  { 4.62,  -11.3,  415.1,    -51.2,  415.1,    -51.2,   4.62,  -11.3}},
    {3500,  { 4.81,  -11.6,  406.9,    -51.1,  406.9,    -51.1,   4.81,  -11.6}},
    {3600,  { 5.00,  -12.3,  399.1,    -51.1,  399.1,    -51.1,   5.00,  -12.3}},
    {3700,  { 5.19,  -13.0,  391.8,    -51.0,  391.8,    -51.0,   5.19,  -13.0}},
    {3800,  { 5.37,  -13.4,  384.9,    -51.0,  384.9,    -51.0,   5.37,  -13.4}},
    {3900,  { 5.56,  -13.8,  378.3,    -50.9,  378.3,    -50.9,   5.56,  -13.8}},
    {4000,  { 5.74,  -14.4,  372.0,    -50.8,  372.0,    -50.8,   5.74,  -14.4}}
};


/* V.56bis ETSI LL-2, non-loaded loop */

struct
{
    int freq;
    float ad[8];
} etsi_ll2[] =
{
    { 200,  {-0.10,   15.0,  850.3,     -3.4,  850.3,     -3.4,  -0.10,   15.0}},
    { 300,  {-0.09,    8.0,  848.1,     -5.1,  848.1,     -5.1,  -0.09,    8.0}},
    { 400,  {-0.09,    7.0,  845.1,     -6.7,  845.1,     -6.7,  -0.09,    7.0}},
    { 500,  {-0.08,    5.0,  841.3,     -8.4,  841.3,     -8.4,  -0.08,    5.0}},
    { 600,  {-0.07,    4.6,  836.7,    -10.0,  836.7,    -10.0,  -0.07,    4.6}},
    { 700,  {-0.06,    4.3,  831.3,    -11.6,  831.3,    -11.6,  -0.06,    4.3}},
    { 800,  {-0.04,    3.8,  825.3,    -13.2,  825.3,    -13.2,  -0.04,    3.8}},
    { 900,  {-0.02,    3.4,  818.6,    -14.8,  818.6,    -14.8,  -0.02,    3.4}},
    {1000,  { 1.80,    3.0,  811.4,    -16.3,  811.4,    -16.3,   1.8,     3.0}},
    {1100,  { 0.02,    2.6,  803.6,    -17.8,  803.6,    -17.8,   0.02,    2.6}},
    {1200,  { 0.04,    2.3,  795.3,    -19.3,  795.3,    -19.3,   0.04,    2.3}},
    {1300,  { 0.06,    1.3,  786.6,    -20.7,  786.6,    -20.7,   0.06,    1.3}},
    {1400,  { 0.09,    0.9,  777.5,    -22.1,  777.5,    -22.1,   0.09,    0.9}},
    {1500,  { 0.12,    0.6,  768.1,    -23.5,  768.1,    -23.5,   0.12,    0.6}},
    {1600,  { 0.15,    0.3,  758.4,    -24.8,  758.4,    -24.8,   0.15,    0.3}},
    {1700,  { 0.18,    0.0,  748.4,    -26.1,  748.4,    -26.1,   0.18,    0.0}},
    {1800,  { 0.21,     15,  738.4,    -27.3,  738.4,    -27.3,   0.21,   15.0}},
    {1900,  { 0.24,   -1.0,  728.1,    -28.5,  728.1,    -28.5,   0.24,   -1.0}},
    {2000,  { 0.28,   -2.3,  717.8,    -29.7,  717.8,    -29.7,   0.28,   -2.3}},
    {2100,  { 0.32,   -2.6,  707.4,    -30.8,  707.4,    -30.8,   0.32,   -2.6}},
    {2200,  { 0.36,   -3.0,  697.0,    -31.9,  697.0,    -31.9,   0.36,   -3.0}},
    {2300,  { 0.40,   -3.3,  686.6,    -33.0,  686.6,    -33.0,   0.40,   -3.3}},
    {2400,  { 0.44,   -3.6,  676.2,    -34.0,  676.2,    -34.0,   0.44,   -3.6}},
    {2500,  { 0.48,   -4.5,  665.9,    -35.0,  665.9,    -35.0,   0.48,   -4.5}},
    {2600,  { 0.53,   -5.4,  655.6,    -35.9,  655.6,    -35.9,   0.53,   -5.4}},
    {2700,  { 0.57,   -6.3,  645.5,    -36.8,  645.5,    -36.8,   0.57,   -6.3}},
    {2800,  { 0.62,   -6.6,  635.5,    -37.7,  635.5,    -37.7,   0.62,   -6.6}},
    {2900,  { 0.67,   -6.9,  625.6,    -38.6,  625.6,    -38.6,   0.67,   -6.9}},
    {3000,  { 0.72,   -7.5,  615.8,    -39.4,  615.8,    -39.4,   0.72,   -7.5}},
    {3100,  { 0.77,   -8.3,  606.2,    -40.2,  606.2,    -40.2,   0.77,   -8.3}},
    {3200,  { 0.82,   -8.6,  596.7,    -40.9,  596.7,    -40.9,   0.82,   -8.6}},
    {3300,  { 0.87,   -9.3,  587.4,    -41.6,  587.4,    -41.6,   0.87,   -9.3}},
    {3400,  { 0.92,   -9.6,  578.3,    -42.3,  578.3,    -42.3,   0.92,   -9.6}},
    {3500,  { 0.98,  -10.3,  569.3,    -43.0,  569.3,    -43.0,   0.98,  -10.3}},
    {3600,  { 1.03,  -10.6,  560.6,    -43.7,  560.6,    -43.7,   1.03,  -10.6}},
    {3700,  { 1.09,  -11.3,  552.0,    -44.3,  552.0,    -44.3,   1.09,  -11.3}},
    {3800,  { 1.14,  -11.6,  543.5,    -44.9,  543.5,    -44.9,   1.14,  -11.6}},
    {3900,  { 1.20,  -12.3,  535.3,    -45.4,  535.3,    -45.4,   1.20,  -12.3}},
    {4000,  { 1.26,  -13.3,  527.2,    -46.0,  527.2,    -46.0,   1.26,  -13.3}}
};

/* V.56bis AD-1 AD-5 AD-6 AD-7 AD-8 AD-9 */

struct
{
    int freq;
    float ad[6];
} ad[] =
{
    {   0,  {90.0,   90.0,   90.0,   90.0,   90.0,   90.0}},
    { 200,  { 6.0,    3.2,    3.0,    2.9,   11.6,   23.3}},
    { 300,  { 1.3,    1.4,    1.2,    1.1,    6.9,   13.9}},
    { 400,  { 0.0,    0.4,    0.3,    0.3,    4.0,    7.9}},
    { 500,  { 0.0,   -0.1,    0.0,    0.1,    2.0,    4.1}},
    { 600,  { 0.0,   -0.1,    0.0,    0.1,    1.2,    2.4}},
    { 700,  { 0.0,    0.1,    0.0,    0.0,    0.8,    1.7}},
    { 800,  { 0.0,    0.0,    0.0,   -0.1,    0.5,    1.1}},
    { 900,  { 0.0,    0.0,    0.0,   -0.1,    0.2,    0.4}},
    {1000,  { 0.0,    0.0,    0.0,    0.0,    0.0,    0.0}},
    {1100,  { 0.0,    0.0,    0.1,    0.0,   -0.1,   -0.2}},
    {1200,  { 0.0,    0.0,    0.1,    0.1,   -0.1,   -0.2}},
    {1300,  { 0.0,    0.1,    0.2,    0.3,   -0.1,   -0.2}},
    {1400,  { 0.0,    0.2,    0.3,    0.4,   -0.1,   -0.3}},
    {1500,  { 0.0,    0.2,    0.3,    0.4,   -0.2,   -0.4}},
    {1600,  { 0.0,    0.3,    0.5,    0.5,   -0.1,   -0.3}},
    {1700,  { 0.0,    0.3,    0.5,    0.6,   -0.1,   -0.1}},
    {1800,  { 0.0,    0.3,    0.5,    0.6,    0.0,    0.0}},
    {1900,  { 0.0,    0.4,    0.7,    0.7,    0.1,    0.2}},
    {2000,  { 0.0,    0.5,    0.8,    0.9,    0.2,    0.5}},
    {2100,  { 0.1,    0.6,    1.0,    1.0,    0.5,    0.9}},
    {2200,  { 0.2,    0.7,    1.1,    1.1,    0.6,    1.1}},
    {2300,  { 0.3,    0.9,    1.2,    1.4,    0.8,    1.5}},
    {2400,  { 0.4,    1.1,    1.5,    1.6,    0.9,    1.8}},
    {2500,  { 0.5,    1.3,    1.8,    2.0,    1.1,    2.3}},
    {2600,  { 0.6,    1.6,    2.4,    2.7,    1.4,    2.8}},
    {2700,  { 0.7,    2.0,    3.0,    3.5,    1.7,    3.4}},
    {2800,  { 0.7,    2.3,    3.5,    4.3,    2.0,    4.0}},
    {2900,  { 0.9,    2.8,    4.2,    5.0,    2.4,    4.9}},
    {3000,  { 1.1,    3.2,    4.9,    5.8,    3.0,    5.9}},
    {3100,  { 1.2,    3.5,    5.6,    6.7,    3.4,    6.8}},
    {3200,  { 1.3,    4.1,    6.7,    8.0,    3.9,    7.7}},
    {3300,  { 1.6,    4.8,    8.0,    9.6,    4.6,    9.2}},
    {3400,  { 1.8,    5.3,    9.1,   11.0,    5.4,   10.7}},
    {3500,  { 2.4,    5.7,   10.3,   12.2,    6.3,   12.6}},
    {3600,  { 3.0,    6.6,   12.1,   13.9,    7.8,   15.5}},
    {3700,  { 5.7,    8.9,   15.8,   17.3,   10.3,   20.5}},
    {3800,  {13.5,   15.7,   24.4,   25.7,   16.2,   32.4}},
    {3900,  {31.2,   31.1,   42.2,   43.3,   29.9,   59.9}},
    {4000,  {31.2,   31.1,   42.2,   43.3,   29.9,   59.9}}
};

/* V.56bis EDD-1 EDD-2 EDD-3 */

struct
{
    int freq;
    float edd[3];
} edd[] =
{
    {   0,    {3.98,    3.76,    8.00}},
    { 200,    {3.98,    3.76,    8.00}},
    { 300,    {2.70,    3.76,    8.00}},
    { 400,    {1.69,    2.20,    6.90}},
    { 500,    {1.15,    1.36,    5.50}},
    { 600,    {0.80,    0.91,    4.40}},
    { 700,    {0.60,    0.64,    3.40}},
    { 800,    {0.50,    0.46,    2.80}},
    { 900,    {0.40,    0.34,    2.00}},
    {1000,    {0.30,    0.24,    1.50}},
    {1100,    {0.20,    0.16,    1.00}},
    {1200,    {0.20,    0.11,    0.70}},
    {1300,    {0.10,    0.07,    0.40}},
    {1400,    {0.05,    0.05,    0.30}},
    {1500,    {0.00,    0.03,    0.20}},
    {1600,    {0.00,    0.01,    0.10}},
    {1700,    {0.00,    0.00,    0.10}},
    {1800,    {0.00,    0.00,    0.00}},
    {1900,    {0.00,    0.02,    0.10}},
    {2000,    {0.00,    0.04,    0.10}},
    {2100,    {0.02,    0.08,    0.10}},
    {2200,    {0.02,    0.12,    0.20}},
    {2300,    {0.02,    0.16,    0.20}},
    {2400,    {0.02,    0.20,    0.30}},
    {2500,    {0.10,    0.27,    0.40}},
    {2600,    {0.12,    0.36,    0.50}},
    {2700,    {0.15,    0.47,    0.80}},
    {2800,    {0.20,    0.60,    1.10}},
    {2900,    {0.27,    0.77,    1.50}},
    {3000,    {0.40,    1.01,    2.00}},
    {3100,    {0.56,    1.32,    2.60}},
    {3200,    {0.83,    1.78,    3.20}},
    {3300,    {1.07,    1.78,    4.00}},
    {3400,    {1.39,    1.78,    4.00}},
    {3500,    {1.39,    1.78,    4.00}},
    {3600,    {1.39,    1.78,    4.00}},
    {3700,    {1.39,    1.78,    4.00}},
    {3800,    {1.39,    1.78,    4.00}},
    {3900,    {1.39,    1.78,    4.00}},
    {4000,    {1.39,    1.78,    4.00}}
};

/* V.56bis PCM AD-1, AD-2, AD-3 */

struct
{
    int freq;
    float ad[3];
} pcm_ad[] =
{
    {  50,    {41.4,    77.8,   114.2}},
    { 100,    {15.5,    27.7,    39.9}},
    { 150,    { 3.7,     6.1,     8.6}},
    { 200,    { 0.5,     0.8,     1.0}},
    { 250,    {-0.2,    -0.2,    -0.3}},
    { 300,    {-0.2,    -0.3,    -0.4}},
    { 400,    { 0.0,    -0.2,    -0.3}},
    { 500,    {-0.2,    -0.4,    -0.5}},
    { 600,    {-0.2,    -0.3,    -0.5}},
    { 700,    {-0.2,    -0.3,    -0.5}},
    { 800,    {-0.2,    -0.4,    -0.5}},
    { 900,    {-0.2,    -0.3,    -0.4}},
    {1000,    {-0.1,    -0.2,    -0.3}},
    {1100,    {-0.2,    -0.3,    -0.3}},
    {1200,    {-0.2,    -0.3,    -0.4}},
    {1300,    {-0.2,    -0.3,    -0.5}},
    {1400,    {-0.1,    -0.3,    -0.4}},
    {1500,    {-0.1,    -0.3,    -0.4}},
    {1600,    {-0.1,    -0.2,    -0.3}},
    {1700,    {-0.1,    -0.3,    -0.4}},
    {1800,    {-0.2,    -0.3,    -0.4}},
    {1900,    {-0.2,    -0.3,    -0.3}},
    {2000,    {-0.1,    -0.2,    -0.3}},
    {2100,    {-0.1,    -0.2,    -0.3}},
    {2200,    {-0.1,    -0.3,    -0.4}},
    {2300,    {-0.1,    -0.1,    -0.2}},
    {2400,    {-0.1,    -0.1,    -0.2}},
    {2500,    { 0.0,    -0.1,    -0.1}},
    {2600,    { 0.0,    -0.1,    -0.1}},
    {2700,    { 0.0,     0.0,     0.1}},
    {2800,    { 0.0,     0.0,     0.1}},
    {2900,    { 0.1,     0.2,     0.2}},
    {3000,    { 0.0,     0.0,     0.1}},
    {3100,    { 0.0,     0.0,     0.0}},
    {3200,    { 0.0,     0.0,     0.1}},
    {3300,    { 0.3,     0.7,     1.0}},
    {3400,    { 1.2,     2.4,     3.6}},
    {3500,    { 3.2,     6.3,     9.5}},
    {3550,    { 5.0,     9.6,    14.3}},
    {3600,    { 7.0,    13.5,    19.9}},
    {3650,    {10.0,    18.7,    27.5}},
    {3700,    {13.4,    24.6,    35.8}},
    {3750,    {18.1,    32.1,    46.2}},
    {3800,    {24.3,    41.2,    58.2}},
    {3850,    {32.5,    52.6,    72.7}},
    {3900,    {43.4,    66.6,    89.8}},
    {4000,    {43.4,    66.6,    89.8}}
};

/* V.56bis PCM EDD-1, EDD-2, EDD-3 */

struct
{
    int freq;
    float edd[3];
} pcm_edd[] =
{
    { 150,   { 2.76,    5.5,    8.3}},
    { 200,   { 1.70,    3.4,    5.1}},
    { 250,   { 0.92,    1.8,    2.8}},
    { 300,   { 0.55,    1.1,    1.7}},
    { 400,   { 0.25,    0.5,    0.7}},
    { 500,   { 0.12,    0.2,    0.4}},
    { 600,   { 0.06,    0.1,    0.2}},
    { 700,   { 0.03,    0.1,    0.1}},
    { 800,   { 0.01,    0.0,    0.0}},
    { 900,   { 0.00,    0.0,    0.0}},
    {1000,   {-0.01,    0.0,    0.0}},
    {1100,   {-0.01,    0.0,    0.0}},
    {1200,   {-0.02,    0.0,   -0.1}},
    {1300,   {-0.02,    0.0,   -0.1}},
    {1400,   {-0.01,    0.0,    0.0}},
    {1500,   {-0.01,    0.0,    0.0}},
    {1600,   { 0.00,    0.0,    0.0}},
    {1700,   { 0.00,    0.0,    0.0}},
    {1800,   { 0.01,    0.0,    0.0}},
    {1900,   { 0.02,    0.0,    0.0}},
    {2000,   { 0.02,    0.0,    0.1}},
    {2100,   { 0.04,    0.1,    0.1}},
    {2200,   { 0.05,    0.1,    0.2}},
    {2300,   { 0.06,    0.1,    0.2}},
    {2400,   { 0.07,    0.1,    0.2}},
    {2500,   { 0.10,    0.2,    0.3}},
    {2600,   { 0.11,    0.2,    0.3}},
    {2700,   { 0.14,    0.3,    0.4}},
    {2800,   { 0.18,    0.4,    0.5}},
    {2900,   { 0.22,    0.4,    0.6}},
    {3000,   { 0.27,    0.5,    0.8}},
    {3100,   { 0.34,    0.7,    1.0}},
    {3200,   { 0.45,    0.9,    1.4}},
    {3250,   { 0.52,    1.0,    1.6}},
    {3300,   { 0.60,    1.2,    1.8}},
    {3350,   { 0.66,    1.3,    2.0}},
    {3400,   { 0.74,    1.5,    2.2}},
    {3450,   { 0.79,    1.6,    2.4}},
    {3500,   { 0.83,    1.7,    2.5}},
    {3550,   { 0.84,    1.7,    2.5}},
    {3600,   { 0.81,    1.6,    2.4}},
    {3700,   { 0.81,    1.6,    2.4}},
    {3800,   { 0.81,    1.6,    2.4}},
    {3900,   { 0.81,    1.6,    2.4}},
    {4000,   { 0.81,    1.6,    2.4}}
};

FILE *outfile;

float impulse_responses[100][LINE_FILTER_SIZE];
int filter_sets = 0;

static void generate_ad_edd(void)
{
    float f;
    float offset;
    float amp;
    float phase;
    //float delay;
    float pw;
#if defined(HAVE_FFTW3_H)
    double in[FFT_SIZE][2];
    double out[FFT_SIZE][2];
#else
    fftw_complex in[FFT_SIZE];
    fftw_complex out[FFT_SIZE];
#endif
    fftw_plan p;
    int i;
    int j;
    int k;
    int l;

#if defined(HAVE_FFTW3_H)
    p = fftw_plan_dft_1d(FFT_SIZE, in, out, FFTW_BACKWARD, FFTW_ESTIMATE);
#else
    p = fftw_create_plan(FFT_SIZE, FFTW_BACKWARD, FFTW_ESTIMATE);
#endif
    for (j = 0;  j < 6;  j++)
    {
        for (k = 0;  k < 3;  k++)
        {
            for (i = 0;  i < FFT_SIZE;  i++)
            {
#if defined(HAVE_FFTW3_H)
                in[i][0] =
                in[i][1] = 0.0f;
#else
                in[i].re =
                in[i].im = 0.0f;
#endif
            }
            for (i = 1;  i < FFT_SIZE/2;  i++)
            {
                f = (float) i*SAMPLE_RATE/FFT_SIZE;
                amp = 0.0f;
                for (l = 0;  l < (int) (sizeof(ad)/sizeof(ad[0]));  l++)
                {
                    if (f < ad[l].freq)
                        break;
                }
                if (l < (int) (sizeof(ad)/sizeof(ad[0])))
                {
                    offset = (f - ad[l - 1].freq)/(ad[l].freq - ad[l - 1].freq);
                    amp = (1.0 - offset)*ad[l - 1].ad[j] + offset*ad[l].ad[j];
                    amp = pow(10.0, -amp/20.0);
                }
                //delay = 0.0f;
                for (l = 0;  l < (int) (sizeof(edd)/sizeof(edd[0]));  l++)
                {
                    if (f < edd[l].freq)
                        break;
                }
                if (l < (int) (sizeof(edd)/sizeof(edd[0])))
                {
                    offset = (f - edd[l - 1].freq)/(edd[l].freq - edd[l - 1].freq);
                    //delay = (1.0f - offset)*edd[l - 1].edd[k] + offset*edd[l].edd[k];
                }
                //phase = 2.0f*M_PI*f*delay*0.001f;
                phase = 0.0f;
#if defined(HAVE_FFTW3_H)
                in[i][0] = amp*cosf(phase);
                in[i][1] = amp*sinf(phase);
                in[FFT_SIZE - i][0] = in[i][0];
                in[FFT_SIZE - i][1] = -in[i][1];
#else
                in[i].re = amp*cosf(phase);
                in[i].im = amp*sinf(phase);
                in[FFT_SIZE - i].re = in[i].re;
                in[FFT_SIZE - i].im = -in[i].im;
#endif
            }
#if 0
            for (i = 0;  i < FFT_SIZE;  i++)
                fprintf(outfile, "%5d %15.5f,%15.5f\n", i, in[i].re, in[i].im);
#endif
#if defined(HAVE_FFTW3_H)
            fftw_execute(p);
#else
            fftw_one(p, in, out);
#endif

            fprintf(outfile, "/* V.56bis AD-%d, EDD%d */\n", (j == 0)  ?  1  :  j + 4, k + 1);

            fprintf(outfile, "const float ad_%d_edd_%d_model[] =\n", (j == 0)  ?  1  :  j + 4, k + 1);
            fprintf(outfile, "{\n");
            /* Normalise the filter's gain */
            pw = 0.0f;
            l = FFT_SIZE - (LINE_FILTER_SIZE - 1)/2;
            for (i = 0;  i < LINE_FILTER_SIZE;  i++)
            {
#if defined(HAVE_FFTW3_H)
                pw += out[l][0]*out[l][0];
#else
                pw += out[l].re*out[l].re;
#endif
                if (++l == FFT_SIZE)
                    l = 0;
            }
            pw = sqrt(pw);
            l = FFT_SIZE - (LINE_FILTER_SIZE - 1)/2;
            for (i = 0;  i < LINE_FILTER_SIZE;  i++)
            {
#if defined(HAVE_FFTW3_H)
                impulse_responses[filter_sets][i] = out[l][0]/pw;
#else
                impulse_responses[filter_sets][i] = out[l].re/pw;
#endif
                fprintf(outfile, "%15.5f,\n", impulse_responses[filter_sets][i]);
                if (++l == FFT_SIZE)
                    l = 0;
            }
            fprintf(outfile, "};\n\n");
            filter_sets++;
        }
    }
}

static void generate_proakis(void)
{
    float f;
    float f1;
    float offset;
    float amp;
    float phase;
    //float delay;
    float pw;
    int index;
    int i;
    int l;
#if defined(HAVE_FFTW3_H)
    double in[FFT_SIZE][2];
    double out[FFT_SIZE][2];
#else
    fftw_complex in[FFT_SIZE];
    fftw_complex out[FFT_SIZE];
#endif
    fftw_plan p;

#if defined(HAVE_FFTW3_H)
    p = fftw_plan_dft_1d(FFT_SIZE, in, out, FFTW_BACKWARD, FFTW_ESTIMATE);
#else
    p = fftw_create_plan(FFT_SIZE, FFTW_BACKWARD, FFTW_ESTIMATE);
#endif
    for (i = 0;  i < FFT_SIZE;  i++)
    {
#if defined(HAVE_FFTW3_H)
        in[i][0] =
        in[i][1] = 0.0f;
#else
        in[i].re =
        in[i].im = 0.0f;
#endif
    }
    for (i = 1;  i < FFT_SIZE/2;  i++)
    {
        f = (float) i*SAMPLE_RATE/FFT_SIZE;
        f1 = f/200.0f;
        offset = f1 - floor(f1);
        index = (int) floor(f1);

        /* Linear interpolation */
        amp = ((1.0f - offset)*proakis[index].amp + offset*proakis[index + 1].amp)/2.3f;
        //delay = (1.0f - offset)*proakis[index].delay + offset*proakis[index + 1].delay;
        //phase = 2.0f*M_PI*f*delay*0.001f;
        phase = 0.0f;
#if defined(HAVE_FFTW3_H)
        in[i][0] = amp*cosf(phase);
        in[i][1] = amp*sinf(phase);
        in[FFT_SIZE - i][0] = in[i][0];
        in[FFT_SIZE - i][1] = -in[i][1];
#else
        in[i].re = amp*cosf(phase);
        in[i].im = amp*sinf(phase);
        in[FFT_SIZE - i].re = in[i].re;
        in[FFT_SIZE - i].im = -in[i].im;
#endif
    }

#if defined(HAVE_FFTW3_H)
    fftw_execute(p);
#else
    fftw_one(p, in, out);
#endif

    fprintf(outfile, "/* Medium range telephone line response\n");
    fprintf(outfile, "   (from p 537, Digital Communication, John G. Proakis */\n");

    fprintf(outfile, "const float proakis_line_model[] =\n");
    fprintf(outfile, "{\n");
    /* Normalise the filter's gain */
    pw = 0.0f;
    l = FFT_SIZE - (LINE_FILTER_SIZE - 1)/2;
    for (i = 0;  i < LINE_FILTER_SIZE;  i++)
    {
#if defined(HAVE_FFTW3_H)
        pw += out[l][0]*out[l][0];
#else
        pw += out[l].re*out[l].re;
#endif
        if (++l == FFT_SIZE)
            l = 0;
    }
    pw = sqrt(pw);
    l = FFT_SIZE - (LINE_FILTER_SIZE - 1)/2;
    for (i = 0;  i < LINE_FILTER_SIZE;  i++)
    {
#if defined(HAVE_FFTW3_H)
        impulse_responses[filter_sets][i] = out[l][0]/pw;
#else
        impulse_responses[filter_sets][i] = out[l].re/pw;
#endif
        fprintf(outfile, "%15.5f,\n", impulse_responses[filter_sets][i]);
        if (++l == FFT_SIZE)
            l = 0;
    }
    fprintf(outfile, "};\n\n");
    filter_sets++;
}

int main(int argc, char *argv[])
{
    int i;
    int j;

    if ((outfile = fopen(LINE_MODEL_FILE_NAME, "w")) == NULL)
    {
        fprintf(stderr, "Failed to open %s\n", "line_model.txt");
        exit(2);
    }

    generate_proakis();
    generate_ad_edd();

    fclose(outfile);

    if (argc > 1)
    {
        for (i = 0;  i < LINE_FILTER_SIZE;  i++)
        {
            printf("%d, ", i);
            for (j = 0;  j < filter_sets;  j++)
            {
                printf("%15.5f, ", impulse_responses[j][i]);
            }
            printf("\n");
        }
    }
    return 0;
}