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freeswitch/libs/spandsp/spandsp-sim/line_model.c
Michael Jerris 8e5eed8999 update to snapshot spandsp-20090204 
git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@11612 d0543943-73ff-0310-b7d9-9358b9ac24b2
2009-02-03 18:50:18 +00:00

568 lines
14 KiB
C
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/*
* SpanDSP - a series of DSP components for telephony
*
* line_model.c - Model a telephone line.
*
* 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.
*
* $Id: line_model.c,v 1.8 2009/02/03 16:28:39 steveu Exp $
*/
#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif
#include <stdlib.h>
#include <unistd.h>
#include <inttypes.h>
#include <string.h>
#include <time.h>
#include <stdio.h>
#include <fcntl.h>
#include <audiofile.h>
#if defined(HAVE_TGMATH_H)
#include <tgmath.h>
#endif
#if defined(HAVE_MATH_H)
#define GEN_CONST
#include <math.h>
#endif
#include "floating_fudge.h"
#define SPANDSP_EXPOSE_INTERNAL_STRUCTURES
#include "spandsp.h"
#include "spandsp-sim.h"
#include "spandsp/g168models.h"
#if !defined(NULL)
#define NULL (void *) 0
#endif
float null_line_model[] =
{
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0,
1.0
};
static float *models[] =
{
null_line_model, /* 0 */
proakis_line_model,
ad_1_edd_1_model,
ad_1_edd_2_model,
ad_1_edd_3_model,
ad_5_edd_1_model, /* 5 */
ad_5_edd_2_model,
ad_5_edd_3_model,
ad_6_edd_1_model,
ad_6_edd_2_model,
ad_6_edd_3_model, /* 10 */
ad_7_edd_1_model,
ad_7_edd_2_model,
ad_7_edd_3_model,
ad_8_edd_1_model,
ad_8_edd_2_model, /* 15 */
ad_8_edd_3_model,
ad_9_edd_1_model,
ad_9_edd_2_model,
ad_9_edd_3_model
};
static float calc_near_line_filter(one_way_line_model_state_t *s, float v)
{
float sum;
int j;
int p;
/* Add the sample in the filter buffer */
p = s->near_buf_ptr;
s->near_buf[p] = v;
if (++p == s->near_filter_len)
p = 0;
s->near_buf_ptr = p;
/* Apply the filter */
sum = 0;
for (j = 0; j < s->near_filter_len; j++)
{
sum += s->near_filter[j]*s->near_buf[p];
if (++p >= s->near_filter_len)
p = 0;
}
/* Add noise */
sum += awgn(&s->near_noise);
return sum;
}
/*- End of function --------------------------------------------------------*/
static float calc_far_line_filter(one_way_line_model_state_t *s, float v)
{
float sum;
int j;
int p;
/* Add the sample in the filter buffer */
p = s->far_buf_ptr;
s->far_buf[p] = v;
if (++p == s->far_filter_len)
p = 0;
s->far_buf_ptr = p;
/* Apply the filter */
sum = 0;
for (j = 0; j < s->far_filter_len; j++)
{
sum += s->far_filter[j]*s->far_buf[p];
if (++p >= s->far_filter_len)
p = 0;
}
/* Add noise */
sum += awgn(&s->far_noise);
return sum;
}
/*- End of function --------------------------------------------------------*/
void one_way_line_model(one_way_line_model_state_t *s,
int16_t output[],
const int16_t input[],
int samples)
{
int i;
float in;
float out;
float out1;
int16_t amp[1];
/* The path being modelled is:
terminal
| < hybrid
|
| < noise and filtering
|
| < hybrid
CO
|
| < A-law distortion + bulk delay
|
CO
| < hybrid
|
| < noise and filtering
|
| < hybrid
terminal
*/
for (i = 0; i < samples; i++)
{
in = input[i];
/* Near end analogue section */
/* Line model filters & noise */
out = calc_near_line_filter(s, in);
/* Long distance digital section */
amp[0] = out;
codec_munge(s->munge, amp, 1);
out = amp[0];
/* Introduce the bulk delay of the long distance link. */
out1 = s->bulk_delay_buf[s->bulk_delay_ptr];
s->bulk_delay_buf[s->bulk_delay_ptr] = out;
out = out1;
if (++s->bulk_delay_ptr >= s->bulk_delay)
s->bulk_delay_ptr = 0;
/* Far end analogue section */
/* Line model filters & noise */
out = calc_far_line_filter(s, out);
if (s->mains_interference)
{
tone_gen(&s->mains_tone, amp, 1);
out += amp[0];
}
output[i] = out + s->dc_offset;
}
}
/*- End of function --------------------------------------------------------*/
void one_way_line_model_set_dc(one_way_line_model_state_t *s, float dc)
{
s->dc_offset = dc;
}
/*- End of function --------------------------------------------------------*/
void one_way_line_model_set_mains_pickup(one_way_line_model_state_t *s, int f, float level)
{
tone_gen_descriptor_t mains_tone_desc;
if (f)
{
make_tone_gen_descriptor(&mains_tone_desc, f, (int) (level - 10.0f), f*3, (int) level, 1, 0, 0, 0, TRUE);
tone_gen_init(&s->mains_tone, &mains_tone_desc);
}
s->mains_interference = f;
}
/*- End of function --------------------------------------------------------*/
void both_ways_line_model(both_ways_line_model_state_t *s,
int16_t output1[],
const int16_t input1[],
int16_t output2[],
const int16_t input2[],
int samples)
{
int i;
float in1;
float in2;
float out1;
float out2;
float tmp1;
float tmp2;
int16_t amp[1];
/* The path being modelled is:
terminal
| < hybrid echo
|
| < noise and filtering
|
| < hybrid echo
CO
|
| < A-law distortion + bulk delay
|
CO
| < hybrid echo
|
| < noise and filtering
|
| < hybrid echo
terminal
*/
for (i = 0; i < samples; i++)
{
in1 = input1[i];
in2 = input2[i];
/* Near end analogue sections */
/* Echo from each terminal's CO hybrid */
tmp1 = in1 + s->fout2*s->line1.near_co_hybrid_echo;
tmp2 = in2 + s->fout1*s->line2.near_co_hybrid_echo;
/* Line model filters & noise */
s->fout1 = calc_near_line_filter(&s->line1, tmp1);
s->fout2 = calc_near_line_filter(&s->line2, tmp2);
/* Long distance digital section */
/* Introduce distortion due to A-law or u-law munging. */
amp[0] = s->fout1;
codec_munge(s->line1.munge, amp, 1);
s->fout1 = amp[0];
amp[0] = s->fout2;
codec_munge(s->line2.munge, amp, 1);
s->fout2 = amp[0];
/* Introduce the bulk delay of the long distance digital link. */
out1 = s->line1.bulk_delay_buf[s->line1.bulk_delay_ptr];
s->line1.bulk_delay_buf[s->line1.bulk_delay_ptr] = s->fout1;
s->fout1 = out1;
if (++s->line1.bulk_delay_ptr >= s->line1.bulk_delay)
s->line1.bulk_delay_ptr = 0;
out2 = s->line2.bulk_delay_buf[s->line2.bulk_delay_ptr];
s->line2.bulk_delay_buf[s->line2.bulk_delay_ptr] = s->fout2;
s->fout2 = out2;
if (++s->line2.bulk_delay_ptr >= s->line2.bulk_delay)
s->line2.bulk_delay_ptr = 0;
/* Far end analogue sections */
/* Echo from each terminal's own hybrid */
out1 += in2*s->line1.far_cpe_hybrid_echo;
out2 += in1*s->line2.far_cpe_hybrid_echo;
/* Line model filters & noise */
out1 = calc_far_line_filter(&s->line1, out1);
out2 = calc_far_line_filter(&s->line2, out2);
output1[i] = fsaturate(out1 + s->line1.dc_offset);
output2[i] = fsaturate(out2 + s->line2.dc_offset);
}
}
/*- End of function --------------------------------------------------------*/
void both_ways_line_model_set_dc(both_ways_line_model_state_t *s, float dc1, float dc2)
{
s->line1.dc_offset = dc1;
s->line2.dc_offset = dc2;
}
/*- End of function --------------------------------------------------------*/
void both_ways_line_model_set_mains_pickup(both_ways_line_model_state_t *s, int f, float level1, float level2)
{
tone_gen_descriptor_t mains_tone_desc;
if (f)
{
make_tone_gen_descriptor(&mains_tone_desc, f, (int) (level1 - 10.0f), f*3, (int) level1, 1, 0, 0, 0, TRUE);
tone_gen_init(&s->line1.mains_tone, &mains_tone_desc);
make_tone_gen_descriptor(&mains_tone_desc, f, (int) (level2 - 10.0f), f*3, (int) level2, 1, 0, 0, 0, TRUE);
tone_gen_init(&s->line2.mains_tone, &mains_tone_desc);
}
s->line1.mains_interference = f;
s->line2.mains_interference = f;
}
/*- End of function --------------------------------------------------------*/
one_way_line_model_state_t *one_way_line_model_init(int model, float noise, int codec, int rbs_pattern)
{
one_way_line_model_state_t *s;
if ((s = (one_way_line_model_state_t *) malloc(sizeof(*s))) == NULL)
return NULL;
memset(s, 0, sizeof(*s));
s->bulk_delay = 8;
s->bulk_delay_ptr = 0;
s->munge = codec_munge_init(codec, rbs_pattern);
s->near_filter = models[model];
s->near_filter_len = 129;
s->far_filter = models[model];
s->far_filter_len = 129;
awgn_init_dbm0(&s->near_noise, 1234567, noise);
awgn_init_dbm0(&s->far_noise, 1234567, noise);
s->dc_offset = 0.0f;
s->mains_interference = 0;
return s;
}
/*- End of function --------------------------------------------------------*/
int one_way_line_model_release(one_way_line_model_state_t *s)
{
free(s);
return 0;
}
/*- End of function --------------------------------------------------------*/
both_ways_line_model_state_t *both_ways_line_model_init(int model1,
float noise1,
int model2,
float noise2,
int codec,
int rbs_pattern)
{
float echo_level;
both_ways_line_model_state_t *s;
if ((s = (both_ways_line_model_state_t *) malloc(sizeof(*s))) == NULL)
return NULL;
memset(s, 0, sizeof(*s));
s->line1.munge = codec_munge_init(codec, rbs_pattern);
s->line2.munge = codec_munge_init(codec, rbs_pattern);
s->line1.bulk_delay = 8;
s->line2.bulk_delay = 8;
s->line1.bulk_delay_ptr = 0;
s->line2.bulk_delay_ptr = 0;
s->line1.near_filter = models[model1];
s->line1.near_filter_len = 129;
s->line2.near_filter = models[model2];
s->line2.near_filter_len = 129;
s->line1.far_filter = models[model1];
s->line1.far_filter_len = 129;
s->line2.far_filter = models[model2];
s->line2.far_filter_len = 129;
awgn_init_dbm0(&s->line1.near_noise, 1234567, noise1);
awgn_init_dbm0(&s->line2.near_noise, 7654321, noise2);
awgn_init_dbm0(&s->line1.far_noise, 1234567, noise1);
awgn_init_dbm0(&s->line2.far_noise, 7654321, noise2);
s->line1.dc_offset = 0.0f;
s->line2.dc_offset = 0.0f;
s->line1.mains_interference = 0;
s->line2.mains_interference = 0;
/* Echos */
echo_level = -15; /* in dB */
s->line1.near_co_hybrid_echo = pow(10, echo_level/20.0);
s->line2.near_co_hybrid_echo = pow(10, echo_level/20.0);
s->line1.near_cpe_hybrid_echo = pow(10, echo_level/20.0);
s->line2.near_cpe_hybrid_echo = pow(10, echo_level/20.0);
return s;
}
/*- End of function --------------------------------------------------------*/
int both_ways_line_model_release(both_ways_line_model_state_t *s)
{
free(s);
return 0;
}
/*- End of function --------------------------------------------------------*/
/*- End of file ------------------------------------------------------------*/
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