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freeswitch/libs/spandsp/src/super_tone_rx.c

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/*
* SpanDSP - a series of DSP components for telephony
*
* super_tone_rx.c - Flexible telephony supervisory tone detection.
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2003 Steve Underwood
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1,
* 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*! \file */
#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <ctype.h>
#include <time.h>
#include <inttypes.h>
#if defined(HAVE_TGMATH_H)
#include <tgmath.h>
#endif
#if defined(HAVE_MATH_H)
#include <math.h>
#endif
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/alloc.h"
#include "spandsp/fast_convert.h"
#include "spandsp/complex.h"
#include "spandsp/vector_float.h"
#include "spandsp/complex_vector_float.h"
#include "spandsp/tone_detect.h"
#include "spandsp/tone_generate.h"
#include "spandsp/super_tone_rx.h"
#include "spandsp/private/super_tone_rx.h"
#if defined(SPANDSP_USE_FIXED_POINT)
#define DETECTION_THRESHOLD 16439 /* -42dBm0 [((SUPER_TONE_BINS*SUPER_TONE_BINS*32768.0/(1.4142*128.0))*10^((-42 - DBM0_MAX_SINE_POWER)/20.0))^2] */
#define TONE_TWIST 4 /* 6dB */
#define TONE_TO_TOTAL_ENERGY 64 /* -3dB */
#else
#define DETECTION_THRESHOLD 2104205.6f /* -42dBm0 [((SUPER_TONE_BINS*SUPER_TONE_BINS*32768.0/1.4142)*10^((-42 - DBM0_MAX_SINE_POWER)/20.0))^2] */
#define TONE_TWIST 3.981f /* 6dB */
#define TONE_TO_TOTAL_ENERGY 1.995f /* 3dB */
#endif
static int add_super_tone_freq(super_tone_rx_descriptor_t *desc, int freq)
{
int i;
if (freq == 0)
return -1;
/* Look for an existing frequency */
for (i = 0; i < desc->used_frequencies; i++)
{
if (desc->pitches[i][0] == freq)
return desc->pitches[i][1];
}
/* Look for an existing tone which is very close. We may need to merge
the detectors. */
for (i = 0; i < desc->used_frequencies; i++)
{
if ((desc->pitches[i][0] - 10) <= freq && freq <= (desc->pitches[i][0] + 10))
{
/* Merge these two */
desc->pitches[desc->used_frequencies][0] = freq;
desc->pitches[desc->used_frequencies][1] = i;
make_goertzel_descriptor(&desc->desc[desc->pitches[i][1]], (float) (freq + desc->pitches[i][0])/2, SUPER_TONE_BINS);
desc->used_frequencies++;
return desc->pitches[i][1];
}
}
desc->pitches[i][0] = freq;
desc->pitches[i][1] = desc->monitored_frequencies;
if (desc->monitored_frequencies%5 == 0)
{
desc->desc = (goertzel_descriptor_t *) span_realloc(desc->desc, (desc->monitored_frequencies + 5)*sizeof(goertzel_descriptor_t));
}
make_goertzel_descriptor(&desc->desc[desc->monitored_frequencies++], (float) freq, SUPER_TONE_BINS);
desc->used_frequencies++;
return desc->pitches[i][1];
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) super_tone_rx_add_tone(super_tone_rx_descriptor_t *desc)
{
if (desc->tones%5 == 0)
{
desc->tone_list = (super_tone_rx_segment_t **) span_realloc(desc->tone_list, (desc->tones + 5)*sizeof(super_tone_rx_segment_t *));
desc->tone_segs = (int *) span_realloc(desc->tone_segs, (desc->tones + 5)*sizeof(int));
}
desc->tone_list[desc->tones] = NULL;
desc->tone_segs[desc->tones] = 0;
desc->tones++;
return desc->tones - 1;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) super_tone_rx_add_element(super_tone_rx_descriptor_t *desc,
int tone,
int f1,
int f2,
int min,
int max)
{
int step;
step = desc->tone_segs[tone];
if (step%5 == 0)
{
desc->tone_list[tone] = (super_tone_rx_segment_t *) span_realloc(desc->tone_list[tone], (step + 5)*sizeof(super_tone_rx_segment_t));
}
desc->tone_list[tone][step].f1 = add_super_tone_freq(desc, f1);
desc->tone_list[tone][step].f2 = add_super_tone_freq(desc, f2);
desc->tone_list[tone][step].min_duration = min*8;
desc->tone_list[tone][step].max_duration = (max == 0) ? 0x7FFFFFFF : max*8;
desc->tone_segs[tone]++;
return step;
}
/*- End of function --------------------------------------------------------*/
static int test_cadence(super_tone_rx_segment_t *pattern,
int steps,
super_tone_rx_segment_t *test,
int rotation)
{
int i;
int j;
if (rotation >= 0)
{
/* Check only for the sustaining of a tone in progress. This means
we only need to check each block if the latest step is compatible
with the tone template. */
if (steps < 0)
{
/* A -ve value for steps indicates we just changed step, and need to
check the last one ended within spec. If we don't do this
extra test a low duration segment might be accepted as OK. */
steps = -steps;
j = (rotation + steps - 2)%steps;
if (pattern[j].f1 != test[8].f1 || pattern[j].f2 != test[8].f2)
return 0;
if (pattern[j].min_duration > test[8].min_duration*SUPER_TONE_BINS
||
pattern[j].max_duration < test[8].min_duration*SUPER_TONE_BINS)
{
return 0;
}
}
j = (rotation + steps - 1)%steps;
if (pattern[j].f1 != test[9].f1 || pattern[j].f2 != test[9].f2)
return 0;
if (pattern[j].max_duration < test[9].min_duration*SUPER_TONE_BINS)
return 0;
}
else
{
/* Look for a complete template match. */
for (i = 0; i < steps; i++)
{
j = i + 10 - steps;
if (pattern[i].f1 != test[j].f1 || pattern[i].f2 != test[j].f2)
return 0;
if (pattern[i].min_duration > test[j].min_duration*SUPER_TONE_BINS
||
pattern[i].max_duration < test[j].min_duration*SUPER_TONE_BINS)
{
return 0;
}
}
}
return 1;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(super_tone_rx_descriptor_t *) super_tone_rx_make_descriptor(super_tone_rx_descriptor_t *desc)
{
if (desc == NULL)
{
if ((desc = (super_tone_rx_descriptor_t *) span_alloc(sizeof(*desc))) == NULL)
return NULL;
}
desc->tone_list = NULL;
desc->tone_segs = NULL;
desc->used_frequencies = 0;
desc->monitored_frequencies = 0;
desc->desc = NULL;
desc->tones = 0;
return desc;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) super_tone_rx_free_descriptor(super_tone_rx_descriptor_t *desc)
{
int i;
if (desc)
{
for (i = 0; i < desc->tones; i++)
{
if (desc->tone_list[i])
span_free(desc->tone_list[i]);
}
if (desc->tone_list)
span_free(desc->tone_list);
if (desc->tone_segs)
span_free(desc->tone_segs);
if (desc->desc)
span_free(desc->desc);
span_free(desc);
}
return 0;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(void) super_tone_rx_tone_callback(super_tone_rx_state_t *s,
tone_report_func_t callback,
void *user_data)
{
s->tone_callback = callback;
s->callback_data = user_data;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(void) super_tone_rx_segment_callback(super_tone_rx_state_t *s,
tone_segment_func_t callback)
{
s->segment_callback = callback;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(super_tone_rx_state_t *) super_tone_rx_init(super_tone_rx_state_t *s,
super_tone_rx_descriptor_t *desc,
tone_report_func_t callback,
void *user_data)
{
int i;
if (desc == NULL)
return NULL;
if (callback == NULL)
return NULL;
if (s == NULL)
{
if ((s = (super_tone_rx_state_t *) span_alloc(sizeof(*s) + desc->monitored_frequencies*sizeof(goertzel_state_t))) == NULL)
return NULL;
}
for (i = 0; i < 11; i++)
{
s->segments[i].f1 = -1;
s->segments[i].f2 = -1;
s->segments[i].min_duration = 0;
}
s->segment_callback = NULL;
s->tone_callback = callback;
s->callback_data = user_data;
if (desc)
s->desc = desc;
s->detected_tone = -1;
#if defined(SPANDSP_USE_FIXED_POINT)
s->energy = 0;
#else
s->energy = 0.0f;
#endif
for (i = 0; i < desc->monitored_frequencies; i++)
goertzel_init(&s->state[i], &s->desc->desc[i]);
return s;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) super_tone_rx_release(super_tone_rx_state_t *s)
{
return 0;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) super_tone_rx_free(super_tone_rx_state_t *s)
{
if (s)
span_free(s);
return 0;
}
/*- End of function --------------------------------------------------------*/
static void super_tone_chunk(super_tone_rx_state_t *s)
{
int i;
int j;
int k1;
int k2;
#if defined(SPANDSP_USE_FIXED_POINT)
int32_t res[SUPER_TONE_BINS/2];
#else
float res[SUPER_TONE_BINS/2];
#endif
for (i = 0; i < s->desc->monitored_frequencies; i++)
res[i] = goertzel_result(&s->state[i]);
/* Find our two best monitored frequencies, which also have adequate energy. */
if (s->energy < DETECTION_THRESHOLD)
{
k1 = -1;
k2 = -1;
}
else
{
if (res[0] > res[1])
{
k1 = 0;
k2 = 1;
}
else
{
k1 = 1;
k2 = 0;
}
for (j = 2; j < s->desc->monitored_frequencies; j++)
{
if (res[j] >= res[k1])
{
k2 = k1;
k1 = j;
}
else if (res[j] >= res[k2])
{
k2 = j;
}
}
if ((res[k1] + res[k2]) < TONE_TO_TOTAL_ENERGY*s->energy)
{
k1 = -1;
k2 = -1;
}
else if (res[k1] > TONE_TWIST*res[k2])
{
k2 = -1;
}
else if (k2 < k1)
{
j = k1;
k1 = k2;
k2 = j;
}
}
/* See if this differs from last time. */
if (k1 != s->segments[10].f1 || k2 != s->segments[10].f2)
{
/* It is different, but this might just be a transitional quirk, or
a one shot hiccup (eg due to noise). Only if this same thing is
seen a second time should we change state. */
s->segments[10].f1 = k1;
s->segments[10].f2 = k2;
/* While things are hopping around, consider this a continuance of the
previous state. */
s->segments[9].min_duration++;
}
else
{
if (k1 != s->segments[9].f1 || k2 != s->segments[9].f2)
{
if (s->detected_tone >= 0)
{
/* Test for the continuance of the existing tone pattern, based on our new knowledge of an
entire segment length. */
if (!test_cadence(s->desc->tone_list[s->detected_tone], -s->desc->tone_segs[s->detected_tone], s->segments, s->rotation++))
{
s->detected_tone = -1;
s->tone_callback(s->callback_data, s->detected_tone, -10, 0);
}
}
if (s->segment_callback)
{
s->segment_callback(s->callback_data,
s->segments[9].f1,
s->segments[9].f2,
s->segments[9].min_duration*SUPER_TONE_BINS/8);
}
memmove(&s->segments[0], &s->segments[1], 9*sizeof(s->segments[0]));
s->segments[9].f1 = k1;
s->segments[9].f2 = k2;
s->segments[9].min_duration = 1;
}
else
{
/* This is a continuance of the previous state */
if (s->detected_tone >= 0)
{
/* Test for the continuance of the existing tone pattern. We must do this here, so we can sense the
discontinuance of the tone on an excessively long segment. */
if (!test_cadence(s->desc->tone_list[s->detected_tone], s->desc->tone_segs[s->detected_tone], s->segments, s->rotation))
{
s->detected_tone = -1;
s->tone_callback(s->callback_data, s->detected_tone, -10, 0);
}
}
s->segments[9].min_duration++;
}
}
if (s->detected_tone < 0)
{
/* Test for the start of any of the monitored tone patterns */
for (j = 0; j < s->desc->tones; j++)
{
if (test_cadence(s->desc->tone_list[j], s->desc->tone_segs[j], s->segments, -1))
{
s->detected_tone = j;
s->rotation = 0;
s->tone_callback(s->callback_data, s->detected_tone, -10, 0);
break;
}
}
}
#if defined(SPANDSP_USE_FIXED_POINT)
s->energy = 0;
#else
s->energy = 0.0f;
#endif
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) super_tone_rx(super_tone_rx_state_t *s, const int16_t amp[], int samples)
{
int i;
int x;
int sample;
#if defined(SPANDSP_USE_FIXED_POINT)
int16_t xamp;
#else
float xamp;
#endif
x = 0;
for (sample = 0; sample < samples; sample += x)
{
for (i = 0; i < s->desc->monitored_frequencies; i++)
x = goertzel_update(&s->state[i], amp + sample, samples - sample);
for (i = 0; i < x; i++)
{
xamp = goertzel_preadjust_amp(amp[sample + i]);
#if defined(SPANDSP_USE_FIXED_POINT)
s->energy += ((int32_t) xamp*xamp);
#else
s->energy += xamp*xamp;
#endif
}
if (s->state[0].current_sample >= SUPER_TONE_BINS)
{
/* We have finished a Goertzel block. */
super_tone_chunk(s);
#if defined(SPANDSP_USE_FIXED_POINT)
s->energy = 0;
#else
s->energy = 0.0f;
#endif
}
}
return samples;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) super_tone_rx_fillin(super_tone_rx_state_t *s, int samples)
{
/* TODO: Roll the detector forward without a state change */
return 0;
}
/*- End of function --------------------------------------------------------*/
/*- End of file ------------------------------------------------------------*/
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