freeswitch/libs/spandsp/src/swept_tone.c

133 lines
3.7 KiB
C

/*
* SpanDSP - a series of DSP components for telephony
*
* swept_tone.c - Swept tone generation
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2009 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 <inttypes.h>
#include <string.h>
#include <stdio.h>
#if defined(HAVE_TGMATH_H)
#include <tgmath.h>
#endif
#if defined(HAVE_MATH_H)
#include <math.h>
#endif
#if defined(HAVE_STDBOOL_H)
#include <stdbool.h>
#else
#include "spandsp/stdbool.h"
#endif
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/alloc.h"
#include "spandsp/logging.h"
#include "spandsp/complex.h"
#include "spandsp/vector_float.h"
#include "spandsp/complex_vector_float.h"
#include "spandsp/vector_int.h"
#include "spandsp/complex_vector_int.h"
#include "spandsp/dds.h"
#include "spandsp/swept_tone.h"
#include "spandsp/private/logging.h"
#include "spandsp/private/swept_tone.h"
SPAN_DECLARE(swept_tone_state_t *) swept_tone_init(swept_tone_state_t *s, float start, float end, float level, int duration, int repeating)
{
if (s == NULL)
{
if ((s = (swept_tone_state_t *) span_alloc(sizeof(*s))) == NULL)
return NULL;
}
memset(s, 0, sizeof(*s));
s->current_phase_inc =
s->starting_phase_inc = dds_phase_rate(start);
s->phase_inc_step = dds_phase_rate((end - start)/(float) duration);
s->scale = dds_scaling_dbm0(level);
s->duration = duration;
s->repeating = repeating;
s->pos = 0;
s->phase = 0;
return s;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) swept_tone(swept_tone_state_t *s, int16_t amp[], int max_len)
{
int i;
int len;
int chunk_len;
for (len = 0; len < max_len; )
{
chunk_len = max_len - len;
if (chunk_len > s->duration - s->pos)
chunk_len = s->duration - s->pos;
for (i = len; i < len + chunk_len; i++)
{
amp[i] = (dds(&s->phase, s->current_phase_inc)*s->scale) >> 15;
s->current_phase_inc += s->phase_inc_step;
}
len += chunk_len;
s->pos += chunk_len;
if (s->pos >= s->duration)
{
if (!s->repeating)
break;
s->pos = 0;
s->current_phase_inc = s->starting_phase_inc;
}
}
return len;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(float) swept_tone_current_frequency(swept_tone_state_t *s)
{
return dds_frequency(s->current_phase_inc);
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) swept_tone_release(swept_tone_state_t *s)
{
return 0;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) swept_tone_free(swept_tone_state_t *s)
{
span_free(s);
return 0;
}
/*- End of function --------------------------------------------------------*/
/*- End of file ------------------------------------------------------------*/