NetBSD/usr.bin/audiocfg/dtmf.c

79 lines
2.6 KiB
C

/* $NetBSD: dtmf.c,v 1.2 2010/09/01 21:54:00 jmcneill Exp $ */
/*
* Copyright (c) 2010 Jared D. McNeill <jmcneill@invisible.ca>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/endian.h>
#include <fcntl.h>
#include <math.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "dtmf.h"
#define PI2 (3.14159265358979323846f * 2)
static void
dtmf_create(int16_t *buf, unsigned int sample_rate,
unsigned short sample_length, unsigned short channels,
unsigned int chanmask, float freq1, float freq2)
{
int c, i;
size_t sample_count = sample_rate * sample_length;
for (i = 0; i < sample_count; i++) {
for (c = 0; c < channels; c++) {
if ((chanmask & (1 << c)) == 0)
continue;
buf[c] = htole16(
(sin(i * PI2 * (freq1 / sample_rate)) +
sin(i * PI2 * (freq2 / sample_rate))) * 16383
);
}
buf += channels;
}
}
void
dtmf_new(int16_t **buf, size_t *buflen, unsigned int sample_rate,
unsigned short sample_length, unsigned short channels,
unsigned int chanmask, float rate1, float rate2)
{
*buflen = sample_rate * sizeof(int16_t) * sample_length * channels;
*buf = calloc(1, *buflen);
if (*buf == NULL) {
perror("calloc");
return;
}
dtmf_create(*buf, sample_rate, sample_length, channels, chanmask,
rate1, rate2);
}