/*
 * Copyright (c) 2001 by Tsuyoshi Iguchi (zinnia@risky-safety.org)
 * 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 AUTHOR 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 AUTHOR 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.
 *
 *	$Id$
 */
/*
 * gcc -o dtmf dtmf.c -lm
 *
 * usage: dtmf 117 > hoge.raw ; sox -t cdr hoge.raw hoge.wav
 *      : sox -t cdr =(dtmf 117) hoge.wav    (for zsh)
 */

#include <stdio.h>
#include <math.h>

const double tonelen = 0.2;
const double brethlen = 0.1;
const int samplerate = 44100;

const int amp = 10;

typedef struct {
  int h; /* dwarf, hobbit */
  int l; /* leprechaun */
} tones;

tones tone[17] = {
  {941, 1336}, /* 0 */
  {697, 1209}, /* 1 */
  {697, 1336}, /* 2 */
  {697, 1477}, /* 3 */
  {770, 1209}, /* 4 */
  {770, 1336}, /* 5 */
  {770, 1477}, /* 6 */
  {852, 1209}, /* 7 */
  {852, 1336}, /* 8 */
  {852, 1477}, /* 9 */
  {697, 1633}, /* A */
  {770, 1633}, /* B */
  {852, 1633}, /* C */
  {941, 1633}, /* D */
  {941, 1209}, /* * */
  {941, 1447}, /* # */
  {0, 0}, /* , */
};

double sine(double f, double t)
{
  return sin(2.0 * M_PI * f * t);
}

int gettoneno(int c)
{
  int d;
  if(isdigit(c)) return c - '0';
  if(c == '*') return 14;
  if(c == '#') return 15;
  if(c == ',') return 16;
  d = tolower(c);
  if(d >= 'a' && d <= 'd') return d - 'a' + 10;
  return -1;
}

void dtmf(char* s)
{
  char* p; int i, j;
  double t, v;
  char q[2];

  for(p = s; *p; p++){
    i = gettoneno(*p);
    if(i == -1) continue;
    for(t = 0; t < tonelen; t += 1.0 / samplerate){
      v = amp * (sine(tone[i].h, t) + sine(tone[i].l, t));
      j = (int)v;
      q[0] = j & 0xff;
      q[1] = (j >> 8) & 0xff;
      fwrite(q, 1, 2, stdout);
      fwrite(q, 1, 2, stdout);
    }
    q[0] = q[1] = 0;
    for(t = 0; t < brethlen; t += 1.0 / samplerate){
      fwrite(q, 1, 2, stdout);
      fwrite(q, 1, 2, stdout);
    }
  }
}

int main(int argc, char* argv[])
{
  static char buf[0x100];
  if(argc < 2){
    while(fgets(buf, 0x100, stdin)){
      dtmf(buf);
    }
  } else {
    dtmf(argv[1]);
  }
  return 0;
}