/// <summary>
/// Get array of touch tones for given string.
/// </summary>
/// <param name="keys">String of touch tone characters to convert to touch tones.</param>
/// <param name="keyDuration">Duration of touch tone key press in seconds, typically fractional.</param>
/// <param name="interKeyPause">Time to wait between key presses in seconds, typically fractional.</param>
/// <returns>Array of touch tones for given string.</returns>
/// <remarks>Non-touch tone characters are ignored. Commas are interpreted as a one second pause.</remarks>
public static DTMF[] GetTouchTones(string keys, double keyDuration, double interKeyPause)
{
List<DTMF> touchTones = new List<DTMF>();
TouchTone touchTone;
DTMF pause = new DTMF(0.0D, 0.0D, interKeyPause);
DTMF longPause = new DTMF(0.0D, 0.0D, 1.0D);
foreach (char key in keys)
{
if (key == ',')
{
// Interpret commas as long pauses
touchTones.Add(longPause);
}
else if (TouchTone.TryParse(key, out touchTone))
{
if (touchTones.Count > 0)
touchTones.Add(pause);
touchTone.Duration = keyDuration;
touchTones.Add(touchTone);
}
}
return touchTones.ToArray();
}
/// <summary>
/// Generates the specified dual-tone multi-frequencies <paramref name="repeatCount"/> times storing them in the specified <see cref="WaveFile"/>.
/// </summary>
/// <param name="destination"><see cref="WaveFile"/> used to store generated dual-tone multi-frequencies.</param>
/// <param name="tones">Dual-tone multi-frequencies to generate.</param>
/// <param name="volume">Volume of generated dual-tones as a percentage (0 to 1).</param>
/// <param name="repeatCount">Number of times to repeat each tone.</param>
/// <exception cref="ArgumentOutOfRangeException">Value must be expressed as a fractional percentage between zero and one.</exception>
/// <exception cref="InvalidOperationException"><see cref="DTMF"/> only generated for <see cref="WaveFile"/> with a sample rate of 8, 16, 24, 32 or 64 bits per sample.</exception>
public static void Generate(WaveFile destination, DTMF[] tones, double volume, int repeatCount)
{
if (volume < 0.0D || volume > 1.0D)
throw new ArgumentOutOfRangeException("volume", "Value must be expressed as a fractional percentage between zero and one");
double amplitude = destination.AmplitudeScalar * volume;
// Iterate through each repeat count
for (int x = 0; x < repeatCount; x++)
{
// Interate through each tone
foreach (DTMF tone in tones)
{
// Iterate through each sample for total DTMF duration
for (long y = 0; y < tone.Duration * destination.SampleRate; y++)
{
// Compute frequencies of DTMF at given time and add to wave file
destination.AddSample(DTMF.ComputeFrequencies(tone, y, destination.SampleRate) * amplitude);
}
}
}
}
/// <summary>
/// Generates a single instance of each of the specified dual-tone multi-frequencies storing them in the specified <see cref="WaveFile"/>.
/// </summary>
/// <param name="destination"><see cref="WaveFile"/> used to store generated dual-tone multi-frequencies.</param>
/// <param name="tones">Dual-tone multi-frequencies to generate.</param>
/// <param name="volume">Volume of generated dual-tones as a percentage (0 to 1).</param>
public static void Generate(WaveFile destination, DTMF[] tones, double volume)
{
Generate(destination, tones, volume, 1);
}
/// <summary>
/// Generates the specified dual-tone multi-frequency <paramref name="repeatCount"/> times storing it in the specified <see cref="WaveFile"/>.
/// </summary>
/// <param name="destination"><see cref="WaveFile"/> used to store generated dual-tone multi-frequencies.</param>
/// <param name="tone">Dual-tone multi-frequency to generate.</param>
/// <param name="volume">Volume of generated dual-tones as a percentage (0 to 1).</param>
/// <param name="repeatCount">Number of times to repeat the tone.</param>
public static void Generate(WaveFile destination, DTMF tone, double volume, int repeatCount)
{
Generate(destination, new DTMF[] { tone }, volume, repeatCount);
}
/// <summary>
/// Generates the specified dual-tone multi-frequency storing it in the specified <see cref="WaveFile"/>.
/// </summary>
/// <param name="destination"><see cref="WaveFile"/> used to store generated dual-tone multi-frequencies.</param>
/// <param name="tone">Dual-tone multi-frequency to generate.</param>
/// <param name="volume">Volume of generated dual-tones as a percentage (0 to 1).</param>
public static void Generate(WaveFile destination, DTMF tone, double volume)
{
Generate(destination, new DTMF[] { tone }, volume, 1);
}
// Static Methods
/// <summary>
/// Computes a dual-tone multi-frequency sound for the given <see cref="DTMF"/> information and time.
/// </summary>
/// <param name="tone">Instance of the <see cref="DTMF"/> specifying the duration as well as the low and high frequencies of the dual-tone.</param>
/// <param name="sampleIndex">Sample index (represents time anywhere from zero to full length of tone).</param>
/// <param name="sampleRate">Number of samples per second.</param>
/// <returns>The amplitude for the dual-tone at the given time.</returns>
/// <remarks>
/// This method computes an amplitude representing the acoustic pressure of a
/// <see cref="DTMF"/> of the given frequency for the given time.
/// </remarks>
public static double ComputeFrequencies(DTMF tone, long sampleIndex, int sampleRate)
{
return (Timbre.PureTone(tone.LowFrequency, sampleIndex, 0, sampleRate) + Timbre.PureTone(tone.HighFrequency, sampleIndex, 0, sampleRate)) / 2;
}
