/// <summary>
/// Method implements simple phaser effect
/// </summary>
/// <param name="signal"></param>
/// <param name="filteringOptions"></param>
/// <returns></returns>
public DiscreteSignal ApplyTo(DiscreteSignal signal,
FilteringOptions filteringOptions = FilteringOptions.Auto)
{
var x = signal.Samples;
var samplingRateInverted = 1.0 / signal.SamplingRate;
var lfo = new TriangleWaveBuilder()
.SetParameter("lo", MinFrequency)
.SetParameter("hi", MaxFrequency)
.SetParameter("freq", LfoFrequency)
.OfLength(signal.Length)
.SampledAt(signal.SamplingRate)
.Build();
var y = new float[x.Length];
for (var i = 2; i < signal.Length; i++)
{
var filter = new NotchFilter((float)(lfo[i] * samplingRateInverted), Q);
var b = filter.Tf.Numerator;
var a = filter.Tf.Denominator;
y[i] = (float)(b[0] * x[i] + b[1] * x[i - 1] + b[2] * x[i - 2] - (a[1] * y[i - 1] + a[2] * y[i - 2]));
}
return(new DiscreteSignal(signal.SamplingRate, y));
}
/// <summary>
/// Method implements simple wah-wah effect
/// </summary>
/// <param name="signal"></param>
/// <param name="filteringOptions"></param>
/// <returns></returns>
public DiscreteSignal ApplyTo(DiscreteSignal signal,
FilteringOptions filteringOptions = FilteringOptions.Auto)
{
var x = signal.Samples;
var samplingRateInverted = 2 * Math.PI / signal.SamplingRate;
var lfo = new TriangleWaveBuilder()
.SetParameter("lo", MinFrequency)
.SetParameter("hi", MaxFrequency)
.SetParameter("freq", LfoFrequency)
.OfLength(signal.Length)
.SampledAt(signal.SamplingRate)
.Build();
var f = 2 * Math.Sin(lfo[0] * samplingRateInverted);
var yh = new float[x.Length];
var yb = new float[x.Length];
var yl = new float[x.Length];
yh[0] = x[0];
yb[0] = (float)(f * yh[0]);
yl[0] = (float)(f * yb[0]);
for (var i = 1; i < signal.Length; i++)
{
yh[i] = x[i] - yl[i - 1] - Q * yb[i - 1];
yb[i] = (float)(f * yh[i] + yb[i - 1]);
yl[i] = (float)(f * yb[i] + yl[i - 1]);
f = 2 * Math.Sin(lfo[i] * samplingRateInverted);
}
var maxYb = yb.Max(y => Math.Abs(y));
return(new DiscreteSignal(signal.SamplingRate, yb.Select(y => y / maxYb)));
}
private void generateSignalButton_Click(object sender, EventArgs e)
{
var sampleCount = int.Parse(durationTextBox.Text);
var samplingRate = _signal1?.SamplingRate ?? 16000;
SignalBuilder signalBuilder;
switch (builderComboBox.Text)
{
case "Sinusoid":
signalBuilder = new SineBuilder();
_signal2 = signalBuilder
.SetParameter("low", -0.4f)
.SetParameter("high", 0.4f)
.SetParameter("freq", 233 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Sawtooth":
signalBuilder = new SawtoothBuilder();
_signal2 = signalBuilder
.SetParameter("low", -0.3f)
.SetParameter("high", 0.3f)
.SetParameter("freq", 233 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Triangle Wave":
signalBuilder = new TriangleWaveBuilder();
_signal2 = signalBuilder
.SetParameter("low", -0.3f)
.SetParameter("high", 0.3f)
.SetParameter("freq", 233 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Square Wave":
signalBuilder = new SquareWaveBuilder();
_signal2 = signalBuilder
.SetParameter("low", -0.25f)
.SetParameter("high", 0.25f)
.SetParameter("freq", 233 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Pulse Wave":
signalBuilder = new PulseWaveBuilder();
_signal2 = signalBuilder
.SetParameter("min", 0)
.SetParameter("max", 0.5f)
.SetParameter("pulse", 0.007f /*sec*/)
.SetParameter("period", 0.020f /*sec*/)
.OfLength(sampleCount)
.DelayedBy(50)
.SampledAt(samplingRate)
.Build();
break;
case "Chirp":
signalBuilder = new ChirpBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.3f)
.SetParameter("max", 0.3f)
.OfLength(sampleCount)
.RepeatedTimes(3)
.SampledAt(samplingRate)
.Build();
break;
case "Sinc":
signalBuilder = new SincBuilder();
_signal2 = signalBuilder
.SetParameter("min", 0)
.SetParameter("max", 0.5f)
.SetParameter("freq", 700 /*Hz*/)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Ramp":
signalBuilder = new RampBuilder();
_signal2 = signalBuilder
.SetParameter("slope", 0.0007f)
.SetParameter("intercept", -0.5f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "AWGN":
signalBuilder = new AwgnBuilder();
_signal2 = signalBuilder
.SetParameter("sigma", 0.25f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Pink Noise":
signalBuilder = new PinkNoiseBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.5f)
.SetParameter("max", 0.5f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Red Noise":
signalBuilder = new RedNoiseBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.5f)
.SetParameter("max", 0.5f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
case "Perlin Noise":
signalBuilder = new PerlinNoiseBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.3f)
.SetParameter("max", 0.7f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
default:
signalBuilder = new WhiteNoiseBuilder();
_signal2 = signalBuilder
.SetParameter("min", -0.5f)
.SetParameter("max", 0.5f)
.OfLength(sampleCount)
.SampledAt(samplingRate)
.Build();
break;
}
builderParametersListBox.Items.Clear();
builderParametersListBox.Items.AddRange(signalBuilder.GetParametersInfo());
builderParametersListBox.Items.Add("");
builderParametersListBox.Items.Add($"min: {_signal2.Samples.Min():F2}");
builderParametersListBox.Items.Add($"max: {_signal2.Samples.Max():F2}");
builderParametersListBox.Items.Add($"avg: {_signal2.Samples.Average():F4}");
if (_signal1 != null)
{
//_signal3 = _signal1 + _signal2;
var positions = Enumerable.Range(0, 3).Select(pos => pos * (_signal2.Length + 2000)).ToArray();
_signal3 = _signal1.SuperimposeMany(_signal2, positions);
superimposedSignalPanel.Signal = _signal3;
}
generatedSignalPanel.Stride = 1;
generatedSignalPanel.Signal = _signal2;
var spectrum = _fft.PowerSpectrum(_signal2.First(512));
spectrumPanel.Line = spectrum.Samples;
spectrumPanel.ToDecibel();
}