public void TestOnlineFeatureExtractor()
{
var mfccOptions = new MfccOptions
{
SamplingRate = 8000,
FeatureCount = 5,
FrameSize = 256,
HopSize = 50,
FilterBankSize = 8
};
var signal = new WhiteNoiseBuilder().OfLength(1000).Build();
var mfccExtractor = new MfccExtractor(mfccOptions);
var mfccVectors = mfccExtractor.ComputeFrom(signal);
var onlineMfccExtractor = new OnlineFeatureExtractor(new MfccExtractor(mfccOptions));
var onlineMfccVectors = new List <float[]>();
var i = 0;
while (i < signal.Length)
{
// emulating online blocks with different sizes:
var size = (i + 1) * 15;
var block = signal.Samples.Skip(i).Take(size).ToArray();
var newVectors = onlineMfccExtractor.ComputeFrom(block);
onlineMfccVectors.AddRange(newVectors);
i += size;
}
var diff = mfccVectors.Zip(onlineMfccVectors, (e, o) => e.Zip(o, (f1, f2) => f1 - f2).Sum());
Assert.That(diff, Is.All.EqualTo(0).Within(1e-7f));
}
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();
}