public static void PreprocessForWordCount(string filePath)
{
Console.WriteLine($"Pre-processing for word count of file {filePath}");
using (var afr = new FileStream(filePath, FileMode.Open))
{
// create a signal file
var waveFile = new WaveFile(afr);
DiscreteSignal signal = waveFile[Channels.Left];
// smooth signal via moving average filter
var maFilter = new MovingAverageFilter(19);
DiscreteSignal smoothedSignal = maFilter.ApplyTo(signal);
// instance of SimpleGate
SimpleGate sg = new SimpleGate(30, 30, smoothedSignal.SamplingRate);
for (int i = 0; i < smoothedSignal.Length; i++)
{
double inValue = smoothedSignal.Samples[i];
sg.Process(ref inValue);
smoothedSignal.Samples[i] = (float)inValue;
}
using (var stream = new FileStream($"{DATA_PATH}/preprocessed.wav", FileMode.Create))
{
var signalFile = new WaveFile(smoothedSignal);
signalFile.SaveTo(stream);
}
}
}
public static DiscreteSignal PreprocessAudio(DiscreteSignal signal)
{
// smooth signal via moving average filter
var maFilter = new MovingAverageFilter(19);
DiscreteSignal smoothedSignal = maFilter.ApplyTo(signal);
using (var stream = new FileStream("smoothedSignal.wav", FileMode.Create))
{
var signalFile = new WaveFile(smoothedSignal);
signalFile.SaveTo(stream);
}
// pre-process signal with SimpleGate
SimpleGate sg = new SimpleGate(30, 30, smoothedSignal.SamplingRate);
// apply for each measured sample
for (int i = 0; i < smoothedSignal.Length; i++)
{
double inValue = smoothedSignal.Samples[i];
sg.Process(ref inValue);
smoothedSignal.Samples[i] = (float)inValue;
}
// apply envelope operation
DiscreteSignal envelopeSignal = Operation.Envelope(smoothedSignal);
using (var stream = new FileStream("envelopeSignal.wav", FileMode.Create))
{
var signalFile = new WaveFile(envelopeSignal);
signalFile.SaveTo(stream);
}
return envelopeSignal;
}
public static void TestMovingAverageFilter(string filePath)
{
Console.WriteLine($"Testing 'MovingAverage' filters on file {filePath}");
using (var afr = new FileStream(filePath, FileMode.Open))
{
// create a signal file
var waveFile = new WaveFile(afr);
DiscreteSignal signal = waveFile[Channels.Left];
int[] wSizes = new int[] { 3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47, 51 };
for (int i = 0; i < wSizes.Length; i++)
{
// build moving average filter of specified window size
int wSize = wSizes[i];
var maFilter = new MovingAverageFilter(wSize);
// apply moving average filter
DiscreteSignal smoothed = maFilter.ApplyTo(signal);
// compute signal differences
DiscreteSignal diff = Operation.SpectralSubtract(signal, smoothed);
using (var stream = new FileStream($"{DATA_PATH}/moving-average-{wSize}.wav", FileMode.Create))
{
var smoothedFile = new WaveFile(smoothed);
smoothedFile.SaveTo(stream);
}
using (var stream = new FileStream($"{DATA_PATH}/diff-original-smoothed-{wSize}.wav", FileMode.Create))
{
var diffFile = new WaveFile(diff);
diffFile.SaveTo(stream);
}
}
}
}
public void Run()
{
var output2 = new float[_signal.Length];
var output4 = new float[_signal.Length];
var output5 = new float[_signal.Length];
var outputZi = new float[_signal.Length];
var samples = _signal.Samples;
for (var i = 0; i < samples.Length; i++)
{
output4[i] = _filterV4BiQuad.Process(samples[i]);
output5[i] = _filterV5BiQuad.Process(samples[i]);
outputZi[i] = _filterZiBiQuad.Process(samples[i]);
}
var diffAverageV4 = output5.Zip(output4, (o5, o4) => Math.Abs(o5 - o4)).Average();
var diffAverageZi = output5.Zip(outputZi, (o5, zi) => Math.Abs(o5 - zi)).Average();
Console.WriteLine($"Average difference Ver.0.9.5 vs. Ver.0.9.4 : {diffAverageV4}");
Console.WriteLine($"Average difference IirFilter vs. ZiFilter : {diffAverageZi}");
for (var i = 0; i < samples.Length; i++)
{
output4[i] = _filterV4Butterworth6.Process(samples[i]);
output5[i] = _filterV5Butterworth6.Process(samples[i]);
outputZi[i] = _filterZiButterworth6.Process(samples[i]);
}
diffAverageV4 = output5.Zip(output4, (o5, o4) => Math.Abs(o5 - o4)).Average();
diffAverageZi = output5.Zip(outputZi, (o5, zi) => Math.Abs(o5 - zi)).Average();
Console.WriteLine($"Average difference Ver.0.9.5 vs. Ver.0.9.4 : {diffAverageV4}");
Console.WriteLine($"Average difference IirFilter vs. ZiFilter : {diffAverageZi}");
// === MISC ====
var med = new MedianFilter();
var med2 = new MedianFilter2();
var medOut = med.ApplyTo(_signal).Samples;
var medOut2 = med2.ApplyTo(_signal).Samples;
var diffAverageMed = medOut.Zip(medOut, (m1, m2) => Math.Abs(m1 - m2)).Average();
Console.WriteLine($"Average difference MedianFilter vs. MedianFilter2 : {diffAverageMed}");
var ma = new MovingAverageFilter();
var maRec = new MovingAverageRecursiveFilter();
var maOut = ma.ApplyTo(_signal).Samples;
var maRecOut = maRec.ApplyTo(_signal).Samples;
var diffAverageMa = maOut.Zip(maRecOut, (m1, m2) => Math.Abs(m1 - m2)).Average();
Console.WriteLine($"Average difference MovingAverageFilter vs. MovingAverageRecursiveFilter : {diffAverageMa}");
// 32bit vs. 64bit
var fir32 = new FirFilter(DesignFilter.FirWinLp(7, 0.1));
var fir64 = new FirFilter64(DesignFilter.FirWinLp(7, 0.1));
var fir32Out = fir32.ApplyTo(_signal).Samples;
var fir64Out = fir64.ApplyTo(_signal.Samples.ToDoubles());
var diffAverageFir = fir64Out.Zip(fir32Out, (m1, m2) => Math.Abs(m1 - m2)).Average();
Console.WriteLine($"Average difference FirFilter vs. FirFilter64 : {diffAverageFir}");
var iir32 = new IirFilter(_filterV5Butterworth6.Tf);
var iir64 = new IirFilter64(_filterV5Butterworth6.Tf);
var iir32Out = iir32.ApplyTo(_signal).Samples;
var iir64Out = iir64.ApplyTo(_signal.Samples.ToDoubles());
var diffAverageIir = iir64Out.Zip(iir32Out, (m1, m2) => Math.Abs(m1 - m2)).Average();
Console.WriteLine($"Average difference IirFilter vs. IirFilter64 : {diffAverageIir}");
var zi32 = new ZiFilter(_filterV5Butterworth6.Tf);
var zi64 = new ZiFilter64(_filterV5Butterworth6.Tf);
var zi32Out = zi32.ApplyTo(_signal).Samples;
var zi64Out = zi64.ApplyTo(_signal.Samples.ToDoubles());
var diffAverageZis = zi64Out.Zip(zi32Out, (m1, m2) => Math.Abs(m1 - m2)).Average();
Console.WriteLine($"Average difference ZiFilter vs. ZiFilter64 : {diffAverageZis}");
zi32Out = zi32.ZeroPhase(_signal).Samples;
zi64Out = zi64.ZeroPhase(_signal.Samples.ToDoubles());
var diffAverageZiZeroPhase = zi64Out.Zip(zi32Out, (m1, m2) => Math.Abs(m1 - m2)).Average();
Console.WriteLine($"Average difference ZiFilter vs. ZiFilter64 (zero-phase): {diffAverageZiZeroPhase}");
}
public void MovingAverageFilter()
{
var output = _filter.ApplyTo(_signal);
}