/// <summary>
/// This method takes an audio recording and returns an octave scale spectrogram.
/// At the present time it only works for recordings with 64000 sample rate and returns a 256 bin sonogram.
/// TODO: generalise this method for other recordings and octave scales.
/// </summary>
public static BaseSonogram ConvertRecordingToOctaveScaleSonogram(AudioRecording recording, FreqScaleType fst)
{
var freqScale = new FrequencyScale(fst);
double windowOverlap = 0.75;
var sonoConfig = new SonogramConfig
{
WindowSize = freqScale.WindowSize,
WindowOverlap = windowOverlap,
SourceFName = recording.BaseName,
NoiseReductionType = NoiseReductionType.None,
NoiseReductionParameter = 0.0,
};
// Generate amplitude sonogram and then conver to octave scale
var sonogram = new AmplitudeSonogram(sonoConfig, recording.WavReader);
// THIS IS THE CRITICAL LINE.
// TODO: SHOULD DEVELOP A SEPARATE UNIT TEST for this method
sonogram.Data = ConvertAmplitudeSpectrogramToDecibelOctaveScale(sonogram.Data, freqScale);
// DO NOISE REDUCTION
var dataMatrix = SNR.NoiseReduce_Standard(sonogram.Data);
sonogram.Data = dataMatrix;
int windowSize = freqScale.FinalBinCount * 2;
sonogram.Configuration.WindowSize = windowSize;
sonogram.Configuration.WindowStep = (int)Math.Round(windowSize * (1 - windowOverlap));
return(sonogram);
}
public static void TestOctaveScale(FreqScaleType fst)
{
var freqScale = new FrequencyScale(fst);
var octaveBinBounds = freqScale.BinBounds;
// now test the octave scale using a test spectrum
int sr = 22050;
int frameSize = 8192; // default for sr = 22050
if (fst == FreqScaleType.Octaves24Nyquist32000 || fst == FreqScaleType.Linear125Octaves7Tones28Nyquist32000)
{
sr = 64000;
frameSize = 16384; // default for sr = 64000
}
// Get a simple test spectrum
var linearSpectrum = GetSimpleTestSpectrum(sr, frameSize);
//do the test
var octaveSpectrum = OctaveSpectrum(octaveBinBounds, linearSpectrum);
// write output
int rowCount = octaveBinBounds.GetLength(0);
for (int i = 0; i < rowCount; i++)
{
Console.WriteLine(i + " bin-" + octaveBinBounds[i, 0] + " " + octaveBinBounds[i, 1] + "Hz " + octaveSpectrum[i]);
}
}
public static void TestMethod_GenerateSignal1()
{
int sampleRate = 22050;
double duration = 20; // signal duration in seconds
int[] harmonics = { 500, 1000, 2000, 4000, 8000 };
int windowSize = 512;
var freqScale = new FrequencyScale(sampleRate / 2, windowSize, 1000);
string path = @"C:\SensorNetworks\Output\Sonograms\UnitTestSonograms\SineSignal1.png";
var recording = GenerateTestRecording(sampleRate, duration, harmonics, WaveType.Cosine);
var sonoConfig = new SonogramConfig
{
WindowSize = freqScale.WindowSize,
WindowOverlap = 0.0,
SourceFName = "Signal1",
NoiseReductionType = NoiseReductionType.Standard,
NoiseReductionParameter = 0.12,
};
var sonogram = new AmplitudeSonogram(sonoConfig, recording.WavReader);
// pick a row, any row
var oneSpectrum = MatrixTools.GetRow(sonogram.Data, 40);
oneSpectrum = DataTools.normalise(oneSpectrum);
var peaks = DataTools.GetPeaks(oneSpectrum, 0.5);
for (int i = 2; i < peaks.Length - 2; i++)
{
if (peaks[i])
{
LoggedConsole.WriteLine($"bin ={freqScale.BinBounds[i, 0]}, Herz={freqScale.BinBounds[i, 1]}-{freqScale.BinBounds[i + 1, 1]} ");
}
}
if (peaks[11] && peaks[22] && peaks[45] && peaks[92] && peaks[185])
{
LoggedConsole.WriteSuccessLine("Spectral Peaks found at correct places");
}
else
{
LoggedConsole.WriteErrorLine("Spectral Peaks found at INCORRECT places");
}
foreach (int h in harmonics)
{
LoggedConsole.WriteLine($"Harmonic {h}Herz should be in bin {freqScale.GetBinIdForHerzValue(h)}");
}
// spectrogram without framing, annotation etc
var image = sonogram.GetImage();
string title = $"Spectrogram of Harmonics: {DataTools.Array2String(harmonics)} SR={sampleRate} Window={windowSize}";
image = sonogram.GetImageFullyAnnotated(image, title, freqScale.GridLineLocations);
image.Save(path);
}
/// <summary>
/// METHOD TO CHECK IF Octave FREQ SCALE IS WORKING
/// Check it on standard one minute recording, SR=22050.
/// </summary>
public static void TESTMETHOD_OctaveFrequencyScale1()
{
var recordingPath = @"G:\SensorNetworks\WavFiles\LewinsRail\FromLizZnidersic\Lewinsrail_TasmanIs_Tractor_SM304253_0151119_0640_1minMono.wav";
var outputDir = @"C:\SensorNetworks\Output\LewinsRail\LewinsRail_ThreeCallTypes".ToDirectoryInfo();
//var recordingPath = @"C:\SensorNetworks\SoftwareTests\TestRecordings\BAC\BAC2_20071008-085040.wav";
//var outputDir = @"C:\SensorNetworks\SoftwareTests\TestFrequencyScale".ToDirectoryInfo();
//var expectedResultsDir = Path.Combine(outputDir.FullName, TestTools.ExpectedResultsDir).ToDirectoryInfo();
var outputImagePath = Path.Combine(outputDir.FullName, "octaveFrequencyScale1NoNoiseReduciton.png");
//var opFileStem = "Lewinsrail_TasmanIs_Tractor";
var recording = new AudioRecording(recordingPath);
// default octave scale
var fst = FreqScaleType.Linear125Octaves6Tones30Nyquist11025;
var freqScale = new FrequencyScale(fst);
var sonoConfig = new SonogramConfig
{
WindowSize = freqScale.WindowSize,
WindowOverlap = 0.75,
SourceFName = recording.BaseName,
NoiseReductionType = NoiseReductionType.None,
NoiseReductionParameter = 0.0,
};
// Generate amplitude sonogram and then conver to octave scale
var sonogram = new AmplitudeSonogram(sonoConfig, recording.WavReader);
sonogram.Data = OctaveFreqScale.ConvertAmplitudeSpectrogramToDecibelOctaveScale(sonogram.Data, freqScale);
// DO NOISE REDUCTION
//var dataMatrix = SNR.NoiseReduce_Standard(sonogram.Data);
//sonogram.Data = dataMatrix;
sonogram.Configuration.WindowSize = freqScale.WindowSize;
var image = sonogram.GetImageFullyAnnotated(sonogram.GetImage(), "SPECTROGRAM: " + fst.ToString(), freqScale.GridLineLocations);
image.Save(outputImagePath);
// DO FILE EQUALITY TEST
//string testName = "test1";
//var expectedTestFile = new FileInfo(Path.Combine(expectedResultsDir.FullName, "FrequencyOctaveScaleTest1.EXPECTED.json"));
//var resultFile = new FileInfo(Path.Combine(outputDir.FullName, opFileStem + "FrequencyOctaveScaleTest1Results.json"));
//Acoustics.Shared.Csv.Csv.WriteMatrixToCsv(resultFile, freqScale.GridLineLocations);
//TestTools.FileEqualityTest(testName, resultFile, expectedTestFile);
LoggedConsole.WriteLine("Completed Octave Frequency Scale test 1");
Console.WriteLine("\n\n");
}
/// <summary>
/// METHOD TO CHECK IF SPECIFIED linear FREQ SCALE IS WORKING
/// Check it on standard one minute recording.
/// </summary>
public static void TESTMETHOD_LinearFrequencyScale()
{
var recordingPath = @"C:\SensorNetworks\SoftwareTests\TestRecordings\BAC2_20071008-085040.wav";
var outputDir = @"C:\SensorNetworks\SoftwareTests\TestFrequencyScale".ToDirectoryInfo();
var expectedResultsDir = Path.Combine(outputDir.FullName, TestTools.ExpectedResultsDir).ToDirectoryInfo();
var outputImagePath = Path.Combine(outputDir.FullName, "linearScaleSonogram.png");
var opFileStem = "BAC2_20071008";
var recording = new AudioRecording(recordingPath);
// specfied linear scale
int nyquist = 11025;
int frameSize = 1024;
int hertzInterval = 1000;
var freqScale = new FrequencyScale(nyquist, frameSize, hertzInterval);
var fst = freqScale.ScaleType;
var sonoConfig = new SonogramConfig
{
WindowSize = freqScale.FinalBinCount * 2,
WindowOverlap = 0.2,
SourceFName = recording.BaseName,
//NoiseReductionType = NoiseReductionType.Standard,
NoiseReductionType = NoiseReductionType.None,
NoiseReductionParameter = 0.0,
};
var sonogram = new SpectrogramStandard(sonoConfig, recording.WavReader);
// DO NOISE REDUCTION
var dataMatrix = SNR.NoiseReduce_Standard(sonogram.Data);
sonogram.Data = dataMatrix;
sonogram.Configuration.WindowSize = freqScale.WindowSize;
var image = sonogram.GetImageFullyAnnotated(sonogram.GetImage(), "SPECTROGRAM: " + fst.ToString(), freqScale.GridLineLocations);
image.Save(outputImagePath);
// DO FILE EQUALITY TEST
string testName = "testName";
var expectedTestFile = new FileInfo(Path.Combine(expectedResultsDir.FullName, "FrequencyLinearScaleTest.EXPECTED.json"));
var resultFile = new FileInfo(Path.Combine(outputDir.FullName, opFileStem + "FrequencyLinearScaleTestResults.json"));
Acoustics.Shared.Csv.Csv.WriteMatrixToCsv(resultFile, freqScale.GridLineLocations);
TestTools.FileEqualityTest(testName, resultFile, expectedTestFile);
LoggedConsole.WriteLine("Completed Linear Frequency Scale test");
Console.WriteLine("\n\n");
}
/// <summary>
/// METHOD TO CHECK IF SPECIFIED MEL FREQ SCALE IS WORKING
/// Check it on standard one minute recording.
/// </summary>
public static void TESTMETHOD_MelFrequencyScale()
{
var recordingPath = @"C:\SensorNetworks\SoftwareTests\TestRecordings\BAC2_20071008-085040.wav";
var outputDir = @"C:\SensorNetworks\SoftwareTests\TestFrequencyScale".ToDirectoryInfo();
var expectedResultsDir = Path.Combine(outputDir.FullName, TestTools.ExpectedResultsDir).ToDirectoryInfo();
var outputImagePath = Path.Combine(outputDir.FullName, "melScaleSonogram.png");
var opFileStem = "BAC2_20071008";
var recording = new AudioRecording(recordingPath);
int nyquist = recording.Nyquist;
int frameSize = 1024;
int finalBinCount = 256;
int hertzInterval = 1000;
FreqScaleType scaleType = FreqScaleType.Mel;
var freqScale = new FrequencyScale(scaleType, nyquist, frameSize, finalBinCount, hertzInterval);
var fst = freqScale.ScaleType;
var sonoConfig = new SonogramConfig
{
WindowSize = frameSize,
WindowOverlap = 0.2,
SourceFName = recording.BaseName,
DoMelScale = (scaleType == FreqScaleType.Mel) ? true : false,
MelBinCount = (scaleType == FreqScaleType.Mel) ? finalBinCount : frameSize / 2,
//NoiseReductionType = NoiseReductionType.Standard,
NoiseReductionType = NoiseReductionType.None,
NoiseReductionParameter = 0.0,
};
var sonogram = new SpectrogramStandard(sonoConfig, recording.WavReader);
// DRAW SPECTROGRAM
var image = sonogram.GetImageFullyAnnotated(sonogram.GetImage(), "SPECTROGRAM: " + fst.ToString(), freqScale.GridLineLocations);
image.Save(outputImagePath);
// DO FILE EQUALITY TEST
string testName = "MelTest";
var expectedTestFile = new FileInfo(Path.Combine(expectedResultsDir.FullName, "MelFrequencyScaleTest.EXPECTED.json"));
var resultFile = new FileInfo(Path.Combine(outputDir.FullName, opFileStem + "MelFrequencyLinearScaleTestResults.json"));
Acoustics.Shared.Csv.Csv.WriteMatrixToCsv(resultFile, freqScale.GridLineLocations);
TestTools.FileEqualityTest(testName, resultFile, expectedTestFile);
LoggedConsole.WriteLine("Completed Mel Frequency Scale test");
Console.WriteLine("\n\n");
}
public static void TESTMETHOD_DrawFrequencyLinesOnImage()
{
string filename = @"C:\SensorNetworks\SoftwareTests\TestFrequencyScale\Clusters50.bmp";
string outputFile = @"C:\SensorNetworks\SoftwareTests\TestFrequencyScale\Clusters50WithGrid.bmp";
var bmp = Image.Load(filename);
int nyquist = 11025;
int frameSize = 1024;
int finalBinCount = 128;
int gridInterval = 1000;
var freqScale = new FrequencyScale(FreqScaleType.Mel, nyquist, frameSize, finalBinCount, gridInterval);
DrawFrequencyLinesOnImage((Image <Rgb24>)bmp, freqScale, includeLabels: false);
bmp.Save(outputFile);
}
/// <summary>
/// METHOD TO CHECK IF Octave FREQ SCALE IS WORKING
/// Check it on MARINE RECORDING from JASCO, SR=64000.
/// 24 BIT JASCO RECORDINGS from GBR must be converted to 16 bit.
/// ffmpeg -i source_file.wav -sample_fmt s16 out_file.wav
/// e.g. ". C:\Work\Github\audio-analysis\Extra Assemblies\ffmpeg\ffmpeg.exe" -i "C:\SensorNetworks\WavFiles\MarineRecordings\JascoGBR\AMAR119-00000139.00000139.Chan_1-24bps.1375012796.2013-07-28-11-59-56.wav" -sample_fmt s16 "C:\SensorNetworks\Output\OctaveFreqScale\JascoeMarineGBR116bit.wav"
/// ffmpeg binaries are in C:\Work\Github\audio-analysis\Extra Assemblies\ffmpeg
/// </summary>
public static void TESTMETHOD_OctaveFrequencyScale2()
{
var recordingPath = @"C:\SensorNetworks\SoftwareTests\TestRecordings\MarineJasco_AMAR119-00000139.00000139.Chan_1-24bps.1375012796.2013-07-28-11-59-56-16bit.wav";
var outputDir = @"C:\SensorNetworks\SoftwareTests\TestFrequencyScale".ToDirectoryInfo();
var expectedResultsDir = Path.Combine(outputDir.FullName, TestTools.ExpectedResultsDir).ToDirectoryInfo();
var outputImagePath = Path.Combine(outputDir.FullName, "JascoMarineGBR1.png");
var opFileStem = "JascoMarineGBR1";
var recording = new AudioRecording(recordingPath);
var fst = FreqScaleType.Linear125Octaves7Tones28Nyquist32000;
var freqScale = new FrequencyScale(fst);
var sonoConfig = new SonogramConfig
{
WindowSize = freqScale.WindowSize,
WindowOverlap = 0.2,
SourceFName = recording.BaseName,
NoiseReductionType = NoiseReductionType.None,
NoiseReductionParameter = 0.0,
};
var sonogram = new AmplitudeSonogram(sonoConfig, recording.WavReader);
sonogram.Data = OctaveFreqScale.ConvertAmplitudeSpectrogramToDecibelOctaveScale(sonogram.Data, freqScale);
// DO NOISE REDUCTION
var dataMatrix = SNR.NoiseReduce_Standard(sonogram.Data);
sonogram.Data = dataMatrix;
sonogram.Configuration.WindowSize = freqScale.WindowSize;
var image = sonogram.GetImageFullyAnnotated(sonogram.GetImage(), "SPECTROGRAM: " + fst.ToString(), freqScale.GridLineLocations);
image.Save(outputImagePath);
// DO FILE EQUALITY TEST
string testName = "test2";
var expectedTestFile = new FileInfo(Path.Combine(expectedResultsDir.FullName, "FrequencyOctaveScaleTest2.EXPECTED.json"));
var resultFile = new FileInfo(Path.Combine(outputDir.FullName, opFileStem + "FrequencyOctaveScaleTest2Results.json"));
Acoustics.Shared.Csv.Csv.WriteMatrixToCsv(resultFile, freqScale.GridLineLocations);
TestTools.FileEqualityTest(testName, resultFile, expectedTestFile);
LoggedConsole.WriteLine("Completed Octave Frequency Scale " + testName);
Console.WriteLine("\n\n");
}
} //end AddHzGridLines()
public static void DrawFrequencyLinesOnImage(Image <Rgb24> bmp, FrequencyScale freqScale, bool includeLabels)
{
DrawFrequencyLinesOnImage(bmp, freqScale.GridLineLocations, includeLabels);
}
/// IMPORTANT NOTE: If you are converting Herz scale from LINEAR to OCTAVE, this conversion MUST be done BEFORE noise reduction
/// <summary>
/// CONSTRUCTION OF Frequency Scales
/// WARNING!: Changing the constants for the octave scales will have undefined effects.
/// The options below have been debugged to give what is required.
/// However other values have not been debugged - so user should check the output to ensure it is what is required.
/// </summary>
public static void GetOctaveScale(FrequencyScale scale)
{
int finalBinCount = 256;
int sr, frameSize, octaveDivisions;
// NOTE: octaveDivisions = the number of fractional Hz steps within one octave. Piano octave contains 12 steps per octave.
FreqScaleType fst = scale.ScaleType;
switch (fst)
{
case FreqScaleType.Linear62Octaves7Tones31Nyquist11025:
// constants required for split linear-octave scale when sr = 22050
sr = 22050;
frameSize = 8192;
scale.OctaveCount = 7;
octaveDivisions = 31; // tone steps within one octave. Note: piano = 12 steps per octave.
scale.LinearBound = 62;
scale.Nyquist = 11025;
break;
case FreqScaleType.Linear125Octaves6Tones30Nyquist11025:
// constants required for split linear-octave scale when sr = 22050
sr = 22050;
frameSize = 8192;
scale.OctaveCount = 6;
octaveDivisions = 32; // tone steps within one octave. Note: piano = 12 steps per octave.
scale.LinearBound = 125;
scale.Nyquist = 11025;
break;
case FreqScaleType.Octaves24Nyquist32000:
//// constants required for full octave scale when sr = 64000
sr = 64000;
frameSize = 16384;
scale.OctaveCount = 8;
octaveDivisions = 24; // tone steps within one octave. Note: piano = 12 steps per octave.
scale.LinearBound = 15;
scale.Nyquist = 32000;
break;
case FreqScaleType.Linear125Octaves7Tones28Nyquist32000:
// constants required for split linear-octave scale when sr = 64000
sr = 64000;
frameSize = 16384; // = 2*8192 or 4*4096;
scale.OctaveCount = 7;
octaveDivisions = 28; // tone steps within one octave. Note: piano = 12 steps per octave.
scale.LinearBound = 125;
scale.Nyquist = 32000;
break;
default:
LoggedConsole.WriteErrorLine("WARNING: UNKNOWN OCTAVE SCALE.");
return;
}
scale.WindowSize = frameSize; // = 2*8192 or 4*4096
scale.FinalBinCount = finalBinCount;
scale.ToneCount = octaveDivisions;
scale.BinBounds = LinearToSplitLinearOctaveScale(sr, frameSize, finalBinCount, scale.LinearBound, scale.Nyquist, scale.ToneCount);
scale.GridLineLocations = GetGridLineLocations(fst, scale.BinBounds);
}
/// <summary>
/// Converts an amplitude spectrogram to a power spectrogram having an octave frequency scale.
/// This method has been copied from a method of same name in the class MFCCStuff.cs and adapted to produce an octave freq scale.
/// It transforms the amplitude spectrogram in the following steps:
/// (1) It removes the DC row or bin 0 iff there is odd number of spectrogram bins. ASSUMPTION: Bin count should be power of 2 from FFT.
/// (1) It converts spectral amplitudes to power, normalising for window power and sample rate.
/// The window contributes power to the signal which must subsequently be removed from the spectral power. Calculate power per sample.
/// See notes in the MFCCStuff.DecibelSpectra for further exp[lanaitons. These normalisations were adapted from MatLab MFCC code.
/// (2) Then reduce the linear scale toan octave scale depending on the sr and required number of bins or filters.
/// </summary>
/// <param name="amplitudeM"> the amplitude spectra </param>
/// <param name="windowPower">value for window power normalisation</param>
/// <param name="sampleRate">to NormaliseMatrixValues for the sampling rate</param>
/// <param name="epsilon">small value to avoid log of zero.</param>
/// <param name="freqScale">the kind of frequency scale</param>
public static double[,] PowerSpectra(double[,] amplitudeM, double windowPower, int sampleRate, double epsilon, FrequencyScale freqScale)
{
int frameCount = amplitudeM.GetLength(0);
int binCount = amplitudeM.GetLength(1);
double minPow = epsilon * epsilon / windowPower / sampleRate;
double minPow2 = epsilon * epsilon * 2 / windowPower / sampleRate;
if (binCount.IsOdd())
{
// remove the DC freq bin 0.
amplitudeM = MatrixTools.Submatrix(amplitudeM, 0, 1, frameCount - 1, binCount - 1);
}
// init the spectrogram as a matrix of spectra
double[,] powerSpectra = new double[frameCount, binCount];
// first square the values to calculate power.
// Must multiply by 2 to accomodate two spectral components, ie positive and neg freq.
for (int j = 0; j < binCount - 1; j++)
{
//foreach time step or frame
for (int i = 0; i < frameCount; i++)
{
if (amplitudeM[i, j] < epsilon)
{
powerSpectra[i, j] = minPow2;
}
else
{
powerSpectra[i, j] = amplitudeM[i, j] * amplitudeM[i, j] * 2 / windowPower / sampleRate;
}
} //end of all frames
} //end of all freq bins
//calculate power of the Nyquist freq bin - last column of matrix
//foreach time step or frame
for (int i = 0; i < frameCount; i++)
{
//calculate power of the DC value
if (amplitudeM[i, binCount - 1] < epsilon)
{
powerSpectra[i, binCount - 1] = minPow;
}
else
{
powerSpectra[i, binCount - 1] = amplitudeM[i, binCount - 1] * amplitudeM[i, binCount - 1] / windowPower / sampleRate;
}
}
powerSpectra = ConvertLinearSpectrogramToOctaveFreqScale(powerSpectra, freqScale);
return(powerSpectra);
}
public static double[,] AmplitudeSpectra(double[,] amplitudeM, double windowPower, int sampleRate, double epsilon, FrequencyScale freqScale)
{
double[,] powerSpectra = PowerSpectra(amplitudeM, windowPower, sampleRate, epsilon, freqScale);
// Convert the power values back to amplitude by taking the square root.
var amplitudeSpectra = MatrixTools.SquareRootOfValues(powerSpectra);
return(amplitudeSpectra);
}
public static double[,] DecibelSpectra(double[,] amplitudeM, double windowPower, int sampleRate, double epsilon, FrequencyScale freqScale)
{
double[,] powerSpectra = PowerSpectra(amplitudeM, windowPower, sampleRate, epsilon, freqScale);
// Convert the power values to log using: dB = 10*log(power)
double min, max;
var decibelSpectra = MatrixTools.Power2DeciBels(powerSpectra, out min, out max);
return(decibelSpectra);
}
/// <summary>
/// Converts a spectrogram having linear freq scale to one having an Octave freq scale.
/// Note that the sample rate (sr) and the frame size both need to be apporpriate to the choice of FreqScaleType.
/// TODO: SHOULD DEVELOP A SEPARATE UNIT TEST for this method
/// </summary>
public static double[,] ConvertLinearSpectrogramToOctaveFreqScale(double[,] inputSpgram, FrequencyScale freqScale)
{
if (freqScale == null)
{
throw new ArgumentNullException(nameof(freqScale));
}
if (freqScale.ScaleType == FreqScaleType.Linear)
{
LoggedConsole.WriteLine("Linear Hz Scale is not valid for this Octave method.");
throw new ArgumentNullException(nameof(freqScale));
}
// get the octave bin bounds for this octave scale type
var octaveBinBounds = freqScale.BinBounds;
//var octaveBinBounds = GetOctaveScale(freqScale.ScaleType);
int newBinCount = octaveBinBounds.GetLength(0);
// set up the new octave spectrogram
int frameCount = inputSpgram.GetLength(0);
//int binCount = inputSpgram.GetLength(1);
double[,] octaveSpectrogram = new double[frameCount, newBinCount];
for (int row = 0; row < frameCount; row++)
{
//get each frame or spectrum in turn
var linearSpectrum = MatrixTools.GetRow(inputSpgram, row);
// convert the spectrum to its octave form
var octaveSpectrum = OctaveSpectrum(octaveBinBounds, linearSpectrum);
//return the spectrum to output spectrogram.
MatrixTools.SetRow(octaveSpectrogram, row, octaveSpectrum);
}
return(octaveSpectrogram);
}
public static double[,] ConvertAmplitudeSpectrogramToDecibelOctaveScale(double[,] inputSpgram, FrequencyScale freqScale)
{
//var dataMatrix = MatrixTools.Submatrix(inputSpgram, 0, 1, inputSpgram.GetLength(0) - 1, inputSpgram.GetLength(1) - 1);
//square the values to produce power spectrogram
var dataMatrix = MatrixTools.SquareValues(inputSpgram);
//convert spectrogram to octave scale
dataMatrix = ConvertLinearSpectrogramToOctaveFreqScale(dataMatrix, freqScale);
double min, max;
dataMatrix = MatrixTools.Power2DeciBels(dataMatrix, out min, out max);
return(dataMatrix);
}
public static void TestMethod_GenerateSignal2()
{
int sampleRate = 64000;
double duration = 30; // signal duration in seconds
int[] harmonics = { 500, 1000, 2000, 4000, 8000 };
var freqScale = new FrequencyScale(FreqScaleType.Linear125Octaves7Tones28Nyquist32000);
string path = @"C:\SensorNetworks\Output\Sonograms\UnitTestSonograms\SineSignal2.png";
var recording = GenerateTestRecording(sampleRate, duration, harmonics, WaveType.Cosine);
// init the default sonogram config
var sonoConfig = new SonogramConfig
{
WindowSize = freqScale.WindowSize,
WindowOverlap = 0.2,
SourceFName = "Signal2",
NoiseReductionType = NoiseReductionType.None,
NoiseReductionParameter = 0.0,
};
var sonogram = new AmplitudeSonogram(sonoConfig, recording.WavReader);
sonogram.Data = OctaveFreqScale.ConvertAmplitudeSpectrogramToDecibelOctaveScale(sonogram.Data, freqScale);
// pick a row, any row
var oneSpectrum = MatrixTools.GetRow(sonogram.Data, 40);
oneSpectrum = DataTools.normalise(oneSpectrum);
var peaks = DataTools.GetPeaks(oneSpectrum, 0.5);
var peakIds = new List <int>();
for (int i = 5; i < peaks.Length - 5; i++)
{
if (peaks[i])
{
int peakId = freqScale.BinBounds[i, 0];
peakIds.Add(peakId);
LoggedConsole.WriteLine($"Spectral peak located in bin {peakId}, Herz={freqScale.BinBounds[i, 1]}");
}
}
//if (peaks[129] && peaks[257] && peaks[513] && peaks[1025] && peaks[2049])
if (peakIds[0] == 129 && peakIds[1] == 257 && peakIds[2] == 513 && peakIds[3] == 1025 && peakIds[4] == 2049)
{
LoggedConsole.WriteSuccessLine("Spectral Peaks found at correct places");
}
else
{
LoggedConsole.WriteErrorLine("Spectral Peaks found at INCORRECT places");
}
foreach (int h in harmonics)
{
LoggedConsole.WriteLine($"Harmonic {h}Hertz should be in bin {freqScale.GetBinIdForHerzValue(h)}");
}
// spectrogram without framing, annotation etc
var image = sonogram.GetImage();
string title = $"Spectrogram of Harmonics: {DataTools.Array2String(harmonics)} SR={sampleRate} Window={freqScale.WindowSize}";
image = sonogram.GetImageFullyAnnotated(image, title, freqScale.GridLineLocations);
image.Save(path);
}
