Produce Mel frequency scale spectorgrams

Issue #332 Get Mel frequency scale spectrograms working.
Start work on Octave scale spectrograms.

src/AudioAnalysisTools/StandardSpectrograms/BaseSonogramConfig.cs

@@ -133,6 +133,7 @@ public static SonogramConfig Load(string configFile)
         /// <summary>
         /// Initializes a new instance of the <see cref="SonogramConfig"/> class.
         /// Default Constructor - initialises a configuration with the default values.
+        /// This sets the default values for most spectrogram types, including Mel-scale and MFCC spectrograms.
         /// </summary>
         public SonogramConfig()
         {

src/AudioAnalysisTools/StandardSpectrograms/SpectrogramMelScale.cs

@@ -66,7 +66,7 @@ public SpectrogramMelScale(AmplitudeSonogram sg, int minHz, int maxHz)
         /// <param name="amplitudeM">Matrix of amplitude values.</param>
         public override void Make(double[,] amplitudeM)
         {
-            var tuple = MakeMelScaleSpectrogram(this.Configuration, amplitudeM, this.DecibelsNormalised, this.SampleRate);
+            var tuple = MakeMelScaleSpectrogram(this.Configuration, amplitudeM, this.SampleRate);
             this.Data = tuple.Item1;
             this.ModalNoiseProfile = tuple.Item2; //store the full bandwidth modal noise profile
         }
@@ -76,34 +76,28 @@ public override void Make(double[,] amplitudeM)
         /// <summary>
         /// NOTE!!!! The decibel array has been normalised in 0 - 1.
         /// </summary>
-        protected static Tuple<double[,], double[]> MakeMelScaleSpectrogram(SonogramConfig config, double[,] matrix, double[] decibels, int sampleRate)
+        protected static Tuple<double[,], double[]> MakeMelScaleSpectrogram(SonogramConfig config, double[,] matrix, int sampleRate)
         {
             double[,] m = matrix;
             int nyquist = sampleRate / 2;
             double epsilon = config.epsilon;
-            bool includeDelta = config.mfccConfig.IncludeDelta;
-            bool includeDoubleDelta = config.mfccConfig.IncludeDoubleDelta;
 
             //(i) APPLY FILTER BANK
             int bandCount = config.mfccConfig.FilterbankCount;
-            bool doMelScale = config.mfccConfig.DoMelScale;
-            int ccCount = config.mfccConfig.CcCount;
             int fftBinCount = config.FreqBinCount;  //number of Hz bands = 2^N +1. Subtract DC bin
-            int minHz = config.MinFreqBand ?? 0;
-            int maxHz = config.MaxFreqBand ?? nyquist;
 
             Log.WriteIfVerbose("ApplyFilterBank(): Dim prior to filter bank  =" + matrix.GetLength(1));
 
             //error check that filterBankCount < Number of FFT bins
             if (bandCount > fftBinCount)
             {
                 throw new Exception(
-                    "## FATAL ERROR in BaseSonogram.MakeCepstrogram():- Can't calculate cepstral coefficients. Filterbank Count > number of FFT bins. (" +
+                    "## FATAL ERROR in MakeMelScaleSpectrogram(): Filterbank Count > number of FFT bins. (" +
                     bandCount + " > " + fftBinCount + ")\n\n");
             }
 
             //this is the filter count for full bandwidth 0-Nyquist. This number is trimmed proportionately to fit the required bandwidth.
-            m = doMelScale ? MFCCStuff.MelFilterBank(m, bandCount, nyquist, minHz, maxHz) : MFCCStuff.LinearFilterBank(m, bandCount, nyquist, minHz, maxHz);
+            m = MFCCStuff.MelFilterBank(m, bandCount, nyquist, 0, nyquist);
 
             Log.WriteIfVerbose("\tDim after filter bank=" + m.GetLength(1) + " (Max filter bank=" + bandCount + ")");
 

src/AudioAnalysisTools/StandardSpectrograms/SpectrogramOctaveScale.cs

@@ -72,7 +72,7 @@ public SpectrogramOctaveScale(AmplitudeSonogram sg, int minHz, int maxHz)
         /// <param name="amplitudeM">Matrix of amplitude values.</param>
         public override void Make(double[,] amplitudeM)
         {
-            var tuple = MakeOctaveScaleSpectrogram(this.Configuration, amplitudeM, this.DecibelsNormalised, this.SampleRate);
+            var tuple = MakeOctaveScaleSpectrogram(this.Configuration, amplitudeM, this.SampleRate);
             this.Data = tuple.Item1;
             this.ModalNoiseProfile = tuple.Item2; //store the full bandwidth modal noise profile
         }
@@ -82,35 +82,29 @@ public override void Make(double[,] amplitudeM)
         /// <summary>
         /// NOTE!!!! The decibel array has been normalised in 0 - 1.
         /// </summary>
-        protected static Tuple<double[,], double[]> MakeOctaveScaleSpectrogram(SonogramConfig config, double[,] matrix, double[] decibels, int sampleRate)
+        protected static Tuple<double[,], double[]> MakeOctaveScaleSpectrogram(SonogramConfig config, double[,] matrix, int sampleRate)
         {
             double[,] m = matrix;
             int nyquist = sampleRate / 2;
             double epsilon = config.epsilon;
-            bool includeDelta = config.mfccConfig.IncludeDelta;
-            bool includeDoubleDelta = config.mfccConfig.IncludeDoubleDelta;
 
             //(i) APPLY FILTER BANK
             int bandCount = config.mfccConfig.FilterbankCount;
-            bool doMelScale = config.mfccConfig.DoMelScale;
-            int ccCount = config.mfccConfig.CcCount;
             int fftBinCount = config.FreqBinCount;  //number of Hz bands = 2^N +1. Subtract DC bin
-            int minHz = config.MinFreqBand ?? 0;
-            int maxHz = config.MaxFreqBand ?? nyquist;
 
             Log.WriteIfVerbose("ApplyFilterBank(): Dim prior to filter bank  =" + matrix.GetLength(1));
 
             //error check that filterBankCount < Number of FFT bins
             if (bandCount > fftBinCount)
             {
                 throw new Exception(
-                    "## FATAL ERROR in BaseSonogram.MakeCepstrogram():- Can't calculate cepstral coefficients. Filterbank Count > number of FFT bins. (" +
+                    "## FATAL ERROR in MakeOctaveScaleSpectrogram(): Filterbank Count > number of FFT bins. (" +
                     bandCount + " > " + fftBinCount + ")\n\n");
             }
 
             //this is the filter count for full bandwidth 0-Nyquist
             // TODO ADJUST THIS TO OCTAVE SCALE
-            m = doMelScale ? MFCCStuff.MelFilterBank(m, bandCount, nyquist, minHz, maxHz) : MFCCStuff.LinearFilterBank(m, bandCount, nyquist, minHz, maxHz);
+            m = MFCCStuff.MelFilterBank(m, bandCount, nyquist, 0, nyquist);
 
             Log.WriteIfVerbose("\tDim after filter bank=" + m.GetLength(1) + " (Max filter bank=" + bandCount + ")");