StephaneLenclud@273: using System;
StephaneLenclud@273: using System.Collections.Generic;
StephaneLenclud@273: using System.ComponentModel;
StephaneLenclud@273: using System.Diagnostics;
StephaneLenclud@273: using CSCore;
StephaneLenclud@273: using CSCore.DSP;
StephaneLenclud@273: 
StephaneLenclud@273: namespace Visualization
StephaneLenclud@273: {
StephaneLenclud@273:     public class SpectrumBase : INotifyPropertyChanged
StephaneLenclud@273:     {
StephaneLenclud@273:         private const int ScaleFactorLinear = 9;
StephaneLenclud@273:         protected const int ScaleFactorSqr = 2;
StephaneLenclud@273:         protected const double MinDbValue = -90;
StephaneLenclud@273:         protected const double MaxDbValue = 0;
StephaneLenclud@273:         protected const double DbScale = (MaxDbValue - MinDbValue);
StephaneLenclud@273: 
StephaneLenclud@274: 
StephaneLenclud@274:         protected float[] iFftBuffer;
StephaneLenclud@274:         private int _fftSize;        
StephaneLenclud@273:         private bool _isXLogScale;
StephaneLenclud@273:         private int _maxFftIndex;
StephaneLenclud@273:         private int _maximumFrequency = 20000;
StephaneLenclud@273:         private int _maximumFrequencyIndex;
StephaneLenclud@273:         private int _minimumFrequency = 20; //Default spectrum from 20Hz to 20kHz
StephaneLenclud@273:         private int _minimumFrequencyIndex;
StephaneLenclud@273:         private ScalingStrategy _scalingStrategy;
StephaneLenclud@273:         private int[] _spectrumIndexMax;
StephaneLenclud@273:         private int[] _spectrumLogScaleIndexMax;
StephaneLenclud@273:         private ISpectrumProvider _spectrumProvider;
StephaneLenclud@273: 
StephaneLenclud@273:         protected int SpectrumResolution;
StephaneLenclud@273:         private bool _useAverage;
StephaneLenclud@273: 
StephaneLenclud@273:         public int MaximumFrequency
StephaneLenclud@273:         {
StephaneLenclud@273:             get { return _maximumFrequency; }
StephaneLenclud@273:             set
StephaneLenclud@273:             {
StephaneLenclud@273:                 if (value <= MinimumFrequency)
StephaneLenclud@273:                 {
StephaneLenclud@273:                     throw new ArgumentOutOfRangeException("value",
StephaneLenclud@273:                         "Value must not be less or equal the MinimumFrequency.");
StephaneLenclud@273:                 }
StephaneLenclud@273:                 _maximumFrequency = value;
StephaneLenclud@273:                 UpdateFrequencyMapping();
StephaneLenclud@273: 
StephaneLenclud@273:                 RaisePropertyChanged("MaximumFrequency");
StephaneLenclud@273:             }
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         public int MinimumFrequency
StephaneLenclud@273:         {
StephaneLenclud@273:             get { return _minimumFrequency; }
StephaneLenclud@273:             set
StephaneLenclud@273:             {
StephaneLenclud@273:                 if (value < 0)
StephaneLenclud@273:                     throw new ArgumentOutOfRangeException("value");
StephaneLenclud@273:                 _minimumFrequency = value;
StephaneLenclud@273:                 UpdateFrequencyMapping();
StephaneLenclud@273: 
StephaneLenclud@273:                 RaisePropertyChanged("MinimumFrequency");
StephaneLenclud@273:             }
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         [BrowsableAttribute(false)]
StephaneLenclud@273:         public ISpectrumProvider SpectrumProvider
StephaneLenclud@273:         {
StephaneLenclud@273:             get { return _spectrumProvider; }
StephaneLenclud@273:             set
StephaneLenclud@273:             {
StephaneLenclud@273:                 if (value == null)
StephaneLenclud@273:                     throw new ArgumentNullException("value");
StephaneLenclud@273:                 _spectrumProvider = value;
StephaneLenclud@273: 
StephaneLenclud@273:                 RaisePropertyChanged("SpectrumProvider");
StephaneLenclud@273:             }
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         public bool IsXLogScale
StephaneLenclud@273:         {
StephaneLenclud@273:             get { return _isXLogScale; }
StephaneLenclud@273:             set
StephaneLenclud@273:             {
StephaneLenclud@273:                 _isXLogScale = value;
StephaneLenclud@273:                 UpdateFrequencyMapping();
StephaneLenclud@273:                 RaisePropertyChanged("IsXLogScale");
StephaneLenclud@273:             }
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         public ScalingStrategy ScalingStrategy
StephaneLenclud@273:         {
StephaneLenclud@273:             get { return _scalingStrategy; }
StephaneLenclud@273:             set
StephaneLenclud@273:             {
StephaneLenclud@273:                 _scalingStrategy = value;
StephaneLenclud@273:                 RaisePropertyChanged("ScalingStrategy");
StephaneLenclud@273:             }
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         public bool UseAverage
StephaneLenclud@273:         {
StephaneLenclud@273:             get { return _useAverage; }
StephaneLenclud@273:             set
StephaneLenclud@273:             {
StephaneLenclud@273:                 _useAverage = value;
StephaneLenclud@273:                 RaisePropertyChanged("UseAverage");
StephaneLenclud@273:             }
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         [BrowsableAttribute(false)]
StephaneLenclud@273:         public FftSize FftSize
StephaneLenclud@273:         {
StephaneLenclud@273:             get { return (FftSize) _fftSize; }
StephaneLenclud@273:             protected set
StephaneLenclud@273:             {
StephaneLenclud@273:                 if ((int) Math.Log((int) value, 2) % 1 != 0)
StephaneLenclud@273:                     throw new ArgumentOutOfRangeException("value");
StephaneLenclud@273: 
StephaneLenclud@273:                 _fftSize = (int) value;
StephaneLenclud@273:                 _maxFftIndex = _fftSize / 2 - 1;
StephaneLenclud@274:                 iFftBuffer = new float[_fftSize];
StephaneLenclud@273: 
StephaneLenclud@273:                 RaisePropertyChanged("FFTSize");
StephaneLenclud@273:             }
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         public event PropertyChangedEventHandler PropertyChanged;
StephaneLenclud@273: 
StephaneLenclud@273:         protected virtual void UpdateFrequencyMapping()
StephaneLenclud@273:         {
StephaneLenclud@273:             _maximumFrequencyIndex = Math.Min(_spectrumProvider.GetFftBandIndex(MaximumFrequency) + 1, _maxFftIndex);
StephaneLenclud@273:             _minimumFrequencyIndex = Math.Min(_spectrumProvider.GetFftBandIndex(MinimumFrequency), _maxFftIndex);
StephaneLenclud@273: 
StephaneLenclud@273:             int actualResolution = SpectrumResolution;
StephaneLenclud@273: 
StephaneLenclud@273:             int indexCount = _maximumFrequencyIndex - _minimumFrequencyIndex;
StephaneLenclud@273:             double linearIndexBucketSize = Math.Round(indexCount / (double) actualResolution, 3);
StephaneLenclud@273: 
StephaneLenclud@273:             _spectrumIndexMax = _spectrumIndexMax.CheckBuffer(actualResolution, true);
StephaneLenclud@273:             _spectrumLogScaleIndexMax = _spectrumLogScaleIndexMax.CheckBuffer(actualResolution, true);
StephaneLenclud@273: 
StephaneLenclud@273:             double maxLog = Math.Log(actualResolution, actualResolution);
StephaneLenclud@273:             for (int i = 1; i < actualResolution; i++)
StephaneLenclud@273:             {
StephaneLenclud@273:                 int logIndex =
StephaneLenclud@273:                     (int) ((maxLog - Math.Log((actualResolution + 1) - i, (actualResolution + 1))) * indexCount) +
StephaneLenclud@273:                     _minimumFrequencyIndex;
StephaneLenclud@273: 
StephaneLenclud@273:                 _spectrumIndexMax[i - 1] = _minimumFrequencyIndex + (int) (i * linearIndexBucketSize);
StephaneLenclud@273:                 _spectrumLogScaleIndexMax[i - 1] = logIndex;
StephaneLenclud@273:             }
StephaneLenclud@273: 
StephaneLenclud@273:             if (actualResolution > 0)
StephaneLenclud@273:             {
StephaneLenclud@273:                 _spectrumIndexMax[_spectrumIndexMax.Length - 1] =
StephaneLenclud@273:                     _spectrumLogScaleIndexMax[_spectrumLogScaleIndexMax.Length - 1] = _maximumFrequencyIndex;
StephaneLenclud@273:             }
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         protected virtual SpectrumPointData[] CalculateSpectrumPoints(double maxValue, float[] fftBuffer)
StephaneLenclud@273:         {
StephaneLenclud@273:             var dataPoints = new List<SpectrumPointData>();
StephaneLenclud@273: 
StephaneLenclud@273:             double value0 = 0, value = 0;
StephaneLenclud@273:             double lastValue = 0;
StephaneLenclud@273:             double actualMaxValue = maxValue;
StephaneLenclud@273:             int spectrumPointIndex = 0;
StephaneLenclud@273: 
StephaneLenclud@273:             for (int i = _minimumFrequencyIndex; i <= _maximumFrequencyIndex; i++)
StephaneLenclud@273:             {
StephaneLenclud@273:                 switch (ScalingStrategy)
StephaneLenclud@273:                 {
StephaneLenclud@273:                     case ScalingStrategy.Decibel:
StephaneLenclud@273:                         value0 = (((20 * Math.Log10(fftBuffer[i])) - MinDbValue) / DbScale) * actualMaxValue;
StephaneLenclud@273:                         break;
StephaneLenclud@273:                     case ScalingStrategy.Linear:
StephaneLenclud@273:                         value0 = (fftBuffer[i] * ScaleFactorLinear) * actualMaxValue;
StephaneLenclud@273:                         break;
StephaneLenclud@273:                     case ScalingStrategy.Sqrt:
StephaneLenclud@273:                         value0 = ((Math.Sqrt(fftBuffer[i])) * ScaleFactorSqr) * actualMaxValue;
StephaneLenclud@273:                         break;
StephaneLenclud@273:                 }
StephaneLenclud@273: 
StephaneLenclud@273:                 bool recalc = true;
StephaneLenclud@273: 
StephaneLenclud@273:                 value = Math.Max(0, Math.Max(value0, value));
StephaneLenclud@273: 
StephaneLenclud@273:                 while (spectrumPointIndex <= _spectrumIndexMax.Length - 1 &&
StephaneLenclud@273:                        i ==
StephaneLenclud@273:                        (IsXLogScale
StephaneLenclud@273:                            ? _spectrumLogScaleIndexMax[spectrumPointIndex]
StephaneLenclud@273:                            : _spectrumIndexMax[spectrumPointIndex]))
StephaneLenclud@273:                 {
StephaneLenclud@273:                     if (!recalc)
StephaneLenclud@273:                         value = lastValue;
StephaneLenclud@273: 
StephaneLenclud@273:                     if (value > maxValue)
StephaneLenclud@273:                         value = maxValue;
StephaneLenclud@273: 
StephaneLenclud@273:                     if (_useAverage && spectrumPointIndex > 0)
StephaneLenclud@273:                         value = (lastValue + value) / 2.0;
StephaneLenclud@273: 
StephaneLenclud@273:                     dataPoints.Add(new SpectrumPointData {SpectrumPointIndex = spectrumPointIndex, Value = value});
StephaneLenclud@273: 
StephaneLenclud@273:                     lastValue = value;
StephaneLenclud@273:                     value = 0.0;
StephaneLenclud@273:                     spectrumPointIndex++;
StephaneLenclud@273:                     recalc = false;
StephaneLenclud@273:                 }
StephaneLenclud@273: 
StephaneLenclud@273:                 //value = 0;
StephaneLenclud@273:             }
StephaneLenclud@273: 
StephaneLenclud@273:             return dataPoints.ToArray();
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         protected void RaisePropertyChanged(string propertyName)
StephaneLenclud@273:         {
StephaneLenclud@273:             if (PropertyChanged != null && !String.IsNullOrEmpty(propertyName))
StephaneLenclud@273:                 PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
StephaneLenclud@273:         }
StephaneLenclud@273: 
StephaneLenclud@273:         [DebuggerDisplay("{Value}")]
StephaneLenclud@273:         protected struct SpectrumPointData
StephaneLenclud@273:         {
StephaneLenclud@273:             public int SpectrumPointIndex;
StephaneLenclud@273:             public double Value;
StephaneLenclud@273:         }
StephaneLenclud@273:     }
StephaneLenclud@273: }