annotate dsp/keydetection/GetKeyMode.cpp @ 73:dcb555b90924

* Key detector: when returning key strengths, use the peak value of the
  three underlying chromagram correlations (from 36-bin chromagram)
  corresponding to each key, instead of the mean.
  Rationale: This is the same method as used when returning the key value,
  and it's nice to have the same results in both returned value and plot.
  The peak performed better than the sum with a simple test set of triads,
  so it seems reasonable to change the plot to match the key output rather
  than the other way around.

* FFT: kiss_fftr returns only the non-conjugate bins, synthesise the rest
  rather than leaving them (perhaps dangerously) undefined.  Fixes an
  uninitialised data error in chromagram that could cause garbage results
  from key detector.

* Constant Q: remove precalculated values again, I reckon they're not
  proving such a good tradeoff.

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

// GetKeyMode.cpp: implementation of the CGetKeyMode class.
//
//////////////////////////////////////////////////////////////////////

#include "GetKeyMode.h"
#include "maths/MathUtilities.h"
#include "base/Pitch.h"

#include <iostream>

#include <cstring>
#include <cstdlib>

// Chords profile
static double MajProfile[36] = 
{ 0.0384, 0.0629, 0.0258, 0.0121, 0.0146, 0.0106, 0.0364, 0.0610, 0.0267,
  0.0126, 0.0121, 0.0086, 0.0364, 0.0623, 0.0279, 0.0275, 0.0414, 0.0186, 
  0.0173, 0.0248, 0.0145, 0.0364, 0.0631, 0.0262, 0.0129, 0.0150, 0.0098,
  0.0312, 0.0521, 0.0235, 0.0129, 0.0142, 0.0095, 0.0289, 0.0478, 0.0239};

static double MinProfile[36] =
{ 0.0375, 0.0682, 0.0299, 0.0119, 0.0138, 0.0093, 0.0296, 0.0543, 0.0257,
  0.0292, 0.0519, 0.0246, 0.0159, 0.0234, 0.0135, 0.0291, 0.0544, 0.0248,
  0.0137, 0.0176, 0.0104, 0.0352, 0.0670, 0.0302, 0.0222, 0.0349, 0.0164,
  0.0174, 0.0297, 0.0166, 0.0222, 0.0401, 0.0202, 0.0175, 0.0270, 0.0146};
//
    

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

GetKeyMode::GetKeyMode( int sampleRate, float tuningFrequency,
			double hpcpAverage, double medianAverage ) :
    m_hpcpAverage( hpcpAverage ),
    m_medianAverage( medianAverage ),
    m_ChrPointer(0),
    m_DecimatedBuffer(0),
    m_ChromaBuffer(0),
    m_MeanHPCP(0),
    m_MajCorr(0),
    m_MinCorr(0),
    m_Keys(0),
    m_MedianFilterBuffer(0),
    m_SortedBuffer(0),
    m_keyStrengths(0)
{
    m_DecimationFactor = 8;
        
    // Chromagram configuration parameters
    m_ChromaConfig.normalise = MathUtilities::NormaliseUnitMax;
    m_ChromaConfig.FS = lrint(sampleRate/(double)m_DecimationFactor);
    if (m_ChromaConfig.FS < 1) m_ChromaConfig.FS = 1;

    // Set C (= MIDI #12) as our base :
    // This implies that key = 1 => Cmaj, key = 12 => Bmaj, key = 13 => Cmin, etc.
    m_ChromaConfig.min = Pitch::getFrequencyForPitch
        (48, 0, tuningFrequency);
    m_ChromaConfig.max = Pitch::getFrequencyForPitch
        (96, 0, tuningFrequency);

    m_ChromaConfig.BPO = 36;
    m_ChromaConfig.CQThresh = 0.0054;

    // Chromagram inst.
    m_Chroma = new Chromagram( m_ChromaConfig );

    // Get calculated parameters from chroma object
    m_ChromaFrameSize = m_Chroma->getFrameSize();
    // override hopsize for this application
    m_ChromaHopSize = m_ChromaFrameSize;
    m_BPO = m_ChromaConfig.BPO;

//    std::cerr << "chroma frame size = " << m_ChromaFrameSize << ", decimation factor = " << m_DecimationFactor << " therefore block size = " << getBlockSize() << std::endl;

    // Chromagram average and estimated key median filter lengths
    m_ChromaBuffersize = (int)ceil( m_hpcpAverage * m_ChromaConfig.FS/m_ChromaFrameSize );
    m_MedianWinsize = (int)ceil( m_medianAverage * m_ChromaConfig.FS/m_ChromaFrameSize );
    
    // Reset counters
    m_bufferindex = 0;
    m_ChromaBufferFilling = 0;
    m_MedianBufferFilling = 0;

    // Spawn objectc/arrays
    m_DecimatedBuffer = new double[m_ChromaFrameSize];
    
    m_ChromaBuffer = new double[m_BPO * m_ChromaBuffersize];
    memset( m_ChromaBuffer, 0, sizeof(double) * m_BPO * m_ChromaBuffersize);
    
    m_MeanHPCP = new double[m_BPO];
    
    m_MajCorr = new double[m_BPO];
    m_MinCorr = new double[m_BPO];
    m_Keys  = new double[2*m_BPO];
    
    m_MedianFilterBuffer = new int[ m_MedianWinsize ];
    memset( m_MedianFilterBuffer, 0, sizeof(int)*m_MedianWinsize);
    
    m_SortedBuffer = new int[ m_MedianWinsize ];
    memset( m_SortedBuffer, 0, sizeof(int)*m_MedianWinsize);	
    
    m_Decimator = new Decimator
        ( m_ChromaFrameSize*m_DecimationFactor, m_DecimationFactor );

    m_keyStrengths = new double[24];
}

GetKeyMode::~GetKeyMode()
{

    delete m_Chroma;
    delete m_Decimator;
    
    delete [] m_DecimatedBuffer;
    delete [] m_ChromaBuffer;
    delete [] m_MeanHPCP;
    delete [] m_MajCorr;
    delete [] m_MinCorr;
    delete [] m_Keys;
    delete [] m_MedianFilterBuffer;
    delete [] m_SortedBuffer;

    delete[] m_keyStrengths;
}

double GetKeyMode::krumCorr(double *pData1, double *pData2, unsigned int length)
{
    double retVal= 0.0;
    
    double num = 0;
    double den = 0;
    double mX = MathUtilities::mean( pData1, length );
    double mY = MathUtilities::mean( pData2, length );
    
    double sum1 = 0;
    double sum2 = 0;
    
    for( unsigned int i = 0; i <length; i++ )
    {
        num += ( pData1[i] - mX ) * ( pData2[i] - mY );

        sum1 += ( (pData1[i]-mX) * (pData1[i]-mX) );
        sum2 += ( (pData2[i]-mY) * (pData2[i]-mY) );
    }
	
    den = sqrt(sum1 * sum2);
	
    if( den>0 )
        retVal = num/den;
    else
        retVal = 0;


    return retVal;
}

int GetKeyMode::process(double *PCMData)
{
    int key;

    unsigned int j,k;

    //////////////////////////////////////////////
    m_Decimator->process( PCMData, m_DecimatedBuffer);

    m_ChrPointer = m_Chroma->process( m_DecimatedBuffer );		

	
    // Move bins such that the centre of the base note is in the
    // middle of its three bins :
    // Added 21.11.07 by Chris Sutton based on debugging with Katy
    // Noland + comparison with Matlab equivalent.
    MathUtilities::circShift( m_ChrPointer, m_BPO, 1);
/*
    std::cout << "raw chroma: ";
    for (int ii = 0; ii < m_BPO; ++ii) {
      if (ii % (m_BPO/12) == 0) std::cout << "\n";
        std::cout << m_ChrPointer[ii] << " ";
    }
    std::cout << std::endl;
*/
    // populate hpcp values;
    int cbidx;
    for( j = 0; j < m_BPO; j++ )
    {
        cbidx = (m_bufferindex * m_BPO) + j;
        m_ChromaBuffer[ cbidx ] = m_ChrPointer[j];
    }

    //keep track of input buffers;
    if( m_bufferindex++ >= m_ChromaBuffersize - 1) 
        m_bufferindex = 0;

    // track filling of chroma matrix
    if( m_ChromaBufferFilling++ >= m_ChromaBuffersize)
        m_ChromaBufferFilling = m_ChromaBuffersize;

    //calculate mean 		
    for( k = 0; k < m_BPO; k++ )
    {
        double mnVal = 0.0;
        for( j = 0; j < m_ChromaBufferFilling; j++ )
        {
            mnVal += m_ChromaBuffer[ k + (j*m_BPO) ];
        }

        m_MeanHPCP[k] = mnVal/(double)m_ChromaBufferFilling;
    }


    for( k = 0; k < m_BPO; k++ )
    {
        m_MajCorr[k] = krumCorr( m_MeanHPCP, MajProfile, m_BPO );
        m_MinCorr[k] = krumCorr( m_MeanHPCP, MinProfile, m_BPO );

        MathUtilities::circShift( MajProfile, m_BPO, 1 );
        MathUtilities::circShift( MinProfile, m_BPO, 1 );
    }
	
    for( k = 0; k < m_BPO; k++ )
    {
        m_Keys[k] = m_MajCorr[k];
        m_Keys[k+m_BPO] = m_MinCorr[k];
    }

    for (k = 0; k < 24; ++k) {
        m_keyStrengths[k] = 0;
    }

    for( k = 0; k < m_BPO*2; k++ )
    {
        int idx = k / (m_BPO/12);
        int rem = k % (m_BPO/12);
        if (rem == 0 || m_Keys[k] > m_keyStrengths[idx]) {
            m_keyStrengths[idx] = m_Keys[k];
        }

//        m_keyStrengths[k/(m_BPO/12)] += m_Keys[k];
    }

/*
  std::cout << "raw keys: ";
  for (int ii = 0; ii < 2*m_BPO; ++ii) {
      if (ii % (m_BPO/12) == 0) std::cout << "\n";
      std::cout << m_Keys[ii] << " ";
  }
  std::cout << std::endl;

  std::cout << "key strengths: ";
  for (int ii = 0; ii < 24; ++ii) {
      if (ii % 6 == 0) std::cout << "\n";
      std::cout << m_keyStrengths[ii] << " ";
  }
  std::cout << std::endl;
*/
    double dummy;
    // '1 +' because we number keys 1-24, not 0-23.
    key = 1 + (int)ceil( (double)MathUtilities::getMax( m_Keys, 2* m_BPO, &dummy )/3 );

//    std::cout << "key pre-sorting: " << key << std::endl;


    //Median filtering

    // track Median buffer initial filling
    if( m_MedianBufferFilling++ >= m_MedianWinsize)
        m_MedianBufferFilling = m_MedianWinsize;
		
    //shift median buffer
    for( k = 1; k < m_MedianWinsize; k++ )
    {
        m_MedianFilterBuffer[ k - 1 ] = m_MedianFilterBuffer[ k ];
    }

    //write new key value into median buffer
    m_MedianFilterBuffer[ m_MedianWinsize - 1 ] = key;


    //Copy median into sorting buffer, reversed
    unsigned int ijx = 0;
    for( k = 0; k < m_MedianWinsize; k++ )
    {
        m_SortedBuffer[k] = m_MedianFilterBuffer[m_MedianWinsize-1-ijx];
        ijx++;
    }

    qsort(m_SortedBuffer, m_MedianBufferFilling, sizeof(unsigned int),
          MathUtilities::compareInt);
/*
  std::cout << "sorted: ";
  for (int ii = 0; ii < m_MedianBufferFilling; ++ii) {
  std::cout << m_SortedBuffer[ii] << " ";
  }
  std::cout << std::endl;
*/
    int sortlength = m_MedianBufferFilling;
    int midpoint = (int)ceil((double)sortlength/2);

//  std::cout << "midpoint = " << midpoint << endl;

    if( midpoint <= 0 )
        midpoint = 1;

    key = m_SortedBuffer[midpoint-1];

// std::cout << "returning key = " << key << endl;

    return key;
}


bool GetKeyMode::isModeMinor( int key )
{ 
    return (key > 12);
}