annotate dsp/onsets/DetectionFunction.cpp @ 96:88f3cfcff55f

A threshold (delta) is added in the peak picking parameters structure (PPickParams). It is used as an offset when computing the smoothed detection function. A constructor for the structure PPickParams is also added to set the parameters to 0 when a structure instance is created. Hence programmes using the peak picking parameter structure and which do not set the delta parameter (e.g. QM Vamp note onset detector) won't be affected by the modifications.

Functions modified:
- dsp/onsets/PeakPicking.cpp
- dsp/onsets/PeakPicking.h
- dsp/signalconditioning/DFProcess.cpp
- dsp/signalconditioning/DFProcess.h

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

/*
    QM DSP Library

    Centre for Digital Music, Queen Mary, University of London.
    This file 2005-2006 Christian Landone.

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#include "DetectionFunction.h"
#include <cstring>

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

DetectionFunction::DetectionFunction( DFConfig Config ) :
    m_window(0)
{
    m_magHistory = NULL;
    m_phaseHistory = NULL;
    m_phaseHistoryOld = NULL;
    m_magPeaks = NULL;

    initialise( Config );
}

DetectionFunction::~DetectionFunction()
{
    deInitialise();
}


void DetectionFunction::initialise( DFConfig Config )
{
    m_dataLength = Config.frameLength;
    m_halfLength = m_dataLength/2;

    m_DFType = Config.DFType;
    m_stepSize = Config.stepSize;

    m_whiten = Config.adaptiveWhitening;
    m_whitenRelaxCoeff = Config.whiteningRelaxCoeff;
    m_whitenFloor = Config.whiteningFloor;
    if (m_whitenRelaxCoeff < 0) m_whitenRelaxCoeff = 0.9997;
    if (m_whitenFloor < 0) m_whitenFloor = 0.01;

    m_magHistory = new double[ m_halfLength ];
    memset(m_magHistory,0, m_halfLength*sizeof(double));
		
    m_phaseHistory = new double[ m_halfLength ];
    memset(m_phaseHistory,0, m_halfLength*sizeof(double));

    m_phaseHistoryOld = new double[ m_halfLength ];
    memset(m_phaseHistoryOld,0, m_halfLength*sizeof(double));

    m_magPeaks = new double[ m_halfLength ];
    memset(m_magPeaks,0, m_halfLength*sizeof(double));

    // See note in process(const double *) below
    int actualLength = MathUtilities::previousPowerOfTwo(m_dataLength);
    m_phaseVoc = new PhaseVocoder(actualLength);

    m_DFWindowedFrame = new double[ m_dataLength ];
    m_magnitude = new double[ m_halfLength ];
    m_thetaAngle = new double[ m_halfLength ];

    m_window = new Window<double>(HanningWindow, m_dataLength);
}

void DetectionFunction::deInitialise()
{
    delete [] m_magHistory ;
    delete [] m_phaseHistory ;
    delete [] m_phaseHistoryOld ;
    delete [] m_magPeaks ;

    delete m_phaseVoc;

    delete [] m_DFWindowedFrame;
    delete [] m_magnitude;
    delete [] m_thetaAngle;

    delete m_window;
}

double DetectionFunction::process( const double *TDomain )
{
    m_window->cut( TDomain, m_DFWindowedFrame );

    // Our own FFT implementation supports power-of-two sizes only.
    // If we have to use this implementation (as opposed to the
    // version of process() below that operates on frequency domain
    // data directly), we will have to use the next smallest power of
    // two from the block size.  Results may vary accordingly!

    int actualLength = MathUtilities::previousPowerOfTwo(m_dataLength);

    if (actualLength != m_dataLength) {
        // Pre-fill mag and phase vectors with zero, as the FFT output
        // will not fill the arrays
        for (int i = actualLength/2; i < m_dataLength/2; ++i) {
            m_magnitude[i] = 0;
            m_thetaAngle[0] = 0;
        }
    }

    m_phaseVoc->process(m_DFWindowedFrame, m_magnitude, m_thetaAngle);

    if (m_whiten) whiten();

    return runDF();
}

double DetectionFunction::process( const double *magnitudes, const double *phases )
{
    for (size_t i = 0; i < m_halfLength; ++i) {
        m_magnitude[i] = magnitudes[i];
        m_thetaAngle[i] = phases[i];
    }

    if (m_whiten) whiten();

    return runDF();
}

void DetectionFunction::whiten()
{
    for (unsigned int i = 0; i < m_halfLength; ++i) {
        double m = m_magnitude[i];
        if (m < m_magPeaks[i]) {
            m = m + (m_magPeaks[i] - m) * m_whitenRelaxCoeff;
        }
        if (m < m_whitenFloor) m = m_whitenFloor;
        m_magPeaks[i] = m;
        m_magnitude[i] /= m;
    }
}

double DetectionFunction::runDF()
{
    double retVal = 0;

    switch( m_DFType )
    {
    case DF_HFC:
	retVal = HFC( m_halfLength, m_magnitude);
	break;
	
    case DF_SPECDIFF:
	retVal = specDiff( m_halfLength, m_magnitude);
	break;
	
    case DF_PHASEDEV:
	retVal = phaseDev( m_halfLength, m_thetaAngle);
	break;
	
    case DF_COMPLEXSD:
	retVal = complexSD( m_halfLength, m_magnitude, m_thetaAngle);
	break;

    case DF_BROADBAND:
        retVal = broadband( m_halfLength, m_magnitude);
        break;
    }
	
    return retVal;
}

double DetectionFunction::HFC(unsigned int length, double *src)
{
    unsigned int i;
    double val = 0;

    for( i = 0; i < length; i++)
    {
	val += src[ i ] * ( i + 1);
    }
    return val;
}

double DetectionFunction::specDiff(unsigned int length, double *src)
{
    unsigned int i;
    double val = 0.0;
    double temp = 0.0;
    double diff = 0.0;

    for( i = 0; i < length; i++)
    {
	temp = fabs( (src[ i ] * src[ i ]) - (m_magHistory[ i ] * m_magHistory[ i ]) );
		
	diff= sqrt(temp);

        // (See note in phaseDev below.)

        val += diff;

	m_magHistory[ i ] = src[ i ];
    }

    return val;
}


double DetectionFunction::phaseDev(unsigned int length, double *srcPhase)
{
    unsigned int i;
    double tmpPhase = 0;
    double tmpVal = 0;
    double val = 0;

    double dev = 0;

    for( i = 0; i < length; i++)
    {
	tmpPhase = (srcPhase[ i ]- 2*m_phaseHistory[ i ]+m_phaseHistoryOld[ i ]);
	dev = MathUtilities::princarg( tmpPhase );

        // A previous version of this code only counted the value here
        // if the magnitude exceeded 0.1.  My impression is that
        // doesn't greatly improve the results for "loud" music (so
        // long as the peak picker is reasonably sophisticated), but
        // does significantly damage its ability to work with quieter
        // music, so I'm removing it and counting the result always.
        // Same goes for the spectral difference measure above.
		
        tmpVal  = fabs(dev);
        val += tmpVal ;

	m_phaseHistoryOld[ i ] = m_phaseHistory[ i ] ;
	m_phaseHistory[ i ] = srcPhase[ i ];
    }
	
	
    return val;
}


double DetectionFunction::complexSD(unsigned int length, double *srcMagnitude, double *srcPhase)
{
    unsigned int i;
    double val = 0;
    double tmpPhase = 0;
    double tmpReal = 0;
    double tmpImag = 0;
   
    double dev = 0;
    ComplexData meas = ComplexData( 0, 0 );
    ComplexData j = ComplexData( 0, 1 );

    for( i = 0; i < length; i++)
    {
	tmpPhase = (srcPhase[ i ]- 2*m_phaseHistory[ i ]+m_phaseHistoryOld[ i ]);
	dev= MathUtilities::princarg( tmpPhase );
		
	meas = m_magHistory[i] - ( srcMagnitude[ i ] * exp( j * dev) );

	tmpReal = real( meas );
	tmpImag = imag( meas );

	val += sqrt( (tmpReal * tmpReal) + (tmpImag * tmpImag) );
		
	m_phaseHistoryOld[ i ] = m_phaseHistory[ i ] ;
	m_phaseHistory[ i ] = srcPhase[ i ];
	m_magHistory[ i ] = srcMagnitude[ i ];
    }

    return val;
}

double DetectionFunction::broadband(unsigned int length, double *src)
{
    double val = 0;
    for (unsigned int i = 0; i < length; ++i) {
        double sqrmag = src[i] * src[i];
        if (m_magHistory[i] > 0.0) {
            double diff = 10.0 * log10(sqrmag / m_magHistory[i]);
            if (diff > m_dbRise) val = val + 1;
        }
        m_magHistory[i] = sqrmag;
    }
    return val;
}        

double* DetectionFunction::getSpectrumMagnitude()
{
    return m_magnitude;
}