annotate dsp/chromagram/Chromagram.cpp @ 321:f1e6be2de9a5

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 <iostream>
#include <cmath>
#include "maths/MathUtilities.h"
#include "Chromagram.h"

//----------------------------------------------------------------------------

Chromagram::Chromagram( ChromaConfig Config ) :
    m_skGenerated(false)
{
    initialise( Config );
}

int Chromagram::initialise( ChromaConfig Config )
{	
    m_FMin = Config.min;		// min freq
    m_FMax = Config.max;		// max freq
    m_BPO  = Config.BPO;		// bins per octave
    m_normalise = Config.normalise;     // if frame normalisation is required

    // No. of constant Q bins
    m_uK = ( unsigned int ) ceil( m_BPO * log(m_FMax/m_FMin)/log(2.0));	

    // Create array for chroma result
    m_chromadata = new double[ m_BPO ];

    // Create Config Structure for ConstantQ operator
    CQConfig ConstantQConfig;

    // Populate CQ config structure with parameters
    // inherited from the Chroma config
    ConstantQConfig.FS	 = Config.FS;
    ConstantQConfig.min = m_FMin;
    ConstantQConfig.max = m_FMax;
    ConstantQConfig.BPO = m_BPO;
    ConstantQConfig.CQThresh = Config.CQThresh;
	
    // Initialise ConstantQ operator
    m_ConstantQ = new ConstantQ( ConstantQConfig );

    // Initialise working arrays
    m_frameSize = m_ConstantQ->getfftlength();
    m_hopSize = m_ConstantQ->gethop();

    // Initialise FFT object	
    m_FFT = new FFTReal(m_frameSize);

    m_FFTRe = new double[ m_frameSize ];
    m_FFTIm = new double[ m_frameSize ];
    m_CQRe  = new double[ m_uK ];
    m_CQIm  = new double[ m_uK ];

    m_window = 0;
    m_windowbuf = 0;

    return 1;
}

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

int Chromagram::deInitialise()
{
    delete[] m_windowbuf;
    delete m_window;

    delete [] m_chromadata;

    delete m_FFT;

    delete m_ConstantQ;

    delete [] m_FFTRe;
    delete [] m_FFTIm;
    delete [] m_CQRe;
    delete [] m_CQIm;
    return 1;
}

//----------------------------------------------------------------------------------
// returns the absolute value of complex number xx + i*yy
double Chromagram::kabs(double xx, double yy)
{
    double ab = sqrt(xx*xx + yy*yy);
    return(ab);
}
//-----------------------------------------------------------------------------------


void Chromagram::unityNormalise(double *src)
{
    double min, max;

    double val = 0;

    MathUtilities::getFrameMinMax( src, m_BPO, & min, &max );

    for( unsigned int i = 0; i < m_BPO; i++ )
    {
	val = src[ i ] / max;

	src[ i ] = val;
    }
}


double* Chromagram::process( const double *data )
{
    if (!m_skGenerated) {
        // Generate CQ Kernel 
        m_ConstantQ->sparsekernel();
        m_skGenerated = true;
    }

    if (!m_window) {
        m_window = new Window<double>(HammingWindow, m_frameSize);
        m_windowbuf = new double[m_frameSize];
    }

    for (int i = 0; i < m_frameSize; ++i) {
        m_windowbuf[i] = data[i];
    }
    m_window->cut(m_windowbuf);

    // FFT of current frame
    m_FFT->process(false, m_windowbuf, m_FFTRe, m_FFTIm);

    return process(m_FFTRe, m_FFTIm);
}

double* Chromagram::process( const double *real, const double *imag )
{
    if (!m_skGenerated) {
        // Generate CQ Kernel 
        m_ConstantQ->sparsekernel();
        m_skGenerated = true;
    }

    // initialise chromadata to 0
    for (unsigned i = 0; i < m_BPO; i++) m_chromadata[i] = 0;

    double cmax = 0.0;
    double cval = 0;

    // Calculate ConstantQ frame
    m_ConstantQ->process( real, imag, m_CQRe, m_CQIm );
	
    // add each octave of cq data into Chromagram
    const unsigned octaves = (int)floor(double( m_uK/m_BPO))-1;
    for (unsigned octave = 0; octave <= octaves; octave++) 
    {
	unsigned firstBin = octave*m_BPO;
	for (unsigned i = 0; i < m_BPO; i++) 
	{
	    m_chromadata[i] += kabs( m_CQRe[ firstBin + i ], m_CQIm[ firstBin + i ]);
	}
    }

    MathUtilities::normalise(m_chromadata, m_BPO, m_normalise);

    return m_chromadata;
}