annotate dsp/onsets/PeakPicking.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.

    Modifications:

    - delta threshold
    Description: add delta threshold used as offset in the smoothed
    detection function
    Author: Mathieu Barthet
    Date: June 2010

    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 "PeakPicking.h"
#include "maths/Polyfit.h"

#include <iostream>
#include <cstring>


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

PeakPicking::PeakPicking( PPickParams Config )
{
    m_workBuffer = NULL;
    initialise( Config );
}

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

void PeakPicking::initialise( PPickParams Config )
{
    m_DFLength = Config.length ;
    Qfilta = Config.QuadThresh.a ;
    Qfiltb = Config.QuadThresh.b ;
    Qfiltc = Config.QuadThresh.c ;
	
    m_DFProcessingParams.length = m_DFLength; 
    m_DFProcessingParams.LPOrd = Config.LPOrd; 
    m_DFProcessingParams.LPACoeffs = Config.LPACoeffs; 
    m_DFProcessingParams.LPBCoeffs = Config.LPBCoeffs; 
    m_DFProcessingParams.winPre  = Config.WinT.pre;
    m_DFProcessingParams.winPost = Config.WinT.post; 
    m_DFProcessingParams.AlphaNormParam = Config.alpha;
    m_DFProcessingParams.isMedianPositive = false;
    m_DFProcessingParams.Delta = Config.delta; //add the delta threshold as an adjustable parameter

    m_DFSmoothing = new DFProcess( m_DFProcessingParams );

    m_workBuffer = new double[ m_DFLength ];
    memset( m_workBuffer, 0, sizeof(double)*m_DFLength);
}

void PeakPicking::deInitialise()
{
    delete [] m_workBuffer;
    delete m_DFSmoothing;
    m_workBuffer = NULL;
}

void PeakPicking::process( double* src, unsigned int len, vector<int> &onsets )
{
    if (len < 4) return;

    vector <double> m_maxima;	

    // Signal conditioning 
    m_DFSmoothing->process( src, m_workBuffer );
	
    for( unsigned int u = 0; u < len; u++)
    {
	m_maxima.push_back( m_workBuffer[ u ] );		
    }
	
    quadEval( m_maxima, onsets );

    for( int b = 0; b <  m_maxima.size(); b++)
    {
	src[ b ] = m_maxima[ b ];
    }
}

int PeakPicking::quadEval( vector<double> &src, vector<int> &idx )
{
    unsigned int maxLength;

    vector <int> m_maxIndex;
    vector <int> m_onsetPosition;
	
    vector <double> m_maxFit;
    vector <double> m_poly;
    vector <double> m_err;

    double p;

    m_poly.push_back(0);
    m_poly.push_back(0);
    m_poly.push_back(0);

    for(  int t = -2; t < 3; t++)
    {
	m_err.push_back( (double)t );
    }
    for( unsigned int i = 2; i < src.size() - 2; i++)
    {
	if( (src[i] > src[i-1]) && (src[i] > src[i+1]) && (src[i] > 0) )
	{
//	    m_maxIndex.push_back(  i + 1 );
            m_maxIndex.push_back(i);
	}
    }

    maxLength = m_maxIndex.size();

    double selMax = 0;

    for( unsigned int j = 0; j < maxLength ; j++)
    {
        for (int k = -2; k <= 2; ++k)
	{
	    selMax = src[ m_maxIndex[j] + k ] ;
	    m_maxFit.push_back(selMax);			
	}

	p = TPolyFit::PolyFit2( m_err, m_maxFit, m_poly);

	double f = m_poly[0];
	double g = m_poly[1];
	double h = m_poly[2];

	int kk = m_poly.size();

	if (h < -Qfilta || f > Qfiltc)
	{
	    idx.push_back(m_maxIndex[j]);
	}
		
	m_maxFit.clear();
    }

    return 1;
}