annotate dsp/tempotracking/TempoTrack.cpp @ 40:163f6e03e9e7

* Add key strength output; increase chromagram lower bound so as to shorten
  hop size

/* -*- 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 copyright 2005-2006 Christian Landone.
    All rights reserved.
*/

#include "TempoTrack.h"

#include "maths/MathAliases.h"
#include "maths/MathUtilities.h"

#include <iostream>


#define RAY43VAL

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

TempoTrack::TempoTrack( TTParams Params )
{
    m_tempoScratch = NULL;
    m_rawDFFrame = NULL;
    m_smoothDFFrame = NULL;
    m_frameACF = NULL;
	m_smoothRCF = NULL;

    m_dataLength = 0;
    m_winLength = 0;
    m_lagLength = 0;

    m_rayparam = 0;
    m_sigma = 0;
    m_DFWVNnorm = 0;

    initialise( Params );
}

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

void TempoTrack::initialise( TTParams Params )
{	
    m_winLength = Params.winLength;
    m_lagLength = Params.lagLength;

    m_rayparam	 = 43.0;
    m_sigma = sqrt(3.9017);
    m_DFWVNnorm = exp( ( log( 2.0 ) / m_rayparam ) * ( m_winLength + 2 ) );

    m_rawDFFrame = new double[ m_winLength ];
    m_smoothDFFrame = new double[ m_winLength ];
    m_frameACF = new double[ m_winLength ];
    m_tempoScratch = new double[ m_lagLength ];
	m_smoothRCF = new double[ m_lagLength ];


    unsigned int winPre = Params.WinT.pre;
    unsigned int winPost = Params.WinT.post;

    m_DFFramer.configure( m_winLength, m_lagLength );
	
    m_DFPParams.length = m_winLength;
    m_DFPParams.AlphaNormParam = Params.alpha;
    m_DFPParams.LPOrd = Params.LPOrd;
    m_DFPParams.LPACoeffs = Params.LPACoeffs;
    m_DFPParams.LPBCoeffs = Params.LPBCoeffs;
    m_DFPParams.winPre = Params.WinT.pre;
    m_DFPParams.winPost = Params.WinT.post;
    m_DFPParams.isMedianPositive = true;
	
    m_DFConditioning = new DFProcess( m_DFPParams );


	// these are parameters for smoothing m_tempoScratch
    m_RCFPParams.length = m_lagLength;
    m_RCFPParams.AlphaNormParam = Params.alpha;
    m_RCFPParams.LPOrd = Params.LPOrd;
    m_RCFPParams.LPACoeffs = Params.LPACoeffs;
    m_RCFPParams.LPBCoeffs = Params.LPBCoeffs;
    m_RCFPParams.winPre = Params.WinT.pre;
    m_RCFPParams.winPost = Params.WinT.post;
    m_RCFPParams.isMedianPositive = true;

    m_RCFConditioning = new DFProcess( m_RCFPParams );

}

void TempoTrack::deInitialise()
{	
    delete [] m_rawDFFrame;
	
    delete [] m_smoothDFFrame;

	delete [] m_smoothRCF;	
	
    delete [] m_frameACF;

    delete [] m_tempoScratch;

    delete m_DFConditioning;
	
	delete m_RCFConditioning;

}

void TempoTrack::createCombFilter(double* Filter, unsigned int winLength, unsigned int TSig, double beatLag)
{
    unsigned int i;

    if( beatLag == 0 )
    {
	for( i = 0; i < winLength; i++ )
	{    
	    Filter[ i ] = ( ( i + 1 ) / pow( m_rayparam, 2.0) ) * exp( ( -pow(( i + 1 ),2.0 ) / ( 2.0 * pow( m_rayparam, 2.0))));
	}
    }
    else
    {	
	m_sigma = beatLag/4;
	for( i = 0; i < winLength; i++ )
	{
	    double dlag = (double)(i+1) - beatLag;
	    Filter[ i ] =  exp(-0.5 * pow(( dlag / m_sigma), 2.0) ) / (sqrt( 2 * PI) * m_sigma);
	}
    }
}

double TempoTrack::tempoMM(double* ACF, double* weight, int tsig)
{

    double period = 0;
    double maxValRCF = 0.0;
    unsigned int maxIndexRCF = 0;

    double* pdPeaks;

    unsigned int maxIndexTemp;
    double	maxValTemp;
    unsigned int count; 
	
    unsigned int numelem,i,j;
    int a, b;

    for( i = 0; i < m_lagLength; i++ )
	m_tempoScratch[ i ] = 0.0;

    if( tsig == 0 ) 
    {
	//if time sig is unknown, use metrically unbiased version of Filterbank
	numelem = 4;
    }
    else
    {
	numelem = tsig;
    }

    for(i=1;i<m_lagLength-1;i++)
    {
	//first and last output values are left intentionally as zero
	for (a=1;a<=numelem;a++)
	{
	    for(b=(1-a);b<a;b++)
	    {
		if( tsig == 0 )
		{					
		    m_tempoScratch[i] += ACF[a*(i+1)+b-1] * (1.0 / (2.0 * (double)a-1)) * weight[i];
		}
		else
		{
		    m_tempoScratch[i] += ACF[a*(i+1)+b-1] * 1 * weight[i];
		}
	    }
	}
    }


	//////////////////////////////////////////////////
	// MODIFIED BEAT PERIOD EXTRACTION //////////////
	/////////////////////////////////////////////////

	// find smoothed version of RCF ( as applied to Detection Function)
	m_RCFConditioning->process( m_tempoScratch, m_smoothRCF);

	if (tsig != 0) // i.e. in context dependent state
	{	
//     NOW FIND MAX INDEX OF ACFOUT
    	for( i = 0; i < m_lagLength; i++)
    	{
			if( m_tempoScratch[ i ] > maxValRCF)
			{
	    		maxValRCF = m_tempoScratch[ i ];
	    		maxIndexRCF = i;
			}
 	   }
	}
	else // using rayleigh weighting
	{
		vector <vector<double> > rcfMat;
	
		double sumRcf = 0.;
	
		double maxVal = 0.;
		// now find the two values which minimise rcfMat
		double minVal = 0.;
		int p_i = 1; // periodicity for row i;
		int p_j = 1; //periodicity for column j;
	
	
		for ( i=0; i<m_lagLength; i++)
		{
			m_tempoScratch[i] =m_smoothRCF[i];
		}	

		// normalise m_tempoScratch so that it sums to zero.
		for ( i=0; i<m_lagLength; i++)
		{
			sumRcf += m_tempoScratch[i];
		}	
	
		for( i=0; i<m_lagLength; i++)
		{
			m_tempoScratch[i] /= sumRcf;
		}	
	
		// create a matrix to store m_tempoScratchValues modified by log2 ratio
		for ( i=0; i<m_lagLength; i++)
		{
			rcfMat.push_back  ( vector<double>() ); // adds a new row...
		}
	
		for (i=0; i<m_lagLength; i++)
		{
			for (j=0; j<m_lagLength; j++)
			{
				rcfMat[i].push_back (0.);
			}
		}
	
		// the 'i' and 'j' indices deliberately start from '1' and not '0'
		for ( i=1; i<m_lagLength; i++)
		{
			for (j=1; j<m_lagLength; j++)
			{
				double log2PeriodRatio = log( static_cast<double>(i)/static_cast<double>(j) ) / log(2.0);
				rcfMat[i][j] = ( abs(1.0-abs(log2PeriodRatio)) );
				rcfMat[i][j] += ( 0.01*( 1./(m_tempoScratch[i]+m_tempoScratch[j]) ) );
			}
		}
		
		// set diagonal equal to maximum value in rcfMat 
		// we don't want to pick one strong middle peak - we need a combination of two peaks.
	
		for ( i=1; i<m_lagLength; i++)
		{
			for (j=1; j<m_lagLength; j++)
			{
				if (rcfMat[i][j] > maxVal)
				{	
					maxVal = rcfMat[i][j];
				}
			}
		}
	
		for ( i=1; i<m_lagLength; i++)
		{
			rcfMat[i][i] = maxVal;
		}
	
		// now find the row and column number which minimise rcfMat
		minVal = maxVal;
		
		for ( i=1; i<m_lagLength; i++)
		{
			for ( j=1; j<m_lagLength; j++)
			{
				if (rcfMat[i][j] < minVal)
				{	
					minVal = rcfMat[i][j];
					p_i = i;
					p_j = j;
				}
			}
		}
	
	
		// initially choose p_j (arbitrary) - saves on an else statement
		int beatPeriod = p_j;
		if (m_tempoScratch[p_i] > m_tempoScratch[p_j])
		{
			beatPeriod = p_i;
		}
		
		// now write the output
		maxIndexRCF = static_cast<int>(beatPeriod);

	}


    double locked = 5168.f / maxIndexRCF;
    if (locked >= 30 && locked <= 180) {
        m_lockedTempo = locked;
    }

    if( tsig == 0 )
	tsig = 4;

	
    if( tsig == 4 )
    {
	pdPeaks = new double[ 4 ];
	for( i = 0; i < 4; i++ ){ pdPeaks[ i ] = 0.0;}

	pdPeaks[ 0 ] = ( double )maxIndexRCF + 1;

	maxIndexTemp = 0;
	maxValTemp = 0.0;
	count = 0;

	for( i = (2 * maxIndexRCF + 1) - 1; i < (2 * maxIndexRCF + 1) + 2; i++ )
	{
	    if( ACF[ i ] > maxValTemp )
	    {
		maxValTemp = ACF[ i ];
		maxIndexTemp = count;
	    }
	    count++;
	}
	pdPeaks[ 1 ] = (double)( maxIndexTemp + 1 + ( (2 * maxIndexRCF + 1 ) - 2 ) + 1 )/2;

	maxIndexTemp = 0;
	maxValTemp = 0.0;
	count = 0;

	for( i = (3 * maxIndexRCF + 2 ) - 2; i < (3 * maxIndexRCF + 2 ) + 3; i++ )
	{
	    if( ACF[ i ] > maxValTemp )
	    {
		maxValTemp = ACF[ i ];
		maxIndexTemp = count;
	    }
	    count++;
	}
	pdPeaks[ 2 ] = (double)( maxIndexTemp + 1 + ( (3 * maxIndexRCF + 2) - 4 ) + 1 )/3;

	maxIndexTemp = 0;
	maxValTemp = 0.0;
	count = 0;

	for( i = ( 4 * maxIndexRCF + 3) - 3; i < ( 4 * maxIndexRCF + 3) + 4; i++ )
	{
	    if( ACF[ i ] > maxValTemp )
	    {
		maxValTemp = ACF[ i ];
		maxIndexTemp = count;
	    }
	    count++;
	}
	pdPeaks[ 3 ] = (double)( maxIndexTemp + 1 + ( (4 * maxIndexRCF + 3) - 9 ) + 1 )/4 ;


	period = MathUtilities::mean( pdPeaks, 4 );
    }
    else
    {
	pdPeaks = new double[ 3 ];
	for( i = 0; i < 3; i++ ){ pdPeaks[ i ] = 0.0;}

	pdPeaks[ 0 ] = ( double )maxIndexRCF + 1;

	maxIndexTemp = 0;
	maxValTemp = 0.0;
	count = 0;

	for( i = (2 * maxIndexRCF + 1) - 1; i < (2 * maxIndexRCF + 1) + 2; i++ )
	{
	    if( ACF[ i ] > maxValTemp )
	    {
		maxValTemp = ACF[ i ];
		maxIndexTemp = count;
	    }
	    count++;
	}
	pdPeaks[ 1 ] = (double)( maxIndexTemp + 1 + ( (2 * maxIndexRCF + 1 ) - 2 ) + 1 )/2;

	maxIndexTemp = 0;
	maxValTemp = 0.0;
	count = 0;

	for( i = (3 * maxIndexRCF + 2 ) - 2; i < (3 * maxIndexRCF + 2 ) + 3; i++ )
	{
	    if( ACF[ i ] > maxValTemp )
	    {
		maxValTemp = ACF[ i ];
		maxIndexTemp = count;
	    }
	    count++;
	}
	pdPeaks[ 2 ] = (double)( maxIndexTemp + 1 + ( (3 * maxIndexRCF + 2) - 4 ) + 1 )/3;


	period = MathUtilities::mean( pdPeaks, 3 );
    }

    delete [] pdPeaks;

    return period;
}

void TempoTrack::stepDetect( double* periodP, double* periodG, int currentIdx, int* flag )
{
    double stepthresh = 1 * 3.9017;

    if( *flag )
    {
	if(abs(periodG[ currentIdx ] - periodP[ currentIdx ]) > stepthresh)
	{
	    // do nuffin'
	}
    }
    else
    {
	if(fabs(periodG[ currentIdx ]-periodP[ currentIdx ]) > stepthresh)
	{
	    *flag = 3;
	}
    }
}

void TempoTrack::constDetect( double* periodP, int currentIdx, int* flag )
{
    double constthresh = 2 * 3.9017;

    if( fabs( 2 * periodP[ currentIdx ] - periodP[ currentIdx - 1] - periodP[ currentIdx - 2] ) < constthresh)
    {
	*flag = 1;
    }
    else
    {
	*flag = 0;
    }
}

int TempoTrack::findMeter(double *ACF, unsigned int len, double period)
{
    int i;
    int p = (int)MathUtilities::round( period );
    int tsig;

    double Energy_3 = 0.0;
    double Energy_4 = 0.0;

    double temp3A = 0.0;
    double temp3B = 0.0;
    double temp4A = 0.0;
    double temp4B = 0.0;

    double* dbf = new double[ len ]; int t = 0;
    for( unsigned int u = 0; u < len; u++ ){ dbf[ u ] = 0.0; }

    if( (double)len < 6 * p + 2 )
    {
	for( i = ( 3 * p - 2 ); i < ( 3 * p + 2 ) + 1; i++ )
	{
	    temp3A += ACF[ i ];
	    dbf[ t++ ] = ACF[ i ];
	}
	
	for( i = ( 4 * p - 2 ); i < ( 4 * p + 2 ) + 1; i++ )
	{
	    temp4A += ACF[ i ];
	}

	Energy_3 = temp3A;
	Energy_4 = temp4A;
    }
    else
    {
	for( i = ( 3 * p - 2 ); i < ( 3 * p + 2 ) + 1; i++ )
	{
	    temp3A += ACF[ i ];
	}
	
	for( i = ( 4 * p - 2 ); i < ( 4 * p + 2 ) + 1; i++ )
	{
	    temp4A += ACF[ i ];
	}

	for( i = ( 6 * p - 2 ); i < ( 6 * p + 2 ) + 1; i++ )
	{
	    temp3B += ACF[ i ];
	}
	
	for( i = ( 2 * p - 2 ); i < ( 2 * p + 2 ) + 1; i++ )
	{
	    temp4B += ACF[ i ];
	}

	Energy_3 = temp3A + temp3B;
	Energy_4 = temp4A + temp4B;
    }

    if (Energy_3 > Energy_4)
    {
	tsig = 3;
    }
    else
    {
	tsig = 4;
    }


    return tsig;
}

void TempoTrack::createPhaseExtractor(double *Filter, unsigned int winLength, double period, unsigned int fsp, unsigned int lastBeat)
{	
    int p = (int)MathUtilities::round( period );
    int predictedOffset = 0;

    double* phaseScratch = new double[ p*2 ];

	
    if( lastBeat != 0 )
    {
	lastBeat = (int)MathUtilities::round((double)lastBeat );///(double)winLength);

	    predictedOffset = lastBeat + p - fsp;

	    if (predictedOffset < 0) 
	    {
		lastBeat = 0;
	    }
    }

    if( lastBeat != 0 )
    {
	int mu = p;
	double sigma = (double)p/8;
	double PhaseMin = 0.0;
	double PhaseMax = 0.0;
	unsigned int scratchLength = p*2;
	double temp = 0.0;

	for(  int i = 0; i < scratchLength; i++ )
	{
	    phaseScratch[ i ] = exp( -0.5 * pow( ( i - mu ) / sigma, 2 ) ) / ( sqrt( 2*PI ) *sigma );
	}

	MathUtilities::getFrameMinMax( phaseScratch, scratchLength, &PhaseMin, &PhaseMax );
			
	for(int i = 0; i < scratchLength; i ++)
	{
	    temp = phaseScratch[ i ];
	    phaseScratch[ i ] = (temp - PhaseMin)/PhaseMax;
	}

	unsigned int index = 0;
	for(int i = p - ( predictedOffset - 1); i < p + ( p - predictedOffset) + 1; i++)
	{
	    Filter[ index++ ] = phaseScratch[ i ];
	}
    }
    else
    {
	for( int i = 0; i < p; i ++)
	{
	    Filter[ i ] = 1;
	}
    }
	
    delete [] phaseScratch;
}

int TempoTrack::phaseMM(double *DF, double *weighting, unsigned int winLength, double period)
{
    int alignment = 0;
    int p = (int)MathUtilities::round( period );

    double temp = 0.0;

    double* y = new double[ winLength ];
    double* align = new double[ p ];

    for( int i = 0; i < winLength; i++ )
    {	
	y[ i ] = (double)( -i + winLength  )/(double)winLength;
	y[ i ] = pow(y [i ],2.0); // raise to power 2.
    }

    for( int o = 0; o < p; o++ )
    { 
	temp = 0.0;
	for(int i = 1 + (o - 1); i< winLength; i += (p + 1))
	{
	    temp = temp + DF[ i ] * y[ i ]; 
	}
	align[ o ] = temp * weighting[ o ];       
    }


    double valTemp = 0.0;
    for(int i = 0; i < p; i++)
    {
	if( align[ i ] > valTemp )
	{
	    valTemp = align[ i ];
	    alignment = i;
	}
    }

    delete [] y;
    delete [] align;

    return alignment;
}

int TempoTrack::beatPredict(unsigned int FSP0, double alignment, double period, unsigned int step )
{
    int beat = 0;

    int p = (int)MathUtilities::round( period );
    int align = (int)MathUtilities::round( alignment );
    int FSP = (int)MathUtilities::round( FSP0 );

    int FEP = FSP + ( step );

    beat = FSP + align;

    m_beats.push_back( beat );

    while( beat + p < FEP )
    {
	beat += p;
		
	m_beats.push_back( beat );
    }

    return beat;
}

vector<int> TempoTrack::process(double *DF, unsigned int length)
{
    m_dataLength = length;
	
    double	period = 0.0;
    int stepFlag = 0;
    int constFlag = 0;
    int FSP = 0;
    int tsig = 0;
    int lastBeat = 0;

	
    double* RW = new double[ m_lagLength ];
    for( unsigned int clear = 0; clear < m_lagLength; clear++){ RW[ clear ] = 0.0;}

    double* GW = new double[ m_lagLength ];
    for(unsigned int clear = 0; clear < m_lagLength; clear++){ GW[ clear ] = 0.0;}

    double* PW = new double[ m_lagLength ];
    for(unsigned int clear = 0; clear < m_lagLength; clear++){ PW[ clear ] = 0.0;}

    m_DFFramer.setSource( DF, m_dataLength );

    unsigned int TTFrames = m_DFFramer.getMaxNoFrames();
	
    double* periodP = new double[ TTFrames ];
    for(unsigned int  clear = 0; clear < TTFrames; clear++){ periodP[ clear ] = 0.0;}
	
    double* periodG = new double[ TTFrames ];
    for(unsigned int  clear = 0; clear < TTFrames; clear++){ periodG[ clear ] = 0.0;}
	
    double* alignment = new double[ TTFrames ];
    for(unsigned int  clear = 0; clear < TTFrames; clear++){ alignment[ clear ] = 0.0;}

    m_beats.clear();

    createCombFilter( RW, m_lagLength, 0, 0 );

    int TTLoopIndex = 0;

    for( unsigned int i = 0; i < TTFrames; i++ )
    {
	m_DFFramer.getFrame( m_rawDFFrame );

	m_DFConditioning->process( m_rawDFFrame, m_smoothDFFrame );

	m_correlator.doAutoUnBiased( m_smoothDFFrame, m_frameACF, m_winLength );
		
	periodP[ TTLoopIndex ] = tempoMM( m_frameACF, RW, 0 );

	if( GW[ 0 ] != 0 )
	{
	    periodG[ TTLoopIndex ] = tempoMM( m_frameACF, GW, tsig );
	}
	else
	{
	    periodG[ TTLoopIndex ] = 0.0;
	}

	stepDetect( periodP, periodG, TTLoopIndex, &stepFlag );

	if( stepFlag == 1)
	{
	    constDetect( periodP, TTLoopIndex, &constFlag );
	    stepFlag = 0;
	}
	else
	{
	    stepFlag -= 1;
	}

	if( stepFlag < 0 )
	{
	    stepFlag = 0;
	}

	if( constFlag != 0)
	{
	    tsig = findMeter( m_frameACF, m_winLength, periodP[ TTLoopIndex ] );
	
	    createCombFilter( GW, m_lagLength, tsig, periodP[ TTLoopIndex ] );
			
	    periodG[ TTLoopIndex ] = tempoMM( m_frameACF, GW, tsig ); 

	    period = periodG[ TTLoopIndex ];

		// am temporarily changing the last input parameter to lastBeat instead of '0'
	    createPhaseExtractor( PW, m_winLength, period, FSP, lastBeat ); 

	    constFlag = 0;

	}
	else
	{
	    if( GW[ 0 ] != 0 )
	    {
		period = periodG[ TTLoopIndex ];
		createPhaseExtractor( PW, m_winLength, period, FSP, lastBeat ); 

	    }
	    else
	    {
		period = periodP[ TTLoopIndex ];
		createPhaseExtractor( PW, m_winLength, period, FSP, 0 ); 
	    }
	}

	alignment[ TTLoopIndex ] = phaseMM( m_rawDFFrame, PW, m_winLength, period ); 

	lastBeat = beatPredict(FSP, alignment[ TTLoopIndex ], period, m_lagLength );

	FSP += (m_lagLength);

	TTLoopIndex++;
    }


    delete [] periodP;
    delete [] periodG;
    delete [] alignment;

    delete [] RW;
    delete [] GW;
    delete [] PW;

    return m_beats;
}





vector<int> TempoTrack::process( vector <double> DF,
                                 vector <double> *tempoReturn )
{
    m_dataLength = DF.size();
	
    m_lockedTempo = 0.0;

    double	period = 0.0;
    int stepFlag = 0;
    int constFlag = 0;
    int FSP = 0;
    int tsig = 0;
    int lastBeat = 0;

    vector <double> causalDF;

    causalDF = DF;

    //Prepare Causal Extension DFData
    unsigned int DFCLength = m_dataLength + m_winLength;
	
    for( unsigned int j = 0; j < m_winLength; j++ )
    {
	causalDF.push_back( 0 );
    }
	
	
    double* RW = new double[ m_lagLength ];
    for( unsigned int clear = 0; clear < m_lagLength; clear++){ RW[ clear ] = 0.0;}

    double* GW = new double[ m_lagLength ];
    for(unsigned int clear = 0; clear < m_lagLength; clear++){ GW[ clear ] = 0.0;}

    double* PW = new double[ m_lagLength ];
    for(unsigned clear = 0; clear < m_lagLength; clear++){ PW[ clear ] = 0.0;}

    m_DFFramer.setSource( &causalDF[0], m_dataLength );

    unsigned int TTFrames = m_DFFramer.getMaxNoFrames();
	
    double* periodP = new double[ TTFrames ];
    for(unsigned clear = 0; clear < TTFrames; clear++){ periodP[ clear ] = 0.0;}
	
    double* periodG = new double[ TTFrames ];
    for(unsigned clear = 0; clear < TTFrames; clear++){ periodG[ clear ] = 0.0;}
	
    double* alignment = new double[ TTFrames ];
    for(unsigned clear = 0; clear < TTFrames; clear++){ alignment[ clear ] = 0.0;}

    m_beats.clear();

    createCombFilter( RW, m_lagLength, 0, 0 );

    int TTLoopIndex = 0;

    for( unsigned int i = 0; i < TTFrames; i++ )
    {
	m_DFFramer.getFrame( m_rawDFFrame );

	m_DFConditioning->process( m_rawDFFrame, m_smoothDFFrame );

	m_correlator.doAutoUnBiased( m_smoothDFFrame, m_frameACF, m_winLength );
		
	periodP[ TTLoopIndex ] = tempoMM( m_frameACF, RW, 0 );

	if( GW[ 0 ] != 0 )
	{
	    periodG[ TTLoopIndex ] = tempoMM( m_frameACF, GW, tsig );
	}
	else
	{
	    periodG[ TTLoopIndex ] = 0.0;
	}

	stepDetect( periodP, periodG, TTLoopIndex, &stepFlag );

	if( stepFlag == 1)
	{
	    constDetect( periodP, TTLoopIndex, &constFlag );
	    stepFlag = 0;
	}
	else
	{
	    stepFlag -= 1;
	}

	if( stepFlag < 0 )
	{
	    stepFlag = 0;
	}

	if( constFlag != 0)
	{
	    tsig = findMeter( m_frameACF, m_winLength, periodP[ TTLoopIndex ] );
	
	    createCombFilter( GW, m_lagLength, tsig, periodP[ TTLoopIndex ] );
			
	    periodG[ TTLoopIndex ] = tempoMM( m_frameACF, GW, tsig ); 

	    period = periodG[ TTLoopIndex ];

	    createPhaseExtractor( PW, m_winLength, period, FSP, 0 ); 

	    constFlag = 0;

	}
	else
	{
	    if( GW[ 0 ] != 0 )
	    {
		period = periodG[ TTLoopIndex ];
		createPhaseExtractor( PW, m_winLength, period, FSP, lastBeat ); 

	    }
	    else
	    {
		period = periodP[ TTLoopIndex ];
		createPhaseExtractor( PW, m_winLength, period, FSP, 0 ); 
	    }
	}

	alignment[ TTLoopIndex ] = phaseMM( m_rawDFFrame, PW, m_winLength, period ); 

	lastBeat = beatPredict(FSP, alignment[ TTLoopIndex ], period, m_lagLength );

	FSP += (m_lagLength);

        if (tempoReturn) tempoReturn->push_back(m_lockedTempo);

	TTLoopIndex++;
    }


    delete [] periodP;
    delete [] periodG;
    delete [] alignment;

    delete [] RW;
    delete [] GW;
    delete [] PW;

    return m_beats;
}