adamstark@46: //=======================================================================
adamstark@46: /** @file OnsetDetectionFunction.cpp
adamstark@46:  *  @brief A class for calculating onset detection functions
adamstark@46:  *  @author Adam Stark
adamstark@46:  *  @copyright Copyright (C) 2008-2014  Queen Mary University of London
adamstark@46:  *
adamstark@46:  * This program is free software: you can redistribute it and/or modify
adamstark@46:  * it under the terms of the GNU General Public License as published by
adamstark@46:  * the Free Software Foundation, either version 3 of the License, or
adamstark@46:  * (at your option) any later version.
adamstark@46:  *
adamstark@46:  * This program is distributed in the hope that it will be useful,
adamstark@46:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
adamstark@46:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
adamstark@46:  * GNU General Public License for more details.
adamstark@46:  *
adamstark@46:  * You should have received a copy of the GNU General Public License
adamstark@46:  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
adamstark@46:  */
adamstark@46: //=======================================================================
adamstark@46: 
adamstark@46: #include <math.h>
adamstark@46: #include <iostream>
adamstark@46: #include "OnsetDetectionFunction.h"
adamstark@46: using namespace std;
adamstark@46: 
adamstark@46: //-------------------------------------------------------------------------------
adamstark@46: // Constructor
adamstark@46: OnsetDetectionFunction :: OnsetDetectionFunction()
adamstark@46: {	
adamstark@46: 	// indicate that we have not initialised yet
adamstark@46: 	initialised = 0;		
adamstark@46: 	
adamstark@46: 	// set pi
adamstark@46: 	pi = 3.14159265358979;	
adamstark@46: 	
adamstark@46: 	// initialise with hopsize = 512, framesize = 1024, complex spectral difference DF and hanning window
adamstark@46: 	initialise(512,1024,6,1);	
adamstark@46: }
adamstark@46: 
adamstark@46: 
adamstark@46: //-------------------------------------------------------------------------------
adamstark@46: // Constructor (with arguments)
adamstark@46: OnsetDetectionFunction :: OnsetDetectionFunction(int arg_hsize,int arg_fsize,int arg_df_type,int arg_win_type)
adamstark@46: {	
adamstark@46: 	// indicate that we have not initialised yet
adamstark@46: 	initialised = 0;		
adamstark@46: 	
adamstark@46: 	// set pi
adamstark@46: 	pi = 3.14159265358979;	
adamstark@46: 	
adamstark@46: 	// initialise with arguments to constructor
adamstark@46: 	initialise(arg_hsize,arg_fsize,arg_df_type,arg_win_type);
adamstark@46: }
adamstark@46: 
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // Destructor
adamstark@46: OnsetDetectionFunction :: ~OnsetDetectionFunction()
adamstark@46: {
adamstark@46: 	// destroy fft plan
adamstark@46:     fftw_destroy_plan(p);
adamstark@46: 	fftw_free(in); 
adamstark@46: 	fftw_free(out);
adamstark@46: 	
adamstark@46: 	// deallocate memory
adamstark@46: 	delete [] frame;
adamstark@46: 	frame = NULL;	
adamstark@46: 	delete [] window;
adamstark@46: 	window = NULL;									
adamstark@46: 	delete [] wframe;
adamstark@46: 	wframe = NULL;											
adamstark@46: 	delete [] mag;
adamstark@46: 	mag = NULL;
adamstark@46: 	delete [] mag_old;
adamstark@46: 	mag_old = NULL;
adamstark@46: 	delete [] phase;
adamstark@46: 	phase = NULL;
adamstark@46: 	delete [] phase_old;
adamstark@46: 	phase_old = NULL;	
adamstark@46: 	delete [] phase_old_2;
adamstark@46: 	phase_old_2 = NULL;
adamstark@46: }
adamstark@46: 
adamstark@46: //-------------------------------------------------------------------------------
adamstark@46: // Initialisation
adamstark@46: void OnsetDetectionFunction :: initialise(int arg_hsize,int arg_fsize,int arg_df_type,int arg_win_type)
adamstark@46: {
adamstark@46: 	if (initialised == 1) // if we have already initialised some buffers and an FFT plan
adamstark@46: 	{
adamstark@46: 		//////////////////////////////////
adamstark@46: 		// TIDY UP FIRST - If initialise is called after the class has been initialised
adamstark@46: 		// then we want to free up memory and cancel existing FFT plans
adamstark@46: 	
adamstark@46: 		// destroy fft plan
adamstark@46: 		fftw_destroy_plan(p);
adamstark@46: 		fftw_free(in); 
adamstark@46: 		fftw_free(out);
adamstark@46: 	
adamstark@46: 	
adamstark@46: 		// deallocate memory
adamstark@46: 		delete [] frame;
adamstark@46: 		frame = NULL;	
adamstark@46: 		delete [] window;
adamstark@46: 		window = NULL;									
adamstark@46: 		delete [] wframe;
adamstark@46: 		wframe = NULL;											
adamstark@46: 		delete [] mag;
adamstark@46: 		mag = NULL;
adamstark@46: 		delete [] mag_old;
adamstark@46: 		mag_old = NULL;
adamstark@46: 		delete [] phase;
adamstark@46: 		phase = NULL;
adamstark@46: 		delete [] phase_old;
adamstark@46: 		phase_old = NULL;	
adamstark@46: 		delete [] phase_old_2;
adamstark@46: 		phase_old_2 = NULL;
adamstark@46: 	
adamstark@46: 		////// END TIDY UP ///////////////
adamstark@46: 		//////////////////////////////////
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	hopsize = arg_hsize; // set hopsize
adamstark@46: 	framesize = arg_fsize; // set framesize
adamstark@46: 	
adamstark@46: 	df_type = arg_df_type; // set detection function type
adamstark@46: 		
adamstark@46: 	// initialise buffers
adamstark@46: 	frame = new double[framesize];											
adamstark@46: 	window = new double[framesize];	
adamstark@46: 	wframe = new double[framesize];		
adamstark@46: 	
adamstark@46: 	mag = new double[framesize];											
adamstark@46: 	mag_old = new double[framesize];
adamstark@46: 	
adamstark@46: 	phase = new double[framesize];
adamstark@46: 	phase_old = new double[framesize];
adamstark@46: 	phase_old_2 = new double[framesize];
adamstark@46: 	
adamstark@46: 	
adamstark@46: 	// set the window to the specified type
adamstark@46: 	switch (arg_win_type){
adamstark@46: 		case 0:
adamstark@46: 			set_win_rectangular();		// Rectangular window
adamstark@46: 			break;	
adamstark@46: 		case 1:	
adamstark@46: 			set_win_hanning();			// Hanning Window
adamstark@46: 			break;
adamstark@46: 		case 2:
adamstark@46: 			set_win_hamming();			// Hamming Window
adamstark@46: 			break;
adamstark@46: 		case 3:
adamstark@46: 			set_win_blackman();			// Blackman Window
adamstark@46: 			break;
adamstark@46: 		case 4:
adamstark@46: 			set_win_tukey();			// Tukey Window
adamstark@46: 			break;
adamstark@46: 		default:
adamstark@46: 			set_win_hanning();			// DEFAULT: Hanning Window
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	
adamstark@46: 	
adamstark@46: 	
adamstark@46: 	// initialise previous magnitude spectrum to zero
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		mag_old[i] = 0.0;
adamstark@46: 		phase_old[i] = 0.0;
adamstark@46: 		phase_old_2[i] = 0.0;
adamstark@46: 		frame[i] = 0.0;
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	energy_sum_old = 0.0;	// initialise previous energy sum value to zero
adamstark@46: 	
adamstark@46: 	/*  Init fft */
adamstark@46: 	in = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * framesize);		// complex array to hold fft data
adamstark@46: 	out = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * framesize);	// complex array to hold fft data
adamstark@46: 	p = fftw_plan_dft_1d(framesize, in, out, FFTW_FORWARD, FFTW_ESTIMATE);	// FFT plan initialisation
adamstark@46: 	
adamstark@46: 	initialised = 1;
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // set the detection function type to that specified by the argument
adamstark@46: void OnsetDetectionFunction :: set_df_type(int arg_df_type)
adamstark@46: {
adamstark@46: 	df_type = arg_df_type; // set detection function type
adamstark@46: }
adamstark@46: 
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a single detection function sample from a single audio frame.
adamstark@46: double OnsetDetectionFunction :: getDFsample(double inputbuffer[])
adamstark@46: {	
adamstark@46: 	double df_sample;
adamstark@46: 		
adamstark@46: 	// shift audio samples back in frame by hop size
adamstark@46: 	for (int i = 0; i < (framesize-hopsize);i++)
adamstark@46: 	{
adamstark@46: 		frame[i] = frame[i+hopsize];
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	// add new samples to frame from input buffer
adamstark@46: 	int j = 0;
adamstark@46: 	for (int i = (framesize-hopsize);i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		frame[i] = inputbuffer[j];
adamstark@46: 		j++;
adamstark@46: 	}
adamstark@46: 		
adamstark@46: 	switch (df_type){
adamstark@46: 		case 0:
adamstark@46: 			df_sample = energy_envelope();	// calculate energy envelope detection function sample
adamstark@46: 			break;	
adamstark@46: 		case 1:
adamstark@46: 			df_sample = energy_difference();	// calculate half-wave rectified energy difference detection function sample
adamstark@46: 			break;
adamstark@46: 		case 2:
adamstark@46: 			df_sample = spectral_difference();	// calculate spectral difference detection function sample
adamstark@46: 			break;
adamstark@46: 		case 3:
adamstark@46: 			df_sample = spectral_difference_hwr(); // calculate spectral difference detection function sample (half wave rectified)
adamstark@46: 			break;
adamstark@46: 		case 4:
adamstark@46: 			df_sample = phase_deviation();		// calculate phase deviation detection function sample (half wave rectified)
adamstark@46: 			break;
adamstark@46: 		case 5:
adamstark@46: 			df_sample = complex_spectral_difference(); // calcualte complex spectral difference detection function sample
adamstark@46: 			break;
adamstark@46: 		case 6:
adamstark@46: 			df_sample = complex_spectral_difference_hwr();  // calcualte complex spectral difference detection function sample (half-wave rectified)
adamstark@46: 			break;
adamstark@46: 		case 7:
adamstark@46: 			df_sample = high_frequency_content(); // calculate high frequency content detection function sample
adamstark@46: 			break;
adamstark@46: 		case 8:
adamstark@46: 			df_sample = high_frequency_spectral_difference(); // calculate high frequency spectral difference detection function sample
adamstark@46: 			break;
adamstark@46: 		case 9:
adamstark@46: 			df_sample = high_frequency_spectral_difference_hwr(); // calculate high frequency spectral difference detection function (half-wave rectified)
adamstark@46: 			break;
adamstark@46: 		default:
adamstark@46: 			df_sample = 1.0;
adamstark@46: 	}
adamstark@46: 		
adamstark@46: 	return df_sample;
adamstark@46: }
adamstark@46: 
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // performs the fft, storing the complex result in 'out'
adamstark@46: void OnsetDetectionFunction :: perform_FFT()
adamstark@46: {
adamstark@46: 	int fsize2 = (framesize/2);
adamstark@46: 	
adamstark@46: 	// window frame and copy to complex array, swapping the first and second half of the signal
adamstark@46: 	for (int i = 0;i < fsize2;i++)
adamstark@46: 	{
adamstark@46: 		in[i][0] = frame[i+fsize2] * window[i+fsize2];
adamstark@46: 		in[i][1] = 0.0;
adamstark@46: 		in[i+fsize2][0] = frame[i] * window[i];
adamstark@46: 		in[i+fsize2][1] = 0.0;
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	// perform the fft
adamstark@46: 	fftw_execute(p);
adamstark@46: }
adamstark@46: 
adamstark@46: ////////////////////////////////////////////////////////////////////////////////////////////////
adamstark@46: ////////////////////////////////////////////////////////////////////////////////////////////////
adamstark@46: ////////////////////////////// Methods for Detection Functions /////////////////////////////////
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates an energy envelope detection function sample
adamstark@46: double OnsetDetectionFunction :: energy_envelope()
adamstark@46: {
adamstark@46: 	double sum;
adamstark@46: 	
adamstark@46: 	sum = 0;	// initialise sum
adamstark@46: 	
adamstark@46: 	// sum the squares of the samples
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		sum = sum + (frame[i]*frame[i]);
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	return sum;		// return sum
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a half-wave rectified energy difference detection function sample
adamstark@46: double OnsetDetectionFunction :: energy_difference()
adamstark@46: {
adamstark@46: 	double sum;
adamstark@46: 	double sample;
adamstark@46: 	
adamstark@46: 	sum = 0;	// initialise sum
adamstark@46: 	
adamstark@46: 	// sum the squares of the samples
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		sum = sum + (frame[i]*frame[i]);
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	sample = sum - energy_sum_old;	// sample is first order difference in energy
adamstark@46: 	
adamstark@46: 	energy_sum_old = sum;	// store energy value for next calculation
adamstark@46: 	
adamstark@46: 	if (sample > 0)
adamstark@46: 	{
adamstark@46: 		return sample;		// return difference
adamstark@46: 	}
adamstark@46: 	else
adamstark@46: 	{
adamstark@46: 		return 0;
adamstark@46: 	}
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a spectral difference detection function sample
adamstark@46: double OnsetDetectionFunction :: spectral_difference()
adamstark@46: {
adamstark@46: 	double diff;
adamstark@46: 	double sum;
adamstark@46: 	
adamstark@46: 	// perform the FFT
adamstark@46: 	perform_FFT();
adamstark@46: 	
adamstark@46: 	// compute first (N/2)+1 mag values
adamstark@46: 	for (int i = 0;i < (framesize/2)+1;i++)
adamstark@46: 	{
adamstark@46: 		mag[i] = sqrt(pow(out[i][0],2) + pow(out[i][1],2));
adamstark@46: 	}
adamstark@46: 	// mag spec symmetric above (N/2)+1 so copy previous values
adamstark@46: 	for (int i = (framesize/2)+1;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		mag[i] = mag[framesize-i];		
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	sum = 0;	// initialise sum to zero
adamstark@46: 
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		// calculate difference
adamstark@46: 		diff = mag[i] - mag_old[i];
adamstark@46: 		
adamstark@46: 		// ensure all difference values are positive
adamstark@46: 		if (diff < 0)
adamstark@46: 		{
adamstark@46: 			diff = diff*-1;
adamstark@46: 		}
adamstark@46: 		
adamstark@46: 		// add difference to sum
adamstark@46: 		sum = sum+diff;
adamstark@46: 		
adamstark@46: 		// store magnitude spectrum bin for next detection function sample calculation
adamstark@46: 		mag_old[i] = mag[i];
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	return sum;		
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a spectral difference detection function sample
adamstark@46: double OnsetDetectionFunction :: spectral_difference_hwr()
adamstark@46: {
adamstark@46: 	double diff;
adamstark@46: 	double sum;
adamstark@46: 	
adamstark@46: 	// perform the FFT
adamstark@46: 	perform_FFT();
adamstark@46: 	
adamstark@46: 	// compute first (N/2)+1 mag values
adamstark@46: 	for (int i = 0;i < (framesize/2)+1;i++)
adamstark@46: 	{
adamstark@46: 		mag[i] = sqrt(pow(out[i][0],2) + pow(out[i][1],2));
adamstark@46: 	}
adamstark@46: 	// mag spec symmetric above (N/2)+1 so copy previous values
adamstark@46: 	for (int i = (framesize/2)+1;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		mag[i] = mag[framesize-i];		
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	sum = 0;	// initialise sum to zero
adamstark@46: 	
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		// calculate difference
adamstark@46: 		diff = mag[i] - mag_old[i];
adamstark@46: 		
adamstark@46: 		// only add up positive differences
adamstark@46: 		if (diff > 0)
adamstark@46: 		{
adamstark@46: 			// add difference to sum
adamstark@46: 			sum = sum+diff;
adamstark@46: 		}
adamstark@46: 		
adamstark@46: 		
adamstark@46: 		
adamstark@46: 		// store magnitude spectrum bin for next detection function sample calculation
adamstark@46: 		mag_old[i] = mag[i];
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	return sum;		
adamstark@46: }
adamstark@46: 
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a phase deviation detection function sample
adamstark@46: double OnsetDetectionFunction :: phase_deviation()
adamstark@46: {
adamstark@46: 	double dev,pdev;
adamstark@46: 	double sum;
adamstark@46: 	
adamstark@46: 	// perform the FFT
adamstark@46: 	perform_FFT();
adamstark@46: 	
adamstark@46: 	sum = 0; // initialise sum to zero
adamstark@46: 	
adamstark@46: 	// compute phase values from fft output and sum deviations
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		// calculate phase value
adamstark@46: 		phase[i] = atan2(out[i][1],out[i][0]);
adamstark@46: 		
adamstark@46: 		// calculate magnitude value
adamstark@46: 		mag[i] = sqrt(pow(out[i][0],2) + pow(out[i][1],2));
adamstark@46: 		
adamstark@46: 		
adamstark@46: 		// if bin is not just a low energy bin then examine phase deviation
adamstark@46: 		if (mag[i] > 0.1)
adamstark@46: 		{
adamstark@46: 			dev = phase[i] - (2*phase_old[i]) + phase_old_2[i];	// phase deviation
adamstark@46: 			pdev = princarg(dev);	// wrap into [-pi,pi] range
adamstark@46: 		
adamstark@46: 			// make all values positive
adamstark@46: 			if (pdev < 0)	
adamstark@46: 			{
adamstark@46: 				pdev = pdev*-1;
adamstark@46: 			}
adamstark@46: 						
adamstark@46: 			// add to sum
adamstark@46: 			sum = sum + pdev;
adamstark@46: 		}
adamstark@46: 				
adamstark@46: 		// store values for next calculation
adamstark@46: 		phase_old_2[i] = phase_old[i];
adamstark@46: 		phase_old[i] = phase[i];
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	return sum;		
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a complex spectral difference detection function sample
adamstark@46: double OnsetDetectionFunction :: complex_spectral_difference()
adamstark@46: {
adamstark@46: 	double dev,pdev;
adamstark@46: 	double sum;
adamstark@46: 	double mag_diff,phase_diff;
adamstark@46: 	double value;
adamstark@46: 	
adamstark@46: 	// perform the FFT
adamstark@46: 	perform_FFT();
adamstark@46: 	
adamstark@46: 	sum = 0; // initialise sum to zero
adamstark@46: 	
adamstark@46: 	// compute phase values from fft output and sum deviations
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		// calculate phase value
adamstark@46: 		phase[i] = atan2(out[i][1],out[i][0]);
adamstark@46: 		
adamstark@46: 		// calculate magnitude value
adamstark@46: 		mag[i] = sqrt(pow(out[i][0],2) + pow(out[i][1],2));
adamstark@46: 		
adamstark@46: 		
adamstark@46: 		// phase deviation
adamstark@46: 		dev = phase[i] - (2*phase_old[i]) + phase_old_2[i];	
adamstark@46: 		
adamstark@46: 		// wrap into [-pi,pi] range
adamstark@46: 		pdev = princarg(dev);	
adamstark@46: 		
adamstark@46: 		
adamstark@46: 		// calculate magnitude difference (real part of Euclidean distance between complex frames)
adamstark@46: 		mag_diff = mag[i] - mag_old[i];
adamstark@46: 		
adamstark@46: 		// calculate phase difference (imaginary part of Euclidean distance between complex frames)
adamstark@46: 		phase_diff = -mag[i]*sin(pdev);
adamstark@46: 		
adamstark@46: 
adamstark@46: 		
adamstark@46: 		// square real and imaginary parts, sum and take square root
adamstark@46: 		value = sqrt(pow(mag_diff,2) + pow(phase_diff,2));
adamstark@46: 	
adamstark@46: 			
adamstark@46: 		// add to sum
adamstark@46: 		sum = sum + value;
adamstark@46: 		
adamstark@46: 		
adamstark@46: 		// store values for next calculation
adamstark@46: 		phase_old_2[i] = phase_old[i];
adamstark@46: 		phase_old[i] = phase[i];
adamstark@46: 		mag_old[i] = mag[i];
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	return sum;		
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a complex spectral difference detection function sample (half-wave rectified)
adamstark@46: double OnsetDetectionFunction :: complex_spectral_difference_hwr()
adamstark@46: {
adamstark@46: 	double dev,pdev;
adamstark@46: 	double sum;
adamstark@46: 	double mag_diff,phase_diff;
adamstark@46: 	double value;
adamstark@46: 	
adamstark@46: 	// perform the FFT
adamstark@46: 	perform_FFT();
adamstark@46: 	
adamstark@46: 	sum = 0; // initialise sum to zero
adamstark@46: 	
adamstark@46: 	// compute phase values from fft output and sum deviations
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{
adamstark@46: 		// calculate phase value
adamstark@46: 		phase[i] = atan2(out[i][1],out[i][0]);
adamstark@46: 		
adamstark@46: 		// calculate magnitude value
adamstark@46: 		mag[i] = sqrt(pow(out[i][0],2) + pow(out[i][1],2));
adamstark@46: 		
adamstark@46: 		
adamstark@46: 		// phase deviation
adamstark@46: 		dev = phase[i] - (2*phase_old[i]) + phase_old_2[i];	
adamstark@46: 		
adamstark@46: 		// wrap into [-pi,pi] range
adamstark@46: 		pdev = princarg(dev);	
adamstark@46: 		
adamstark@46: 		
adamstark@46: 		// calculate magnitude difference (real part of Euclidean distance between complex frames)
adamstark@46: 		mag_diff = mag[i] - mag_old[i];
adamstark@46: 		
adamstark@46: 		// if we have a positive change in magnitude, then include in sum, otherwise ignore (half-wave rectification)
adamstark@46: 		if (mag_diff > 0)
adamstark@46: 		{
adamstark@46: 			// calculate phase difference (imaginary part of Euclidean distance between complex frames)
adamstark@46: 			phase_diff = -mag[i]*sin(pdev);
adamstark@46: 
adamstark@46: 			// square real and imaginary parts, sum and take square root
adamstark@46: 			value = sqrt(pow(mag_diff,2) + pow(phase_diff,2));
adamstark@46: 		
adamstark@46: 			// add to sum
adamstark@46: 			sum = sum + value;
adamstark@46: 		}
adamstark@46: 		
adamstark@46: 		// store values for next calculation
adamstark@46: 		phase_old_2[i] = phase_old[i];
adamstark@46: 		phase_old[i] = phase[i];
adamstark@46: 		mag_old[i] = mag[i];
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	return sum;		
adamstark@46: }
adamstark@46: 
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a high frequency content detection function sample
adamstark@46: double OnsetDetectionFunction :: high_frequency_content()
adamstark@46: {
adamstark@46: 	double sum;
adamstark@46: 	double mag_diff;
adamstark@46: 	
adamstark@46: 	// perform the FFT
adamstark@46: 	perform_FFT();
adamstark@46: 	
adamstark@46: 	sum = 0; // initialise sum to zero
adamstark@46: 	
adamstark@46: 	// compute phase values from fft output and sum deviations
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{		
adamstark@46: 		// calculate magnitude value
adamstark@46: 		mag[i] = sqrt(pow(out[i][0],2) + pow(out[i][1],2));
adamstark@46: 		
adamstark@46: 		
adamstark@46: 		sum = sum + (mag[i]*((double) (i+1)));
adamstark@46: 		
adamstark@46: 		// store values for next calculation
adamstark@46: 		mag_old[i] = mag[i];
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	return sum;		
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a high frequency spectral difference detection function sample
adamstark@46: double OnsetDetectionFunction :: high_frequency_spectral_difference()
adamstark@46: {
adamstark@46: 	double sum;
adamstark@46: 	double mag_diff;
adamstark@46: 	
adamstark@46: 	// perform the FFT
adamstark@46: 	perform_FFT();
adamstark@46: 	
adamstark@46: 	sum = 0; // initialise sum to zero
adamstark@46: 	
adamstark@46: 	// compute phase values from fft output and sum deviations
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{		
adamstark@46: 		// calculate magnitude value
adamstark@46: 		mag[i] = sqrt(pow(out[i][0],2) + pow(out[i][1],2));
adamstark@46: 		
adamstark@46: 		// calculate difference
adamstark@46: 		mag_diff = mag[i] - mag_old[i];
adamstark@46: 		
adamstark@46: 		if (mag_diff < 0)
adamstark@46: 		{
adamstark@46: 			mag_diff = -mag_diff;
adamstark@46: 		}
adamstark@46: 		
adamstark@46: 		sum = sum + (mag_diff*((double) (i+1)));
adamstark@46: 		
adamstark@46: 		// store values for next calculation
adamstark@46: 		mag_old[i] = mag[i];
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	return sum;		
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // calculates a high frequency spectral difference detection function sample (half-wave rectified)
adamstark@46: double OnsetDetectionFunction :: high_frequency_spectral_difference_hwr()
adamstark@46: {
adamstark@46: 	double sum;
adamstark@46: 	double mag_diff;
adamstark@46: 	
adamstark@46: 	// perform the FFT
adamstark@46: 	perform_FFT();
adamstark@46: 	
adamstark@46: 	sum = 0; // initialise sum to zero
adamstark@46: 	
adamstark@46: 	// compute phase values from fft output and sum deviations
adamstark@46: 	for (int i = 0;i < framesize;i++)
adamstark@46: 	{		
adamstark@46: 		// calculate magnitude value
adamstark@46: 		mag[i] = sqrt(pow(out[i][0],2) + pow(out[i][1],2));
adamstark@46: 		
adamstark@46: 		// calculate difference
adamstark@46: 		mag_diff = mag[i] - mag_old[i];
adamstark@46: 		
adamstark@46: 		if (mag_diff > 0)
adamstark@46: 		{
adamstark@46: 			sum = sum + (mag_diff*((double) (i+1)));
adamstark@46: 		}
adamstark@46: 
adamstark@46: 		// store values for next calculation
adamstark@46: 		mag_old[i] = mag[i];
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	return sum;		
adamstark@46: }
adamstark@46: 
adamstark@46: 
adamstark@46: ////////////////////////////////////////////////////////////////////////////////////////////////
adamstark@46: ////////////////////////////////////////////////////////////////////////////////////////////////
adamstark@46: ////////////////////////////// Methods to Calculate Windows ////////////////////////////////////
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // HANNING: set the window in the buffer 'window' to a Hanning window
adamstark@46: void OnsetDetectionFunction :: set_win_hanning()
adamstark@46: {
adamstark@46: 	double N;		// variable to store framesize minus 1
adamstark@46: 	
adamstark@46: 	N = (double) (framesize-1);	// framesize minus 1
adamstark@46: 	
adamstark@46: 	// Hanning window calculation
adamstark@46: 	for (int n = 0;n < framesize;n++)
adamstark@46: 	{
adamstark@46: 		window[n] = 0.5*(1-cos(2*pi*(n/N)));
adamstark@46: 	}
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // HAMMING: set the window in the buffer 'window' to a Hanning window
adamstark@46: void OnsetDetectionFunction :: set_win_hamming()
adamstark@46: {
adamstark@46: 	double N;		// variable to store framesize minus 1
adamstark@46: 	double n_val;	// double version of index 'n'
adamstark@46: 	
adamstark@46: 	N = (double) (framesize-1);	// framesize minus 1
adamstark@46: 	n_val = 0;
adamstark@46: 	
adamstark@46: 	// Hamming window calculation
adamstark@46: 	for (int n = 0;n < framesize;n++)
adamstark@46: 	{
adamstark@46: 		window[n] = 0.54 - (0.46*cos(2*pi*(n_val/N)));
adamstark@46: 		n_val = n_val+1;
adamstark@46: 	}
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // BLACKMAN: set the window in the buffer 'window' to a Blackman window
adamstark@46: void OnsetDetectionFunction :: set_win_blackman()
adamstark@46: {
adamstark@46: 	double N;		// variable to store framesize minus 1
adamstark@46: 	double n_val;	// double version of index 'n'
adamstark@46: 	
adamstark@46: 	N = (double) (framesize-1);	// framesize minus 1
adamstark@46: 	n_val = 0;
adamstark@46: 	
adamstark@46: 	// Blackman window calculation
adamstark@46: 	for (int n = 0;n < framesize;n++)
adamstark@46: 	{
adamstark@46: 		window[n] = 0.42 - (0.5*cos(2*pi*(n_val/N))) + (0.08*cos(4*pi*(n_val/N)));
adamstark@46: 		n_val = n_val+1;
adamstark@46: 	}
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // TUKEY: set the window in the buffer 'window' to a Tukey window
adamstark@46: void OnsetDetectionFunction :: set_win_tukey()
adamstark@46: {
adamstark@46: 	double N;		// variable to store framesize minus 1
adamstark@46: 	double n_val;	// double version of index 'n'
adamstark@46: 	double alpha;	// alpha [default value = 0.5];
adamstark@46: 	
adamstark@46: 	int lim1,lim2;
adamstark@46: 	
adamstark@46: 	alpha = 0.5;
adamstark@46: 	
adamstark@46: 	N = (double) (framesize-1);	// framesize minus 1
adamstark@46: 		
adamstark@46: 	// Tukey window calculation
adamstark@46: 	
adamstark@46: 	n_val = (double) (-1*((framesize/2)))+1;
adamstark@46: 
adamstark@46: 	for (int n = 0;n < framesize;n++)	// left taper
adamstark@46: 	{
adamstark@46: 		if ((n_val >= 0) && (n_val <= (alpha*(N/2))))
adamstark@46: 		{
adamstark@46: 			window[n] = 1.0;
adamstark@46: 		}
adamstark@46: 		else if ((n_val <= 0) && (n_val >= (-1*alpha*(N/2))))
adamstark@46: 		{
adamstark@46: 			window[n] = 1.0;
adamstark@46: 		}
adamstark@46: 		else
adamstark@46: 		{
adamstark@46: 			window[n] = 0.5*(1+cos(pi*(((2*n_val)/(alpha*N))-1)));
adamstark@46: 		}
adamstark@46: 
adamstark@46: 		n_val = n_val+1;			 
adamstark@46: 	}
adamstark@46: 
adamstark@46: }
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // RECTANGULAR: set the window in the buffer 'window' to a Rectangular window
adamstark@46: void OnsetDetectionFunction :: set_win_rectangular()
adamstark@46: {
adamstark@46: 	// Rectangular window calculation
adamstark@46: 	for (int n = 0;n < framesize;n++)
adamstark@46: 	{
adamstark@46: 		window[n] = 1.0;
adamstark@46: 	}
adamstark@46: }
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: ////////////////////////////////////////////////////////////////////////////////////////////////
adamstark@46: ////////////////////////////////////////////////////////////////////////////////////////////////
adamstark@46: ///////////////////////////////// Other Handy Methods //////////////////////////////////////////
adamstark@46: 
adamstark@46: //--------------------------------------------------------------------------------------
adamstark@46: // set phase values to the range [-pi,pi]
adamstark@46: double OnsetDetectionFunction :: princarg(double phaseval)
adamstark@46: {	
adamstark@46: 	// if phase value is less than or equal to -pi then add 2*pi
adamstark@46: 	while (phaseval <= (-pi)) 
adamstark@46: 	{
adamstark@46: 		phaseval = phaseval + (2*pi);
adamstark@46: 	}
adamstark@46: 	
adamstark@46: 	// if phase value is larger than pi, then subtract 2*pi
adamstark@46: 	while (phaseval > pi)
adamstark@46: 	{
adamstark@46: 		phaseval = phaseval - (2*pi);
adamstark@46: 	}
adamstark@46: 			
adamstark@46: 	return phaseval;
adamstark@46: }
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: 
adamstark@46: