andrew@0: 
andrew@0: 
andrew@0: #include "Chromagram.h"
andrew@0: #include <iostream>
andrew@0: #include <math.h>
andrew@0: using namespace std;
andrew@0: 
andrew@0: Chromagram :: Chromagram()
andrew@0: {
andrew@0: 	pi = 3.14159265;
andrew@0: 	bsize = 8192;
andrew@0: 		
andrew@0: 	// array init
andrew@0: 	buffer = new float[8192]; // make audio buffer
andrew@0: 	wbuffer = new float[8192]; // to hold windowed audio buffer
andrew@0: 	win = new float[8192];
andrew@0: 	d_frame = new float[128];
andrew@0: 	hop = new float[1024];
andrew@0: 	mag = new float[(bsize/2)+1];
andrew@0: 	
andrew@0: 	maximumChromaValue = 0;
andrew@0: 	
andrew@0: 	float base = 130.81278265;
andrew@0: 	
andrew@0: 	for (int i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		note[i] = base*pow(2,(((float) i)/12));
andrew@0: 	}
andrew@0: 	
andrew@0: 	harmonics = 2;
andrew@0: 	octaves = 2;
andrew@0: 	search = 2;  // p is number of bins either side of target to search for other peaks
andrew@0: 		
andrew@0: 	out = (fftwf_complex*) fftwf_malloc(sizeof(fftwf_complex) * bsize);		// complex array to hold fft
andrew@0: 	p = fftwf_plan_dft_r2c_1d(bsize,wbuffer,out,FFTW_FORWARD*-1);	// plan for executing fft of wbuffer
andrew@0: 	
andrew@0: 	chromaready = 0;
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // destructor
andrew@0: Chromagram :: ~Chromagram()
andrew@0: {
andrew@0: 	// destroy fft plan
andrew@0:     fftwf_destroy_plan(p);
andrew@0: 	
andrew@0: 	// deallocate memory
andrew@0: 	win = NULL;	
andrew@0: 	delete [] win;	
andrew@0: 	buffer = NULL;	
andrew@0: 	delete [] buffer;										
andrew@0: 	wbuffer = NULL;	
andrew@0: 	delete [] wbuffer;											
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // Initialises all framesize dependent variables. Should be called to properly initialise variables and anytime the frame size changes.
andrew@0: void Chromagram :: initialise(int framesize,int hsize)
andrew@0: {
andrew@0: 	fsize = framesize;
andrew@0: 	hopsize = hsize;
andrew@0: 	
andrew@0: 	d_frame = new float[fsize/4];
andrew@0: 	hop = new float[hopsize];
andrew@0: 
andrew@0: 
andrew@0: 	calcrate = (hopsize*4)/fsize;
andrew@0: 
andrew@0: 	count = 0;
andrew@0: 	
andrew@0: 	//fsize = framesize; // set frame size
andrew@0: 		
andrew@0: 	ratio = ((float) 11025) / ((float) 8192);	
andrew@0: 	hamming(bsize);		// define a hanning window offline	
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // Processes a single frame
andrew@0: void Chromagram :: processframe(float frame[])
andrew@0: {
andrew@0: 	int i;
andrew@0: 	int j;
andrew@0: 	int c;
andrew@0: 
andrew@0: 	chromaready = 0; // default case that chroma isn't ready
andrew@0: 
andrew@0: 	// downsample frame
andrew@0: 	downsampleframe(frame);
andrew@0: 		
andrew@0: 	if (count < calcrate)
andrew@0: 	{
andrew@0:         c = count*(fsize/4);
andrew@0: 		
andrew@0: 		j = 0;
andrew@0: 		for (i = c;i < c+(fsize/4);i++)
andrew@0: 		{
andrew@0: 			hop[i] = d_frame[j];
andrew@0: 			j++;
andrew@0: 		}
andrew@0: 		count = count + 1;
andrew@0: 	}
andrew@0: 	    
andrew@0:     if (count == calcrate)
andrew@0: 	{
andrew@0: 		for (i=0;i < 8192-hopsize;i++)
andrew@0: 		{
andrew@0: 			buffer[i] = buffer[i+hopsize];
andrew@0: 		}
andrew@0: 		
andrew@0: 		j = 0;
andrew@0: 		for (i=8192-hopsize;i < bsize;i++)
andrew@0: 		{
andrew@0: 			buffer[i] = hop[j];
andrew@0: 			j++;
andrew@0: 		}
andrew@0: 		        
andrew@0: 		chromacalc(buffer);
andrew@0: 		
andrew@0:         count = 0;
andrew@0:     }
andrew@0: 	
andrew@0: 
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // Processes a single frame
andrew@0: void Chromagram :: downsampleframe(float frame[])
andrew@0: {
andrew@0: 	float filt_frame[fsize];
andrew@0: 	
andrew@0: 	float b0,b1,b2,a1,a2;
andrew@0: 	float x_1,x_2,y_1,y_2;
andrew@0: 	
andrew@0: 	b0 = 0.2929;
andrew@0: 	b1 = 0.5858;
andrew@0: 	b2 = 0.2929;   
andrew@0: 	a1 = -0.0000;
andrew@0: 	a2 = 0.1716;
andrew@0: 
andrew@0: 	x_1 = 0;
andrew@0: 	x_2 = 0;
andrew@0: 	y_1 = 0;
andrew@0: 	y_2 = 0;
andrew@0: 
andrew@0: 	for (int i=0;i < fsize;i++)
andrew@0: 	{
andrew@0: 		filt_frame[i] = frame[i]*b0 + x_1*b1 + x_2*b2 - y_1*a1 - y_2*a2;
andrew@0:     
andrew@0: 		x_2 = x_1;
andrew@0: 		x_1 = frame[i];
andrew@0: 		y_2 = y_1;
andrew@0: 		y_1 = filt_frame[i];
andrew@0: 	}
andrew@0: 	
andrew@0: 	for (int i=0;i < (fsize/4);i++)
andrew@0: 	{
andrew@0: 		d_frame[i] = filt_frame[i*4];
andrew@0: 	}
andrew@0: 
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // main function to be called with 8192 sample frame at 11025 Hz
andrew@0: void Chromagram :: chromacalc(float frame[])
andrew@0: {
andrew@0: 	int i;
andrew@0: 		
andrew@0: 	// apply hanning window to buffer
andrew@0: 	for (i = 0; i < bsize;i++)
andrew@0: 	{
andrew@0: 		wbuffer[i] = frame[i] * win[i];
andrew@0: 	}
andrew@0: 	
andrew@0: 	getmagspectrum();
andrew@0: 	
andrew@0: 	generatechromagram();
andrew@0: 		
andrew@0: 	chromaready = 1;	
andrew@0: 		
andrew@0: //	for (i = 0;i < 12;i++)
andrew@0: //	{
andrew@0: //		cout << chroma[i] << " ";
andrew@0: //	}	
andrew@0: //	
andrew@0: //	cout << endl;
andrew@0: 		
andrew@0: 	//cout << "root: " << root << "  type: " << type << "  features: " << features << endl;
andrew@0: 	
andrew@0: 	//cout << root << " " << quality << " " << intervals << endl;
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // creates a chromagram from the magnitude spectrum of the input signal
andrew@0: void Chromagram :: generatechromagram()
andrew@0: {
andrew@0: 	int i;
andrew@0: 	float sum;
andrew@0: 	float notesum = 0;
andrew@0: 	float noteval;
andrew@0: 	int index;
andrew@0: 	float maxval = 0;
andrew@0: 	int searchlength;
andrew@0: 	
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		sum = 0;
andrew@0: 		
andrew@0: 		for (int oct = 1;oct <= octaves;oct++)
andrew@0: 		{
andrew@0: 			noteval = (note[i]/ratio)*((float) oct);
andrew@0: 			notesum = 0;
andrew@0: 			
andrew@0: 			for (int h = 1;h <= harmonics;h++)
andrew@0: 			{
andrew@0: 				index = round(noteval*((float) h));
andrew@0: 				
andrew@0: 				searchlength = search*h;
andrew@0: 				
andrew@0: 				maxval = 0;
andrew@0: 				for (int n = (index-searchlength);n <= index+searchlength;n++)
andrew@0: 				{
andrew@0: 					if (mag[n] > maxval)
andrew@0: 					{
andrew@0: 						maxval = mag[n];
andrew@0: 					}
andrew@0: 				}
andrew@0: 				
andrew@0: 				notesum = notesum+(maxval*(1/((float) h)));
andrew@0: 			}
andrew@0: 			sum = sum + notesum;
andrew@0: 			
andrew@0: 			if (oct == 1)
andrew@0: 			{
andrew@0: 				chroma_low[i] = notesum;
andrew@0: 			}
andrew@0: 		}
andrew@0: 		
andrew@0: 		chroma[i] = sum;
andrew@0: 		rawChroma[i] = sum;
andrew@0: 		
andrew@0: 		if (sum > maximumChromaValue)
andrew@0: 		maximumChromaValue = sum;
andrew@0: 		
andrew@0: 	}
andrew@0: 	
andrew@0: 	
andrew@0: 	// normalise chromagram
andrew@0: 	maxval = max(chroma,12);
andrew@0: 	
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		chroma[i] = chroma[i] / maxval;
andrew@0: 	}
andrew@0: 	
andrew@0: }
andrew@0: 
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // main function to be called with 8192 sample frame at 11025 Hz
andrew@0: void Chromagram :: hamming(int N)
andrew@0: {
andrew@0: 	int n;
andrew@0: 		
andrew@0: 	// apply hanning window to buffer
andrew@0: 	for (n = 0; n < N;n++)
andrew@0: 	{
andrew@0: 		win[n] = 0.54 - 0.46*cos(2*pi*(((float) n)/((float) N)));
andrew@0: 	}
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // finds mag spectrum of input
andrew@0: void Chromagram :: getmagspectrum()
andrew@0: {
andrew@0: 	int i = 0;	
andrew@0: 
andrew@0: 	// execute fft plan, i.e. compute fft of buffer
andrew@0:     fftwf_execute(p);
andrew@0: 
andrew@0: 	// compute first (N/2)+1 mag values
andrew@0: 	for (i = 0;i < (bsize/2)+1;i++)
andrew@0: 	{
andrew@0: 		mag[i] = sqrt(pow(out[i][0],2) + pow(out[i][1],2));
andrew@0: 		mag[i] = sqrt(mag[i]);
andrew@0: 	}
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // returns max value of an array
andrew@0: float Chromagram :: max(float array[],int length)
andrew@0: {
andrew@0: 	float max = 0;
andrew@0: 	
andrew@0: 	for (int i=0;i < length;i++)
andrew@0: 	{
andrew@0: 		if (array[i] > max)
andrew@0: 		{
andrew@0: 			max = array[i];
andrew@0: 		}
andrew@0: 	}
andrew@0: 	
andrew@0: 	return max;
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // returns index of minimum value of array
andrew@0: int Chromagram :: minindex(float array[],int length)
andrew@0: {
andrew@0: 	float min = 10000;
andrew@0: 	int minindex = 0;
andrew@0: 	int i;
andrew@0: 	
andrew@0: 	for (i = 0;i < length;i++)
andrew@0: 	{
andrew@0: 		if (array[i] < min)
andrew@0: 		{
andrew@0: 			min = array[i];
andrew@0: 			minindex = i;
andrew@0: 		}
andrew@0: 	}
andrew@0: 	
andrew@0: 	return minindex;
andrew@0: }