andrew@0: /*
andrew@0:  *  ChordDetect.cpp
andrew@0:  *  ChordDetect
andrew@0:  *
andrew@0:  *  Created by Adam Stark on 28/04/2008.
andrew@0:  *  Copyright 2008 __MyCompanyName__. All rights reserved.
andrew@0:  *
andrew@0:  */
andrew@0: 
andrew@0: #include "ChordDetect.h"
andrew@0: #include <iostream>
andrew@0: #include <math.h>
andrew@0: using namespace std;
andrew@0: 
andrew@0: ChordDetect :: ChordDetect()
andrew@0: {
andrew@0: 	
andrew@0: 	bias = 1.06;
andrew@0: 	
andrew@0: 	makeprofiles();
andrew@0: 		
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // destructor
andrew@0: ChordDetect :: ~ChordDetect()
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 ChordDetect :: C_Detect(float c[],float c_low[])
andrew@0: {
andrew@0: 	for (int i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		chroma[i] = c[i];
andrew@0: 		chroma_low[i] = c_low[i];
andrew@0: 	}
andrew@0: 	
andrew@0: 	calculateweightings();
andrew@0: 	
andrew@0: 	classifychromagram();
andrew@0: 		
andrew@0: 	//cout << root << " " << quality << " " << intervals << endl;
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // analyse the chromagram and assign it a root note, chord type and any features
andrew@0: void ChordDetect :: classifychromagram()
andrew@0: {
andrew@0: 	int i;
andrew@0: 	int j;
andrew@0: 	int fifth;
andrew@0: 	int chordindex;
andrew@0: 	
andrew@0: 	// remove some of the 5th note energy from chromagram
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		fifth = (i+7) % 12;
andrew@0: 		chroma[fifth] = chroma[fifth] - (0.1*chroma[i]);
andrew@0: 		
andrew@0: 		if (chroma[fifth] < 0)
andrew@0: 		{
andrew@0: 			chroma[fifth] = 0;
andrew@0: 		}
andrew@0: 		
andrew@0: 	}
andrew@0: 	
andrew@0: 	
andrew@0: 	// major chords
andrew@0: 	for (j=0;j < 12;j++)
andrew@0: 	{
andrew@0: 		chord[j] = calcchordvalue(chroma,profiles[j],bias,3);
andrew@0: 	}
andrew@0: 	
andrew@0: 	// minor chords
andrew@0: 	for (j=12;j < 24;j++)
andrew@0: 	{
andrew@0: 		chord[j] = calcchordvalue(chroma,profiles[j],bias,3);
andrew@0: 	}
andrew@0: 	
andrew@0: 	// diminished 5th chords
andrew@0: 	for (j=24;j < 36;j++)
andrew@0: 	{
andrew@0: 		chord[j] = calcchordvalue(chroma,profiles[j],bias,3);
andrew@0: 	}
andrew@0: 	
andrew@0: 	// augmented 5th chords
andrew@0: 	for (j=36;j < 48;j++)
andrew@0: 	{
andrew@0: 		chord[j] = calcchordvalue(chroma,profiles[j],bias,3);
andrew@0: 		
andrew@0: 		chord[j] = chord[j] / weight_aug[j-36];
andrew@0: 	}
andrew@0: 	
andrew@0: 	// sus2 chords
andrew@0: 	for (j=48;j < 60;j++)
andrew@0: 	{
andrew@0: 		chord[j] = calcchordvalue(chroma,profiles[j],1,3);
andrew@0: 		
andrew@0: 		chord[j] = chord[j] / weight_sus[j-48];
andrew@0: 	}
andrew@0: 	
andrew@0: 	// sus4 chords
andrew@0: 	for (j=60;j < 72;j++)
andrew@0: 	{
andrew@0: 		chord[j] = calcchordvalue(chroma,profiles[j],1,3);
andrew@0: 		
andrew@0: 		chord[j] = chord[j] / weight_sus[j-60];
andrew@0: 	}
andrew@0: 	
andrew@0: 	// major 7th chords
andrew@0: 	for (j=72;j < 84;j++)
andrew@0: 	{
andrew@0: 		chord[j] = calcchordvalue(chroma,profiles[j],1,4);
andrew@0: 	}
andrew@0: 	
andrew@0: 	// minor 7th chords
andrew@0: 	for (j=84;j < 96;j++)
andrew@0: 	{
andrew@0: 		chord[j] = calcchordvalue(chroma,profiles[j],bias,4);
andrew@0: 	}
andrew@0: 
andrew@0: 	// dominant 7th chords
andrew@0: 	for (j=96;j < 108;j++)
andrew@0: 	{
andrew@0: 		chord[j] = calcchordvalue(chroma,profiles[j],bias,4);
andrew@0: 	}
andrew@0: 	
andrew@0: 	chordindex = minindex(chord,108);
andrew@0: 	
andrew@0: 	// major
andrew@0: 	if (chordindex < 12)
andrew@0: 	{
andrew@0: 		root = chordindex;
andrew@0: 		quality = 1;
andrew@0: 		intervals = 0;
andrew@0: 	}
andrew@0: 	
andrew@0: 	// minor
andrew@0: 	if ((chordindex >= 12) && (chordindex < 24))
andrew@0: 	{
andrew@0: 		root = chordindex-12;
andrew@0: 		quality = 0;
andrew@0: 		intervals = 0;
andrew@0: 	}
andrew@0: 	
andrew@0: 	// diminished 5th
andrew@0: 	if ((chordindex >= 24) && (chordindex < 36))
andrew@0: 	{
andrew@0: 		root = chordindex-24;
andrew@0: 		quality = 4;
andrew@0: 		intervals = 0;
andrew@0: 	}
andrew@0: 	
andrew@0: 	// augmented 5th
andrew@0: 	if ((chordindex >= 36) && (chordindex < 48))
andrew@0: 	{
andrew@0: 		root = chordindex-36;
andrew@0: 		quality = 6;
andrew@0: 		intervals = 0;
andrew@0: 	}
andrew@0: 	
andrew@0: 	// sus2
andrew@0: 	if ((chordindex >= 48) && (chordindex < 60))
andrew@0: 	{
andrew@0: 		root = chordindex-48;
andrew@0: 		quality = 2;
andrew@0: 		intervals = 2;
andrew@0: 	}
andrew@0: 	
andrew@0: 	// sus4
andrew@0: 	if ((chordindex >= 60) && (chordindex < 72))
andrew@0: 	{
andrew@0: 		root = chordindex-60;
andrew@0: 		quality = 2;
andrew@0: 		intervals = 4;
andrew@0: 	}
andrew@0: 	
andrew@0: 	// major 7th
andrew@0: 	if ((chordindex >= 72) && (chordindex < 84))
andrew@0: 	{
andrew@0: 		root = chordindex-72;
andrew@0: 		quality = 1;
andrew@0: 		intervals = 7;
andrew@0: 	}
andrew@0: 	
andrew@0: 	// minor 7th
andrew@0: 	if ((chordindex >= 84) && (chordindex < 96))
andrew@0: 	{
andrew@0: 		root = chordindex-84;
andrew@0: 		quality = 0;
andrew@0: 		intervals = 7;
andrew@0: 	}
andrew@0: 	
andrew@0: 	// dominant 7th
andrew@0: 	if ((chordindex >= 96) && (chordindex < 108))
andrew@0: 	{
andrew@0: 		root = chordindex-96;
andrew@0: 		quality = 2;
andrew@0: 		intervals = 7;
andrew@0: 	}
andrew@0: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // calculate weightings to help distinguish between sus2/sus4 and aug chords
andrew@0: void ChordDetect :: calculateweightings()
andrew@0: {
andrew@0: 	int i;
andrew@0: 	float maxval = 0;
andrew@0: 	int fifth;
andrew@0: 	int augfifth;
andrew@0: 	
andrew@0: 	maxval = max(chroma_low,12); 
andrew@0: 		
andrew@0: 	// normalise chroma low
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		chroma_low[i] = chroma_low[i] / maxval;
andrew@0: 	}
andrew@0: 	
andrew@0: 	// make weight for sus chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		fifth = i+7;
andrew@0: 		augfifth = i+8;
andrew@0: 		
andrew@0: 		if (fifth >= 12)
andrew@0: 		{
andrew@0: 			fifth = fifth-12;
andrew@0: 		}
andrew@0: 		
andrew@0: 		if (augfifth >= 12)
andrew@0: 		{
andrew@0: 			augfifth = augfifth-12;
andrew@0: 		}
andrew@0: 		
andrew@0: 		weight_sus[i] = chroma_low[i] + (chroma_low[fifth]/2);
andrew@0: 		weight_aug[i] = chroma_low[i] + (chroma_low[augfifth]/2);
andrew@0: 	}
andrew@0: 	
andrew@0: 	maxval = max(weight_sus,12);
andrew@0: 	// normalise weight_sus
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		weight_sus[i] = weight_sus[i] / maxval;
andrew@0: 	}
andrew@0: 	
andrew@0: 	maxval = max(weight_aug,12);
andrew@0: 	// normalise weight_aug
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		weight_aug[i] = weight_aug[i] / maxval;
andrew@0: 	}
andrew@0: 	
andrew@0: 	
andrew@0: }
andrew@0: 
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // return delta value indicating how similar the chroma is to the chord template - lower value = more similar
andrew@0: float ChordDetect :: calcchordvalue(float c[],float T[],float biasval, float N)
andrew@0: {
andrew@0: 	float sum = 0;
andrew@0: 	float delta;
andrew@0: 
andrew@0: 	for (int i=0;i < 12;i++)
andrew@0: 	{
andrew@0: 		sum = sum + ((1-T[i])*(pow(c[i],2)));
andrew@0: 	}
andrew@0: 
andrew@0: 	delta = sqrt(sum) / ((12 - N)*biasval);
andrew@0: 	
andrew@0: 	return delta;
andrew@0: }
andrew@0: 
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // returns max value of an array
andrew@0: float ChordDetect :: 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 ChordDetect :: 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: }
andrew@0: 
andrew@0: //--------------------------------------------------------------------------------------
andrew@0: // calculates bit mask chord profiles
andrew@0: void ChordDetect :: makeprofiles()
andrew@0: {
andrew@0: 	int i;
andrew@0: 	int t;
andrew@0: 	int j = 0;
andrew@0: 	int root;
andrew@0: 	int third;
andrew@0: 	int fifth;
andrew@0: 	int seventh;
andrew@0: 	
andrew@0: 	float v1 = 1;
andrew@0: 	float v2 = 1;
andrew@0: 	float v3 = 1;
andrew@0: 	
andrew@0: 	// set profiles matrix to all zeros
andrew@0: 	for (j = 0;j < 108;j++)
andrew@0: 	{
andrew@0: 		for (t = 0;t < 12;t++)
andrew@0: 		{
andrew@0: 			profiles[j][t] = 0;
andrew@0: 		}
andrew@0: 	}
andrew@0: 	
andrew@0: 	// reset j to zero to begin creating profiles
andrew@0: 	j = 0;
andrew@0: 	
andrew@0: 	// major chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		root = i % 12;
andrew@0: 		third = (i+4) % 12;
andrew@0: 		fifth = (i+7) % 12;
andrew@0: 		
andrew@0: 		profiles[j][root] = v1;
andrew@0: 		profiles[j][third] = v2;
andrew@0: 		profiles[j][fifth] = v3;
andrew@0: 		
andrew@0: 		j++;				
andrew@0: 	}
andrew@0: 
andrew@0: 	// minor chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		root = i % 12;
andrew@0: 		third = (i+3) % 12;
andrew@0: 		fifth = (i+7) % 12;
andrew@0: 		
andrew@0: 		profiles[j][root] = v1;
andrew@0: 		profiles[j][third] = v2;
andrew@0: 		profiles[j][fifth] = v3;
andrew@0: 		
andrew@0: 		j++;				
andrew@0: 	}
andrew@0: 
andrew@0: 	// diminished chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		root = i % 12;
andrew@0: 		third = (i+3) % 12;
andrew@0: 		fifth = (i+6) % 12;
andrew@0: 		
andrew@0: 		profiles[j][root] = v1;
andrew@0: 		profiles[j][third] = v2;
andrew@0: 		profiles[j][fifth] = v3;
andrew@0: 		
andrew@0: 		j++;				
andrew@0: 	}	
andrew@0: 	
andrew@0: 	// augmented chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		root = i % 12;
andrew@0: 		third = (i+4) % 12;
andrew@0: 		fifth = (i+8) % 12;
andrew@0: 		
andrew@0: 		profiles[j][root] = v1;
andrew@0: 		profiles[j][third] = v2;
andrew@0: 		profiles[j][fifth] = v3;
andrew@0: 		
andrew@0: 		j++;				
andrew@0: 	}	
andrew@0: 	
andrew@0: 	// sus2 chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		root = i % 12;
andrew@0: 		third = (i+2) % 12;
andrew@0: 		fifth = (i+7) % 12;
andrew@0: 		
andrew@0: 		profiles[j][root] = v1;
andrew@0: 		profiles[j][third] = v2;
andrew@0: 		profiles[j][fifth] = v3;
andrew@0: 		
andrew@0: 		j++;				
andrew@0: 	}
andrew@0: 	
andrew@0: 	// sus4 chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		root = i % 12;
andrew@0: 		third = (i+5) % 12;
andrew@0: 		fifth = (i+7) % 12;
andrew@0: 		
andrew@0: 		profiles[j][root] = v1;
andrew@0: 		profiles[j][third] = v2;
andrew@0: 		profiles[j][fifth] = v3;
andrew@0: 		
andrew@0: 		j++;				
andrew@0: 	}		
andrew@0: 	
andrew@0: 	// major 7th chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		root = i % 12;
andrew@0: 		third = (i+4) % 12;
andrew@0: 		fifth = (i+7) % 12;
andrew@0: 		seventh = (i+11) % 12;
andrew@0: 		
andrew@0: 		profiles[j][root] = v1;
andrew@0: 		profiles[j][third] = v2;
andrew@0: 		profiles[j][fifth] = v3;
andrew@0: 		profiles[j][seventh] = v3;
andrew@0: 		
andrew@0: 		j++;				
andrew@0: 	}	
andrew@0: 	
andrew@0: 	// minor 7th chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		root = i % 12;
andrew@0: 		third = (i+3) % 12;
andrew@0: 		fifth = (i+7) % 12;
andrew@0: 		seventh = (i+10) % 12;
andrew@0: 		
andrew@0: 		profiles[j][root] = v1;
andrew@0: 		profiles[j][third] = v2;
andrew@0: 		profiles[j][fifth] = v3;
andrew@0: 		profiles[j][seventh] = v3;
andrew@0: 		
andrew@0: 		j++;				
andrew@0: 	}
andrew@0: 	
andrew@0: 	// dominant 7th chords
andrew@0: 	for (i = 0;i < 12;i++)
andrew@0: 	{
andrew@0: 		root = i % 12;
andrew@0: 		third = (i+4) % 12;
andrew@0: 		fifth = (i+7) % 12;
andrew@0: 		seventh = (i+10) % 12;
andrew@0: 		
andrew@0: 		profiles[j][root] = v1;
andrew@0: 		profiles[j][third] = v2;
andrew@0: 		profiles[j][fifth] = v3;
andrew@0: 		profiles[j][seventh] = v3;
andrew@0: 		
andrew@0: 		j++;				
andrew@0: 	}
andrew@0: }