Chris@37: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@37: 
Chris@37: /*
Chris@37:     Vamp feature extraction plugin using the MATCH audio alignment
Chris@37:     algorithm.
Chris@37: 
Chris@37:     Centre for Digital Music, Queen Mary, University of London.
Chris@37:     This file copyright 2007 Simon Dixon, Chris Cannam and QMUL.
Chris@37:     
Chris@37:     This program is free software; you can redistribute it and/or
Chris@37:     modify it under the terms of the GNU General Public License as
Chris@37:     published by the Free Software Foundation; either version 2 of the
Chris@37:     License, or (at your option) any later version.  See the file
Chris@37:     COPYING included with this distribution for more information.
Chris@37: */
Chris@37: 
Chris@37: #include "FeatureExtractor.h"
Chris@37: 
Chris@37: #include <iostream>
Chris@37: 
Chris@37: #include <cstdlib>
Chris@37: #include <cassert>
Chris@37: #include <cmath>
Chris@37: 
Chris@37: using namespace std;
Chris@37: 
Chris@140: //#define DEBUG_FEATURE_EXTRACTOR 1
Chris@140: 
Chris@37: FeatureExtractor::FeatureExtractor(Parameters parameters) :
Chris@103:     m_params(parameters)
Chris@37: {
Chris@74:     m_featureSize = getFeatureSizeFor(parameters);
Chris@37:     makeFreqMap();
Chris@140: 
Chris@140: #ifdef DEBUG_FEATURE_EXTRACTOR
Chris@140:     cerr << "*** FeatureExtractor: sampleRate = " << parameters.sampleRate
Chris@140:          << ", useChromaFrequencyMap = " << parameters.useChromaFrequencyMap
Chris@140:          << ", fftSize = " << parameters.fftSize << endl;
Chris@140: #endif
Chris@37: }
Chris@37: 
Chris@74: int
Chris@74: FeatureExtractor::getFeatureSizeFor(Parameters parameters)
Chris@74: {
Chris@74:     if (parameters.useChromaFrequencyMap) {
Chris@74: 	return 13;
Chris@74:     } else {
Chris@74: 	return 84;
Chris@74:     }
Chris@74: }
Chris@74: 
Chris@37: void
Chris@37: FeatureExtractor::makeFreqMap()
Chris@37: {
Chris@37:     m_freqMap = vector<int>(m_params.fftSize / 2 + 1, 0);
Chris@37: 
Chris@37:     if (m_params.useChromaFrequencyMap) {
Chris@140: #ifdef DEBUG_FEATURE_EXTRACTOR
Chris@37:         cerr << "makeFreqMap: calling makeChromaFrequencyMap" << endl;
Chris@37: #endif
Chris@37:         makeChromaFrequencyMap();
Chris@37:     } else {
Chris@140: #ifdef DEBUG_FEATURE_EXTRACTOR
Chris@37:         cerr << "makeFreqMap: calling makeStandardFrequencyMap" << endl;
Chris@37: #endif
Chris@37:         makeStandardFrequencyMap();
Chris@37:     }
Chris@37: }
Chris@37: 
Chris@37: void
Chris@37: FeatureExtractor::makeStandardFrequencyMap()
Chris@37: {
Chris@37:     double binWidth = m_params.sampleRate / m_params.fftSize;
Chris@37:     int crossoverBin = (int)(2 / (pow(2, 1/12.0) - 1));
Chris@37:     int crossoverMidi = lrint(log(crossoverBin*binWidth/440.0)/
Chris@37:                               log(2.0) * 12 + 69);
Chris@37: 
Chris@37:     // freq = 440 * Math.pow(2, (midi-69)/12.0) / binWidth;
Chris@37:     
Chris@37:     int i = 0;
Chris@37:     while (i <= crossoverBin) {
Chris@37:         m_freqMap[i] = i;
Chris@37:         ++i;
Chris@37:     }
Chris@37: 
Chris@37:     while (i <= m_params.fftSize/2) {
Chris@37:         double midi = log(i*binWidth/440.0) / log(2.0) * 12 + 69;
Chris@37:         if (midi > 127) midi = 127;
Chris@40:         int target = crossoverBin + lrint(midi) - crossoverMidi;
Chris@40:         if (target >= m_featureSize) target = m_featureSize - 1;
Chris@40:         m_freqMap[i++] = target;
Chris@37:     }
Chris@37: }
Chris@37: 
Chris@37: void
Chris@37: FeatureExtractor::makeChromaFrequencyMap()
Chris@37: {
Chris@37:     double binWidth = m_params.sampleRate / m_params.fftSize;
Chris@37:     int crossoverBin = (int)(1 / (pow(2, 1/12.0) - 1));
Chris@37:     int i = 0;
Chris@37:     while (i <= crossoverBin) {
Chris@37:         m_freqMap[i++] = 0;
Chris@37:     }
Chris@37:     while (i <= m_params.fftSize/2) {
Chris@37:         double midi = log(i*binWidth/440.0) / log(2.0) * 12 + 69;
Chris@37:         m_freqMap[i++] = (lrint(midi)) % 12 + 1;
Chris@37:     }
Chris@37: }
Chris@37: 
Chris@37: vector<double>
Chris@37: FeatureExtractor::process(const vector<double> &real, const vector<double> &imag)
Chris@37: {
Chris@37:     vector<double> frame(m_featureSize, 0.0);
Chris@37:     
Chris@37:     for (int i = 0; i <= m_params.fftSize/2; i++) {
Chris@37:         double mag = real[i] * real[i] + imag[i] * imag[i];
Chris@37:         frame[m_freqMap[i]] += mag;
Chris@37:     }
Chris@37: 
Chris@103:     return frame;
Chris@74: }
Chris@74: 
Chris@74: vector<double>
Chris@74: FeatureExtractor::process(const float *cframe)
Chris@74: {
Chris@74:     vector<double> frame(m_featureSize, 0.0);
Chris@74:     
Chris@74:     for (int i = 0; i <= m_params.fftSize/2; i++) {
Chris@74:         double mag = cframe[i*2] * cframe[i*2] + cframe[i*2+1] * cframe[i*2+1];
Chris@74:         frame[m_freqMap[i]] += mag;
Chris@74:     }
Chris@74: 
Chris@103:     return frame;
Chris@74: }
Chris@74: