CircularPeakTunner.hxx

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/*
 * Copyright (c) 2001-2006 MUSIC TECHNOLOGY GROUP (MTG)
 *                         UNIVERSITAT POMPEU FABRA
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#ifndef CircularPeakTunner_hxx
#define CircularPeakTunner_hxx
#include <list>
#include <vector>
#include <cmath>

namespace Simac
{

class CircularPeakTunner
{
public:
        typedef std::vector<std::pair<double, double> > PeakList;
        typedef std::vector<std::pair<double, double> > PitchProfile;
private:
        double _referenceTunning;
        PeakList _output;
        static const unsigned nSemitones = 12;
        static const unsigned binsPerSemitone = 3;
public:
        CircularPeakTunner(double referenceTunning)
                : _referenceTunning(referenceTunning)
        {
                _output.reserve(nSemitones*binsPerSemitone);
        }
        ~CircularPeakTunner()
        {
        }
        unsigned chromagramToSemitone(double tunning, double peakPosition)
        {
                double scaledPosition = peakPosition/binsPerSemitone;
                double scaledTunning = tunning/binsPerSemitone;
                double scaledReference = _referenceTunning/binsPerSemitone;

                double shift = tunningShift(scaledReference, scaledTunning);
                double tunnedPosition = tune(scaledPosition, shift);

                int quantizedSemitone = int(tunnedPosition + .5);
                unsigned refoldedSemitone = (quantizedSemitone+nSemitones)%nSemitones;
                return refoldedSemitone;
        }

        static double tunningShift(double reference, double tunning)
        {
                return - tunning - std::floor(reference-tunning+0.5);
        }
        static double tune(double peakPosition, double shift)
        {
                double tunnedPosition = peakPosition + shift;
                while (tunnedPosition<0) tunnedPosition += nSemitones;
                while (tunnedPosition>= nSemitones) tunnedPosition -= nSemitones;
                return tunnedPosition;
        }

        void doIt(double center, const PeakList & peaks)
        {
                _output.resize(0);
                const unsigned nPeaks=peaks.size();
                double shift= tunningShift(_referenceTunning, center);
                for (unsigned i=0; i<nPeaks; i++)
                {
                        double tunnedPosition =  tune(peaks[i].first,shift);
                        _output.push_back(std::make_pair(tunnedPosition,peaks[i].second));
                }
        }

        const PeakList & output() const
        {
                return _output;
        }
};

} // namespace Simac

#endif// CircularPeakTunner_hxx