C++ Constant-Q

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*

    Constant-Q library

    Copyright (c) 2013-2015 Queen Mary, University of London

    Permission is hereby granted, free of charge, to any person

    obtaining a copy of this software and associated documentation

    files (the "Software"), to deal in the Software without

    restriction, including without limitation the rights to use, copy,

    modify, merge, publish, distribute, sublicense, and/or sell copies

    of the Software, and to permit persons to whom the Software is

    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be

    included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY

    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF

    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION

    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

    Except as contained in this notice, the names of the Centre for

    Digital Music; Queen Mary, University of London; and Chris Cannam

    shall not be used in advertising or otherwise to promote the sale,

    use or other dealings in this Software without prior written

    authorization.

*/

#include "Chromagram.h"

#include "CQSpectrogram.h"

#include "Pitch.h"

#include <cstdio>

using namespace std;

Chromagram::Chromagram(Parameters params) :

    m_params(params),

    m_cq(0)

{

    int highestOctave = m_params.lowestOctave + m_params.octaveCount - 1;

    int midiPitchLimit = (1 + highestOctave) * 12 + 12; // C just beyond top

    double midiPitchLimitFreq = Pitch::getFrequencyForPitch

        (midiPitchLimit, 0, m_params.tuningFrequency);

    // Max frequency is frequency of the MIDI pitch just beyond the

    // top octave range (midiPitchLimit) minus one bin, then minus

    // floor(bins per semitone / 2)

    int bps = m_params.binsPerOctave / 12;

    m_maxFrequency = midiPitchLimitFreq /

        pow(2.0, (1.0 + floor(bps/2)) / m_params.binsPerOctave);

    // Min frequency is frequency of midiPitchLimit lowered by the

    // appropriate number of octaveCount.

    m_minFrequency = midiPitchLimitFreq /

        pow(2.0, m_params.octaveCount + 1);

    CQParameters p

        (params.sampleRate, m_minFrequency, m_maxFrequency, params.binsPerOctave);

    p.q = params.q;

    p.atomHopFactor = params.atomHopFactor;

    p.threshold = params.threshold;

    p.window = params.window;

    m_cq = new CQSpectrogram(p, CQSpectrogram::InterpolateLinear);

}

Chromagram::~Chromagram()

{

    delete m_cq;

}

bool

Chromagram::isValid() const

{

    return m_cq->isValid();

}

int

Chromagram::getColumnHop() const

{

    return m_cq->getColumnHop();

}

int

Chromagram::getLatency() const

{

    return m_cq->getLatency();

}

string

Chromagram::getBinName(int bin) const

{

    static const char *names[] = {

        "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"

    };

    float freq = m_cq->getBinFrequency(m_params.binsPerOctave - bin - 1);

    int note = Pitch::getPitchForFrequency(freq, 0, m_params.tuningFrequency);

    float nearestFreq =

        Pitch::getFrequencyForPitch(note, 0, m_params.tuningFrequency);

    char name[40];

    sprintf(name, "%d", bin);

    if (fabs(freq - nearestFreq) < 0.01) {

        return (name + std::string(" ") + names[note % 12]);

    } else {

        return (name);

    }

}

CQBase::RealBlock

Chromagram::process(const CQBase::RealSequence &data)

{

    return convert(m_cq->process(data));

}

CQBase::RealBlock

Chromagram::getRemainingOutput()

{

    return convert(m_cq->getRemainingOutput());

}

CQBase::RealBlock

Chromagram::convert(const CQBase::RealBlock &cqout)

{    

    CQBase::RealBlock chroma;

    int width = cqout.size();

    for (int i = 0; i < width; ++i) {

        CQBase::RealSequence column(m_params.binsPerOctave, 0.);

        // fold and invert to put low frequencies at the start

        int thisHeight = cqout[i].size();

        for (int j = 0; j < thisHeight; ++j) {

            column[m_params.binsPerOctave - (j % m_params.binsPerOctave) - 1]

                += cqout[i][j];

        }

        chroma.push_back(column);

    }

    return chroma;

}