annotate src/Chromagram.cpp @ 170:b96b0addbca7

Pull out chroma class into library

/* -*- 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

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

#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.octaves - 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.bpo / 12;
    m_maxFrequency = midiPitchLimitFreq /
        pow(2, (1.0 + floor(bps/2)) / m_params.bpo);

    // Min frequency is frequency of midiPitchLimit lowered by the
    // appropriate number of octaves.
    m_minFrequency = midiPitchLimitFreq /
        pow(2, m_params.octaves + 1);

    CQParameters p
        (params.sampleRate, m_minFrequency, m_maxFrequency, params.bpo);
    
    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.bpo - 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.bpo, 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.bpo - (j % m_params.bpo) - 1] += cqout[i][j];
	}

        chroma.push_back(column);
    }

    return chroma;
}