DownBeat.h

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

/*
    QM DSP Library

    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2008-2009 Matthew Davies and QMUL.

    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.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef QM_DSP_DOWNBEAT_H
#define QM_DSP_DOWNBEAT_H

#include <vector>
#include <cstddef>

#include "dsp/rateconversion/Decimator.h"

class FFTReal;

class DownBeat
{
public:
    DownBeat(float originalSampleRate,
             size_t decimationFactor,
             size_t dfIncrement);
    ~DownBeat();

    void setBeatsPerBar(int bpb);

    void findDownBeats(const float *audio, // downsampled
                       size_t audioLength, // after downsampling
                       const std::vector<double> &beats,
                       std::vector<int> &downbeats);

    void getBeatSD(std::vector<double> &beatsd) const;
    
    void pushAudioBlock(const float *audio);
    
    const float *getBufferedAudio(size_t &length) const;

    void resetAudioBuffer();

private:
    typedef std::vector<int> i_vec_t;
    typedef std::vector<std::vector<int> > i_mat_t;
    typedef std::vector<double> d_vec_t;
    typedef std::vector<std::vector<double> > d_mat_t;

    void makeDecimators();
    double measureSpecDiff(d_vec_t oldspec, d_vec_t newspec);

    int m_bpb;
    float m_rate;
    size_t m_factor;
    size_t m_increment;
    Decimator *m_decimator1;
    Decimator *m_decimator2;
    float *m_buffer;
    float *m_decbuf;
    size_t m_bufsiz;
    size_t m_buffill;
    size_t m_beatframesize;
    double *m_beatframe;
    FFTReal *m_fft;
    double *m_fftRealOut;
    double *m_fftImagOut;
    d_vec_t m_beatsd;
};

#endif