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livetrax/libs/qm-dsp/dsp/tempotracking/TempoTrackV2.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 TEMPOTRACKV2_H
#define TEMPOTRACKV2_H
#include <vector>
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using namespace std;
//!!! Question: how far is this actually sample rate dependent? I
// think it does produce plausible results for e.g. 48000 as well as
// 44100, but surely the fixed window sizes and comb filtering will
// make it prefer double or half time when run at e.g. 96000?
class TempoTrackV2
{
public:
/**
* Construct a tempo tracker that will operate on beat detection
* function data calculated from audio at the given sample rate
* with the given frame increment.
*
* Currently the sample rate and increment are used only for the
* conversion from beat frame location to bpm in the tempo array.
*/
TempoTrackV2(float sampleRate, size_t dfIncrement);
~TempoTrackV2();
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// Returned beat periods are given in df increment units; inputtempo and tempi in bpm
void calculateBeatPeriod(const vector<double> &df,
vector<double> &beatPeriod,
vector<double> &tempi) {
calculateBeatPeriod(df, beatPeriod, tempi, 120.0, false);
}
// Returned beat periods are given in df increment units; inputtempo and tempi in bpm
// MEPD 28/11/12 Expose inputtempo and constraintempo parameters
// Note, if inputtempo = 120 and constraintempo = false, then functionality is as it was before
void calculateBeatPeriod(const vector<double> &df,
vector<double> &beatPeriod,
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vector<double> &tempi,
double inputtempo, bool constraintempo);
// Returned beat positions are given in df increment units
void calculateBeats(const vector<double> &df,
const vector<double> &beatPeriod,
vector<double> &beats) {
calculateBeats(df, beatPeriod, beats, 0.9, 4.0);
}
// Returned beat positions are given in df increment units
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// MEPD 28/11/12 Expose alpha and tightness parameters
// Note, if alpha = 0.9 and tightness = 4, then functionality is as it was before
void calculateBeats(const vector<double> &df,
const vector<double> &beatPeriod,
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vector<double> &beats,
double alpha, double tightness);
private:
typedef vector<int> i_vec_t;
typedef vector<vector<int> > i_mat_t;
typedef vector<double> d_vec_t;
typedef vector<vector<double> > d_mat_t;
float m_rate;
size_t m_increment;
void adapt_thresh(d_vec_t &df);
double mean_array(const d_vec_t &dfin, int start, int end);
void filter_df(d_vec_t &df);
void get_rcf(const d_vec_t &dfframe, const d_vec_t &wv, d_vec_t &rcf);
void viterbi_decode(const d_mat_t &rcfmat, const d_vec_t &wv,
d_vec_t &bp, d_vec_t &tempi);
double get_max_val(const d_vec_t &df);
int get_max_ind(const d_vec_t &df);
void normalise_vec(d_vec_t &df);
};
#endif