Resampler.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 by Chris Cannam.

    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_RESAMPLER_H
#define QM_DSP_RESAMPLER_H

#include <vector>

class Resampler
{
public:
    Resampler(int sourceRate, int targetRate);

    Resampler(int sourceRate, int targetRate,
              double snr, double bandwidth);

    virtual ~Resampler();

    int process(const double *src, double *dst, int n);

    std::vector<double> process(const double *src, int n);

    int getLatency() const { return m_latency; }

    static std::vector<double> resample
    (int sourceRate, int targetRate, const double *data, int n);

private:
    int m_sourceRate;
    int m_targetRate;
    int m_gcd;
    int m_filterLength;
    int m_latency;
    double m_peakToPole;
    
    struct Phase {
        int nextPhase;
        std::vector<double> filter;
        int drop;
    };

    Phase *m_phaseData;
    int m_phase;
    std::vector<double> m_buffer;
    int m_bufferOrigin;

    void initialise(double, double);
    double reconstructOne();
};

#endif