SincResampler.h

/*
 * This file is part of libsidplayfp, a SID player engine.
 *
 * Copyright 2011-2024 Leandro Nini <drfiemost@users.sourceforge.net>
 * Copyright 2007-2010 Antti Lankila
 * Copyright 2004 Dag Lem <resid@nimrod.no>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
 
#ifndef SINCRESAMPLER_H
#define SINCRESAMPLER_H
 
#include "Resampler.h"
 
#include "../array.h"
 
namespace reSIDfp
{
 
class SincResampler final : public Resampler
{
private:
    static constexpr int RINGSIZE = 2048;
 
#ifdef RUNTIME_DISPATCH
private:
    using convolve_func_t = auto (*)(const int*, const short*, int) -> int;
 
    convolve_func_t simd_convolve;
#endif
 
private:
    matrix_t* firTable;
 
    int sampleIndex = 0;
 
    int firRES;
 
    int firN;
 
    const int cyclesPerSample;
 
    int sampleOffset = 0;
 
    int outputValue = 0;
 
    int sample[RINGSIZE * 2];
 
private:
    int fir(int subcycle);
 
public:
    SincResampler(
        double clockFrequency,
        double samplingFrequency,
        double highestAccurateFrequency);
    ~SincResampler() override;
 
    bool input(int input) override;
 
    int output() const override { return outputValue; }
 
    void reset() override;
};
 
} // namespace reSIDfp
 
#endif