89 lines
2.1 KiB
Plaintext
89 lines
2.1 KiB
Plaintext
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/*
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* This file is part of libsidplayfp, a SID player engine.
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*
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* Copyright 2011-2013 Leandro Nini <drfiemost@users.sourceforge.net>
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* Copyright 2007-2010 Antti Lankila
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#ifndef ZEROORDER_RESAMPLER_H
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#define ZEROORDER_RESAMPLER_H
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#include "Resampler.h"
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#include "sidcxx11.h"
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namespace reSIDfp
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{
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/**
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* Return sample with linear interpolation.
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*
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* @author Antti Lankila
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*/
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class ZeroOrderResampler final : public Resampler
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{
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private:
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/// Last sample
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int cachedSample;
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/// Number of cycles per sample
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const int cyclesPerSample;
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int sampleOffset;
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/// Calculated sample
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int outputValue;
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public:
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ZeroOrderResampler(double clockFrequency, double samplingFrequency) :
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cachedSample(0),
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cyclesPerSample(static_cast<int>(clockFrequency / samplingFrequency * 1024.)),
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sampleOffset(0),
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outputValue(0) {}
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bool input(int sample) override
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{
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bool ready = false;
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if (sampleOffset < 1024)
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{
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outputValue = cachedSample + (sampleOffset * (sample - cachedSample) >> 10);
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ready = true;
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sampleOffset += cyclesPerSample;
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}
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sampleOffset -= 1024;
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cachedSample = sample;
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return ready;
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}
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int output() const override { return outputValue; }
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void reset() override
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{
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sampleOffset = 0;
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cachedSample = 0;
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}
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};
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} // namespace reSIDfp
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#endif
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