81 lines
1.9 KiB
C++
81 lines
1.9 KiB
C++
/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
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/*
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Rubber Band
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An audio time-stretching and pitch-shifting library.
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Copyright 2007 Chris Cannam.
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version. See the file
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COPYING included with this distribution for more information.
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*/
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#include "PercussiveAudioCurve.h"
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#include <cmath>
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namespace RubberBand
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{
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PercussiveAudioCurve::PercussiveAudioCurve(size_t sampleRate, size_t blockSize) :
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AudioCurve(sampleRate, blockSize)
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{
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m_prevMag = new double[m_blockSize/2 + 1];
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for (size_t i = 0; i <= m_blockSize/2; ++i) {
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m_prevMag[i] = 0.f;
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}
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}
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PercussiveAudioCurve::~PercussiveAudioCurve()
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{
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delete[] m_prevMag;
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}
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void
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PercussiveAudioCurve::reset()
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{
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for (size_t i = 0; i <= m_blockSize/2; ++i) {
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m_prevMag[i] = 0;
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}
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}
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void
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PercussiveAudioCurve::setBlockSize(size_t newSize)
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{
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delete[] m_prevMag;
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m_blockSize = newSize;
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m_prevMag = new double[m_blockSize/2 + 1];
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reset();
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}
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float
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PercussiveAudioCurve::process(float *mag, size_t increment)
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{
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static float threshold = pow(10, 0.3);
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static float zeroThresh = pow(10, -16);
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size_t count = 0;
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size_t nonZeroCount = 0;
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for (size_t n = 1; n <= m_blockSize / 2; ++n) {
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//!!! adjust threshold so that this multiplication is unnecessary
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float sqrmag = mag[n] * mag[n];
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bool above = ((sqrmag / m_prevMag[n]) >= threshold);
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if (above) ++count;
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if (sqrmag > zeroThresh) ++nonZeroCount;
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m_prevMag[n] = sqrmag;
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}
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//!!! return float(count) / float(m_blockSize);
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if (nonZeroCount == 0) return 0;
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else return float(count) / float(nonZeroCount);
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}
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}
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