80 lines
2.0 KiB
C++
80 lines
2.0 KiB
C++
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
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/*
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QM DSP Library
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Centre for Digital Music, Queen Mary, University of London.
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This file 2005-2006 Christian Landone.
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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 "PhaseVocoder.h"
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#include "dsp/transforms/FFT.h"
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#include <math.h>
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//////////////////////////////////////////////////////////////////////
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// Construction/Destruction
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//////////////////////////////////////////////////////////////////////
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PhaseVocoder::PhaseVocoder(unsigned int n) :
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m_n(n)
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{
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m_fft = new FFTReal(m_n);
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m_realOut = new double[m_n];
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m_imagOut = new double[m_n];
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}
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PhaseVocoder::~PhaseVocoder()
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{
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delete [] m_realOut;
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delete [] m_imagOut;
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delete m_fft;
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}
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void PhaseVocoder::FFTShift(unsigned int size, double *src)
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{
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const int hs = size/2;
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for (int i = 0; i < hs; ++i) {
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double tmp = src[i];
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src[i] = src[i + hs];
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src[i + hs] = tmp;
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}
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}
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void PhaseVocoder::process(double *src, double *mag, double *theta)
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{
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FFTShift( m_n, src);
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m_fft->process(0, src, m_realOut, m_imagOut);
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getMagnitude( m_n/2, mag, m_realOut, m_imagOut);
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getPhase( m_n/2, theta, m_realOut, m_imagOut);
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}
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void PhaseVocoder::getMagnitude(unsigned int size, double *mag, double *real, double *imag)
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{
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unsigned int j;
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for( j = 0; j < size; j++)
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{
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mag[ j ] = sqrt( real[ j ] * real[ j ] + imag[ j ] * imag[ j ]);
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}
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}
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void PhaseVocoder::getPhase(unsigned int size, double *theta, double *real, double *imag)
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{
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unsigned int k;
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// Phase Angle "matlab" style
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//Watch out for quadrant mapping !!!
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for( k = 0; k < size; k++)
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{
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theta[ k ] = atan2( -imag[ k ], real[ k ]);
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}
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}
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