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livetrax/libs/qm-dsp/dsp/phasevocoder/PhaseVocoder.h

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C++

/* -*- 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 2005-2006 Christian Landone, copyright 2013 QMUL.
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 PHASEVOCODER_H
#define PHASEVOCODER_H
class FFTReal;
class PhaseVocoder
{
public:
PhaseVocoder(int size, int hop);
virtual ~PhaseVocoder();
/**
* Given one frame of time-domain samples, FFT and return the
* magnitudes, instantaneous phases, and unwrapped phases.
*
* src must have size values (where size is the frame size value
* as passed to the PhaseVocoder constructor), and should have
* been windowed as necessary by the caller (but not fft-shifted).
*
* mag, phase, and unwrapped must each be non-NULL and point to
* enough space for size/2 + 1 values. The redundant conjugate
* half of the output is not returned.
*/
void processTimeDomain(const double *src,
double *mag, double *phase, double *unwrapped);
/**
* Given one frame of frequency-domain samples, return the
* magnitudes, instantaneous phases, and unwrapped phases.
*
* reals and imags must each contain size/2+1 values (where size
* is the frame size value as passed to the PhaseVocoder
* constructor).
*
* mag, phase, and unwrapped must each be non-NULL and point to
* enough space for size/2+1 values.
*/
void processFrequencyDomain(const double *reals, const double *imags,
double *mag, double *phase, double *unwrapped);
/**
* Reset the stored phases to zero. Note that this may be
* necessary occasionally (depending on the application) to avoid
* loss of floating-point precision in the accumulated unwrapped
* phase values as they grow.
*/
void reset();
protected:
void FFTShift(double *src);
void getMagnitudes(double *mag);
void getPhases(double *theta);
void unwrapPhases(double *theta, double *unwrapped);
int m_n;
int m_hop;
FFTReal *m_fft;
double *m_time;
double *m_imag;
double *m_real;
double *m_phase;
double *m_unwrapped;
};
#endif