c@225: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
c@225: 
c@225: /*
c@225:     QM DSP Library
c@225: 
c@225:     Centre for Digital Music, Queen Mary, University of London.
c@340:     This file 2005-2006 Christian Landone, copyright 2013 QMUL.
c@309: 
c@309:     This program is free software; you can redistribute it and/or
c@309:     modify it under the terms of the GNU General Public License as
c@309:     published by the Free Software Foundation; either version 2 of the
c@309:     License, or (at your option) any later version.  See the file
c@309:     COPYING included with this distribution for more information.
c@225: */
c@225: 
cannam@489: #ifndef QM_DSP_PHASEVOCODER_H
cannam@489: #define QM_DSP_PHASEVOCODER_H
c@225: 
c@289: class FFTReal;
c@225: 
c@225: class PhaseVocoder  
c@225: {
c@225: public:
c@340:     PhaseVocoder(int size, int hop);
c@225:     virtual ~PhaseVocoder();
c@225: 
c@340:     /**
c@340:      * Given one frame of time-domain samples, FFT and return the
c@340:      * magnitudes, instantaneous phases, and unwrapped phases.
c@340:      *
c@340:      * src must have size values (where size is the frame size value
c@340:      * as passed to the PhaseVocoder constructor), and should have
c@340:      * been windowed as necessary by the caller (but not fft-shifted).
c@340:      *
c@340:      * mag, phase, and unwrapped must each be non-NULL and point to
c@340:      * enough space for size/2 + 1 values. The redundant conjugate
c@340:      * half of the output is not returned.
c@340:      */
c@344:     void processTimeDomain(const double *src,
c@344:                            double *mag, double *phase, double *unwrapped);
c@344: 
c@344:     /**
c@344:      * Given one frame of frequency-domain samples, return the
c@344:      * magnitudes, instantaneous phases, and unwrapped phases.
c@344:      *
c@344:      * reals and imags must each contain size/2+1 values (where size
c@344:      * is the frame size value as passed to the PhaseVocoder
c@344:      * constructor).
c@344:      *
c@344:      * mag, phase, and unwrapped must each be non-NULL and point to
c@344:      * enough space for size/2+1 values.
c@344:      */
c@344:     void processFrequencyDomain(const double *reals, const double *imags,
c@344:                                 double *mag, double *phase, double *unwrapped);
c@340: 
c@340:     /**
c@340:      * Reset the stored phases to zero. Note that this may be
c@340:      * necessary occasionally (depending on the application) to avoid
c@340:      * loss of floating-point precision in the accumulated unwrapped
c@340:      * phase values as they grow.
c@340:      */
c@340:     void reset();
c@225: 
c@225: protected:
c@340:     void FFTShift(double *src);
c@340:     void getMagnitudes(double *mag);
c@340:     void getPhases(double *theta);
c@340:     void unwrapPhases(double *theta, double *unwrapped);
c@225: 
c@340:     int m_n;
c@340:     int m_hop;
c@289:     FFTReal *m_fft;
c@344:     double *m_time;
c@340:     double *m_imag;
c@340:     double *m_real;
c@340:     double *m_phase;
c@340:     double *m_unwrapped;
c@225: };
c@225: 
c@225: #endif