cannam@0: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
cannam@0: 
cannam@0: /*
cannam@0:     QM DSP Library
cannam@0: 
cannam@0:     Centre for Digital Music, Queen Mary, University of London.
Chris@115:     This file 2005-2006 Christian Landone, copyright 2013 QMUL.
Chris@84: 
Chris@84:     This program is free software; you can redistribute it and/or
Chris@84:     modify it under the terms of the GNU General Public License as
Chris@84:     published by the Free Software Foundation; either version 2 of the
Chris@84:     License, or (at your option) any later version.  See the file
Chris@84:     COPYING included with this distribution for more information.
cannam@0: */
cannam@0: 
cannam@0: #ifndef PHASEVOCODER_H
cannam@0: #define PHASEVOCODER_H
cannam@0: 
cannam@64: class FFTReal;
cannam@0: 
cannam@0: class PhaseVocoder  
cannam@0: {
cannam@0: public:
Chris@115:     PhaseVocoder(int size, int hop);
cannam@0:     virtual ~PhaseVocoder();
cannam@0: 
Chris@115:     /**
Chris@115:      * Given one frame of time-domain samples, FFT and return the
Chris@115:      * magnitudes, instantaneous phases, and unwrapped phases.
Chris@115:      *
Chris@115:      * src must have size values (where size is the frame size value
Chris@115:      * as passed to the PhaseVocoder constructor), and should have
Chris@115:      * been windowed as necessary by the caller (but not fft-shifted).
Chris@115:      *
Chris@115:      * mag, phase, and unwrapped must each be non-NULL and point to
Chris@115:      * enough space for size/2 + 1 values. The redundant conjugate
Chris@115:      * half of the output is not returned.
Chris@115:      */
Chris@115:     void process(double *src, double *mag, double *phase, double *unwrapped);
Chris@115: 
Chris@115:     /**
Chris@115:      * Reset the stored phases to zero. Note that this may be
Chris@115:      * necessary occasionally (depending on the application) to avoid
Chris@115:      * loss of floating-point precision in the accumulated unwrapped
Chris@115:      * phase values as they grow.
Chris@115:      */
Chris@115:     void reset();
cannam@0: 
cannam@0: protected:
Chris@115:     void FFTShift(double *src);
Chris@115:     void getMagnitudes(double *mag);
Chris@115:     void getPhases(double *theta);
Chris@115:     void unwrapPhases(double *theta, double *unwrapped);
cannam@0: 
Chris@115:     int m_n;
Chris@115:     int m_hop;
cannam@64:     FFTReal *m_fft;
Chris@115:     double *m_imag;
Chris@115:     double *m_real;
Chris@115:     double *m_phase;
Chris@115:     double *m_unwrapped;
cannam@0: };
cannam@0: 
cannam@0: #endif