fft.h

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/*
    Copyright (C) 2008 Paul Davis
    Author: Sampo Savolainen

    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.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#ifndef __ardour_fft_h__
#define __ardour_fft_h__


#include <iostream>

#include <stdio.h>
#include <sys/types.h>
#include <complex> // this needs to be included before fftw3.h
#include <fftw3.h>


#include "ardour/types.h"

namespace GTKArdour {

class FFT
{
        public:
                FFT(uint32_t);
                ~FFT();

                enum WindowingType {
                        NONE,
                        HANN
                };

                void reset();
                void analyze(ARDOUR::Sample *, WindowingType w = NONE);
                void calculate();

                uint32_t bins() const { return _data_size; }

                float power_at_bin(uint32_t i) const { return _power_at_bin[i]; }
                float phase_at_bin(uint32_t i) const { return _phase_at_bin[i]; }


        private:

                float *get_hann_window();

                uint32_t const _window_size;
                uint32_t const _data_size;
                uint32_t _iterations;

                float *_hann_window;

                float *_fftInput;
                float *_fftOutput;

                float *_power_at_bin;
                float *_phase_at_bin;

                fftwf_plan _plan;
};

}

#endif