fft.h

Go to the documentation of this file.

/*
 * Copyright (C) 2008 Sampo Savolainen <v2@iki.fi>
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#pragma once
 
 
#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;
};
 
}