gtk2_ardour/fft.h

   1 /*
   2     Copyright (C) 2008 Paul Davis
   3     Author: Sampo Savolainen
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18
  19 */
  20
  21 #ifndef __ardour_fft_h__
  22 #define __ardour_fft_h__
  23
  24
  25 #include <iostream>
  26
  27 #include <stdio.h>
  28 #include <sys/types.h>
  29 #include <complex> // this needs to be included before fftw3.h
  30 #include <fftw3.h>
  31
  32
  33 #include "ardour/types.h"
  34
  35 namespace GTKArdour {
  36
  37 class FFT
  38 {
  39         public:
  40                 FFT(uint32_t);
  41                 ~FFT();
  42
  43                 enum WindowingType {
  44                         NONE,
  45                         HANN
  46                 };
  47
  48                 void reset();
  49                 void analyze(ARDOUR::Sample *, WindowingType w = NONE);
  50                 void calculate();
  51
  52                 uint32_t bins() const { return _data_size; }
  53
  54                 float power_at_bin(uint32_t i) const { return _power_at_bin[i]; }
  55                 float phase_at_bin(uint32_t i) const { return _phase_at_bin[i]; }
  56
  57
  58         private:
  59
  60                 float *get_hann_window();
  61
  62                 uint32_t const _window_size;
  63                 uint32_t const _data_size;
  64                 uint32_t _iterations;
  65
  66                 float *_hann_window;
  67
  68                 float *_fftInput;
  69                 float *_fftOutput;
  70
  71                 float *_power_at_bin;
  72                 float *_phase_at_bin;
  73
  74                 fftwf_plan _plan;
  75 };
  76
  77 }
  78
  79 #endif