gtk2_ardour/fft_result.cc

   1 /*
   2     Copyright (C) 2006 Paul Davis
   3         Written by 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 #include <fft_result.h>
  22 #include <fft_graph.h>
  23 #include <cstdlib>
  24 #include <cstring>
  25 #include <string>
  26 #include <cmath>
  27
  28 #include <iostream>
  29
  30 using namespace std;
  31
  32 FFTResult::FFTResult(FFTGraph *graph, Gdk::Color color, string trackname)
  33 {
  34         _graph = graph;
  35
  36         _windowSize = _graph->windowSize();
  37         _dataSize   = _windowSize / 2;
  38
  39         _averages = 0;
  40
  41         _data_avg = (float *) malloc(sizeof(float) * _dataSize);
  42         memset(_data_avg,0,sizeof(float) * _dataSize);
  43
  44         _data_min = (float *) malloc(sizeof(float) * _dataSize);
  45         _data_max = (float *) malloc(sizeof(float) * _dataSize);
  46
  47         for (int i = 0; i < _dataSize; i++) {
  48                 _data_min[i] = FLT_MAX;
  49                 _data_max[i] = FLT_MIN;
  50         }
  51
  52         _color     = color;
  53         _trackname = trackname;
  54 }
  55
  56 void
  57 FFTResult::analyzeWindow(float *window)
  58 {
  59         float *_hanning = _graph->_hanning;
  60         float *_in = _graph->_in;
  61         float *_out = _graph->_out;
  62
  63         int i;
  64         // Copy the data and apply the hanning window
  65         for (i = 0; i < _windowSize; i++) {
  66                 _in[i] = window[ i ] * _hanning[ i ];
  67         }
  68
  69         fftwf_execute(_graph->_plan);
  70
  71         float b = _out[0] * _out[0];
  72
  73         _data_avg[0] += b;
  74         if (b < _data_min[0]) _data_min[0] = b;
  75         if (b > _data_max[0]) _data_max[0] = b;
  76
  77         for (i=1; i < _dataSize - 1; i++) { // TODO: check with Jesse whether this is really correct
  78                 b = (_out[i] * _out[i]);
  79
  80                 _data_avg[i] += b;  // + (_out[_windowSize-i] * _out[_windowSize-i]);, TODO: thanks to Stefan Kost
  81
  82                 if (_data_min[i] > b)  _data_min[i] = b;
  83                 if (_data_max[i] < b ) _data_max[i] = b;
  84         }
  85
  86
  87         _averages++;
  88 }
  89
  90 void
  91 FFTResult::finalize()
  92 {
  93         if (_averages == 0) {
  94                 _minimum = 0.0;
  95                 _maximum = 0.0;
  96                 return;
  97         }
  98
  99         // Average & scale
 100         for (int i = 0; i < _dataSize; i++) {
 101                 _data_avg[i] /= _averages;
 102                 _data_avg[i]  = 10.0f * log10f(_data_avg[i]);
 103
 104                 _data_min[i]  = 10.0f * log10f(_data_min[i]);
 105                 if (_data_min[i] < -10000.0f) {
 106                         _data_min[i] = -10000.0f;
 107                 }
 108                 _data_max[i]  = 10.0f * log10f(_data_max[i]);
 109         }
 110
 111         // find min & max
 112         _minimum = _maximum = _data_avg[0];
 113
 114         for (int i = 1; i < _dataSize; i++) {
 115                 if (_data_avg[i] < _minimum        && !isinf(_data_avg[i])) {
 116                         _minimum = _data_avg[i];
 117                 } else if (_data_avg[i] > _maximum && !isinf(_data_avg[i])) {
 118                         _maximum = _data_avg[i];
 119                 }
 120         }
 121
 122         _averages = 0;
 123 }
 124
 125 FFTResult::~FFTResult()
 126 {
 127         free(_data_avg);
 128         free(_data_min);
 129         free(_data_max);
 130 }
 131
 132
 133 float
 134 FFTResult::avgAt(int x)
 135 {
 136         if (x < 0 || x>= _dataSize)
 137                 return 0.0f;
 138
 139         return _data_avg[x];
 140 }
 141
 142 float
 143 FFTResult::minAt(int x)
 144 {
 145         if (x < 0 || x>= _dataSize)
 146                 return 0.0f;
 147
 148         return _data_min[x];
 149 }
 150
 151 float
 152 FFTResult::maxAt(int x)
 153 {
 154         if (x < 0 || x>= _dataSize)
 155                 return 0.0f;
 156
 157         return _data_max[x];
 158 }
 159