ardour/gtk2_ardour/fft_result.cc
2022-11-26 12:29:23 +01:00

125 lines
3.6 KiB
C++

/*
* Copyright (C) 2008-2009 David Robillard <d@drobilla.net>
*
* 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.
*/
#include "fft_result.h"
#include "fft_graph.h"
#include <cstdlib>
#include <cstring>
#include <string>
#include <cmath>
#include <algorithm>
using namespace std;
FFTResult::FFTResult(FFTGraph *graph, Gdk::Color color, string trackname) :
_graph(graph),
_windowSize(_graph->windowSize()),
_dataSize(_windowSize / 2),
_averages(0),
_min_flat(0.0),
_max_flat(0.0),
_min_prop(0.0),
_max_prop(0.0),
_data_flat_avg(_dataSize, 0),
_data_flat_max(_dataSize, FLT_MIN),
_data_flat_min(_dataSize, FLT_MAX),
_data_prop_avg(_dataSize, 0),
_data_prop_max(_dataSize, FLT_MIN),
_data_prop_min(_dataSize, FLT_MAX),
_color(color),
_trackname(trackname)
{}
void
FFTResult::analyzeWindow(float *window)
{
float const * const _hanning = _graph->_hanning;
float *_in = _graph->_in;
float *_out = _graph->_out;
// Copy the data and apply the hanning window
for (unsigned int i = 0; i < _windowSize; ++i) {
_in[i] = window[i] * _hanning[i];
}
fftwf_execute(_graph->_plan);
// calculate signal power per bin
float b = _out[0] * _out[0];
_data_flat_avg[0] += b;
if (b < _data_flat_min[0]) _data_flat_min[0] = b;
if (b > _data_flat_max[0]) _data_flat_max[0] = b;
for (unsigned int i = 1; i < _dataSize - 1; ++i) {
b = (_out[i] * _out[i]) + (_out[_windowSize - i] * _out[_windowSize - i]);
_data_flat_avg[i] += b;
if (_data_flat_min[i] > b) _data_flat_min[i] = b;
if (_data_flat_max[i] < b ) _data_flat_max[i] = b;
}
_averages++;
}
void
FFTResult::finalize()
{
if (_averages == 0) {
_min_flat = _max_flat = 0.0;
_min_prop = _max_prop = 0.0;
return;
}
// Average & scale
for (unsigned int i = 0; i < _dataSize - 1; ++i) {
_data_flat_avg[i] /= _averages;
// proportional, pink spectrum @ -18dB
_data_prop_avg[i] = _data_flat_avg [i] * i / 63.096f;
_data_prop_min[i] = _data_flat_min [i] * i / 63.096f;
_data_prop_max[i] = _data_flat_max [i] * i / 63.096f;
}
_data_prop_avg[0] = _data_flat_avg [0] / 63.096f;
_data_prop_min[0] = _data_flat_min [0] / 63.096f;
_data_prop_max[0] = _data_flat_max [0] / 63.096f;
// calculate power
for (unsigned int i = 0; i < _dataSize - 1; ++i) {
_data_flat_min[i] = power_to_db (_data_flat_min[i]);
_data_flat_max[i] = power_to_db (_data_flat_max[i]);
_data_flat_avg[i] = power_to_db (_data_flat_avg[i]);
_data_prop_min[i] = power_to_db (_data_prop_min[i]);
_data_prop_max[i] = power_to_db (_data_prop_max[i]);
_data_prop_avg[i] = power_to_db (_data_prop_avg[i]);
}
// find min & max
_min_flat = _max_flat = _data_flat_avg[0];
_min_prop = _max_prop = _data_prop_avg[0];
for (unsigned int i = 1; i < _dataSize - 1; ++i) {
_min_flat = std::min (_min_flat, _data_flat_avg[i]);
_max_flat = std::max (_max_flat, _data_flat_avg[i]);
_min_prop = std::min (_min_prop, _data_prop_avg[i]);
_max_prop = std::max (_max_prop, _data_prop_avg[i]);
}
_averages = 0;
}