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livetrax/gtk2_ardour/fft_result.cc

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/*
Copyright (C) 2006 Paul Davis
Written by 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.
*/
#include <fft_result.h>
#include <fft_graph.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <iostream>
using namespace std;
FFTResult::FFTResult(FFTGraph *graph, Gdk::Color color, string trackname)
{
_graph = graph;
_windowSize = _graph->windowSize();
_dataSize = _windowSize / 2;
_averages = 0;
_data = (float *) malloc(sizeof(float) * _dataSize);
memset(_data,0,sizeof(float) * _dataSize);
_color = color;
_trackname = trackname;
}
void
FFTResult::analyzeWindow(float *window)
{
_graph->analyze(window, _data);
_averages++;
}
void
FFTResult::finalize()
{
if (_averages == 0) {
_minimum = 0.0;
_maximum = 0.0;
return;
}
// Average & scale
for (int i = 0; i < _dataSize; i++) {
_data[i] /= _averages;
_data[i] = 10.0f * log10f(_data[i]);
}
// find min & max
_minimum = _maximum = _data[0];
for (int i = 1; i < _dataSize; i++) {
if (_data[i] < _minimum && !isinf(_data[i])) {
_minimum = _data[i];
} else if (_data[i] > _maximum && !isinf(_data[i])) {
_maximum = _data[i];
}
}
_averages = 0;
}
FFTResult::~FFTResult()
{
free(_data);
}
float
FFTResult::sampleAt(int x)
{
if (x < 0 || x>= _dataSize)
return 0.0f;
return _data[x];
}