overhaul region/range spectrum analysis

1 files changed, 83 insertions, 97 deletions

diff --git a/gtk2_ardour/fft_result.cc b/gtk2_ardour/fft_result.cc
index a83b65e854..b4a82c2586 100644
--- a/gtk2_ardour/fft_result.cc
+++ b/gtk2_ardour/fft_result.cc
@@ -1,22 +1,21 @@
 /*
-    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.
-
-*/
+ * Copyright (C) 2006, 2016 Paul Davis
+ * Written by Sampo Savolainen & Robin Gareus
+ *
+ * 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"
@@ -24,8 +23,7 @@
 #include <cstring>
 #include <string>
 #include <cmath>
-
-#include <iostream>
+#include <algorithm>
 
 using namespace std;
 
@@ -35,18 +33,24 @@ FFTResult::FFTResult(FFTGraph *graph, Gdk::Color color, string trackname)
 
 	_windowSize = _graph->windowSize();
 	_dataSize   = _windowSize / 2;
-
 	_averages = 0;
-
-	_data_avg = (float *) malloc(sizeof(float) * _dataSize);
-	memset(_data_avg,0,sizeof(float) * _dataSize);
-
-	_data_min = (float *) malloc(sizeof(float) * _dataSize);
-	_data_max = (float *) malloc(sizeof(float) * _dataSize);
-
-	for (int i = 0; i < _dataSize; i++) {
-		_data_min[i] = FLT_MAX;
-		_data_max[i] = FLT_MIN;
+	_min_flat = _max_flat = 0.0;
+	_min_prop = _max_prop = 0.0;
+
+	_data_flat_avg = (float *) malloc (sizeof(float) * _dataSize);
+	_data_flat_min = (float *) malloc (sizeof(float) * _dataSize);
+	_data_flat_max = (float *) malloc (sizeof(float) * _dataSize);
+	_data_prop_avg = (float *) malloc (sizeof(float) * _dataSize);
+	_data_prop_min = (float *) malloc (sizeof(float) * _dataSize);
+	_data_prop_max = (float *) malloc (sizeof(float) * _dataSize);
+
+	for (unsigned int i = 0; i < _dataSize; i++) {
+		_data_flat_min[i] = FLT_MAX;
+		_data_flat_max[i] = FLT_MIN;
+		_data_flat_avg[i] = 0;
+		_data_prop_min[i] = FLT_MAX;
+		_data_prop_max[i] = FLT_MIN;
+		_data_prop_avg[i] = 0;
 	}
 
 	_color     = color;
@@ -56,34 +60,31 @@ FFTResult::FFTResult(FFTGraph *graph, Gdk::Color color, string trackname)
 void
 FFTResult::analyzeWindow(float *window)
 {
-	float *_hanning = _graph->_hanning;
+	float const * const _hanning = _graph->_hanning;
 	float *_in = _graph->_in;
 	float *_out = _graph->_out;
 
-	int i;
 	// Copy the data and apply the hanning window
-	for (i = 0; i < _windowSize; i++) {
-		_in[i] = window[ i ] * _hanning[ i ];
+	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_avg[0] += b;
-	if (b < _data_min[0]) _data_min[0] = b;
-	if (b > _data_max[0]) _data_max[0] = b;
-
-	for (i=1; i < _dataSize - 1; i++) { // TODO: check with Jesse whether this is really correct
-		b = (_out[i] * _out[i]);
-
-		_data_avg[i] += b;  // + (_out[_windowSize-i] * _out[_windowSize-i]);, TODO: thanks to Stefan Kost
+	_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;
 
-		if (_data_min[i] > b)  _data_min[i] = b;
-		if (_data_max[i] < b ) _data_max[i] = 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++;
 }
 
@@ -91,32 +92,43 @@ void
 FFTResult::finalize()
 {
 	if (_averages == 0) {
-		_minimum = 0.0;
-		_maximum = 0.0;
+		_min_flat = _max_flat = 0.0;
+		_min_prop = _max_prop = 0.0;
 		return;
 	}
 
 	// Average & scale
-	for (int i = 0; i < _dataSize; i++) {
-		_data_avg[i] /= _averages;
-		_data_avg[i]  = 10.0f * log10f(_data_avg[i]);
-
-		_data_min[i]  = 10.0f * log10f(_data_min[i]);
-		if (_data_min[i] < -10000.0f) {
-			_data_min[i] = -10000.0f;
-		}
-		_data_max[i]  = 10.0f * log10f(_data_max[i]);
+	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
-	_minimum = _maximum = _data_avg[0];
-
-	for (int i = 1; i < _dataSize; i++) {
-		if (_data_avg[i] < _minimum        && !isinf(_data_avg[i])) {
-			_minimum = _data_avg[i];
-		} else if (_data_avg[i] > _maximum && !isinf(_data_avg[i])) {
-			_maximum = _data_avg[i];
-		}
+	_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;
@@ -124,36 +136,10 @@ FFTResult::finalize()
 
 FFTResult::~FFTResult()
 {
-	free(_data_avg);
-	free(_data_min);
-	free(_data_max);
+	free(_data_flat_avg);
+	free(_data_flat_min);
+	free(_data_flat_max);
+	free(_data_prop_avg);
+	free(_data_prop_min);
+	free(_data_prop_max);
 }
-
-
-float
-FFTResult::avgAt(int x)
-{
-	if (x < 0 || x>= _dataSize)
-		return 0.0f;
-
-	return _data_avg[x];
-}
-
-float
-FFTResult::minAt(int x)
-{
-	if (x < 0 || x>= _dataSize)
-		return 0.0f;
-
-	return _data_min[x];
-}
-
-float
-FFTResult::maxAt(int x)
-{
-	if (x < 0 || x>= _dataSize)
-		return 0.0f;
-
-	return _data_max[x];
-}
-