First draft of the EQ visualization system. Now force fed to all plugin UIs.

git-svn-id: svn://localhost/ardour2/branches/3.0@3958 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 107 insertions, 0 deletions

diff --git a/gtk2_ardour/fft.cc b/gtk2_ardour/fft.cc
new file mode 100644
index 0000000000..92f52bb64e
--- /dev/null
+++ b/gtk2_ardour/fft.cc
@@ -0,0 +1,107 @@
+/*
+    Copyright (C) 2008 Paul Davis
+    Author: 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.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+FFT::FFT(uint32_t windowSize)
+	: _windowSize(windowSize),
+	  _dataSize(_windowSize/2),
+	_iterations(0)
+{
+	_fftInput  = (float *) fftwf_malloc(sizeof(float) * _windowSize);
+
+	_fftOutput = (float *) fftwf_malloc(sizeof(float) * _windowSize);
+
+	_powerAtBin  = (float *) malloc(sizeof(float) * _dataSize);
+	_phaseAtBin  = (float *) malloc(sizeof(float) * _dataSize);
+
+	_plan = fftwf_plan_r2r_1d(_windowSize, _fftInput, _fftOutput, FFTW_R2HC, FFTW_ESTIMATE);
+
+	reset();
+}
+
+void
+FFT::reset()
+{
+	memset(_powerAtBin, 0, sizeof(float) * _dataSize);
+	memset(_phaseAtBin, 0, sizeof(float) * _dataSize);
+	
+	_iterations = 0;
+}
+
+void
+FFT::analyze(ARDOUR::Sample *input)
+{
+	_iterations++;
+
+	memcpy(_fftInput, input, sizeof(float) * _windowSize);
+
+	fftwf_execute(_plan);
+
+	_powerAtBin[0] += _fftOutput[0] * _fftOutput[0];
+	_phaseAtBin[0] += 0.0;
+
+	float power;
+	float phase;
+
+#define Re (_fftOutput[i])
+#define Im (_fftOutput[_windowSize-i])
+       	for (uint32_t i=1; i < _dataSize - 1; i++) { 
+
+		power = (Re * Re) + (Im * Im);
+		phase = atanf(Im / Re);
+	
+		if (Re < 0.0 && Im > 0.0) {
+			phase += M_PI;
+		} else if (Re < 0.0 && Im < 0.0) {
+			phase -= M_PI;
+		}
+
+		_powerAtBin[i] += power;
+		_phaseAtBin[i] += phase;
+	}
+#undef Re
+#undef Im
+}
+
+void
+FFT::calculate()
+{
+	if (_iterations > 1) {
+	       	for (uint32_t i=0; i < _dataSize - 1; i++) { 
+			_powerAtBin[i] /= (float)_iterations;
+			_phaseAtBin[i] /= (float)_iterations;
+		}
+		_iterations = 1;
+	}
+}
+
+
+FFT::~FFT()
+{
+	fftwf_destroy_plan(_plan);
+	free(_powerAtBin);
+	free(_phaseAtBin);
+	free(_fftOutput);
+	free(_fftInput);
+}