1 files changed, 79 insertions, 0 deletions
diff --git a/libs/qm-dsp/dsp/phasevocoder/PhaseVocoder.cpp b/libs/qm-dsp/dsp/phasevocoder/PhaseVocoder.cpp
new file mode 100644
index 0000000000..71865267a4
--- /dev/null
+++ b/libs/qm-dsp/dsp/phasevocoder/PhaseVocoder.cpp
@@ -0,0 +1,79 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    QM DSP Library
+
+    Centre for Digital Music, Queen Mary, University of London.
+    This file 2005-2006 Christian Landone.
+
+    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.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#include "PhaseVocoder.h"
+#include "dsp/transforms/FFT.h"
+#include <math.h>
+
+//////////////////////////////////////////////////////////////////////
+// Construction/Destruction
+//////////////////////////////////////////////////////////////////////
+
+PhaseVocoder::PhaseVocoder(unsigned int n) :
+    m_n(n)
+{
+    m_fft = new FFTReal(m_n);
+    m_realOut = new double[m_n];
+    m_imagOut = new double[m_n];
+}
+
+PhaseVocoder::~PhaseVocoder()
+{
+    delete [] m_realOut;
+    delete [] m_imagOut;
+    delete m_fft;
+}
+
+void PhaseVocoder::FFTShift(unsigned int size, double *src)
+{
+    const int hs = size/2;
+    for (int i = 0; i < hs; ++i) {
+        double tmp = src[i];
+        src[i] = src[i + hs];
+        src[i + hs] = tmp;
+    }
+}
+
+void PhaseVocoder::process(double *src, double *mag, double *theta)
+{
+    FFTShift( m_n, src);
+	
+    m_fft->process(0, src, m_realOut, m_imagOut);
+
+    getMagnitude( m_n/2, mag, m_realOut, m_imagOut);
+    getPhase( m_n/2, theta, m_realOut, m_imagOut);
+}
+
+void PhaseVocoder::getMagnitude(unsigned int size, double *mag, double *real, double *imag)
+{	
+    unsigned int j;
+
+    for( j = 0; j < size; j++)
+    {
+	mag[ j ] = sqrt( real[ j ] * real[ j ] + imag[ j ] * imag[ j ]);
+    }
+}
+
+void PhaseVocoder::getPhase(unsigned int size, double *theta, double *real, double *imag)
+{
+    unsigned int k;
+
+    // Phase Angle "matlab" style 
+    //Watch out for quadrant mapping  !!!
+    for( k = 0; k < size; k++)
+    {
+	theta[ k ] = atan2( -imag[ k ], real[ k ]);
+    }	
+}