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-rw-r--r--libs/qm-dsp/dsp/signalconditioning/FiltFilt.cpp130
1 files changed, 130 insertions, 0 deletions
diff --git a/libs/qm-dsp/dsp/signalconditioning/FiltFilt.cpp b/libs/qm-dsp/dsp/signalconditioning/FiltFilt.cpp
new file mode 100644
index 0000000000..3163bfe0e3
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+++ b/libs/qm-dsp/dsp/signalconditioning/FiltFilt.cpp
@@ -0,0 +1,130 @@
+/* -*- 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 "FiltFilt.h"
+
+//////////////////////////////////////////////////////////////////////
+// Construction/Destruction
+//////////////////////////////////////////////////////////////////////
+
+FiltFilt::FiltFilt( FiltFiltConfig Config )
+{
+ m_filtScratchIn = NULL;
+ m_filtScratchOut = NULL;
+ m_ord = 0;
+
+ initialise( Config );
+}
+
+FiltFilt::~FiltFilt()
+{
+ deInitialise();
+}
+
+void FiltFilt::initialise( FiltFiltConfig Config )
+{
+ m_ord = Config.ord;
+ m_filterConfig.ord = Config.ord;
+ m_filterConfig.ACoeffs = Config.ACoeffs;
+ m_filterConfig.BCoeffs = Config.BCoeffs;
+
+ m_filter = new Filter( m_filterConfig );
+}
+
+void FiltFilt::deInitialise()
+{
+ delete m_filter;
+}
+
+
+void FiltFilt::process(double *src, double *dst, unsigned int length)
+{
+ unsigned int i;
+
+ if (length == 0) return;
+
+ unsigned int nFilt = m_ord + 1;
+ unsigned int nFact = 3 * ( nFilt - 1);
+ unsigned int nExt = length + 2 * nFact;
+
+ m_filtScratchIn = new double[ nExt ];
+ m_filtScratchOut = new double[ nExt ];
+
+
+ for( i = 0; i< nExt; i++ )
+ {
+ m_filtScratchIn[ i ] = 0.0;
+ m_filtScratchOut[ i ] = 0.0;
+ }
+
+ // Edge transients reflection
+ double sample0 = 2 * src[ 0 ];
+ double sampleN = 2 * src[ length - 1 ];
+
+ unsigned int index = 0;
+ for( i = nFact; i > 0; i-- )
+ {
+ m_filtScratchIn[ index++ ] = sample0 - src[ i ];
+ }
+ index = 0;
+ for( i = 0; i < nFact; i++ )
+ {
+ m_filtScratchIn[ (nExt - nFact) + index++ ] = sampleN - src[ (length - 2) - i ];
+ }
+
+ index = 0;
+ for( i = 0; i < length; i++ )
+ {
+ m_filtScratchIn[ i + nFact ] = src[ i ];
+ }
+
+ ////////////////////////////////
+ // Do 0Ph filtering
+ m_filter->process( m_filtScratchIn, m_filtScratchOut, nExt);
+
+ // reverse the series for FILTFILT
+ for ( i = 0; i < nExt; i++)
+ {
+ m_filtScratchIn[ i ] = m_filtScratchOut[ nExt - i - 1];
+ }
+
+ // do FILTER again
+ m_filter->process( m_filtScratchIn, m_filtScratchOut, nExt);
+
+ // reverse the series back
+ for ( i = 0; i < nExt; i++)
+ {
+ m_filtScratchIn[ i ] = m_filtScratchOut[ nExt - i - 1 ];
+ }
+ for ( i = 0;i < nExt; i++)
+ {
+ m_filtScratchOut[ i ] = m_filtScratchIn[ i ];
+ }
+
+ index = 0;
+ for( i = 0; i < length; i++ )
+ {
+ dst[ index++ ] = m_filtScratchOut[ i + nFact ];
+ }
+
+ delete [] m_filtScratchIn;
+ delete [] m_filtScratchOut;
+
+}
+
+void FiltFilt::reset()
+{
+
+}