diff dsp/signalconditioning/FiltFilt.cpp @ 225:49844bc8a895

* Queen Mary C++ DSP library

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dsp/signalconditioning/FiltFilt.cpp	Wed Apr 05 17:35:59 2006 +0000
@@ -0,0 +1,124 @@
+/* -*- 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 copyright 2005-2006 Christian Landone.
+    All rights reserved.
+*/
+
+#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;
+
+    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()
+{
+
+}