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

* Queen Mary C++ DSP library

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dsp/signalconditioning/Filter.cpp	Wed Apr 05 17:35:59 2006 +0000
@@ -0,0 +1,82 @@
+/* -*- 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 "Filter.h"
+
+//////////////////////////////////////////////////////////////////////
+// Construction/Destruction
+//////////////////////////////////////////////////////////////////////
+
+Filter::Filter( FilterConfig Config )
+{
+    m_ord = 0;
+    m_outBuffer = NULL;
+    m_inBuffer = NULL;
+
+    initialise( Config );
+}
+
+Filter::~Filter()
+{
+    deInitialise();
+}
+
+void Filter::initialise( FilterConfig Config )
+{
+    m_ord = Config.ord;
+    m_ACoeffs = Config.ACoeffs;
+    m_BCoeffs = Config.BCoeffs;
+
+    m_inBuffer = new double[ m_ord + 1 ];
+    m_outBuffer = new double[ m_ord + 1 ];
+
+    reset();
+}
+
+void Filter::deInitialise()
+{
+    delete[] m_inBuffer;
+    delete[] m_outBuffer;
+}
+
+void Filter::reset()
+{
+    for( unsigned int i = 0; i < m_ord+1; i++ ){ m_inBuffer[ i ] = 0.0; }
+    for(unsigned int  i = 0; i < m_ord+1; i++ ){ m_outBuffer[ i ] = 0.0; }
+}
+
+void Filter::process( double *src, double *dst, unsigned int length )
+{
+    unsigned int SP,i,j;
+
+    double xin,xout;
+
+    for (SP=0;SP<length;SP++)
+    {
+        xin=src[SP];
+        /* move buffer */
+        for ( i = 0; i < m_ord; i++) {m_inBuffer[ m_ord - i ]=m_inBuffer[ m_ord - i - 1 ];}
+        m_inBuffer[0]=xin;
+
+        xout=0.0;
+        for (j=0;j< m_ord + 1; j++)
+	    xout = xout + m_BCoeffs[ j ] * m_inBuffer[ j ];
+        for (j = 0; j < m_ord; j++)
+	    xout= xout - m_ACoeffs[ j + 1 ] * m_outBuffer[ j ];
+
+        dst[ SP ] = xout;
+        for ( i = 0; i < m_ord - 1; i++ ) { m_outBuffer[ m_ord - i - 1 ] = m_outBuffer[ m_ord - i - 2 ];}
+        m_outBuffer[0]=xout;
+
+    } /* end of SP loop */
+}
+
+
+