qm-dsp
1.8
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00001 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ 00002 00003 /* 00004 QM DSP Library 00005 00006 Centre for Digital Music, Queen Mary, University of London. 00007 This file 2005-2006 Christian Landone. 00008 00009 This program is free software; you can redistribute it and/or 00010 modify it under the terms of the GNU General Public License as 00011 published by the Free Software Foundation; either version 2 of the 00012 License, or (at your option) any later version. See the file 00013 COPYING included with this distribution for more information. 00014 */ 00015 00016 #include "Filter.h" 00017 00019 // Construction/Destruction 00021 00022 Filter::Filter( FilterConfig Config ) 00023 { 00024 m_ord = 0; 00025 m_outBuffer = NULL; 00026 m_inBuffer = NULL; 00027 00028 initialise( Config ); 00029 } 00030 00031 Filter::~Filter() 00032 { 00033 deInitialise(); 00034 } 00035 00036 void Filter::initialise( FilterConfig Config ) 00037 { 00038 m_ord = Config.ord; 00039 m_ACoeffs = Config.ACoeffs; 00040 m_BCoeffs = Config.BCoeffs; 00041 00042 m_inBuffer = new double[ m_ord + 1 ]; 00043 m_outBuffer = new double[ m_ord + 1 ]; 00044 00045 reset(); 00046 } 00047 00048 void Filter::deInitialise() 00049 { 00050 delete[] m_inBuffer; 00051 delete[] m_outBuffer; 00052 } 00053 00054 void Filter::reset() 00055 { 00056 for( unsigned int i = 0; i < m_ord+1; i++ ){ m_inBuffer[ i ] = 0.0; } 00057 for(unsigned int i = 0; i < m_ord+1; i++ ){ m_outBuffer[ i ] = 0.0; } 00058 } 00059 00060 void Filter::process( double *src, double *dst, unsigned int length ) 00061 { 00062 unsigned int SP,i,j; 00063 00064 double xin,xout; 00065 00066 for (SP=0;SP<length;SP++) 00067 { 00068 xin=src[SP]; 00069 /* move buffer */ 00070 for ( i = 0; i < m_ord; i++) {m_inBuffer[ m_ord - i ]=m_inBuffer[ m_ord - i - 1 ];} 00071 m_inBuffer[0]=xin; 00072 00073 xout=0.0; 00074 for (j=0;j< m_ord + 1; j++) 00075 xout = xout + m_BCoeffs[ j ] * m_inBuffer[ j ]; 00076 for (j = 0; j < m_ord; j++) 00077 xout= xout - m_ACoeffs[ j + 1 ] * m_outBuffer[ j ]; 00078 00079 dst[ SP ] = xout; 00080 for ( i = 0; i < m_ord - 1; i++ ) { m_outBuffer[ m_ord - i - 1 ] = m_outBuffer[ m_ord - i - 2 ];} 00081 m_outBuffer[0]=xout; 00082 00083 } /* end of SP loop */ 00084 } 00085 00086 00087