qm-dsp  1.8
Filter.cpp
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1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
2 
3 /*
4  QM DSP Library
5 
6  Centre for Digital Music, Queen Mary, University of London.
7  This file 2005-2006 Christian Landone.
8 
9  This program is free software; you can redistribute it and/or
10  modify it under the terms of the GNU General Public License as
11  published by the Free Software Foundation; either version 2 of the
12  License, or (at your option) any later version. See the file
13  COPYING included with this distribution for more information.
14 */
15 
16 #include "Filter.h"
17 
19 // Construction/Destruction
21 
23 {
24  m_ord = 0;
25  m_outBuffer = NULL;
26  m_inBuffer = NULL;
27 
28  initialise( Config );
29 }
30 
32 {
33  deInitialise();
34 }
35 
37 {
38  m_ord = Config.ord;
39  m_ACoeffs = Config.ACoeffs;
40  m_BCoeffs = Config.BCoeffs;
41 
42  m_inBuffer = new double[ m_ord + 1 ];
43  m_outBuffer = new double[ m_ord + 1 ];
44 
45  reset();
46 }
47 
49 {
50  delete[] m_inBuffer;
51  delete[] m_outBuffer;
52 }
53 
55 {
56  for( unsigned int i = 0; i < m_ord+1; i++ ){ m_inBuffer[ i ] = 0.0; }
57  for(unsigned int i = 0; i < m_ord+1; i++ ){ m_outBuffer[ i ] = 0.0; }
58 }
59 
60 void Filter::process( double *src, double *dst, unsigned int length )
61 {
62  unsigned int SP,i,j;
63 
64  double xin,xout;
65 
66  for (SP=0;SP<length;SP++)
67  {
68  xin=src[SP];
69  /* move buffer */
70  for ( i = 0; i < m_ord; i++) {m_inBuffer[ m_ord - i ]=m_inBuffer[ m_ord - i - 1 ];}
71  m_inBuffer[0]=xin;
72 
73  xout=0.0;
74  for (j=0;j< m_ord + 1; j++)
75  xout = xout + m_BCoeffs[ j ] * m_inBuffer[ j ];
76  for (j = 0; j < m_ord; j++)
77  xout= xout - m_ACoeffs[ j + 1 ] * m_outBuffer[ j ];
78 
79  dst[ SP ] = xout;
80  for ( i = 0; i < m_ord - 1; i++ ) { m_outBuffer[ m_ord - i - 1 ] = m_outBuffer[ m_ord - i - 2 ];}
81  m_outBuffer[0]=xout;
82 
83  } /* end of SP loop */
84 }
85 
86 
87 
double * BCoeffs
Definition: Filter.h:32
Filter specification.
Definition: Filter.h:29
virtual ~Filter()
Definition: Filter.cpp:31
double * m_outBuffer
Definition: Filter.h:55
double * m_ACoeffs
Definition: Filter.h:57
unsigned int m_ord
Definition: Filter.h:52
void process(double *src, double *dst, unsigned int length)
Definition: Filter.cpp:60
double * m_inBuffer
Definition: Filter.h:54
double * ACoeffs
Definition: Filter.h:31
#define NULL
Definition: Filter.h:20
void reset()
Definition: Filter.cpp:54
double * m_BCoeffs
Definition: Filter.h:58
void deInitialise()
Definition: Filter.cpp:48
Filter(FilterConfig Config)
Definition: Filter.cpp:22
void initialise(FilterConfig Config)
Definition: Filter.cpp:36
unsigned int ord
Definition: Filter.h:30