diff options
Diffstat (limited to 'libs/qm-dsp/dsp/signalconditioning/Filter.cpp')
| -rw-r--r-- | libs/qm-dsp/dsp/signalconditioning/Filter.cpp | 148 |
1 files changed, 93 insertions, 55 deletions
diff --git a/libs/qm-dsp/dsp/signalconditioning/Filter.cpp b/libs/qm-dsp/dsp/signalconditioning/Filter.cpp index fcc12e590a..e9523e229d 100644 --- a/libs/qm-dsp/dsp/signalconditioning/Filter.cpp +++ b/libs/qm-dsp/dsp/signalconditioning/Filter.cpp @@ -4,7 +4,6 @@ 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 @@ -15,73 +14,112 @@ #include "Filter.h" -////////////////////////////////////////////////////////////////////// -// Construction/Destruction -////////////////////////////////////////////////////////////////////// +#include <stdexcept> -Filter::Filter( FilterConfig Config ) -{ - m_ord = 0; - m_outBuffer = NULL; - m_inBuffer = NULL; +using namespace std; - initialise( Config ); +Filter::Filter(Parameters params) +{ + if (params.a.empty()) { + m_fir = true; + if (params.b.empty()) { + throw logic_error("Filter must have at least one pair of coefficients"); + } + } else { + m_fir = false; + if (params.a.size() != params.b.size()) { + throw logic_error("Inconsistent numbers of filter coefficients"); + } + } + + m_sz = int(params.b.size()); + m_order = m_sz - 1; + + m_a = params.a; + m_b = params.b; + + // We keep some empty space at the start of the buffer, and + // encroach gradually into it as we add individual sample + // calculations at the start. Then when we run out of space, we + // move the buffer back to the end and begin again. This is + // significantly faster than moving the whole buffer along in + // 1-sample steps every time. + + m_offmax = 20; + m_offa = m_offmax; + m_offb = m_offmax; + + if (!m_fir) { + m_bufa.resize(m_order + m_offmax); + } + + m_bufb.resize(m_sz + m_offmax); } Filter::~Filter() { - deInitialise(); } -void Filter::initialise( FilterConfig Config ) +void +Filter::reset() { - m_ord = Config.ord; - m_ACoeffs = Config.ACoeffs; - m_BCoeffs = Config.BCoeffs; + m_offb = m_offmax; + m_offa = m_offmax; - m_inBuffer = new double[ m_ord + 1 ]; - m_outBuffer = new double[ m_ord + 1 ]; - - reset(); -} + if (!m_fir) { + m_bufa.assign(m_bufa.size(), 0.0); + } -void Filter::deInitialise() -{ - delete[] m_inBuffer; - delete[] m_outBuffer; + m_bufb.assign(m_bufb.size(), 0.0); } -void Filter::reset() +void +Filter::process(const double *const __restrict__ in, + double *const __restrict__ out, + const int n) { - 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; } + for (int s = 0; s < n; ++s) { + + if (m_offb > 0) --m_offb; + else { + for (int i = m_sz - 2; i >= 0; --i) { + m_bufb[i + m_offmax + 1] = m_bufb[i]; + } + m_offb = m_offmax; + } + m_bufb[m_offb] = in[s]; + + double b_sum = 0.0; + for (int i = 0; i < m_sz; ++i) { + b_sum += m_b[i] * m_bufb[i + m_offb]; + } + + double outval; + + if (m_fir) { + + outval = b_sum; + + } else { + + double a_sum = 0.0; + for (int i = 0; i < m_order; ++i) { + a_sum += m_a[i + 1] * m_bufa[i + m_offa]; + } + + outval = b_sum - a_sum; + + if (m_offa > 0) --m_offa; + else { + for (int i = m_order - 2; i >= 0; --i) { + m_bufa[i + m_offmax + 1] = m_bufa[i]; + } + m_offa = m_offmax; + } + m_bufa[m_offa] = outval; + } + + out[s] = outval; + } } -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 */ -} - - - |