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/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* Copyright 2009-2011 Jörg Hermann Müller
*
* This file is part of AudaSpace.
*
* Audaspace is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* AudaSpace is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Audaspace; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* ***** END GPL LICENSE BLOCK *****
*/
/** \file audaspace/FX/AUD_IIRFilterReader.cpp
* \ingroup audfx
*/
#include "AUD_IIRFilterReader.h"
AUD_IIRFilterReader::AUD_IIRFilterReader(boost::shared_ptr<AUD_IReader> reader,
const std::vector<float>& b,
const std::vector<float>& a) :
AUD_BaseIIRFilterReader(reader, b.size(), a.size()), m_a(a), m_b(b)
{
if(m_a.empty() == false)
{
for(int i = 1; i < m_a.size(); i++)
m_a[i] /= m_a[0];
for(int i = 0; i < m_b.size(); i++)
m_b[i] /= m_a[0];
m_a[0] = 1;
}
}
sample_t AUD_IIRFilterReader::filter()
{
sample_t out = 0;
for(int i = 1; i < m_a.size(); i++)
out -= y(-i) * m_a[i];
for(int i = 0; i < m_b.size(); i++)
out += x(-i) * m_b[i];
return out;
}
void AUD_IIRFilterReader::setCoefficients(const std::vector<float>& b,
const std::vector<float>& a)
{
setLengths(b.size(), a.size());
m_a = a;
m_b = b;
}
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