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extern/audaspace/src/fx/IIRFilterReader.cpp
- This file was added.
| /******************************************************************************* | |||||
| * Copyright 2009-2016 Jörg Müller | |||||
| * | |||||
| * Licensed under the Apache License, Version 2.0 (the "License"); | |||||
| * you may not use this file except in compliance with the License. | |||||
| * You may obtain a copy of the License at | |||||
| * | |||||
| * http://www.apache.org/licenses/LICENSE-2.0 | |||||
| * | |||||
| * Unless required by applicable law or agreed to in writing, software | |||||
| * distributed under the License is distributed on an "AS IS" BASIS, | |||||
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |||||
| * See the License for the specific language governing permissions and | |||||
| * limitations under the License. | |||||
| ******************************************************************************/ | |||||
| #include "fx/IIRFilterReader.h" | |||||
| AUD_NAMESPACE_BEGIN | |||||
| IIRFilterReader::IIRFilterReader(std::shared_ptr<IReader> reader, const std::vector<float>& b, const std::vector<float>& a) : | |||||
| 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 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 IIRFilterReader::setCoefficients(const std::vector<float>& b, const std::vector<float>& a) | |||||
| { | |||||
| setLengths(b.size(), a.size()); | |||||
| m_a = a; | |||||
| m_b = b; | |||||
| } | |||||
| AUD_NAMESPACE_END | |||||