diff options
Diffstat (limited to 'extern/audaspace/src/fx/IIRFilterReader.cpp')
| -rw-r--r-- | extern/audaspace/src/fx/IIRFilterReader.cpp | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/extern/audaspace/src/fx/IIRFilterReader.cpp b/extern/audaspace/src/fx/IIRFilterReader.cpp new file mode 100644 index 00000000000..8d879a85846 --- /dev/null +++ b/extern/audaspace/src/fx/IIRFilterReader.cpp @@ -0,0 +1,53 @@ +/******************************************************************************* + * 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 |