cannam@0: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
cannam@0: 
cannam@0: /*
cannam@0:     QM DSP Library
cannam@0: 
cannam@0:     Centre for Digital Music, Queen Mary, University of London.
Chris@84: 
Chris@84:     This program is free software; you can redistribute it and/or
Chris@84:     modify it under the terms of the GNU General Public License as
Chris@84:     published by the Free Software Foundation; either version 2 of the
Chris@84:     License, or (at your option) any later version.  See the file
Chris@84:     COPYING included with this distribution for more information.
cannam@0: */
cannam@0: 
cannam@0: #ifndef FILTER_H
cannam@0: #define FILTER_H
cannam@0: 
Chris@193: #include <vector>
cannam@0: 
Chris@193: class Filter
cannam@0: {
cannam@0: public:
Chris@193:     struct Parameters {
Chris@193:         std::vector<double> a;
Chris@193:         std::vector<double> b;
Chris@193:     };
Chris@193: 
Chris@193:     /**
Chris@193:      * Construct an IIR filter with numerators b and denominators
Chris@193:      * a. The filter will have order b.size()-1. To make an FIR
Chris@193:      * filter, leave the vector a in the param struct empty.
Chris@193:      * Otherwise, a and b must have the same number of values.
Chris@193:      */
Chris@193:     Filter(Parameters params);
Chris@193:     
Chris@193:     ~Filter();
cannam@0: 
cannam@0:     void reset();
cannam@0: 
Chris@193:     /**
Chris@193:      * Filter the input sequence \arg in of length \arg n samples, and
Chris@193:      * write the resulting \arg n samples into \arg out. There must be
Chris@193:      * enough room in \arg out for \arg n samples to be written.
Chris@193:      */
Chris@193:     void process(const double *const __restrict__ in,
Chris@193:                  double *const __restrict__ out,
Chris@193:                  const int n);
cannam@0: 
Chris@193:     int getOrder() const { return m_order; }
Chris@193:     
cannam@0: private:
Chris@193:     int m_order;
Chris@193:     int m_sz;
Chris@193:     std::vector<double> m_a;
Chris@193:     std::vector<double> m_b;
Chris@193:     std::vector<double> m_bufa;
Chris@193:     std::vector<double> m_bufb;
Chris@193:     int m_offa;
Chris@193:     int m_offb;
Chris@193:     int m_offmax;
Chris@193:     bool m_fir;
cannam@0: 
Chris@193:     Filter(const Filter &); // not supplied
Chris@193:     Filter &operator=(const Filter &); // not supplied
cannam@0: };
Chris@193:     
cannam@0: #endif