filterbank.h

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/* -*- c++ -*- */
/*
 * Copyright 2012, 2014 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio 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 3, or (at your option)
 * any later version.
 *
 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */


#ifndef INCLUDED_FILTER_FILTERBANK_H
#define INCLUDED_FILTER_FILTERBANK_H

#include <gnuradio/filter/api.h>
#include <gnuradio/filter/fir_filter.h>

namespace gr {
  namespace filter {
    namespace kernel {

      /*!
       * \brief A filter bank with generic taps.
       *
       * This block takes in a vector of N complex inputs, passes
       * them through N FIR filters, and outputs a vector of N complex
       * outputs.
       *
       * The only advantage of using this block over N individual
       * FIR filter blocks is that it places less of a load on the
       * scheduler.
       *
       * The number of filters cannot be changed dynamically, however
       * filters can be deactivated (i.e. no processing is done for
       * them) by passing a vector of filter taps containing all zeros
       * to them.  In this case their entry in the output vector is a
       * zero.
       *
       */

      class FILTER_API filterbank
      {
      protected:
        unsigned int d_nfilts;
        unsigned int d_ntaps;
        std::vector<kernel::fir_filter_ccf*> d_fir_filters;
        std::vector< std::vector<float> > d_taps;
        std::vector<bool> d_active;
        unsigned int d_taps_per_filter;

      public:
        /*!
         * Build the filterbank.
         *
         * \param taps (vector of vector of floats / list of list of floats)
         *             Populates the filters.
         */
        filterbank(const std::vector<std::vector<float> > &taps);

        ~filterbank();

        /*!
         * Update the filterbank's filter taps.
         *
         * \param taps (vector of vector of floats / list of list of floats)
         *             The prototype filter to populate the filterbank.
         */
        virtual void set_taps(const std::vector<std::vector<float> > &taps);

        /*!
         * Print all of the filterbank taps to screen.
         */
        void print_taps();

        /*!
         * Return a vector<vector<>> of the filterbank taps
         */
        std::vector<std::vector<float> > taps() const;
      };

    } /* namespace kernel */
  } /* namespace filter */
} /* namespace gr */

#endif /* INCLUDED_FILTER_FILTERBANK_H */