/* -*- c++ -*- */

/*

 * Copyright 2004 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_GR_SYNC_DECIMATOR_H

#define INCLUDED_GR_SYNC_DECIMATOR_H

#include <gr_core_api.h>

#include <gr_sync_block.h>

/*!

 * \brief synchronous N:1 input to output with history

 * \ingroup base_blk

 *

 * Override work to provide the signal processing implementation.

 */

class GR_CORE_API gr_sync_decimator : public gr_sync_block

{

 private:

  unsigned        d_decimation;

 protected:

  gr_sync_decimator (const std::string &name,

                     gr_io_signature_sptr input_signature,

                     gr_io_signature_sptr output_signature,

                     unsigned decimation);

 public:

  unsigned decimation () const { return d_decimation; }

  void set_decimation (unsigned decimation)

  {

    d_decimation = decimation;

    set_relative_rate (1.0 / decimation);

  }

  // gr_sync_decimator overrides these to assist work

  void forecast (int noutput_items, gr_vector_int &ninput_items_required);

  int  general_work (int noutput_items,

                     gr_vector_int &ninput_items,

                     gr_vector_const_void_star &input_items,

                     gr_vector_void_star &output_items);

  // derived classes should override work

  int fixed_rate_ninput_to_noutput(int ninput);

  int fixed_rate_noutput_to_ninput(int noutput);

};

#endif /* INCLUDED_GR_SYNC_DECIMATOR_H */