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

/*

 * Copyright 2004,2008 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.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <gr_sync_interpolator.h>

gr_sync_interpolator::gr_sync_interpolator (const std::string &name,

                                            gr_io_signature_sptr input_signature,

                                            gr_io_signature_sptr output_signature,

                                            unsigned interpolation)

  : gr_sync_block (name, input_signature, output_signature)

{

  set_interpolation (interpolation);

}

void

gr_sync_interpolator::forecast (int noutput_items, gr_vector_int &ninput_items_required)

{

  unsigned ninputs = ninput_items_required.size ();

  for (unsigned i = 0; i < ninputs; i++)

    ninput_items_required[i] = fixed_rate_noutput_to_ninput(noutput_items);

}

int

gr_sync_interpolator::fixed_rate_noutput_to_ninput(int noutput_items)

{

  return noutput_items / interpolation() + history() - 1;

}

int

gr_sync_interpolator::fixed_rate_ninput_to_noutput(int ninput_items)

{

  return std::max(0, ninput_items - (int)history() + 1) * interpolation();

}

int

gr_sync_interpolator::general_work (int noutput_items,

                                    gr_vector_int &ninput_items,

                                    gr_vector_const_void_star &input_items,

                                    gr_vector_void_star &output_items)

{

  int        r = work (noutput_items, input_items, output_items);

  if (r > 0)

    consume_each (r / interpolation ());

  return r;

}