gr_null_source.cc

gnuradio软件无线电源程序.现在的手机多基于软件无线电

/* -*- 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 2, 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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gr_null_source.h>
#include <gr_io_signature.h>

gr_null_source::gr_null_source (size_t sizeof_stream_item)
  : gr_sync_block ("null_source",
		   gr_make_io_signature (0, 0, 0),
		   gr_make_io_signature (1, 1, sizeof_stream_item))
{
}

gr_block_sptr
gr_make_null_source (size_t sizeof_stream_item)
{
  return gr_block_sptr (new gr_null_source (sizeof_stream_item));
}

int
gr_null_source::work (int noutput_items,
		      gr_vector_const_void_star &input_items,
		      gr_vector_void_star &output_items)
{
  void *optr = (void *) output_items[0];
  memset (optr, 0, noutput_items * output_signature()->sizeof_stream_item (0));
  return noutput_items;
}