GNU Radio 3.6.3.1 C++ API
gr_sync_decimator.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2004 Free Software Foundation, Inc.
4  *
5  * This file is part of GNU Radio
6  *
7  * GNU Radio is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 3, or (at your option)
10  * any later version.
11  *
12  * GNU Radio is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with GNU Radio; see the file COPYING. If not, write to
19  * the Free Software Foundation, Inc., 51 Franklin Street,
20  * Boston, MA 02110-1301, USA.
21  */
22 
23 #ifndef INCLUDED_GR_SYNC_DECIMATOR_H
24 #define INCLUDED_GR_SYNC_DECIMATOR_H
25 
26 #include <gr_core_api.h>
27 #include <gr_sync_block.h>
28 
29 /*!
30  * \brief synchronous N:1 input to output with history
31  * \ingroup base_blk
32  *
33  * Override work to provide the signal processing implementation.
34  */
36 {
37  private:
38  unsigned d_decimation;
39 
40  protected:
41  gr_sync_decimator (void){} //allows pure virtual interface sub-classes
42  gr_sync_decimator (const std::string &name,
43  gr_io_signature_sptr input_signature,
44  gr_io_signature_sptr output_signature,
45  unsigned decimation);
46  public:
47 
48  unsigned decimation () const { return d_decimation; }
49  void set_decimation (unsigned decimation)
50  {
51  d_decimation = decimation;
52  set_relative_rate (1.0 / decimation);
53  }
54 
55  // gr_sync_decimator overrides these to assist work
56  void forecast (int noutput_items, gr_vector_int &ninput_items_required);
57  int general_work (int noutput_items,
58  gr_vector_int &ninput_items,
59  gr_vector_const_void_star &input_items,
60  gr_vector_void_star &output_items);
61 
62  // derived classes should override work
63 
64  int fixed_rate_ninput_to_noutput(int ninput);
65  int fixed_rate_noutput_to_ninput(int noutput);
66 };
67 
68 
69 #endif /* INCLUDED_GR_SYNC_DECIMATOR_H */