GNU Radio 3.6.2 C++ API
gr_align_on_samplenumbers_ss.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2005 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
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10  * any later version.
11  *
12  * GNU Radio is distributed in the hope that it will be useful,
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14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
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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,
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21  */
22 
23 #ifndef INCLUDED_GR_ALIGN_ON_SAMPLE_NUMBERS_SS_H
24 #define INCLUDED_GR_ALIGN_ON_SAMPLE_NUMBERS_SS_H
25 
26 #include <gr_core_api.h>
27 #include <gr_block.h>
28 
29 /*!
30  * \brief align several complex short (interleaved short) input channels with corresponding unsigned 32 bit sample_counters (provided as interleaved 16 bit values)
31  * \ingroup misc
32  * \param number of complex_short input channels (including the 32 bit counting channel)
33  * \param align_interval is after how much samples (minimally) the sample-alignement is refreshed. Default is 128.
34  * A bigger value means less processing power but also requests more buffer space, which has a maximum.
35  * Decrease the align_interval if you get an error like:
36  * "sched: <gr_block align_on_samplenumbers_ss (0)> is requesting more input data than we can provide.
37  * ninput_items_required = 32768
38  * max_possible_items_available = 16383
39  * If this is a filter, consider reducing the number of taps."
40  * \ingroup block
41  * Pay attention on how you connect this block.
42  * It expects a minimum of 2 usrp_source_s with nchan number of channels and FPGA_MODE_COUNTING_32BIT enabled.
43  * This means that the first complex_short channel on every input is an interleaved 32 bit counter.
44  * The samples are aligned by dropping samples untill the samplenumbers match.
45  */
48 
50 
51 
52 
53 
55 {
56  int d_align_interval;
57  int d_sample_counter;
58  int d_nchan;
59  bool d_in_presync;
60  unsigned int d_ninputs;
61  class GR_CORE_API align_state {
62  public:
63  unsigned int ucounter_end;
64  unsigned int ucounter_begin;
65  int diff;
66  int diff_comp;
67  int diff_end;
68  int diff_comp_end;
69  bool sync_found;
70  bool sync_end_found;
71  int ninput_items;
72  int ninput_items_used;
73  };
74  std::vector<align_state> d_state;
75 
77  gr_align_on_samplenumbers_ss (int nchan,int align_interval);
78 
79  public:
81  bool check_topology (int ninputs, int noutputs);
82  void forecast (int noutput_items,
83  gr_vector_int &ninput_items_required);
84 
85  int general_work (int noutput_items,
86  gr_vector_int &ninput_items,
87  gr_vector_const_void_star &input_items,
88  gr_vector_void_star &output_items);
89 };
90 
91 
92 #endif /* INCLUDED_GR_ALIGN_ON_SAMPLE_NUMBERS_SS_H */