GNU Radio Manual and C++ API Reference  3.7.9.2
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fs_checker_naive_impl.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2002 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,
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21  */
22 
23 #ifndef _ATSC_FS_CHECKER_NAIVE_H_
24 #define _ATSC_FS_CHECKER_NAIVE_H_
25 
26 #include <gnuradio/atsc/api.h>
28 
29 /*!
30  * \brief Naive concrete implementation of field sync checker
31  */
33 
34  private:
35  static const int SRSIZE = 1024; // must be power of two
36  int d_index; // points at oldest sample
37  float d_sample_sr[SRSIZE]; // sample shift register
38  atsc::syminfo d_tag_sr[SRSIZE]; // tag shift register
39  unsigned char d_bit_sr[SRSIZE]; // binary decision shift register
40  int d_field_num;
41  int d_segment_num;
42 
43  static const int OFFSET_511 = 0; // offset to PN 511 pattern
44  static const int LENGTH_511 = 511 + 4; // length of PN 511 pattern (+ 4 seg sync)
45  static const int OFFSET_2ND_63 = 578; // offset to second PN 63 pattern
46  static const int LENGTH_2ND_63 = 63; // length of PN 63 pattern
47 
48  static unsigned char s_511[LENGTH_511]; // PN 511 pattern
49  static unsigned char s_63[LENGTH_2ND_63]; // PN 63 pattern
50 
51  inline static int wrap (int index){ return index & (SRSIZE - 1); }
52  inline static int incr (int index){ return wrap (index + 1); }
53  inline static int decr (int index){ return wrap (index - 1); }
54 
55  public:
56 
57  // CREATORS
60 
61  // MANIPULATORS
62  virtual void reset ();
63  void filter (float input_sample, atsc::syminfo input_tag,
64  float *output_sample, atsc::syminfo *output_tag);
65 
66  // ACCESSORS
67 
68  //! return delay in samples from input to output
69  int delay () const;
70 
71 };
72 
73 
74 #endif /* _ATSC_FS_CHECKER_NAIVE_H_ */
#define ATSC_API
Definition: gr-atsc/include/gnuradio/atsc/api.h:30
virtual void filter(float input_sample, atsc::syminfo input_tag, float *output_sample, atsc::syminfo *output_tag)=0
virtual int delay() const =0
return delay in samples from input to output
Definition: syminfo_impl.h:30
virtual void reset()=0
abstract base class for ATSC field sync checker
Definition: fs_checker_impl.h:51
Naive concrete implementation of field sync checker.
Definition: fs_checker_naive_impl.h:32