1 /* -*- c++ -*- */
2 /*
3  * Copyright 2014 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_DTV_ATSC_EQUALIZER_IMPL_H
24 #define INCLUDED_DTV_ATSC_EQUALIZER_IMPL_H
25 
26 #include "atsc_syminfo_impl.h"
27 #include <gnuradio/dtv/atsc_consts.h>
28 #include <gnuradio/dtv/atsc_equalizer.h>
29 
30 namespace gr {
31 namespace dtv {
32 
33 class atsc_equalizer_impl : public atsc_equalizer
34 {
35 private:
36     static const int NTAPS = 64;
37     static const int NPRETAPS = (int)(NTAPS * 0.8); // probably should be either .2 or .8
38 
39     // the length of the field sync pattern that we know unequivocally
40     static const int KNOWN_FIELD_SYNC_LENGTH = 4 + 511 + 3 * 63;
41 
42     float training_sequence1[KNOWN_FIELD_SYNC_LENGTH];
43     float training_sequence2[KNOWN_FIELD_SYNC_LENGTH];
44 
45     void filterN(const float* input_samples, float* output_samples, int nsamples);
46     void adaptN(const float* input_samples,
47                 const float* training_pattern,
48                 float* output_samples,
49                 int nsamples);
50 
51     std::vector<float> d_taps;
52 
53     float data_mem[ATSC_DATA_SEGMENT_LENGTH + NTAPS]; // Buffer for previous data packet
54     float data_mem2[ATSC_DATA_SEGMENT_LENGTH];
55     unsigned short d_flags;
56     short d_segno;
57 
58     int d_buff_not_filled;
59 
60 public:
61     atsc_equalizer_impl();
62     ~atsc_equalizer_impl();
63 
64     void setup_rpc();
65 
66     std::vector<float> taps() const;
67     std::vector<float> data() const;
68 
69     virtual int general_work(int noutput_items,
70                              gr_vector_int& ninput_items,
71                              gr_vector_const_void_star& input_items,
72                              gr_vector_void_star& output_items);
73 };
74 
75 } /* namespace dtv */
76 } /* namespace gr */
77 
78 #endif /* INCLUDED_DTV_ATSC_EQUALIZER_IMPL_H */
79