1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
/* -*- c++ -*- */
/*
* Copyright 2015,2016 Free Software Foundation, Inc.
*
* This 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 3, or (at your option)
* any later version.
*
* This software 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 this software; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gnuradio/io_signature.h>
#include "dvbt_reed_solomon_enc_impl.h"
#define MPEG_TS_PKT_LENGTH 188
namespace gr {
namespace dtv {
static const int rs_init_symsize = 8;
static const int rs_init_fcr = 0; // first consecutive root
static const int rs_init_prim = 1; // primitive is 1 (alpha)
dvbt_reed_solomon_enc::sptr
dvbt_reed_solomon_enc::make(int p, int m, int gfpoly, int n, int k, int t, int s, int blocks)
{
return gnuradio::get_initial_sptr
(new dvbt_reed_solomon_enc_impl(p, m, gfpoly, n, k, t, s, blocks));
}
/*
* The private constructor
*/
dvbt_reed_solomon_enc_impl::dvbt_reed_solomon_enc_impl(int p, int m, int gfpoly, int n, int k, int t, int s, int blocks)
: block("dvbt_reed_solomon",
io_signature::make(1, 1, sizeof(unsigned char) * blocks * (k - s)),
io_signature::make(1, 1, sizeof(unsigned char) * blocks * (n - s))),
d_n(n), d_k(k), d_s(s), d_blocks(blocks)
{
d_rs = init_rs_char(rs_init_symsize, gfpoly, rs_init_fcr, rs_init_prim, (n - k));
if (d_rs == NULL) {
GR_LOG_FATAL(d_logger, "Reed-Solomon Encoder, cannot allocate memory for d_rs.");
throw std::bad_alloc();
}
d_data = (unsigned char *) malloc(sizeof(unsigned char) * (d_s + MPEG_TS_PKT_LENGTH));
if (d_data == NULL) {
GR_LOG_FATAL(d_logger, "Reed-Solomon Encoder, cannot allocate memory for d_data.");
free_rs_char(d_rs);
throw std::bad_alloc();
}
}
/*
* Our virtual destructor.
*/
dvbt_reed_solomon_enc_impl::~dvbt_reed_solomon_enc_impl()
{
free(d_data);
free_rs_char(d_rs);
}
void
dvbt_reed_solomon_enc_impl::forecast (int noutput_items, gr_vector_int &ninput_items_required)
{
ninput_items_required[0] = noutput_items;
}
void
dvbt_reed_solomon_enc_impl::encode(const unsigned char *in, unsigned char *out)
{
// Shortened Reed-Solomon: prepend zero bytes to message (discarded after encoding)
std::memset(d_data, 0, d_s);
std::memcpy(&d_data[d_s], in, MPEG_TS_PKT_LENGTH);
// Copy input message to output then append Reed-Solomon bits
std::memcpy(out, in, MPEG_TS_PKT_LENGTH);
encode_rs_char(d_rs, d_data, &out[MPEG_TS_PKT_LENGTH]);
}
int
dvbt_reed_solomon_enc_impl::general_work (int noutput_items,
gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
const unsigned char *in = (const unsigned char *) input_items[0];
unsigned char *out = (unsigned char *) output_items[0];
int j = 0;
int k = 0;
for (int i = 0; i < noutput_items * d_blocks; i++) {
encode(in + j, out + k);
j += (d_k - d_s);
k += (d_n - d_s);
}
// Tell runtime system how many input items we consumed on
// each input stream.
consume_each (noutput_items);
// Tell runtime system how many output items we produced.
return noutput_items;
}
} /* namespace dtv */
} /* namespace gr */
|
