1 /* -*- c++ -*- */
2 /*
3 * Copyright 2006,2010,2012 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 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26
27 #include "diff_encoder_bb_impl.h"
28 #include <gnuradio/io_signature.h>
29
30 namespace gr {
31 namespace digital {
32
make(unsigned int modulus)33 diff_encoder_bb::sptr diff_encoder_bb::make(unsigned int modulus)
34 {
35 return gnuradio::get_initial_sptr(new diff_encoder_bb_impl(modulus));
36 }
37
diff_encoder_bb_impl(unsigned int modulus)38 diff_encoder_bb_impl::diff_encoder_bb_impl(unsigned int modulus)
39 : sync_block("diff_encoder_bb",
40 io_signature::make(1, 1, sizeof(unsigned char)),
41 io_signature::make(1, 1, sizeof(unsigned char))),
42 d_last_out(0),
43 d_modulus(modulus)
44 {
45 }
46
~diff_encoder_bb_impl()47 diff_encoder_bb_impl::~diff_encoder_bb_impl() {}
48
work(int noutput_items,gr_vector_const_void_star & input_items,gr_vector_void_star & output_items)49 int diff_encoder_bb_impl::work(int noutput_items,
50 gr_vector_const_void_star& input_items,
51 gr_vector_void_star& output_items)
52 {
53 const unsigned char* in = (const unsigned char*)input_items[0];
54 unsigned char* out = (unsigned char*)output_items[0];
55
56 unsigned last_out = d_last_out;
57 unsigned modulus = d_modulus;
58
59 for (int i = 0; i < noutput_items; i++) {
60 out[i] = (in[i] + last_out) % modulus;
61 last_out = out[i];
62 }
63
64 d_last_out = last_out;
65 return noutput_items;
66 }
67
68 } /* namespace digital */
69 } /* namespace gr */
70