3 * Copyright 2006 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
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 2, or (at your option)
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.
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.
27 #include <gr_diff_encoder_bb.h>
28 #include <gr_io_signature.h>
30 gr_diff_encoder_bb_sptr
31 gr_make_diff_encoder_bb (unsigned int modulus)
33 return gr_diff_encoder_bb_sptr (new gr_diff_encoder_bb(modulus));
36 gr_diff_encoder_bb::gr_diff_encoder_bb (unsigned int modulus)
37 : gr_sync_block ("diff_encoder_bb",
38 gr_make_io_signature (1, 1, sizeof (unsigned char)),
39 gr_make_io_signature (1, 1, sizeof (unsigned char))),
40 d_last_out(0), d_modulus(modulus)
45 gr_diff_encoder_bb::work (int noutput_items,
46 gr_vector_const_void_star &input_items,
47 gr_vector_void_star &output_items)
49 const unsigned char *in = (const unsigned char *) input_items[0];
50 unsigned char *out = (unsigned char *) output_items[0];
52 unsigned last_out = d_last_out;
53 unsigned modulus = d_modulus;
55 for (int i = 0; i < noutput_items; i++){
56 out[i] = (in[i] + last_out) % modulus;
60 d_last_out = last_out;