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/* -*- c++ -*- */
/*
* Copyright 2006 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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.
*
* GNU Radio 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 GNU Radio; 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 <atsc_viterbi_decoder.h>
#include <gr_io_signature.h>
#include <atsc_consts.h>
#include <iostream>
using std::cerr;
using std::endl;
atsc_viterbi_decoder_sptr
atsc_make_viterbi_decoder()
{
return atsc_viterbi_decoder_sptr(new atsc_viterbi_decoder());
}
atsc_viterbi_decoder::atsc_viterbi_decoder()
: gr_sync_block("atsc_viterbi_decoder",
gr_make_io_signature(1, 1, sizeof(atsc_soft_data_segment)),
gr_make_io_signature(1, 1, sizeof(atsc_mpeg_packet_rs_encoded))),
last_start(-1)
{
set_output_multiple(atsci_viterbi_decoder::NCODERS);
reset();
}
int
atsc_viterbi_decoder::work (int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
const atsc_soft_data_segment *in = (const atsc_soft_data_segment *) input_items[0];
atsc_mpeg_packet_rs_encoded *out = (atsc_mpeg_packet_rs_encoded *) output_items[0];
assert (noutput_items % atsci_viterbi_decoder::NCODERS == 0);
// find the first mod 12 boundary to begin decoding
int start;
for (start = 0; start < atsci_viterbi_decoder::NCODERS; start++){
assert (in[start].pli.regular_seg_p ());
if ((in[start].pli.segno () % atsci_viterbi_decoder::NCODERS) == 0)
break;
}
if (start == atsci_viterbi_decoder::NCODERS){
// we didn't find a mod 12 boundary. There's some kind of problem
// upstream of us (not yet sync'd??)
cerr << "!!!atsc_viterbi_decoder: no mod-12 boundary found\7\n";
start = 0;
}
else if (start != last_start){
cerr << "atsc_viterbi_decoder: new starting offset = " << start
<< endl;
last_start = start;
}
for (int i = 0; i < atsci_viterbi_decoder::NCODERS; i += atsci_viterbi_decoder::NCODERS){
d_viterbi_decoder.decode(&out[i], &in[i + start]);
}
return atsci_viterbi_decoder::NCODERS;
}
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