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/* -*- c++ -*- */
/*
* Copyright 2014 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_fs_checker_impl.h"
#include "atsc_types.h"
#include "atsc_syminfo_impl.h"
#include "atsc_pnXXX_impl.h"
#include "gnuradio/dtv/atsc_consts.h"
#include <gnuradio/io_signature.h>
static const int PN511_ERROR_LIMIT = 20; // max number of bits wrong
static const int PN63_ERROR_LIMIT = 5;
namespace gr {
namespace dtv {
atsc_fs_checker::sptr
atsc_fs_checker::make()
{
return gnuradio::get_initial_sptr
(new atsc_fs_checker_impl());
}
atsc_fs_checker_impl::atsc_fs_checker_impl()
: gr::block("dtv_atsc_fs_checker",
io_signature::make(1, 1, sizeof(atsc_soft_data_segment)),
io_signature::make(1, 1, sizeof(atsc_soft_data_segment)))
{
reset();
}
void
atsc_fs_checker_impl::reset()
{
d_index = 0;
memset (d_sample_sr, 0, sizeof (d_sample_sr));
memset (d_tag_sr, 0, sizeof (d_tag_sr));
memset (d_bit_sr, 0, sizeof (d_bit_sr));
d_field_num = 0;
d_segment_num = 0;
}
atsc_fs_checker_impl::~atsc_fs_checker_impl()
{
}
int
atsc_fs_checker_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 atsc_soft_data_segment *in = (const atsc_soft_data_segment *) input_items[0];
atsc_soft_data_segment *out = (atsc_soft_data_segment *) output_items[0];
int output_produced = 0;
for (int i = 0; i < noutput_items; i++) {
// check for a hit on the PN 511 pattern
int errors = 0;
for (int j = 0; j < LENGTH_511 && errors < PN511_ERROR_LIMIT; j++)
errors += (in[i].data[j + OFFSET_511] >= 0) ^ atsc_pn511[j];
//std::cout << errors << std::endl;
if (errors < PN511_ERROR_LIMIT) { // 511 pattern is good.
// determine if this is field 1 or field 2
errors = 0;
for (int j = 0; j < LENGTH_2ND_63; j++)
errors += (in[i].data[j + OFFSET_2ND_63] >= 0) ^ atsc_pn63[j];
// we should have either field 1 (== PN63) or field 2 (== ~PN63)
if (errors <= PN63_ERROR_LIMIT) {
//std::cout << "Found FIELD_SYNC_1" << std::endl;
d_field_num = 1; // We are in field number 1 now
d_segment_num = -1; // This is the first segment
}
else if (errors >= (LENGTH_2ND_63 - PN63_ERROR_LIMIT)) {
//std::cout << "Found FIELD_SYNC_2" << std::endl;
d_field_num = 2; // We are in field number 2 now
d_segment_num = -1; // This is the first segment
}
else {
// should be extremely rare.
std::cerr << "!!! atsc_fs_checker: PN63 error count = " << errors << std::endl;
}
}
if( d_field_num == 1 || d_field_num == 2 ) { // If we have sync
// So we copy out current packet data to an output packet and fill its plinfo
for( int j = 0; j < ATSC_DATA_SEGMENT_LENGTH; j++ )
out[output_produced].data[j] = in[i].data[j];
out[output_produced].pli.set_regular_seg((d_field_num == 2), d_segment_num);
d_segment_num++;
output_produced++;
}
}
consume_each(noutput_items);
return output_produced;
}
} /* namespace dtv */
} /* namespace gr */
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