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/* -*- c++ -*- */
/*
* Copyright 2014,2020 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "atsc_fs_checker_impl.h"
#include "atsc_pnXXX_impl.h"
#include "atsc_syminfo_impl.h"
#include "atsc_types.h"
#include "gnuradio/dtv/atsc_consts.h"
#include <gnuradio/io_signature.h>
#include <string>
#define ATSC_SEGMENTS_PER_DATA_FIELD 313
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)))
{
gr::configure_default_loggers(d_logger, d_debug_logger, "dtv_atsc_fs_checker");
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];
GR_LOG_DEBUG(d_debug_logger,
std::string("second PN63 error count = ") + std::to_string(errors));
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) {
GR_LOG_DEBUG(d_debug_logger, "Found FIELD_SYNC_1")
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)) {
GR_LOG_DEBUG(d_debug_logger, "Found FIELD_SYNC_2")
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.
GR_LOG_WARN(d_logger,
std::string("PN63 error count = ") + std::to_string(errors));
}
}
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++;
if (d_segment_num > (ATSC_SEGMENTS_PER_DATA_FIELD - 1)) {
d_field_num = 0;
d_segment_num = 0;
} else {
output_produced++;
}
}
}
consume_each(noutput_items);
return output_produced;
}
} /* namespace dtv */
} /* namespace gr */
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