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/* -*- c++ -*- */
/*
* Copyright 2014 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_rs_decoder_impl.h"
#include "gnuradio/dtv/atsc_consts.h"
#include <gnuradio/io_signature.h>
namespace gr {
namespace dtv {
static const int rs_init_symsize = 8;
static const int rs_init_gfpoly = 0x11d;
static const int rs_init_fcr = 0; // first consecutive root
static const int rs_init_prim = 1; // primitive is 1 (alpha)
static const int rs_init_nroots = 20;
static const int N = (1 << rs_init_symsize) - 1; // 255
static const int amount_of_pad = N - ATSC_MPEG_RS_ENCODED_LENGTH; // 48
atsc_rs_decoder::sptr atsc_rs_decoder::make()
{
return gnuradio::make_block_sptr<atsc_rs_decoder_impl>();
}
atsc_rs_decoder_impl::atsc_rs_decoder_impl()
: gr::sync_block("dtv_atsc_rs_decoder",
io_signature::make(1, 1, sizeof(atsc_mpeg_packet_rs_encoded)),
io_signature::make(1, 1, sizeof(atsc_mpeg_packet_no_sync)))
{
d_rs = init_rs_char(
rs_init_symsize, rs_init_gfpoly, rs_init_fcr, rs_init_prim, rs_init_nroots);
assert(d_rs != 0);
d_nerrors_corrrected_count = 0;
d_bad_packet_count = 0;
d_total_packets = 0;
}
int atsc_rs_decoder_impl::decode(atsc_mpeg_packet_no_sync& out,
const atsc_mpeg_packet_rs_encoded& in)
{
unsigned char tmp[N];
int ncorrections;
assert((int)(amount_of_pad + sizeof(in.data)) == N);
// add missing prefix zero padding to message
memset(tmp, 0, amount_of_pad);
memcpy(&tmp[amount_of_pad], in.data, sizeof(in.data));
// correct message...
ncorrections = decode_rs_char(d_rs, tmp, 0, 0);
// copy corrected message to output, skipping prefix zero padding
memcpy(out.data, &tmp[amount_of_pad], sizeof(out.data));
return ncorrections;
}
atsc_rs_decoder_impl::~atsc_rs_decoder_impl()
{
if (d_rs)
free_rs_char(d_rs);
d_rs = 0;
}
int atsc_rs_decoder_impl::num_errors_corrected() const
{
return d_nerrors_corrrected_count;
}
int atsc_rs_decoder_impl::num_bad_packets() const { return d_bad_packet_count; }
int atsc_rs_decoder_impl::num_packets() const { return d_total_packets; }
int atsc_rs_decoder_impl::work(int noutput_items,
gr_vector_const_void_star& input_items,
gr_vector_void_star& output_items)
{
const atsc_mpeg_packet_rs_encoded* in =
(const atsc_mpeg_packet_rs_encoded*)input_items[0];
atsc_mpeg_packet_no_sync* out = (atsc_mpeg_packet_no_sync*)output_items[0];
for (int i = 0; i < noutput_items; i++) {
assert(in[i].pli.regular_seg_p());
out[i].pli = in[i].pli; // copy pipeline info...
int nerrors_corrrected = decode(out[i], in[i]);
out[i].pli.set_transport_error(nerrors_corrrected == -1);
if (nerrors_corrrected == -1) {
d_bad_packet_count++;
d_nerrors_corrrected_count +=
10; // lower bound estimate; most this RS can fix
} else {
d_nerrors_corrrected_count += nerrors_corrrected;
}
d_total_packets++;
#if 0
if (d_total_packets > 1000) {
GR_LOG_INFO(d_logger, boost::format("Error rate: %1%\tPacket error rate: %2%") \
% ((float)d_nerrors_corrrected_count/(ATSC_MPEG_DATA_LENGTH*d_total_packets))
% ((float)d_bad_packet_count/d_total_packets));
}
#endif
}
return noutput_items;
}
void atsc_rs_decoder_impl::setup_rpc()
{
#ifdef GR_CTRLPORT
add_rpc_variable(rpcbasic_sptr(new rpcbasic_register_get<atsc_rs_decoder, int>(
alias(),
"num_errors_corrected",
&atsc_rs_decoder::num_errors_corrected,
pmt::from_long(0),
pmt::from_long(10000000),
pmt::from_long(0),
"",
"Number of errors corrected",
RPC_PRIVLVL_MIN,
DISPTIME)));
add_rpc_variable(rpcbasic_sptr(
new rpcbasic_register_get<atsc_rs_decoder, int>(alias(),
"num_bad_packets",
&atsc_rs_decoder::num_bad_packets,
pmt::from_long(0),
pmt::from_long(10000000),
pmt::from_long(0),
"",
"Number of bad packets",
RPC_PRIVLVL_MIN,
DISPTIME)));
add_rpc_variable(rpcbasic_sptr(
new rpcbasic_register_get<atsc_rs_decoder, int>(alias(),
"num_packets",
&atsc_rs_decoder::num_packets,
pmt::from_long(0),
pmt::from_long(10000000),
pmt::from_long(0),
"",
"Number of packets",
RPC_PRIVLVL_MIN,
DISPTIME)));
#endif /* GR_CTRLPORT */
}
} /* namespace dtv */
} /* namespace gr */
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