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/* -*- c++ -*- */
/*
* Copyright 2015 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#include <gnuradio/fec/decoder.h>
#include <gnuradio/fec/ldpc_decoder.h>
#include <gnuradio/fec/maxstar.h>
#include <math.h>
#include <stdio.h>
#include <string.h> // for memcpy
#include <volk/volk.h>
#include <boost/assign/list_of.hpp>
#include <algorithm> // for std::reverse
#include <sstream>
#include <vector>
namespace gr {
namespace fec {
generic_decoder::sptr
ldpc_decoder::make(std::string alist_file, float sigma, int max_iterations)
{
return generic_decoder::sptr(new ldpc_decoder(alist_file, sigma, max_iterations));
}
ldpc_decoder::ldpc_decoder(std::string alist_file, float sigma, int max_iterations)
: generic_decoder("ldpc_decoder")
{
if (!boost::filesystem::exists(alist_file))
throw std::runtime_error("Bad AList file name!");
d_list.read(alist_file.c_str());
d_code.set_alist(d_list);
d_spa.set_alist_sigma(d_list, sigma);
d_rate =
static_cast<double>(d_code.dimension()) / static_cast<double>(d_code.get_N());
set_frame_size(d_code.dimension());
d_spa.set_K(d_output_size);
d_spa.set_max_iterations(max_iterations);
}
int ldpc_decoder::get_output_size() { return d_output_size; }
int ldpc_decoder::get_input_size() { return d_input_size; }
double ldpc_decoder::rate() { return d_rate; }
bool ldpc_decoder::set_frame_size(unsigned int frame_size)
{
if (frame_size % d_code.dimension() != 0) {
GR_LOG_ERROR(d_logger,
boost::format("Frame size (%1% bits) must be a "
"multiple of the information word "
"size of the LDPC matrix, %2%") %
frame_size % (d_code.dimension()));
throw std::runtime_error("ldpc_decoder: cannot use frame size.");
}
d_output_size = frame_size;
d_input_size = static_cast<int>(round(frame_size / d_rate));
return true;
}
void ldpc_decoder::generic_work(void* inBuffer, void* outBuffer)
{
const float* in = (const float*)inBuffer;
unsigned char* out = (unsigned char*)outBuffer;
int j = 0;
std::vector<float> rx(d_code.get_N());
for (int i = 0; i < d_input_size; i += d_code.get_N()) {
for (int k = 0; k < d_code.get_N(); k++) {
rx[k] = in[i + k] * (-1);
}
int n_iterations = 0;
std::vector<uint8_t> estimate(d_spa.decode(rx, &n_iterations));
std::vector<uint8_t> data(d_code.get_systematic_bits(estimate));
memcpy(&out[j], &data[0], d_code.dimension());
d_iterations = n_iterations;
j += d_code.dimension();
}
}
int ldpc_decoder::get_input_item_size() { return sizeof(INPUT_DATATYPE); }
int ldpc_decoder::get_output_item_size() { return sizeof(OUTPUT_DATATYPE); }
int ldpc_decoder::get_history() { return 0; }
float ldpc_decoder::get_shift() { return 0.0; }
const char* ldpc_decoder::get_conversion() { return "none"; }
ldpc_decoder::~ldpc_decoder() {}
} // namespace fec
} // namespace gr
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