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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 "repetition_decoder_impl.h"
#include <volk/volk.h>
#include <cmath>
#include <cstdio>
#include <sstream>
#include <vector>
namespace gr {
namespace fec {
namespace code {
generic_decoder::sptr repetition_decoder::make(int frame_size, int rep, float ap_prob)
{
return generic_decoder::sptr(new repetition_decoder_impl(frame_size, rep, ap_prob));
}
repetition_decoder_impl::repetition_decoder_impl(int frame_size, int rep, float ap_prob)
: generic_decoder("repetition_decoder")
{
// Set max frame size here; all buffers and settings will be
// based on this value.
d_max_frame_size = frame_size;
set_frame_size(frame_size);
if (rep < 0)
throw std::runtime_error("repetition_encoder: repetition rate must be >= 0");
if ((ap_prob < 0) || (ap_prob > 1.0))
throw std::runtime_error(
"repetition_encoder: a priori probability rate must be in [0, 1]");
d_rep = rep;
d_ap_prob = ap_prob;
d_trials.resize(d_rep);
}
repetition_decoder_impl::~repetition_decoder_impl() {}
int repetition_decoder_impl::get_output_size()
{
// unpacked bits
return d_frame_size;
}
int repetition_decoder_impl::get_input_size() { return d_frame_size * d_rep; }
int repetition_decoder_impl::get_input_item_size() { return sizeof(float); }
const char* repetition_decoder_impl::get_input_conversion() { return "none"; }
float repetition_decoder_impl::get_shift() { return 0; }
bool repetition_decoder_impl::set_frame_size(unsigned int frame_size)
{
bool ret = true;
if (frame_size > d_max_frame_size) {
GR_LOG_INFO(d_logger,
boost::format("tried to set frame to %1%; max possible is %2%") %
frame_size % d_max_frame_size);
frame_size = d_max_frame_size;
ret = false;
}
d_frame_size = frame_size;
return ret;
}
double repetition_decoder_impl::rate() { return 1.0 / static_cast<double>(d_rep); }
void repetition_decoder_impl::generic_work(void* inbuffer, void* outbuffer)
{
const float* in = (const float*)inbuffer;
unsigned char* out = (unsigned char*)outbuffer;
for (unsigned int i = 0; i < d_frame_size; i++) {
for (unsigned int r = 0; r < d_rep; r++) {
d_trials[r] = (in[d_rep * i + r] > 0) ? 1.0f : 0.0f;
}
float res = std::count(d_trials.begin(), d_trials.end(), 1.0f);
if ((res / static_cast<float>(d_rep)) > d_ap_prob)
out[i] = 1;
else
out[i] = 0;
}
}
} /* namespace code */
} /* namespace fec */
} /* namespace gr */
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