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/*
Copyright (C) 2005, 2006, 2007, 2008, 2009 Her Majesty the Queen in Right
of Canada (Communications Research Center Canada)
Copyright (C) 2016
Matthias P. Braendli, matthias.braendli@mpb.li
http://www.opendigitalradio.org
*/
/*
This file is part of ODR-DabMux.
ODR-DabMux 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 of the
License, or (at your option) any later version.
ODR-DabMux 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 ODR-DabMux. If not, see <http://www.gnu.org/licenses/>.
*/
#include "ReedSolomon.h"
#include <vector>
#include <algorithm>
#include <stdexcept>
#include <sstream>
#include <cstdio>
#include <cstring> // For memcpy
extern "C" {
#include "fec/fec.h"
}
#include <assert.h>
#define SYMSIZE 8
ReedSolomon::ReedSolomon(int N, int K, bool reverse, int gfpoly, int firstRoot, int primElem)
{
setReverse(reverse);
m_N = N;
m_K = K;
const int symsize = SYMSIZE;
const int nroots = N - K; // For EDI PFT, this must be 48
const int pad = ((1 << symsize) - 1) - N; // is 255-N
rsData = init_rs_char(symsize, gfpoly, firstRoot, primElem, nroots, pad);
if (rsData == nullptr) {
std::stringstream ss;
ss << "Invalid Reed-Solomon parameters! " <<
"N=" << N << " ; K=" << K << " ; pad=" << pad;
throw std::invalid_argument(ss.str());
}
}
ReedSolomon::~ReedSolomon()
{
if (rsData != nullptr) {
free_rs_char(rsData);
}
}
void ReedSolomon::setReverse(bool state)
{
reverse = state;
}
int ReedSolomon::encode(void* data, void* fec, size_t size)
{
uint8_t* input = reinterpret_cast<uint8_t*>(data);
uint8_t* output = reinterpret_cast<uint8_t*>(fec);
int ret = 0;
if (reverse) {
std::vector<uint8_t> buffer(m_N);
memcpy(&buffer[0], input, m_K);
memcpy(&buffer[m_K], output, m_N - m_K);
ret = decode_rs_char(rsData, &buffer[0], nullptr, 0);
if ((ret != 0) && (ret != -1)) {
memcpy(input, &buffer[0], m_K);
memcpy(output, &buffer[m_K], m_N - m_K);
}
}
else {
encode_rs_char(rsData, input, output);
}
return ret;
}
int ReedSolomon::encode(void* data, size_t size)
{
uint8_t* input = reinterpret_cast<uint8_t*>(data);
int ret = 0;
if (reverse) {
ret = decode_rs_char(rsData, input, nullptr, 0);
}
else {
encode_rs_char(rsData, input, &input[m_K]);
}
return ret;
}
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