125 lines
4.1 KiB
C++
125 lines
4.1 KiB
C++
/***************************************************************************
|
|
* Copyright (C) 2021 - 2023 by Federico Amedeo Izzo IU2NUO, *
|
|
* Niccolò Izzo IU2KIN *
|
|
* Frederik Saraci IU2NRO *
|
|
* Silvano Seva IU2KWO *
|
|
* *
|
|
* Adapted from original code written by Rob Riggs, Mobilinkd LLC *
|
|
* *
|
|
* This program 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. *
|
|
* *
|
|
* This program 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 this program; if not, see <http://www.gnu.org/licenses/> *
|
|
***************************************************************************/
|
|
|
|
#ifndef M17_CODE_PUNCTURING_H
|
|
#define M17_CODE_PUNCTURING_H
|
|
|
|
#ifndef __cplusplus
|
|
#error This header is C++ only!
|
|
#endif
|
|
|
|
#include <array>
|
|
#include "M17Utils.hpp"
|
|
|
|
namespace M17
|
|
{
|
|
|
|
/**
|
|
* Puncture matrix for linx setup frame.
|
|
*/
|
|
static constexpr std::array< uint8_t, 61 > LSF_PUNCTURE =
|
|
{
|
|
1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1,
|
|
0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1,
|
|
1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1
|
|
};
|
|
|
|
/**
|
|
* Puncture matrix for audio frames.
|
|
*/
|
|
static constexpr std::array< uint8_t, 12 > DATA_PUNCTURE =
|
|
{
|
|
1, 1, 1, 1, 1, 1,
|
|
1, 1, 1, 1, 1, 0
|
|
};
|
|
|
|
|
|
/**
|
|
* Apply a given puncturing scheme to a byte array.
|
|
*
|
|
* \param input: input byte array.
|
|
* \param output: output byte array, containing puntured data.
|
|
* \param puncture: puncturing matrix, stored as an array of 8 bit values.
|
|
* \return resulting bit count after punturing.
|
|
*/
|
|
template < size_t IN, size_t OUT, size_t P >
|
|
size_t puncture(const std::array< uint8_t, IN >& input,
|
|
std::array< uint8_t, OUT >& output,
|
|
const std::array< uint8_t, P >& puncture)
|
|
{
|
|
size_t outIndex = 0;
|
|
size_t punctIndex = 0;
|
|
size_t bit_count = 0;
|
|
|
|
for(size_t i = 0; i < 8*IN && outIndex < 8*OUT; i++)
|
|
{
|
|
if(puncture[punctIndex++])
|
|
{
|
|
setBit(output, outIndex++, getBit(input, i));
|
|
bit_count++;
|
|
}
|
|
|
|
if(punctIndex == P) punctIndex = 0;
|
|
}
|
|
|
|
return bit_count;
|
|
}
|
|
|
|
/**
|
|
* Apply the inverse puncturing scheme to a byte array, thus expanding its bits.
|
|
*
|
|
* \param input: input byte array, containing puntured data.
|
|
* \param output: output byte array, containing depuntured data.
|
|
* \param puncture: puncturing matrix, stored as an array of 8 bit values.
|
|
* \return number of zero bits added to the input sequence for depunturing.
|
|
*/
|
|
template < size_t IN, size_t OUT, size_t P >
|
|
size_t depuncture(const std::array< uint8_t, IN >& input,
|
|
std::array< uint8_t, OUT >& output,
|
|
const std::array< uint8_t, P >& puncture)
|
|
{
|
|
size_t inpIndex = 0;
|
|
size_t punctIndex = 0;
|
|
size_t bit_count = 0;
|
|
|
|
for(size_t i = 0; i < 8*OUT && inpIndex < 8*IN; i++)
|
|
{
|
|
if(puncture[punctIndex++])
|
|
{
|
|
setBit(output, i, getBit(input, inpIndex++));
|
|
}
|
|
else
|
|
{
|
|
setBit(output, i, 0);
|
|
bit_count++;
|
|
}
|
|
|
|
if(punctIndex == P) punctIndex = 0;
|
|
}
|
|
|
|
return bit_count;
|
|
}
|
|
|
|
} // namespace M17
|
|
|
|
#endif // M17_CODE_PUNCTURING_H
|