Implementation of M17 code puncturing scheme

replace/9a872ef182ba9e5ac6bb9f45922d1f36d7b15dfe
Silvano Seva 2021-08-22 10:26:09 +02:00
rodzic d545071df6
commit ee1b111fb7
7 zmienionych plików z 175 dodań i 15 usunięć

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@ -18,8 +18,8 @@
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef M17CALLSIGN_H
#define M17CALLSIGN_H
#ifndef M17_CALLSIGN_H
#define M17_CALLSIGN_H
#ifndef __cplusplus
#error This header is C++ only!
@ -52,4 +52,4 @@ bool encode_callsign(const std::string& callsign, call_t& encodedCall,
*/
std::string decode_callsign(const call_t& encodedCall);
#endif /* M17CALLSIGN_H */
#endif /* M17_CALLSIGN_H */

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@ -0,0 +1,90 @@
/***************************************************************************
* Copyright (C) 2021 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 <experimental/array>
#include "M17Utils.h"
/**
* Puncture matrix for linx setup frame.
*/
static constexpr auto LSF_puncture = std::experimental::make_array< uint8_t >
(
1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0,
1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0,
1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1,
0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1,
0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,
1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1
);
/**
* Puncture matrix for audio frames.
*/
static constexpr auto Audio_puncture = std::experimental::make_array< uint8_t >
(
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;
}
#endif /* M17_CODE_PUNCTURING_H */

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@ -20,8 +20,8 @@
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef M17CONVOLUTIONALENCODER_H
#define M17CONVOLUTIONALENCODER_H
#ifndef M17_CONVOLUTIONAL_ENCODER_H
#define M17_CONVOLUTIONAL_ENCODER_H
#ifndef __cplusplus
#error This header is C++ only!
@ -111,4 +111,4 @@ private:
uint8_t memory = 0; ///< Convolutional encoder memory.
};
#endif /* M17CONVOLUTIONALENCODER_H */
#endif /* M17_CONVOLUTIONAL_ENCODER_H */

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@ -18,8 +18,8 @@
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef M17DATATYPES_H
#define M17DATATYPES_H
#ifndef M17_DATATYPES_H
#define M17_DATATYPES_H
#include <cstdint>
#include <array>
@ -75,4 +75,4 @@ typedef struct
}
__attribute__((packed)) dataFrame_t;
#endif /* M17DATATYPES_H */
#endif /* M17_DATATYPES_H */

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@ -18,8 +18,8 @@
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef M17FRAME_H
#define M17FRAME_H
#ifndef M17_FRAME_H
#define M17_FRAME_H
#ifndef __cplusplus
#error This header is C++ only!
@ -115,4 +115,4 @@ private:
dataFrame_t data; ///< Underlying frame data.
};
#endif /* M17FRAME_H */
#endif /* M17_FRAME_H */

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@ -18,8 +18,8 @@
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef M17LINKSETUPFRAME_H
#define M17LINKSETUPFRAME_H
#ifndef M17_LINKSETUPFRAME_H
#define M17_LINKSETUPFRAME_H
#ifndef __cplusplus
#error This header is C++ only!
@ -125,4 +125,4 @@ private:
lsf_t data; ///< Underlying frame data.
};
#endif /* M17LINKSETUPFRAME_H */
#endif /* M17_LINKSETUPFRAME_H */

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/***************************************************************************
* Copyright (C) 2021 by Federico Amedeo Izzo IU2NUO, *
* Niccolò Izzo IU2KIN *
* Frederik Saraci IU2NRO *
* Silvano Seva IU2KWO *
* *
* *
* 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_UTILS_H
#define M17_UTILS_H
#ifndef __cplusplus
#error This header is C++ only!
#endif
#include <array>
/**
* Utility function allowing to retrieve the value of a single bit from an array
* of bytes. Bits are counted scanning from left to right, thus bit number zero
* is the leftmost bit of array[0].
*
* \param array: byte array.
* \param pos: bit position inside the array.
* \return value of the indexed bit, as boolean variable.
*/
template < size_t N >
inline bool getBit(const std::array< uint8_t, N >& array, const size_t pos)
{
size_t i = pos / 8;
size_t j = pos % 8;
return (array[i] >> (7 - j)) & 0x01;
}
/**
* Utility function allowing to set the value of a single bit from an array
* of bytes. Bits are counted scanning from left to right, thus bit number zero
* is the leftmost bit of array[0].
*
* \param array: byte array.
* \param pos: bit position inside the array.
* \param bit: bit value to be set.
*/
template < size_t N >
inline void setBit(std::array< uint8_t, N >& array, const size_t pos,
const bool bit)
{
size_t i = pos / 8;
size_t j = pos % 8;
uint8_t mask = 1 << (7 - j);
array[i] = (array[i] & ~mask) |
(bit ? mask : 0x00);
}
#endif /* M17_UTILS_H */