OpenRTX/openrtx/include/protocols/M17/M17FrameEncoder.hpp

106 wiersze
3.8 KiB
C++

/***************************************************************************
* Copyright (C) 2022 - 2023 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 M17FRAMEENCODER_H
#define M17FRAMEENCODER_H
#ifndef __cplusplus
#error This header is C++ only!
#endif
#include <string>
#include <array>
#include "M17ConvolutionalEncoder.hpp"
#include "M17LinkSetupFrame.hpp"
#include "M17StreamFrame.hpp"
namespace M17
{
/**
* M17 frame encoder.
*/
class M17FrameEncoder
{
public:
/**
* Constructor.
*/
M17FrameEncoder();
/**
* Destructor.
*/
~M17FrameEncoder();
/**
* Clear the internal data structures, reset the counter for frame sequence
* number in stream data frames and reset the counter for LICH segment
* sequence.
*/
void reset();
/**
* Encode a Link Setup Frame into a frame ready for transmission, prepended
* with the corresponding sync word. Link Setup data is also copied to an
* internal data structure and used to generate the LICH segments to be
* placed in each stream frame.
*
* @param lsf: Link Setup Frame to be encoded.
* @param output: destination buffer for the encoded data.
*/
void encodeLsf(M17LinkSetupFrame& lsf, frame_t& output);
/**
* Prepare and encode a stream data frame into a frame ready for
* transmission, prepended with the corresponding sync word. The frame
* sequence number is incremented by one on each function call and cleared
* when the reset() function is called. The LICH segment field is filled
* with data obtained from the latest Link Setup Frame encoded.
*
* @param payload: payload data.
* @param output: destination buffer for the encoded data.
* @param isLast: if true, current frame is marked as the last one to be
* transmitted.
* @return the frame sequence number.
*/
uint16_t encodeStreamFrame(const payload_t& payload, frame_t& output,
const bool isLast = false);
/**
* Encode an End Of Transmission marker frame.
*
* @param output: destination buffer for the encoded data.
*/
void encodeEotFrame(frame_t& output);
private:
M17ConvolutionalEncoder encoder; ///< Convolutional encoder.
std::array< lich_t, 6 > lichSegments; ///< Encoded LSF chunks for LICH generation.
uint8_t currentLich; ///< Index of current LSF chunk.
uint16_t streamFrameNumber; ///< Current frame number.
};
} // namespace M17
#endif // M17FRAMEENCODER_H