gr-satnogs/include/satnogs/ax100_decoder.h

118 lines
3.4 KiB
C++

/* -*- c++ -*- */
/*
* gr-satnogs: SatNOGS GNU Radio Out-Of-Tree Module
*
* Copyright (C) 2019, Libre Space Foundation <http://libre.space>
*
* 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 INCLUDED_SATNOGS_AX100_DECODER_H
#define INCLUDED_SATNOGS_AX100_DECODER_H
#include <satnogs/api.h>
#include <satnogs/decoder.h>
#include <satnogs/shift_reg.h>
#include <satnogs/crc.h>
#include <satnogs/whitening.h>
namespace gr {
namespace satnogs {
/*!
* \brief This decoder tries to cover all the supported framing and coding
* schemes of the AX100 product from GOMSpace. It also supports some variants
* that have appear in different missions, including excet the ASM and a
* repeated preamble
*
*/
class SATNOGS_API ax100_decoder : public decoder {
public:
static decoder_sptr
make(const std::vector<uint8_t> &preamble,
size_t preamble_threshold,
const std::vector<uint8_t> &sync,
size_t sync_threshold,
crc::crc_t crc,
whitening::whitening_sptr descrambler,
bool enable_rs);
ax100_decoder(const std::vector<uint8_t> &preamble,
size_t preamble_threshold,
const std::vector<uint8_t> &sync,
size_t sync_threshold,
crc::crc_t crc,
whitening::whitening_sptr descrambler,
bool enable_rs);
~ax100_decoder();
decoder_status_t
decode(const void *in, int len);
void
reset();
size_t
input_multiple() const;
private:
/**
* Decoding FSM
*/
typedef enum {
SEARCHING, //!< when searching for the start of the preamble
SEARCHING_SYNC, //!< We have preamble, search for sync
DECODING_FRAME_LEN, //!< Decoding the frame length
DECODING_PAYLOAD //!< Decoding the payload
} decoding_state_t;
shift_reg d_preamble;
shift_reg d_preamble_shift_reg;
const size_t d_preamble_len;
const size_t d_preamble_thrsh;
shift_reg d_sync;
shift_reg d_sync_shift_reg;
const size_t d_sync_len;
const size_t d_sync_thrsh;
crc::crc_t d_crc;
whitening::whitening_sptr d_descrambler;
const bool d_rs;
decoding_state_t d_state;
size_t d_cnt;
size_t d_len;
size_t d_length_field_len;
uint8_t *d_pdu;
int
search_preamble(const uint8_t *in, int len);
int
search_sync(const uint8_t *in, int len);
int
decode_frame_len(const uint8_t *in, int len);
void
decode_payload(decoder_status_t &status, const uint8_t *in, int len);
bool
check_crc();
};
} // namespace satnogs
} // namespace gr
#endif /* INCLUDED_SATNOGS_AX100_DECODER_H */