Kyle Reed e7e1bedcad
Support squelch in pocsag (#1415)
* Support squelch in pocsag

* Revert smooth threshold
2023-08-27 15:56:40 -07:00

113 lines
3.0 KiB
C++

/*
* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
* Copyright (C) 2016 Furrtek
*
* This file is part of PortaPack.
*
* 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 2, 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; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef __POCSAG_H__
#define __POCSAG_H__
#define POCSAG_PREAMBLE_LENGTH 576
#define POCSAG_TIMEOUT (576 * 2) // Preamble length * 2
#define POCSAG_SYNCWORD 0x7CD215D8
#define POCSAG_IDLEWORD 0x7A89C197
#define POCSAG_AUDIO_RATE 24000
#define POCSAG_BATCH_LENGTH (17 * 32)
#include "pocsag_packet.hpp"
#include "bch_code.hpp"
namespace pocsag {
// TODO: these enums suck, make a better decode_batch
enum Mode : uint32_t {
STATE_CLEAR,
STATE_HAVE_ADDRESS,
STATE_GETTING_MSG
};
enum OutputType : uint32_t {
EMPTY,
IDLE,
ADDRESS,
MESSAGE
};
enum MessageType : uint32_t {
ADDRESS_ONLY,
NUMERIC_ONLY,
ALPHANUMERIC
};
/* Holds error correction arrays. This allows the arrays to
* be freed when POCSAG is not running, saving ~4kb of RAM. */
class EccContainer {
public:
EccContainer();
EccContainer(const EccContainer&) = delete;
EccContainer(EccContainer&&) = delete;
EccContainer& operator=(const EccContainer&) = delete;
EccContainer& operator=(EccContainer&&) = delete;
int error_correct(uint32_t& val);
private:
void setup_ecc();
/* error correction sequence */
uint32_t ecs[32];
uint32_t bch[1025];
};
struct POCSAGState {
EccContainer* ecc = nullptr;
uint8_t codeword_index = 0;
uint32_t function = 0;
uint32_t address = 0;
Mode mode = STATE_CLEAR;
OutputType out_type = EMPTY;
uint32_t ascii_data = 0;
uint32_t ascii_idx = 0;
uint32_t errors = 0;
std::string output{};
};
const pocsag::BitRate pocsag_bitrates[4] = {
pocsag::BitRate::FSK512,
pocsag::BitRate::FSK1200,
pocsag::BitRate::FSK2400,
pocsag::BitRate::FSK3200,
};
std::string bitrate_str(BitRate bitrate);
std::string flag_str(PacketFlag packetflag);
void insert_BCH(BCHCode& BCH_code, uint32_t* codeword);
uint32_t get_digit_code(char code);
void pocsag_encode(const MessageType type, BCHCode& BCH_code, const uint32_t function, const std::string message, const uint32_t address, std::vector<uint32_t>& codewords);
// Returns true if the batch has more to process.
bool pocsag_decode_batch(const POCSAGPacket& batch, POCSAGState& state);
} /* namespace pocsag */
#endif /*__POCSAG_H__*/