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dvmhost/p25/lc/tsbk/OSP_SYNC_BCAST.cpp

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4.9 KiB

/**
* Digital Voice Modem - Host Software
* GPLv2 Open Source. Use is subject to license terms.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* @package DVM / Host Software
*
*/
/*
* Copyright (C) 2022 by Bryan Biedenkapp N2PLL
*
* 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 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, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "Defines.h"
#include "p25/lc/tsbk/OSP_SYNC_BCAST.h"
#include "Log.h"
#include "Utils.h"
using namespace p25::lc::tsbk;
using namespace p25::lc;
using namespace p25;
#include <cassert>
#include <cmath>
#include <chrono>
#include <ctime>
// ---------------------------------------------------------------------------
// Public Class Members
// ---------------------------------------------------------------------------
/// <summary>
/// Initializes a new instance of the OSP_SYNC_BCAST class.
/// </summary>
OSP_SYNC_BCAST::OSP_SYNC_BCAST() : TSBK(),
m_microslotCount(0U)
{
m_lco = TSBK_OSP_SYNC_BCAST;
}
/// <summary>
/// Decode a trunking signalling block.
/// </summary>
/// <param name="data"></param>
/// <param name="rawTSBK"></param>
/// <returns>True, if TSBK was decoded, otherwise false.</returns>
bool OSP_SYNC_BCAST::decode(const uint8_t* data, bool rawTSBK)
{
assert(data != NULL);
/* stub */
return true;
}
/// <summary>
/// Encode a trunking signalling block.
/// </summary>
/// <param name="data"></param>
/// <param name="rawTSBK"></param>
/// <param name="noTrellis"></param>
void OSP_SYNC_BCAST::encode(uint8_t* data, bool rawTSBK, bool noTrellis)
{
assert(data != NULL);
ulong64_t tsbkValue = 0U;
std::chrono::system_clock::time_point now = std::chrono::system_clock::now();
time_t tt = std::chrono::system_clock::to_time_t(now);
tm local_tm = *gmtime(&tt);
uint32_t tmM = (local_tm.tm_mon + 1);
uint32_t tmY = (local_tm.tm_year + 1900) - 2000;
#if DEBUG_P25_TSBK
LogDebug(LOG_P25, "TSBK_OSP_SYNC_BCAST, tmM = %u / %u, tmY = %u / %u", local_tm.tm_mon, tmM, local_tm.tm_year, tmY);
#endif
// determine LTO and direction (positive or negative)
bool negativeLTO = false;
uint8_t lto = fabs(m_siteData.lto()) * 2U; // this will cause a bug for half-hour timezone intervals...
if (m_siteData.lto() < 0)
negativeLTO = true;
// mark the LTO as valid if its non-zero
bool vl = false;
if (lto > 0U)
vl = true;
uint8_t mc = 0U;
// wrap microslot count if necessary
if (m_microslotCount > 7999U)
m_microslotCount = 0U;
tsbkValue = 0x0AU + // US - Unsynced Flag Set / MMU - Microslot/Minute Unlock Flag Set
((mc & 0x03U) >> 1); // Minute Correction MSB
tsbkValue = (tsbkValue << 8) +
((mc & 0x01U) << 7) + // Minute Correction LSB
(vl ? 0x40U : 0x00U) + // Valid LTO Flag
(negativeLTO ? 0x20U : 0x00U) + // Add/Subtract LTO Flag
(lto & 0x1F); // LTO
// Date
tsbkValue = (tsbkValue << 7) + (tmY & 0x7FU); // Number of Years Past 2000
tsbkValue = (tsbkValue << 4) + (tmM & 0x0FU); // Month
tsbkValue = (tsbkValue << 5) + (local_tm.tm_mday & 0x1FU); // Day of Month
// Time
tsbkValue = (tsbkValue << 5) + (local_tm.tm_hour & 0x1FU); // Hour
tsbkValue = (tsbkValue << 6) + (local_tm.tm_min & 0x3FU); // Minute
tsbkValue = (tsbkValue << 13) + (m_microslotCount & 0x1FFFU); // Microslot Count
std::unique_ptr<uint8_t[]> tsbk = TSBK::fromValue(tsbkValue);
TSBK::encode(data, tsbk.get(), rawTSBK, noTrellis);
}
// ---------------------------------------------------------------------------
// Private Class Members
// ---------------------------------------------------------------------------
/// <summary>
/// Internal helper to copy the the class.
/// </summary>
/// <param name="data"></param>
void OSP_SYNC_BCAST::copy(const OSP_SYNC_BCAST& data)
{
TSBK::copy(data);
m_microslotCount = data.m_microslotCount;
}

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