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A semi-working P25 repeater without much FEC.

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This commit is contained in:
Jonathan Naylor 2016-09-12 23:26:05 +01:00
parent 7171af365d
commit 34e0d10343
29 changed files with 713 additions and 74 deletions
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P25NID.cpp Normal file
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/*
* Copyright (C) 2016 by Jonathan Naylor G4KLX
*
* 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 "P25NID.h"
#include "P25Defines.h"
#include <cstdio>
#include <cassert>
const unsigned char BIT_MASK_TABLE[] = { 0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U };
#define WRITE_BIT(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
#define READ_BIT(p,i) (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])
CP25NID::CP25NID() :
m_duid(0U),
m_nac(0U)
{
}
CP25NID::~CP25NID()
{
}
void CP25NID::process(unsigned char* data)
{
assert(data != NULL);
unsigned char nid[P25_NID_LENGTH_BYTES];
unsigned int n = 0U;
for (unsigned int offset = 48U; offset < 114U; offset++) {
if (offset != 70U && offset != 71U) {
bool b = READ_BIT(data, offset);
WRITE_BIT(nid, n, b);
n++;
}
}
// XXX Process FEC here
m_duid = nid[1U] & 0x0FU;
m_nac = (nid[0U] << 4) & 0xFF0U;
m_nac |= (nid[1U] >> 4) & 0x00FU;
n = 0U;
for (unsigned int offset = 48U; offset < 114U; offset++) {
if (offset != 70U && offset != 71U) {
bool b = READ_BIT(nid, n);
WRITE_BIT(data, offset, b);
n++;
}
}
}
unsigned char CP25NID::getDUID() const
{
return m_duid;
}
unsigned int CP25NID::getNAC() const
{
return m_nac;
}