op25/op25/gr-op25_repeater/lib/dstar_header.h

131 lines
3.9 KiB
C

/*
* Copyright (C) 2010,2011,2015 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; version 2 of the License.
*
* 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.
*/
/* from OpenDV/DStarRepeater */
#ifndef INCLUDED_DSTAR_HEADER_H
#define INCLUDED_DSTAR_HEADER_H
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include "CCITTChecksumReverse.h"
#include "bit_utils.h"
static inline uint8_t rev_byte(const uint8_t b) {
uint8_t rc = 0;
for (int i=0; i<8; i++) {
rc |= ((b >> i) & 1) << (7-i);
}
return(rc);
}
static inline void make_dstar_header(
uint8_t header_data_buf[480], // result (bits)
const uint8_t flag1, const uint8_t flag2, const uint8_t flag3,
const char RptCall2[],
const char RptCall1[],
const char YourCall[],
const char MyCall1[],
const char MyCall2[])
{
uint8_t m_headerData[60];
static const unsigned int SLOW_DATA_BLOCK_SIZE = 6U;
static const unsigned int SLOW_DATA_FULL_BLOCK_SIZE = SLOW_DATA_BLOCK_SIZE * 10U;
static const unsigned char SLOW_DATA_TYPE_HEADER = 0x50U;
::memset(m_headerData, 'f', SLOW_DATA_FULL_BLOCK_SIZE);
m_headerData[0U] = SLOW_DATA_TYPE_HEADER | 5U;
m_headerData[1U] = flag1;
m_headerData[2U] = flag2;
m_headerData[3U] = flag3;
m_headerData[4U] = RptCall2[0];
m_headerData[5U] = RptCall2[1];
m_headerData[6U] = SLOW_DATA_TYPE_HEADER | 5U;
m_headerData[7U] = RptCall2[2];
m_headerData[8U] = RptCall2[3];
m_headerData[9U] = RptCall2[4];
m_headerData[10U] = RptCall2[5];
m_headerData[11U] = RptCall2[6];
m_headerData[12U] = SLOW_DATA_TYPE_HEADER | 5U;
m_headerData[13U] = RptCall2[7];
m_headerData[14U] = RptCall1[0];
m_headerData[15U] = RptCall1[1];
m_headerData[16U] = RptCall1[2];
m_headerData[17U] = RptCall1[3];
m_headerData[18U] = SLOW_DATA_TYPE_HEADER | 5U;
m_headerData[19U] = RptCall1[4];
m_headerData[20U] = RptCall1[5];
m_headerData[21U] = RptCall1[6];
m_headerData[22U] = RptCall1[7];
m_headerData[23U] = YourCall[0];
m_headerData[24U] = SLOW_DATA_TYPE_HEADER | 5U;
m_headerData[25U] = YourCall[1];
m_headerData[26U] = YourCall[2];
m_headerData[27U] = YourCall[3];
m_headerData[28U] = YourCall[4];
m_headerData[29U] = YourCall[5];
m_headerData[30U] = SLOW_DATA_TYPE_HEADER | 5U;
m_headerData[31U] = YourCall[6];
m_headerData[32U] = YourCall[7];
m_headerData[33U] = MyCall1[0];
m_headerData[34U] = MyCall1[1];
m_headerData[35U] = MyCall1[2];
m_headerData[36U] = SLOW_DATA_TYPE_HEADER | 5U;
m_headerData[37U] = MyCall1[3];
m_headerData[38U] = MyCall1[4];
m_headerData[39U] = MyCall1[5];
m_headerData[40U] = MyCall1[6];
m_headerData[41U] = MyCall1[7];
m_headerData[42U] = SLOW_DATA_TYPE_HEADER | 5U;
m_headerData[43U] = MyCall2[0];
m_headerData[44U] = MyCall2[1];
m_headerData[45U] = MyCall2[2];
m_headerData[46U] = MyCall2[3];
CCCITTChecksumReverse cksum;
cksum.update(m_headerData + 1U, 5U);
cksum.update(m_headerData + 7U, 5U);
cksum.update(m_headerData + 13U, 5U);
cksum.update(m_headerData + 19U, 5U);
cksum.update(m_headerData + 25U, 5U);
cksum.update(m_headerData + 31U, 5U);
cksum.update(m_headerData + 37U, 5U);
cksum.update(m_headerData + 43U, 4U);
unsigned char checkSum[2U];
cksum.result(checkSum);
m_headerData[47U] = checkSum[0];
m_headerData[48U] = SLOW_DATA_TYPE_HEADER | 1U;
m_headerData[49U] = checkSum[1];
for (int i=0; i<SLOW_DATA_FULL_BLOCK_SIZE; i+=3) {
store_i(rev_byte(m_headerData[i] ^ 0x70), header_data_buf+i*8, 8);
store_i(rev_byte(m_headerData[i+1] ^ 0x4f), header_data_buf+((i+1)*8), 8);
store_i(rev_byte(m_headerData[i+2] ^ 0x93), header_data_buf+((i+2)*8), 8);
}
}
#endif /* INCLUDED_DSTAR_HEADER_H */