MMDVM_CM/YSF2DMR/DMREmbeddedData.cpp

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2018-05-28 11:02:35 -04:00
/*
* Copyright (C) 2015,2016,2017 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 "DMREmbeddedData.h"
#include "Hamming.h"
#include "Utils.h"
#include "CRC.h"
#include <cstdio>
#include <cassert>
#include <cstring>
CDMREmbeddedData::CDMREmbeddedData() :
m_raw(NULL),
m_state(LCS_NONE),
m_data(NULL),
m_FLCO(FLCO_GROUP),
m_valid(false)
{
m_raw = new bool[128U];
m_data = new bool[72U];
}
CDMREmbeddedData::~CDMREmbeddedData()
{
delete[] m_raw;
delete[] m_data;
}
// Add LC data (which may consist of 4 blocks) to the data store
bool CDMREmbeddedData::addData(const unsigned char* data, unsigned char lcss)
{
assert(data != NULL);
bool rawData[40U];
CUtils::byteToBitsBE(data[14U], rawData + 0U);
CUtils::byteToBitsBE(data[15U], rawData + 8U);
CUtils::byteToBitsBE(data[16U], rawData + 16U);
CUtils::byteToBitsBE(data[17U], rawData + 24U);
CUtils::byteToBitsBE(data[18U], rawData + 32U);
// Is this the first block of a 4 block embedded LC ?
if (lcss == 1U) {
for (unsigned int a = 0U; a < 32U; a++)
m_raw[a] = rawData[a + 4U];
// Show we are ready for the next LC block
m_state = LCS_FIRST;
m_valid = false;
return false;
}
// Is this the 2nd block of a 4 block embedded LC ?
if (lcss == 3U && m_state == LCS_FIRST) {
for (unsigned int a = 0U; a < 32U; a++)
m_raw[a + 32U] = rawData[a + 4U];
// Show we are ready for the next LC block
m_state = LCS_SECOND;
return false;
}
// Is this the 3rd block of a 4 block embedded LC ?
if (lcss == 3U && m_state == LCS_SECOND) {
for (unsigned int a = 0U; a < 32U; a++)
m_raw[a + 64U] = rawData[a + 4U];
// Show we are ready for the final LC block
m_state = LCS_THIRD;
return false;
}
// Is this the final block of a 4 block embedded LC ?
if (lcss == 2U && m_state == LCS_THIRD) {
for (unsigned int a = 0U; a < 32U; a++)
m_raw[a + 96U] = rawData[a + 4U];
// Show that we're not ready for any more data
m_state = LCS_NONE;
// Process the complete data block
decodeEmbeddedData();
if (m_valid)
encodeEmbeddedData();
return m_valid;
}
return false;
}
void CDMREmbeddedData::setLC(const CDMRLC& lc)
{
lc.getData(m_data);
m_FLCO = lc.getFLCO();
m_valid = true;
encodeEmbeddedData();
}
void CDMREmbeddedData::encodeEmbeddedData()
{
unsigned int crc;
CCRC::encodeFiveBit(m_data, crc);
bool data[128U];
::memset(data, 0x00U, 128U * sizeof(bool));
data[106U] = (crc & 0x01U) == 0x01U;
data[90U] = (crc & 0x02U) == 0x02U;
data[74U] = (crc & 0x04U) == 0x04U;
data[58U] = (crc & 0x08U) == 0x08U;
data[42U] = (crc & 0x10U) == 0x10U;
unsigned int b = 0U;
for (unsigned int a = 0U; a < 11U; a++, b++)
data[a] = m_data[b];
for (unsigned int a = 16U; a < 27U; a++, b++)
data[a] = m_data[b];
for (unsigned int a = 32U; a < 42U; a++, b++)
data[a] = m_data[b];
for (unsigned int a = 48U; a < 58U; a++, b++)
data[a] = m_data[b];
for (unsigned int a = 64U; a < 74U; a++, b++)
data[a] = m_data[b];
for (unsigned int a = 80U; a < 90U; a++, b++)
data[a] = m_data[b];
for (unsigned int a = 96U; a < 106U; a++, b++)
data[a] = m_data[b];
// Hamming (16,11,4) check each row except the last one
for (unsigned int a = 0U; a < 112U; a += 16U)
CHamming::encode16114(data + a);
// Add the parity bits for each column
for (unsigned int a = 0U; a < 16U; a++)
data[a + 112U] = data[a + 0U] ^ data[a + 16U] ^ data[a + 32U] ^ data[a + 48U] ^ data[a + 64U] ^ data[a + 80U] ^ data[a + 96U];
// The data is packed downwards in columns
b = 0U;
for (unsigned int a = 0U; a < 128U; a++) {
m_raw[a] = data[b];
b += 16U;
if (b > 127U)
b -= 127U;
}
}
unsigned char CDMREmbeddedData::getData(unsigned char* data, unsigned char n) const
{
assert(data != NULL);
if (n >= 1U && n < 5U) {
n--;
bool bits[40U];
::memset(bits, 0x00U, 40U * sizeof(bool));
::memcpy(bits + 4U, m_raw + n * 32U, 32U * sizeof(bool));
unsigned char bytes[5U];
CUtils::bitsToByteBE(bits + 0U, bytes[0U]);
CUtils::bitsToByteBE(bits + 8U, bytes[1U]);
CUtils::bitsToByteBE(bits + 16U, bytes[2U]);
CUtils::bitsToByteBE(bits + 24U, bytes[3U]);
CUtils::bitsToByteBE(bits + 32U, bytes[4U]);
data[14U] = (data[14U] & 0xF0U) | (bytes[0U] & 0x0FU);
data[15U] = bytes[1U];
data[16U] = bytes[2U];
data[17U] = bytes[3U];
data[18U] = (data[18U] & 0x0FU) | (bytes[4U] & 0xF0U);
switch (n) {
case 0U:
return 1U;
case 3U:
return 2U;
default:
return 3U;
}
} else {
data[14U] &= 0xF0U;
data[15U] = 0x00U;
data[16U] = 0x00U;
data[17U] = 0x00U;
data[18U] &= 0x0FU;
return 0U;
}
}
// Unpack and error check an embedded LC
void CDMREmbeddedData::decodeEmbeddedData()
{
// The data is unpacked downwards in columns
bool data[128U];
::memset(data, 0x00U, 128U * sizeof(bool));
unsigned int b = 0U;
for (unsigned int a = 0U; a < 128U; a++) {
data[b] = m_raw[a];
b += 16U;
if (b > 127U)
b -= 127U;
}
// Hamming (16,11,4) check each row except the last one
for (unsigned int a = 0U; a < 112U; a += 16U) {
if (!CHamming::decode16114(data + a))
return;
}
// Check the parity bits
for (unsigned int a = 0U; a < 16U; a++) {
bool parity = data[a + 0U] ^ data[a + 16U] ^ data[a + 32U] ^ data[a + 48U] ^ data[a + 64U] ^ data[a + 80U] ^ data[a + 96U] ^ data[a + 112U];
if (parity)
return;
}
// We have passed the Hamming check so extract the actual payload
b = 0U;
for (unsigned int a = 0U; a < 11U; a++, b++)
m_data[b] = data[a];
for (unsigned int a = 16U; a < 27U; a++, b++)
m_data[b] = data[a];
for (unsigned int a = 32U; a < 42U; a++, b++)
m_data[b] = data[a];
for (unsigned int a = 48U; a < 58U; a++, b++)
m_data[b] = data[a];
for (unsigned int a = 64U; a < 74U; a++, b++)
m_data[b] = data[a];
for (unsigned int a = 80U; a < 90U; a++, b++)
m_data[b] = data[a];
for (unsigned int a = 96U; a < 106U; a++, b++)
m_data[b] = data[a];
// Extract the 5 bit CRC
unsigned int crc = 0U;
if (data[42]) crc += 16U;
if (data[58]) crc += 8U;
if (data[74]) crc += 4U;
if (data[90]) crc += 2U;
if (data[106]) crc += 1U;
// Now CRC check this
if (!CCRC::checkFiveBit(m_data, crc))
return;
m_valid = true;
// Extract the FLCO
unsigned char flco;
CUtils::bitsToByteBE(m_data + 0U, flco);
m_FLCO = FLCO(flco & 0x3FU);
}
CDMRLC* CDMREmbeddedData::getLC() const
{
if (!m_valid)
return NULL;
if (m_FLCO != FLCO_GROUP && m_FLCO != FLCO_USER_USER)
return NULL;
return new CDMRLC(m_data);
}
bool CDMREmbeddedData::isValid() const
{
return m_valid;
}
FLCO CDMREmbeddedData::getFLCO() const
{
return m_FLCO;
}
void CDMREmbeddedData::reset()
{
m_state = LCS_NONE;
m_valid = false;
}
bool CDMREmbeddedData::getRawData(unsigned char* data) const
{
assert(data != NULL);
if (!m_valid)
return false;
CUtils::bitsToByteBE(m_data + 0U, data[0U]);
CUtils::bitsToByteBE(m_data + 8U, data[1U]);
CUtils::bitsToByteBE(m_data + 16U, data[2U]);
CUtils::bitsToByteBE(m_data + 24U, data[3U]);
CUtils::bitsToByteBE(m_data + 32U, data[4U]);
CUtils::bitsToByteBE(m_data + 40U, data[5U]);
CUtils::bitsToByteBE(m_data + 48U, data[6U]);
CUtils::bitsToByteBE(m_data + 56U, data[7U]);
CUtils::bitsToByteBE(m_data + 64U, data[8U]);
return true;
}