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			323 lines
		
	
	
		
			7.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			323 lines
		
	
	
		
			7.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*
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 *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
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 *
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 *   This program is free software; you can redistribute it and/or modify
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 *   it under the terms of the GNU General Public License as published by
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 *   the Free Software Foundation; either version 2 of the License, or
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 *   (at your option) any later version.
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 *
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 *   This program is distributed in the hope that it will be useful,
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 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 *   GNU General Public License for more details.
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 *
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 *   You should have received a copy of the GNU General Public License
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 *   along with this program; if not, write to the Free Software
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 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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 */
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#include "DMREmbeddedData.h"
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#include "Hamming.h"
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#include "Utils.h"
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#include "CRC.h"
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#include <cstdio>
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#include <cassert>
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#include <cstring>
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CDMREmbeddedData::CDMREmbeddedData() :
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m_raw(NULL),
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m_state(LCS_NONE),
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m_data(NULL),
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m_FLCO(FLCO_GROUP),
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m_valid(false)
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{
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	m_raw  = new bool[128U];
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	m_data = new bool[72U];
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}
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CDMREmbeddedData::~CDMREmbeddedData()
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{
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	delete[] m_raw;
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	delete[] m_data;
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}
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// Add LC data (which may consist of 4 blocks) to the data store
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bool CDMREmbeddedData::addData(const unsigned char* data, unsigned char lcss)
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{
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	assert(data != NULL);
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	bool rawData[40U];
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	CUtils::byteToBitsBE(data[14U], rawData + 0U);
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	CUtils::byteToBitsBE(data[15U], rawData + 8U);
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	CUtils::byteToBitsBE(data[16U], rawData + 16U);
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	CUtils::byteToBitsBE(data[17U], rawData + 24U);
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	CUtils::byteToBitsBE(data[18U], rawData + 32U);
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	// Is this the first block of a 4 block embedded LC ?
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	if (lcss == 1U) {
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		for (unsigned int a = 0U; a < 32U; a++)
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			m_raw[a] = rawData[a + 4U];
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		// Show we are ready for the next LC block
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		m_state = LCS_FIRST;
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		m_valid = false;
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		return false;
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	}
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	// Is this the 2nd block of a 4 block embedded LC ?
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	if (lcss == 3U && m_state == LCS_FIRST) {
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		for (unsigned int a = 0U; a < 32U; a++)
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			m_raw[a + 32U] = rawData[a + 4U];
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		// Show we are ready for the next LC block
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		m_state = LCS_SECOND;
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		return false;
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	}
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	// Is this the 3rd block of a 4 block embedded LC ?
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	if (lcss == 3U && m_state == LCS_SECOND) {
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		for (unsigned int a = 0U; a < 32U; a++)
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			m_raw[a + 64U] = rawData[a + 4U];
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		// Show we are ready for the final LC block
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		m_state = LCS_THIRD;
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		return false;
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	}
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	// Is this the final block of a 4 block embedded LC ?
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	if (lcss == 2U && m_state == LCS_THIRD)	{
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		for (unsigned int a = 0U; a < 32U; a++)
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			m_raw[a + 96U] = rawData[a + 4U];
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		// Show that we're not ready for any more data
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		m_state = LCS_NONE;
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		// Process the complete data block
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		decodeEmbeddedData();
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		if (m_valid)
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			encodeEmbeddedData();
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		return m_valid;
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	}
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	return false;
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}
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void CDMREmbeddedData::setLC(const CDMRLC& lc)
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{
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	lc.getData(m_data);
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	m_FLCO  = lc.getFLCO();
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	m_valid = true;
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	encodeEmbeddedData();
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}
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void CDMREmbeddedData::encodeEmbeddedData()
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{
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	unsigned int crc;
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	CCRC::encodeFiveBit(m_data, crc);
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	bool data[128U];
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	::memset(data, 0x00U, 128U * sizeof(bool));
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	data[106U] = (crc & 0x01U) == 0x01U;
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	data[90U]  = (crc & 0x02U) == 0x02U;
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	data[74U]  = (crc & 0x04U) == 0x04U;
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	data[58U]  = (crc & 0x08U) == 0x08U;
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	data[42U]  = (crc & 0x10U) == 0x10U;
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	unsigned int b = 0U;
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	for (unsigned int a = 0U; a < 11U; a++, b++)
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		data[a] = m_data[b];
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	for (unsigned int a = 16U; a < 27U; a++, b++)
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		data[a] = m_data[b];
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	for (unsigned int a = 32U; a < 42U; a++, b++)
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		data[a] = m_data[b];
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	for (unsigned int a = 48U; a < 58U; a++, b++)
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		data[a] = m_data[b];
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	for (unsigned int a = 64U; a < 74U; a++, b++)
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		data[a] = m_data[b];
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	for (unsigned int a = 80U; a < 90U; a++, b++)
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		data[a] = m_data[b];
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	for (unsigned int a = 96U; a < 106U; a++, b++)
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		data[a] = m_data[b];
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	// Hamming (16,11,4) check each row except the last one
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	for (unsigned int a = 0U; a < 112U; a += 16U)
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		CHamming::encode16114(data + a);
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	// Add the parity bits for each column
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	for (unsigned int a = 0U; a < 16U; a++)
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		data[a + 112U] = data[a + 0U] ^ data[a + 16U] ^ data[a + 32U] ^ data[a + 48U] ^ data[a + 64U] ^ data[a + 80U] ^ data[a + 96U];
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	// The data is packed downwards in columns
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	b = 0U;
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	for (unsigned int a = 0U; a < 128U; a++) {
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		m_raw[a] = data[b];
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		b += 16U;
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		if (b > 127U)
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			b -= 127U;
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	}
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}
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unsigned char CDMREmbeddedData::getData(unsigned char* data, unsigned char n) const
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{
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	assert(data != NULL);
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	if (n >= 1U && n < 5U) {
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		n--;
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		bool bits[40U];
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		::memset(bits, 0x00U, 40U * sizeof(bool));
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		::memcpy(bits + 4U, m_raw + n * 32U, 32U * sizeof(bool));
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		unsigned char bytes[5U];
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		CUtils::bitsToByteBE(bits + 0U,  bytes[0U]);
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		CUtils::bitsToByteBE(bits + 8U,  bytes[1U]);
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		CUtils::bitsToByteBE(bits + 16U, bytes[2U]);
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		CUtils::bitsToByteBE(bits + 24U, bytes[3U]);
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		CUtils::bitsToByteBE(bits + 32U, bytes[4U]);
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		data[14U] = (data[14U] & 0xF0U) | (bytes[0U] & 0x0FU);
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		data[15U] = bytes[1U];
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		data[16U] = bytes[2U];
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		data[17U] = bytes[3U];
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		data[18U] = (data[18U] & 0x0FU) | (bytes[4U] & 0xF0U);
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		switch (n) {
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		case 0U:
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			return 1U;
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		case 3U:
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			return 2U;
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		default:
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			return 3U;
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		}
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	} else {
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		data[14U] &= 0xF0U;
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		data[15U]  = 0x00U;
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		data[16U]  = 0x00U;
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		data[17U]  = 0x00U;
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		data[18U] &= 0x0FU;
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		return 0U;
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	}
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}
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// Unpack and error check an embedded LC
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void CDMREmbeddedData::decodeEmbeddedData()
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{
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	// The data is unpacked downwards in columns
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	bool data[128U];
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	::memset(data, 0x00U, 128U * sizeof(bool));
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	unsigned int b = 0U;
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	for (unsigned int a = 0U; a < 128U; a++) {
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		data[b] = m_raw[a];
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		b += 16U;
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		if (b > 127U)
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			b -= 127U;
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	}
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	// Hamming (16,11,4) check each row except the last one
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	for (unsigned int a = 0U; a < 112U; a += 16U) {
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		if (!CHamming::decode16114(data + a))
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			return;
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	}
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	// Check the parity bits
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	for (unsigned int a = 0U; a < 16U; a++) {
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		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];
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		if (parity)
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			return;
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	}
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	// We have passed the Hamming check so extract the actual payload
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	b = 0U;
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	for (unsigned int a = 0U; a < 11U; a++, b++)
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		m_data[b] = data[a];
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	for (unsigned int a = 16U; a < 27U; a++, b++)
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		m_data[b] = data[a];
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	for (unsigned int a = 32U; a < 42U; a++, b++)
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		m_data[b] = data[a];
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	for (unsigned int a = 48U; a < 58U; a++, b++)
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		m_data[b] = data[a];
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	for (unsigned int a = 64U; a < 74U; a++, b++)
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		m_data[b] = data[a];
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	for (unsigned int a = 80U; a < 90U; a++, b++)
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		m_data[b] = data[a];
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	for (unsigned int a = 96U; a < 106U; a++, b++)
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		m_data[b] = data[a];
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	// Extract the 5 bit CRC
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	unsigned int crc = 0U;
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	if (data[42])  crc += 16U;
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	if (data[58])  crc += 8U;
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	if (data[74])  crc += 4U;
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	if (data[90])  crc += 2U;
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	if (data[106]) crc += 1U;
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	// Now CRC check this
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	if (!CCRC::checkFiveBit(m_data, crc))
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		return;
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	m_valid = true;
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	// Extract the FLCO
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	unsigned char flco;
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	CUtils::bitsToByteBE(m_data + 0U, flco);
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	m_FLCO = FLCO(flco & 0x3FU);
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}
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CDMRLC* CDMREmbeddedData::getLC() const
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{
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	if (!m_valid)
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		return NULL;
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	if (m_FLCO != FLCO_GROUP && m_FLCO != FLCO_USER_USER)
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		return NULL;
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	return new CDMRLC(m_data);
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}
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bool CDMREmbeddedData::isValid() const
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{
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	return m_valid;
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}
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FLCO CDMREmbeddedData::getFLCO() const
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{
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	return m_FLCO;
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}
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void CDMREmbeddedData::reset()
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{
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	m_state = LCS_NONE;
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	m_valid = false;
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}
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bool CDMREmbeddedData::getRawData(unsigned char* data) const
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{
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	assert(data != NULL);
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	if (!m_valid)
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		return false;
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	CUtils::bitsToByteBE(m_data + 0U,  data[0U]);
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	CUtils::bitsToByteBE(m_data + 8U,  data[1U]);
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	CUtils::bitsToByteBE(m_data + 16U, data[2U]);
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	CUtils::bitsToByteBE(m_data + 24U, data[3U]);
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	CUtils::bitsToByteBE(m_data + 32U, data[4U]);
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	CUtils::bitsToByteBE(m_data + 40U, data[5U]);
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	CUtils::bitsToByteBE(m_data + 48U, data[6U]);
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	CUtils::bitsToByteBE(m_data + 56U, data[7U]);
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	CUtils::bitsToByteBE(m_data + 64U, data[8U]);
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	return true;
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}
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