MMDVM_CM/DMR2M17/BPTC19696.cpp

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2020-11-02 00:11:30 -05:00
/*
* Copyright (C) 2012 by Ian Wraith
* Copyright (C) 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; 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 "BPTC19696.h"
#include "Hamming.h"
#include "Utils.h"
#include <cstdio>
#include <cassert>
#include <cstring>
CBPTC19696::CBPTC19696() :
m_rawData(NULL),
m_deInterData(NULL)
{
m_rawData = new bool[196];
m_deInterData = new bool[196];
}
CBPTC19696::~CBPTC19696()
{
delete[] m_rawData;
delete[] m_deInterData;
}
// The main decode function
void CBPTC19696::decode(const unsigned char* in, unsigned char* out)
{
assert(in != NULL);
assert(out != NULL);
// Get the raw binary
decodeExtractBinary(in);
// Deinterleave
decodeDeInterleave();
// Error check
decodeErrorCheck();
// Extract Data
decodeExtractData(out);
}
// The main encode function
void CBPTC19696::encode(const unsigned char* in, unsigned char* out)
{
assert(in != NULL);
assert(out != NULL);
// Extract Data
encodeExtractData(in);
// Error check
encodeErrorCheck();
// Deinterleave
encodeInterleave();
// Get the raw binary
encodeExtractBinary(out);
}
void CBPTC19696::decodeExtractBinary(const unsigned char* in)
{
// First block
CUtils::byteToBitsBE(in[0U], m_rawData + 0U);
CUtils::byteToBitsBE(in[1U], m_rawData + 8U);
CUtils::byteToBitsBE(in[2U], m_rawData + 16U);
CUtils::byteToBitsBE(in[3U], m_rawData + 24U);
CUtils::byteToBitsBE(in[4U], m_rawData + 32U);
CUtils::byteToBitsBE(in[5U], m_rawData + 40U);
CUtils::byteToBitsBE(in[6U], m_rawData + 48U);
CUtils::byteToBitsBE(in[7U], m_rawData + 56U);
CUtils::byteToBitsBE(in[8U], m_rawData + 64U);
CUtils::byteToBitsBE(in[9U], m_rawData + 72U);
CUtils::byteToBitsBE(in[10U], m_rawData + 80U);
CUtils::byteToBitsBE(in[11U], m_rawData + 88U);
CUtils::byteToBitsBE(in[12U], m_rawData + 96U);
// Handle the two bits
bool bits[8U];
CUtils::byteToBitsBE(in[20U], bits);
m_rawData[98U] = bits[6U];
m_rawData[99U] = bits[7U];
// Second block
CUtils::byteToBitsBE(in[21U], m_rawData + 100U);
CUtils::byteToBitsBE(in[22U], m_rawData + 108U);
CUtils::byteToBitsBE(in[23U], m_rawData + 116U);
CUtils::byteToBitsBE(in[24U], m_rawData + 124U);
CUtils::byteToBitsBE(in[25U], m_rawData + 132U);
CUtils::byteToBitsBE(in[26U], m_rawData + 140U);
CUtils::byteToBitsBE(in[27U], m_rawData + 148U);
CUtils::byteToBitsBE(in[28U], m_rawData + 156U);
CUtils::byteToBitsBE(in[29U], m_rawData + 164U);
CUtils::byteToBitsBE(in[30U], m_rawData + 172U);
CUtils::byteToBitsBE(in[31U], m_rawData + 180U);
CUtils::byteToBitsBE(in[32U], m_rawData + 188U);
}
// Deinterleave the raw data
void CBPTC19696::decodeDeInterleave()
{
for (unsigned int i = 0U; i < 196U; i++)
m_deInterData[i] = false;
// The first bit is R(3) which is not used so can be ignored
for (unsigned int a = 0U; a < 196U; a++) {
// Calculate the interleave sequence
unsigned int interleaveSequence = (a * 181U) % 196U;
// Shuffle the data
m_deInterData[a] = m_rawData[interleaveSequence];
}
}
// Check each row with a Hamming (15,11,3) code and each column with a Hamming (13,9,3) code
void CBPTC19696::decodeErrorCheck()
{
bool fixing;
unsigned int count = 0U;
do {
fixing = false;
// Run through each of the 15 columns
bool col[13U];
for (unsigned int c = 0U; c < 15U; c++) {
unsigned int pos = c + 1U;
for (unsigned int a = 0U; a < 13U; a++) {
col[a] = m_deInterData[pos];
pos = pos + 15U;
}
if (CHamming::decode1393(col)) {
unsigned int pos = c + 1U;
for (unsigned int a = 0U; a < 13U; a++) {
m_deInterData[pos] = col[a];
pos = pos + 15U;
}
fixing = true;
}
}
// Run through each of the 9 rows containing data
for (unsigned int r = 0U; r < 9U; r++) {
unsigned int pos = (r * 15U) + 1U;
if (CHamming::decode15113_2(m_deInterData + pos))
fixing = true;
}
count++;
} while (fixing && count < 5U);
}
// Extract the 96 bits of payload
void CBPTC19696::decodeExtractData(unsigned char* data) const
{
bool bData[96U];
unsigned int pos = 0U;
for (unsigned int a = 4U; a <= 11U; a++, pos++)
bData[pos] = m_deInterData[a];
for (unsigned int a = 16U; a <= 26U; a++, pos++)
bData[pos] = m_deInterData[a];
for (unsigned int a = 31U; a <= 41U; a++, pos++)
bData[pos] = m_deInterData[a];
for (unsigned int a = 46U; a <= 56U; a++, pos++)
bData[pos] = m_deInterData[a];
for (unsigned int a = 61U; a <= 71U; a++, pos++)
bData[pos] = m_deInterData[a];
for (unsigned int a = 76U; a <= 86U; a++, pos++)
bData[pos] = m_deInterData[a];
for (unsigned int a = 91U; a <= 101U; a++, pos++)
bData[pos] = m_deInterData[a];
for (unsigned int a = 106U; a <= 116U; a++, pos++)
bData[pos] = m_deInterData[a];
for (unsigned int a = 121U; a <= 131U; a++, pos++)
bData[pos] = m_deInterData[a];
CUtils::bitsToByteBE(bData + 0U, data[0U]);
CUtils::bitsToByteBE(bData + 8U, data[1U]);
CUtils::bitsToByteBE(bData + 16U, data[2U]);
CUtils::bitsToByteBE(bData + 24U, data[3U]);
CUtils::bitsToByteBE(bData + 32U, data[4U]);
CUtils::bitsToByteBE(bData + 40U, data[5U]);
CUtils::bitsToByteBE(bData + 48U, data[6U]);
CUtils::bitsToByteBE(bData + 56U, data[7U]);
CUtils::bitsToByteBE(bData + 64U, data[8U]);
CUtils::bitsToByteBE(bData + 72U, data[9U]);
CUtils::bitsToByteBE(bData + 80U, data[10U]);
CUtils::bitsToByteBE(bData + 88U, data[11U]);
}
// Extract the 96 bits of payload
void CBPTC19696::encodeExtractData(const unsigned char* in) const
{
bool bData[96U];
CUtils::byteToBitsBE(in[0U], bData + 0U);
CUtils::byteToBitsBE(in[1U], bData + 8U);
CUtils::byteToBitsBE(in[2U], bData + 16U);
CUtils::byteToBitsBE(in[3U], bData + 24U);
CUtils::byteToBitsBE(in[4U], bData + 32U);
CUtils::byteToBitsBE(in[5U], bData + 40U);
CUtils::byteToBitsBE(in[6U], bData + 48U);
CUtils::byteToBitsBE(in[7U], bData + 56U);
CUtils::byteToBitsBE(in[8U], bData + 64U);
CUtils::byteToBitsBE(in[9U], bData + 72U);
CUtils::byteToBitsBE(in[10U], bData + 80U);
CUtils::byteToBitsBE(in[11U], bData + 88U);
for (unsigned int i = 0U; i < 196U; i++)
m_deInterData[i] = false;
unsigned int pos = 0U;
for (unsigned int a = 4U; a <= 11U; a++, pos++)
m_deInterData[a] = bData[pos];
for (unsigned int a = 16U; a <= 26U; a++, pos++)
m_deInterData[a] = bData[pos];
for (unsigned int a = 31U; a <= 41U; a++, pos++)
m_deInterData[a] = bData[pos];
for (unsigned int a = 46U; a <= 56U; a++, pos++)
m_deInterData[a] = bData[pos];
for (unsigned int a = 61U; a <= 71U; a++, pos++)
m_deInterData[a] = bData[pos];
for (unsigned int a = 76U; a <= 86U; a++, pos++)
m_deInterData[a] = bData[pos];
for (unsigned int a = 91U; a <= 101U; a++, pos++)
m_deInterData[a] = bData[pos];
for (unsigned int a = 106U; a <= 116U; a++, pos++)
m_deInterData[a] = bData[pos];
for (unsigned int a = 121U; a <= 131U; a++, pos++)
m_deInterData[a] = bData[pos];
}
// Check each row with a Hamming (15,11,3) code and each column with a Hamming (13,9,3) code
void CBPTC19696::encodeErrorCheck()
{
// Run through each of the 9 rows containing data
for (unsigned int r = 0U; r < 9U; r++) {
unsigned int pos = (r * 15U) + 1U;
CHamming::encode15113_2(m_deInterData + pos);
}
// Run through each of the 15 columns
bool col[13U];
for (unsigned int c = 0U; c < 15U; c++) {
unsigned int pos = c + 1U;
for (unsigned int a = 0U; a < 13U; a++) {
col[a] = m_deInterData[pos];
pos = pos + 15U;
}
CHamming::encode1393(col);
pos = c + 1U;
for (unsigned int a = 0U; a < 13U; a++) {
m_deInterData[pos] = col[a];
pos = pos + 15U;
}
}
}
// Interleave the raw data
void CBPTC19696::encodeInterleave()
{
for (unsigned int i = 0U; i < 196U; i++)
m_rawData[i] = false;
// The first bit is R(3) which is not used so can be ignored
for (unsigned int a = 0U; a < 196U; a++) {
// Calculate the interleave sequence
unsigned int interleaveSequence = (a * 181U) % 196U;
// Unshuffle the data
m_rawData[interleaveSequence] = m_deInterData[a];
}
}
void CBPTC19696::encodeExtractBinary(unsigned char* data)
{
// First block
CUtils::bitsToByteBE(m_rawData + 0U, data[0U]);
CUtils::bitsToByteBE(m_rawData + 8U, data[1U]);
CUtils::bitsToByteBE(m_rawData + 16U, data[2U]);
CUtils::bitsToByteBE(m_rawData + 24U, data[3U]);
CUtils::bitsToByteBE(m_rawData + 32U, data[4U]);
CUtils::bitsToByteBE(m_rawData + 40U, data[5U]);
CUtils::bitsToByteBE(m_rawData + 48U, data[6U]);
CUtils::bitsToByteBE(m_rawData + 56U, data[7U]);
CUtils::bitsToByteBE(m_rawData + 64U, data[8U]);
CUtils::bitsToByteBE(m_rawData + 72U, data[9U]);
CUtils::bitsToByteBE(m_rawData + 80U, data[10U]);
CUtils::bitsToByteBE(m_rawData + 88U, data[11U]);
// Handle the two bits
unsigned char byte;
CUtils::bitsToByteBE(m_rawData + 96U, byte);
data[12U] = (data[12U] & 0x3FU) | ((byte >> 0) & 0xC0U);
data[20U] = (data[20U] & 0xFCU) | ((byte >> 4) & 0x03U);
// Second block
CUtils::bitsToByteBE(m_rawData + 100U, data[21U]);
CUtils::bitsToByteBE(m_rawData + 108U, data[22U]);
CUtils::bitsToByteBE(m_rawData + 116U, data[23U]);
CUtils::bitsToByteBE(m_rawData + 124U, data[24U]);
CUtils::bitsToByteBE(m_rawData + 132U, data[25U]);
CUtils::bitsToByteBE(m_rawData + 140U, data[26U]);
CUtils::bitsToByteBE(m_rawData + 148U, data[27U]);
CUtils::bitsToByteBE(m_rawData + 156U, data[28U]);
CUtils::bitsToByteBE(m_rawData + 164U, data[29U]);
CUtils::bitsToByteBE(m_rawData + 172U, data[30U]);
CUtils::bitsToByteBE(m_rawData + 180U, data[31U]);
CUtils::bitsToByteBE(m_rawData + 188U, data[32U]);
}