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SSB_HighSpeed_Modem/hsmodem/fec/schifra_error_processes.hpp

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/*
(**************************************************************************)
(* *)
(* Schifra *)
(* Reed-Solomon Error Correcting Code Library *)
(* *)
(* Release Version 0.0.1 *)
(* http://www.schifra.com *)
(* Copyright (c) 2000-2020 Arash Partow, All Rights Reserved. *)
(* *)
(* The Schifra Reed-Solomon error correcting code library and all its *)
(* components are supplied under the terms of the General Schifra License *)
(* agreement. The contents of the Schifra Reed-Solomon error correcting *)
(* code library and all its components may not be copied or disclosed *)
(* except in accordance with the terms of that agreement. *)
(* *)
(* URL: http://www.schifra.com/license.html *)
(* *)
(**************************************************************************)
*/
#ifndef INCLUDE_SCHIFRA_ERROR_PROCESSES_HPP
#define INCLUDE_SCHIFRA_ERROR_PROCESSES_HPP
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <deque>
#include <vector>
#include "schifra_reed_solomon_block.hpp"
#include "schifra_fileio.hpp"
namespace schifra
{
template <std::size_t code_length, std::size_t fec_length>
inline void add_erasure_error(const std::size_t& position, reed_solomon::block<code_length,fec_length>& block)
{
block[position] = (~block[position]) & 0xFF; // Or one can simply equate to zero
}
template <std::size_t code_length, std::size_t fec_length>
inline void add_error(const std::size_t& position, reed_solomon::block<code_length,fec_length>& block)
{
block[position] = (~block[position]) & 0xFF;
}
template <std::size_t code_length, std::size_t fec_length>
inline void add_error_4bit_symbol(const std::size_t& position, reed_solomon::block<code_length,fec_length>& block)
{
block[position] = (~block[position]) & 0x0F;
}
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_all_errors00(reed_solomon::block<code_length,fec_length>& rsblock,
const std::size_t& start_position,
const std::size_t& scale = 1)
{
for (std::size_t i = 0; i < (fec_length >> 1); ++i)
{
add_error((start_position + scale * i) % code_length,rsblock);
}
}
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_all_errors_wth_mask(reed_solomon::block<code_length,fec_length>& rsblock,
const std::size_t& start_position,
const int& mask,
const std::size_t& scale = 1)
{
for (std::size_t i = 0; i < (fec_length >> 1); ++i)
{
std::size_t position = (start_position + scale * i) % code_length;
rsblock[position] = (~rsblock[position]) & mask;
}
}
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_all_errors(schifra::reed_solomon::block<code_length,fec_length>& rsblock,
const std::size_t error_count,
const std::size_t& start_position,
const std::size_t& scale = 1)
{
for (std::size_t i = 0; i < error_count; ++i)
{
add_error((start_position + scale * i) % code_length,rsblock);
}
}
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_all_erasures00(reed_solomon::block<code_length,fec_length>& rsblock,
reed_solomon::erasure_locations_t& erasure_list,
const std::size_t& start_position,
const std::size_t& scale = 1)
{
std::size_t erasures[code_length];
for (std::size_t i = 0; i < code_length; ++i) erasures[i] = 0;
for (std::size_t i = 0; i < fec_length; ++i)
{
std::size_t error_position = (start_position + scale * i) % code_length;
add_erasure_error(error_position,rsblock);
erasures[error_position] = 1;
}
for (std::size_t i = 0; i < code_length; ++i)
{
if (erasures[i] == 1) erasure_list.push_back(i);
}
}
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_all_erasures(reed_solomon::block<code_length,fec_length>& rsblock,
reed_solomon::erasure_locations_t& erasure_list,
const std::size_t erasure_count,
const std::size_t& start_position,
const std::size_t& scale = 1)
{
std::size_t erasures[code_length];
for (std::size_t i = 0; i < code_length; ++i) erasures[i] = 0;
for (std::size_t i = 0; i < erasure_count; ++i)
{
/* Note: Must make sure duplicate erasures are not added */
std::size_t error_position = (start_position + scale * i) % code_length;
add_erasure_error(error_position,rsblock);
erasures[error_position] = 1;
}
for (std::size_t i = 0; i < code_length; ++i)
{
if (erasures[i] == 1) erasure_list.push_back(i);
}
}
namespace error_mode
{
enum type
{
errors_erasures, // Errors first then erasures
erasures_errors // Erasures first then errors
};
}
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_errors_erasures(reed_solomon::block<code_length,fec_length>& rsblock,
const error_mode::type& mode,
const std::size_t& start_position,
const std::size_t& erasure_count,
reed_solomon::erasure_locations_t& erasure_list,
const std::size_t between_space = 0)
{
std::size_t error_count = (fec_length - erasure_count) >> 1;
if ((2 * error_count) + erasure_count > fec_length)
{
std::cout << "corrupt_message_errors_erasures() - ERROR Too many erasures and errors!" << std::endl;
std::cout << "Error Count: " << error_count << std::endl;
std::cout << "Erasure Count: " << error_count << std::endl;
return;
}
std::size_t erasures[code_length];
for (std::size_t i = 0; i < code_length; ++i) erasures[i] = 0;
std::size_t error_position = 0;
switch (mode)
{
case error_mode::erasures_errors : {
for (std::size_t i = 0; i < erasure_count; ++i)
{
error_position = (start_position + i) % code_length;
add_erasure_error(error_position,rsblock);
erasures[error_position] = 1;
}
for (std::size_t i = 0; i < error_count; ++i)
{
error_position = (start_position + erasure_count + between_space + i) % code_length;
add_error(error_position,rsblock);
}
}
break;
case error_mode::errors_erasures : {
for (std::size_t i = 0; i < error_count; ++i)
{
error_position = (start_position + i) % code_length;
add_error(error_position,rsblock);
}
for (std::size_t i = 0; i < erasure_count; ++i)
{
error_position = (start_position + error_count + between_space + i) % code_length;
add_erasure_error(error_position,rsblock);
erasures[error_position] = 1;
}
}
break;
}
for (std::size_t i = 0; i < code_length; ++i)
{
if (erasures[i] == 1) erasure_list.push_back(i);
}
}
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_interleaved_errors_erasures(reed_solomon::block<code_length,fec_length>& rsblock,
const std::size_t& start_position,
const std::size_t& erasure_count,
reed_solomon::erasure_locations_t& erasure_list)
{
std::size_t error_count = (fec_length - erasure_count) >> 1;
if ((2 * error_count) + erasure_count > fec_length)
{
std::cout << "corrupt_message_interleaved_errors_erasures() - [1] ERROR Too many erasures and errors!" << std::endl;
std::cout << "Error Count: " << error_count << std::endl;
std::cout << "Erasure Count: " << error_count << std::endl;
return;
}
std::size_t erasures[code_length];
for (std::size_t i = 0; i < code_length; ++i) erasures[i] = 0;
std::size_t e = 0;
std::size_t s = 0;
std::size_t i = 0;
while ((e < error_count) || (s < erasure_count) || (i < (error_count + erasure_count)))
{
std::size_t error_position = (start_position + i) % code_length;
if (((i & 0x01) == 0) && (s < erasure_count))
{
add_erasure_error(error_position,rsblock);
erasures[error_position] = 1;
s++;
}
else if (((i & 0x01) == 1) && (e < error_count))
{
e++;
add_error(error_position,rsblock);
}
++i;
}
for (std::size_t j = 0; j < code_length; ++j)
{
if (erasures[j] == 1) erasure_list.push_back(j);
}
if ((2 * e) + erasure_list.size() > fec_length)
{
std::cout << "corrupt_message_interleaved_errors_erasures() - [2] ERROR Too many erasures and errors!" << std::endl;
std::cout << "Error Count: " << error_count << std::endl;
std::cout << "Erasure Count: " << error_count << std::endl;
return;
}
}
namespace details
{
template <std::size_t code_length, std::size_t fec_length, bool t>
struct corrupt_message_all_errors_segmented_impl
{
static void process(reed_solomon::block<code_length,fec_length>& rsblock,
const std::size_t& start_position,
const std::size_t& distance_between_blocks = 1)
{
std::size_t block_1_error_count = (fec_length >> 2);
std::size_t block_2_error_count = (fec_length >> 1) - block_1_error_count;
for (std::size_t i = 0; i < block_1_error_count; ++i)
{
add_error((start_position + i) % code_length,rsblock);
}
std::size_t new_start_position = (start_position + (block_1_error_count)) + distance_between_blocks;
for (std::size_t i = 0; i < block_2_error_count; ++i)
{
add_error((new_start_position + i) % code_length,rsblock);
}
}
};
template <std::size_t code_length, std::size_t fec_length>
struct corrupt_message_all_errors_segmented_impl<code_length,fec_length,false>
{
static void process(reed_solomon::block<code_length,fec_length>&,
const std::size_t&, const std::size_t&)
{}
};
}
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_all_errors_segmented(reed_solomon::block<code_length,fec_length>& rsblock,
const std::size_t& start_position,
const std::size_t& distance_between_blocks = 1)
{
details::corrupt_message_all_errors_segmented_impl<code_length,fec_length,(fec_length > 2)>::
process(rsblock,start_position,distance_between_blocks);
}
inline bool check_for_duplicate_erasures(const std::vector<int>& erasure_list)
{
for (std::size_t i = 0; i < erasure_list.size(); ++i)
{
for (std::size_t j = i + 1; j < erasure_list.size(); ++j)
{
if (erasure_list[i] == erasure_list[j])
{
return false;
}
}
}
return true;
}
inline void dump_erasure_list(const schifra::reed_solomon::erasure_locations_t& erasure_list)
{
for (std::size_t i = 0; i < erasure_list.size(); ++i)
{
std::cout << "[" << i << "," << erasure_list[i] << "] ";
}
std::cout << std::endl;
}
template <std::size_t code_length, std::size_t fec_length>
inline bool is_block_equivelent(const reed_solomon::block<code_length,fec_length>& rsblock,
const std::string& data,
const bool display = false,
const bool all_errors = false)
{
std::string::const_iterator it = data.begin();
bool error_found = false;
for (std::size_t i = 0; i < code_length - fec_length; ++i, ++it)
{
if (static_cast<char>(rsblock.data[i] & 0xFF) != (*it))
{
error_found = true;
if (display)
{
printf("is_block_equivelent() - Error at loc : %02d\td1: %02X\td2: %02X\n",
static_cast<unsigned int>(i),
rsblock.data[i],
static_cast<unsigned char>(*it));
}
if (!all_errors)
return false;
}
}
return !error_found;
}
template <std::size_t code_length, std::size_t fec_length>
inline bool are_blocks_equivelent(const reed_solomon::block<code_length,fec_length>& block1,
const reed_solomon::block<code_length,fec_length>& block2,
const std::size_t span = code_length,
const bool display = false,
const bool all_errors = false)
{
bool error_found = false;
for (std::size_t i = 0; i < span; ++i)
{
if (block1[i] != block2[i])
{
error_found = true;
if (display)
{
printf("are_blocks_equivelent() - Error at loc : %02d\td1: %04X\td2: %04X\n",
static_cast<unsigned int>(i),
block1[i],
block2[i]);
}
if (!all_errors)
return false;
}
}
return !error_found;
}
template <std::size_t code_length, std::size_t fec_length, std::size_t stack_size>
inline bool block_stacks_equivelent(const reed_solomon::block<code_length,fec_length> block_stack1[stack_size],
const reed_solomon::block<code_length,fec_length> block_stack2[stack_size])
{
for (std::size_t i = 0; i < stack_size; ++i)
{
if (!are_blocks_equivelent(block_stack1[i],block_stack2[i]))
{
return false;
}
}
return true;
}
template <std::size_t block_length, std::size_t stack_size>
inline bool block_stacks_equivelent(const reed_solomon::data_block<std::size_t,block_length> block_stack1[stack_size],
const reed_solomon::data_block<std::size_t,block_length> block_stack2[stack_size])
{
for (std::size_t i = 0; i < stack_size; ++i)
{
for (std::size_t j = 0; j < block_length; ++j)
{
if (block_stack1[i][j] != block_stack2[i][j])
{
return false;
}
}
}
return true;
}
inline void corrupt_file_with_burst_errors(const std::string& file_name,
const long& start_position,
const long& burst_length)
{
if (!schifra::fileio::file_exists(file_name))
{
std::cout << "corrupt_file() - Error: " << file_name << " does not exist!" << std::endl;
return;
}
if (static_cast<std::size_t>(start_position + burst_length) >= schifra::fileio::file_size(file_name))
{
std::cout << "corrupt_file() - Error: Burst error out of bounds." << std::endl;
return;
}
std::vector<char> data(burst_length);
std::ifstream ifile(file_name.c_str(), std::ios::in | std::ios::binary);
if (!ifile)
{
return;
}
ifile.seekg(start_position,std::ios_base::beg);
ifile.read(&data[0],burst_length);
ifile.close();
for (long i = 0; i < burst_length; ++i)
{
data[i] = ~data[i];
}
std::ofstream ofile(file_name.c_str(), std::ios::in | std::ios::out | std::ios::binary);
if (!ofile)
{
return;
}
ofile.seekp(start_position,std::ios_base::beg);
ofile.write(&data[0],burst_length);
ofile.close();
}
static const std::size_t global_random_error_index[] =
{
13, 170, 148, 66, 228, 208, 182, 92,
4, 137, 97, 99, 237, 151, 15, 0,
119, 243, 41, 222, 33, 211, 188, 5,
44, 30, 210, 111, 54, 79, 61, 223,
239, 149, 73, 115, 201, 234, 194, 62,
147, 70, 19, 49, 72, 52, 164, 29,
102, 225, 203, 153, 18, 205, 40, 217,
165, 177, 166, 134, 236, 68, 231, 154,
116, 136, 47, 240, 46, 89, 120, 183,
242, 28, 161, 226, 241, 230, 10, 131,
207, 132, 83, 171, 202, 195, 227, 206,
112, 88, 90, 146, 117, 180, 26, 78,
118, 254, 107, 110, 220, 7, 192, 187,
31, 175, 127, 209, 32, 12, 84, 128,
190, 156, 95, 105, 104, 246, 91, 215,
219, 142, 36, 186, 247, 233, 167, 133,
160, 16, 140, 169, 23, 96, 155, 235,
179, 76, 253, 103, 238, 67, 35, 121,
100, 27, 213, 58, 77, 248, 174, 39,
214, 56, 42, 200, 106, 21, 129, 114,
252, 113, 168, 53, 25, 216, 64, 232,
81, 75, 2, 224, 250, 60, 135, 204,
48, 196, 94, 63, 244, 191, 93, 126,
138, 159, 9, 85, 249, 34, 185, 163,
17, 65, 184, 82, 109, 172, 108, 69,
150, 3, 20, 221, 162, 212, 152, 59,
198, 74, 229, 55, 87, 178, 141, 199,
57, 130, 80, 173, 101, 122, 144, 51,
139, 11, 8, 125, 158, 124, 123, 37,
14, 24, 22, 43, 197, 50, 98, 6,
176, 251, 86, 218, 193, 71, 145, 1,
45, 38, 189, 143, 245, 157, 181
};
static const std::size_t error_index_size = sizeof(global_random_error_index) / sizeof(std::size_t);
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_all_errors_at_index(schifra::reed_solomon::block<code_length,fec_length>& rsblock,
const std::size_t error_count,
const std::size_t& error_index_start_position,
const bool display_positions = false)
{
schifra::reed_solomon::block<code_length,fec_length> tmp_rsblock = rsblock;
for (std::size_t i = 0; i < error_count; ++i)
{
std::size_t error_position = (global_random_error_index[(error_index_start_position + i) % error_index_size]) % code_length;
add_error(error_position,rsblock);
if (display_positions)
{
std::cout << "Error index: " << error_position << std::endl;
}
}
}
template <std::size_t code_length, std::size_t fec_length>
inline void corrupt_message_all_errors_at_index(schifra::reed_solomon::block<code_length,fec_length>& rsblock,
const std::size_t error_count,
const std::size_t& error_index_start_position,
const std::vector<std::size_t>& random_error_index,
const bool display_positions = false)
{
for (std::size_t i = 0; i < error_count; ++i)
{
std::size_t error_position = (random_error_index[(error_index_start_position + i) % random_error_index.size()]) % code_length;
add_error(error_position,rsblock);
if (display_positions)
{
std::cout << "Error index: " << error_position << std::endl;
}
}
}
inline void generate_error_index(const std::size_t index_size,
std::vector<std::size_t>& random_error_index,
std::size_t seed)
{
if (0 == seed)
{
seed = 0xA5A5A5A5;
}
::srand(static_cast<unsigned int>(seed));
std::deque<std::size_t> index_list;
for (std::size_t i = 0; i < index_size; ++i)
{
index_list.push_back(i);
}
random_error_index.reserve(index_size);
random_error_index.resize(0);
while (!index_list.empty())
{
// possibly the worst way of doing this.
std::size_t index = ::rand() % index_list.size();
random_error_index.push_back(index_list[index]);
index_list.erase(index_list.begin() + index);
}
}
} // namespace schifra
#endif
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