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Bugfix + added M17 decoder to the linux CI

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AlexandreRouma
2021-10-02 17:01:23 +02:00
parent 26fa23c8f5
commit b4213ea049
86 changed files with 6601 additions and 20 deletions
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187
core/libcorrect/src/reed-solomon/reed-solomon.c Normal file
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#include "correct/reed-solomon/reed-solomon.h"
// coeff must be of size nroots + 1
// e.g. 2 roots (x + alpha)(x + alpha^2) yields a poly with 3 terms x^2 + g0*x + g1
static polynomial_t reed_solomon_build_generator(field_t field, unsigned int nroots, field_element_t first_consecutive_root, unsigned int root_gap, polynomial_t generator, field_element_t *roots) {
// generator has order 2*t
// of form (x + alpha^1)(x + alpha^2)...(x - alpha^2*t)
for (unsigned int i = 0; i < nroots; i++) {
roots[i] = field.exp[(root_gap * (i + first_consecutive_root)) % 255];
}
return polynomial_create_from_roots(field, nroots, roots);
}
correct_reed_solomon *correct_reed_solomon_create(field_operation_t primitive_polynomial, field_logarithm_t first_consecutive_root, field_logarithm_t generator_root_gap, size_t num_roots) {
correct_reed_solomon *rs = calloc(1, sizeof(correct_reed_solomon));
rs->field = field_create(primitive_polynomial);
rs->block_length = 255;
rs->min_distance = num_roots;
rs->message_length = rs->block_length - rs->min_distance;
rs->first_consecutive_root = first_consecutive_root;
rs->generator_root_gap = generator_root_gap;
rs->generator_roots = malloc(rs->min_distance * sizeof(field_element_t));
rs->generator = reed_solomon_build_generator(rs->field, rs->min_distance, rs->first_consecutive_root, rs->generator_root_gap, rs->generator, rs->generator_roots);
rs->encoded_polynomial = polynomial_create(rs->block_length - 1);
rs->encoded_remainder = polynomial_create(rs->block_length - 1);
rs->has_init_decode = false;
return rs;
}
void correct_reed_solomon_destroy(correct_reed_solomon *rs) {
field_destroy(rs->field);
polynomial_destroy(rs->generator);
free(rs->generator_roots);
polynomial_destroy(rs->encoded_polynomial);
polynomial_destroy(rs->encoded_remainder);
if (rs->has_init_decode) {
free(rs->syndromes);
free(rs->modified_syndromes);
polynomial_destroy(rs->received_polynomial);
polynomial_destroy(rs->error_locator);
polynomial_destroy(rs->error_locator_log);
polynomial_destroy(rs->erasure_locator);
free(rs->error_roots);
free(rs->error_vals);
free(rs->error_locations);
polynomial_destroy(rs->last_error_locator);
polynomial_destroy(rs->error_evaluator);
polynomial_destroy(rs->error_locator_derivative);
for (unsigned int i = 0; i < rs->min_distance; i++) {
free(rs->generator_root_exp[i]);
}
free(rs->generator_root_exp);
for (field_operation_t i = 0; i < 256; i++) {
free(rs->element_exp[i]);
}
free(rs->element_exp);
polynomial_destroy(rs->init_from_roots_scratch[0]);
polynomial_destroy(rs->init_from_roots_scratch[1]);
}
free(rs);
}
void correct_reed_solomon_debug_print(correct_reed_solomon *rs) {
for (unsigned int i = 0; i < 256; i++) {
printf("%3d %3d %3d %3d\n", i, rs->field.exp[i], i, rs->field.log[i]);
}
printf("\n");
printf("roots: ");
for (unsigned int i = 0; i < rs->min_distance; i++) {
printf("%d", rs->generator_roots[i]);
if (i < rs->min_distance - 1) {
printf(", ");
}
}
printf("\n\n");
printf("generator: ");
for (unsigned int i = 0; i < rs->generator.order + 1; i++) {
printf("%d*x^%d", rs->generator.coeff[i], i);
if (i < rs->generator.order) {
printf(" + ");
}
}
printf("\n\n");
printf("generator (alpha format): ");
for (unsigned int i = rs->generator.order + 1; i > 0; i--) {
printf("alpha^%d*x^%d", rs->field.log[rs->generator.coeff[i - 1]], i - 1);
if (i > 1) {
printf(" + ");
}
}
printf("\n\n");
printf("remainder: ");
bool has_printed = false;
for (unsigned int i = 0; i < rs->encoded_remainder.order + 1; i++) {
if (!rs->encoded_remainder.coeff[i]) {
continue;
}
if (has_printed) {
printf(" + ");
}
has_printed = true;
printf("%d*x^%d", rs->encoded_remainder.coeff[i], i);
}
printf("\n\n");
printf("syndromes: ");
for (unsigned int i = 0; i < rs->min_distance; i++) {
printf("%d", rs->syndromes[i]);
if (i < rs->min_distance - 1) {
printf(", ");
}
}
printf("\n\n");
printf("numerrors: %d\n\n", rs->error_locator.order);
printf("error locator: ");
has_printed = false;
for (unsigned int i = 0; i < rs->error_locator.order + 1; i++) {
if (!rs->error_locator.coeff[i]) {
continue;
}
if (has_printed) {
printf(" + ");
}
has_printed = true;
printf("%d*x^%d", rs->error_locator.coeff[i], i);
}
printf("\n\n");
printf("error roots: ");
for (unsigned int i = 0; i < rs->error_locator.order; i++) {
printf("%d@%d", polynomial_eval(rs->field, rs->error_locator, rs->error_roots[i]), rs->error_roots[i]);
if (i < rs->error_locator.order - 1) {
printf(", ");
}
}
printf("\n\n");
printf("error evaluator: ");
has_printed = false;
for (unsigned int i = 0; i < rs->error_evaluator.order; i++) {
if (!rs->error_evaluator.coeff[i]) {
continue;
}
if (has_printed) {
printf(" + ");
}
has_printed = true;
printf("%d*x^%d", rs->error_evaluator.coeff[i], i);
}
printf("\n\n");
printf("error locator derivative: ");
has_printed = false;
for (unsigned int i = 0; i < rs->error_locator_derivative.order; i++) {
if (!rs->error_locator_derivative.coeff[i]) {
continue;
}
if (has_printed) {
printf(" + ");
}
has_printed = true;
printf("%d*x^%d", rs->error_locator_derivative.coeff[i], i);
}
printf("\n\n");
printf("error locator: ");
for (unsigned int i = 0; i < rs->error_locator.order; i++) {
printf("%d@%d", rs->error_vals[i], rs->error_locations[i]);
if (i < rs->error_locator.order - 1) {
printf(", ");
}
}
printf("\n\n");
}