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cst.c
Go to the documentation of this file.
/*
* This file is part of the Aaru Data Preservation Suite.
* Copyright (c) 2019-2026 Natalia Portillo.
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of the
* License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "aaruformat.h"
AARU_EXPORT int32_t AARU_CALL aaruf_cst_transform(const uint8_t *interleaved, uint8_t *sequential, const size_t length)
{
uint8_t *p = NULL;
uint8_t *q = NULL;
uint8_t *r = NULL;
uint8_t *s = NULL;
uint8_t *t = NULL;
uint8_t *u = NULL;
uint8_t *v = NULL;
uint8_t *w = NULL;
size_t q_start = 0;
size_t r_start = 0;
size_t s_start = 0;
size_t t_start = 0;
size_t u_start = 0;
size_t v_start = 0;
size_t w_start = 0;
size_t i = 0;
if(interleaved == NULL || sequential == NULL) return AARUF_ERROR_BUFFER_TOO_SMALL;
p = malloc(length / 8);
q = malloc(length / 8);
r = malloc(length / 8);
s = malloc(length / 8);
t = malloc(length / 8);
u = malloc(length / 8);
v = malloc(length / 8);
w = malloc(length / 8);
if(p == NULL || q == NULL || r == NULL || s == NULL || t == NULL || u == NULL || v == NULL || w == NULL)
{
free(p);
free(q);
free(r);
free(s);
free(t);
free(u);
free(v);
free(w);
return AARUF_ERROR_NOT_ENOUGH_MEMORY;
}
for(i = 0; i < length; i += 8)
{
p[i / 8] = (uint8_t)(interleaved[i] & 0x80);
p[i / 8] += (interleaved[i + 1] & 0x80) >> 1;
p[i / 8] += (interleaved[i + 2] & 0x80) >> 2;
p[i / 8] += (interleaved[i + 3] & 0x80) >> 3;
p[i / 8] += (interleaved[i + 4] & 0x80) >> 4;
p[i / 8] += (interleaved[i + 5] & 0x80) >> 5;
p[i / 8] += (interleaved[i + 6] & 0x80) >> 6;
p[i / 8] += (interleaved[i + 7] & 0x80) >> 7;
q[i / 8] = (uint8_t)((interleaved[i] & 0x40) << 1);
q[i / 8] += interleaved[i + 1] & 0x40;
q[i / 8] += (interleaved[i + 2] & 0x40) >> 1;
q[i / 8] += (interleaved[i + 3] & 0x40) >> 2;
q[i / 8] += (interleaved[i + 4] & 0x40) >> 3;
q[i / 8] += (interleaved[i + 5] & 0x40) >> 4;
q[i / 8] += (interleaved[i + 6] & 0x40) >> 5;
q[i / 8] += (interleaved[i + 7] & 0x40) >> 6;
r[i / 8] = (uint8_t)((interleaved[i] & 0x20) << 2);
r[i / 8] += (interleaved[i + 1] & 0x20) << 1;
r[i / 8] += interleaved[i + 2] & 0x20;
r[i / 8] += (interleaved[i + 3] & 0x20) >> 1;
r[i / 8] += (interleaved[i + 4] & 0x20) >> 2;
r[i / 8] += (interleaved[i + 5] & 0x20) >> 3;
r[i / 8] += (interleaved[i + 6] & 0x20) >> 4;
r[i / 8] += (interleaved[i + 7] & 0x20) >> 5;
s[i / 8] = (uint8_t)((interleaved[i] & 0x10) << 3);
s[i / 8] += (interleaved[i + 1] & 0x10) << 2;
s[i / 8] += (interleaved[i + 2] & 0x10) << 1;
s[i / 8] += interleaved[i + 3] & 0x10;
s[i / 8] += (interleaved[i + 4] & 0x10) >> 1;
s[i / 8] += (interleaved[i + 5] & 0x10) >> 2;
s[i / 8] += (interleaved[i + 6] & 0x10) >> 3;
s[i / 8] += (interleaved[i + 7] & 0x10) >> 4;
t[i / 8] = (uint8_t)((interleaved[i] & 0x08) << 4);
t[i / 8] += (interleaved[i + 1] & 0x08) << 3;
t[i / 8] += (interleaved[i + 2] & 0x08) << 2;
t[i / 8] += (interleaved[i + 3] & 0x08) << 1;
t[i / 8] += interleaved[i + 4] & 0x08;
t[i / 8] += (interleaved[i + 5] & 0x08) >> 1;
t[i / 8] += (interleaved[i + 6] & 0x08) >> 2;
t[i / 8] += (interleaved[i + 7] & 0x08) >> 3;
u[i / 8] = (uint8_t)((interleaved[i] & 0x04) << 5);
u[i / 8] += (interleaved[i + 1] & 0x04) << 4;
u[i / 8] += (interleaved[i + 2] & 0x04) << 3;
u[i / 8] += (interleaved[i + 3] & 0x04) << 2;
u[i / 8] += (interleaved[i + 4] & 0x04) << 1;
u[i / 8] += interleaved[i + 5] & 0x04;
u[i / 8] += (interleaved[i + 6] & 0x04) >> 1;
u[i / 8] += (interleaved[i + 7] & 0x04) >> 2;
v[i / 8] = (uint8_t)((interleaved[i] & 0x02) << 6);
v[i / 8] += (interleaved[i + 1] & 0x02) << 5;
v[i / 8] += (interleaved[i + 2] & 0x02) << 4;
v[i / 8] += (interleaved[i + 3] & 0x02) << 3;
v[i / 8] += (interleaved[i + 4] & 0x02) << 2;
v[i / 8] += (interleaved[i + 5] & 0x02) << 1;
v[i / 8] += interleaved[i + 6] & 0x02;
v[i / 8] += (interleaved[i + 7] & 0x02) >> 1;
w[i / 8] = (uint8_t)((interleaved[i] & 0x01) << 7);
w[i / 8] += (interleaved[i + 1] & 0x01) << 6;
w[i / 8] += (interleaved[i + 2] & 0x01) << 5;
w[i / 8] += (interleaved[i + 3] & 0x01) << 4;
w[i / 8] += (interleaved[i + 4] & 0x01) << 3;
w[i / 8] += (interleaved[i + 5] & 0x01) << 2;
w[i / 8] += (interleaved[i + 6] & 0x01) << 1;
w[i / 8] += interleaved[i + 7] & 0x01;
}
q_start = length / 8 * 1;
r_start = length / 8 * 2;
s_start = length / 8 * 3;
t_start = length / 8 * 4;
u_start = length / 8 * 5;
v_start = length / 8 * 6;
w_start = length / 8 * 7;
for(i = 0; i < length / 8; i++)
{
sequential[i] = p[i];
sequential[q_start + i] = q[i];
sequential[r_start + i] = r[i];
sequential[s_start + i] = s[i];
sequential[t_start + i] = t[i];
sequential[u_start + i] = u[i];
sequential[v_start + i] = v[i];
sequential[w_start + i] = w[i];
}
free(p);
free(q);
free(r);
free(s);
free(t);
free(u);
free(v);
free(w);
return AARUF_STATUS_OK;
}
AARU_EXPORT int32_t AARU_CALL aaruf_cst_untransform(const uint8_t *sequential, uint8_t *interleaved,
const size_t length)
{
size_t i;
if(interleaved == NULL || sequential == NULL) return AARUF_ERROR_BUFFER_TOO_SMALL;
uint8_t *p = malloc(length / 8);
uint8_t *q = malloc(length / 8);
uint8_t *r = malloc(length / 8);
uint8_t *s = malloc(length / 8);
uint8_t *t = malloc(length / 8);
uint8_t *u = malloc(length / 8);
uint8_t *v = malloc(length / 8);
uint8_t *w = malloc(length / 8);
if(p == NULL || q == NULL || r == NULL || s == NULL || t == NULL || u == NULL || v == NULL || w == NULL)
{
free(p);
free(q);
free(r);
free(s);
free(t);
free(u);
free(v);
free(w);
return AARUF_ERROR_NOT_ENOUGH_MEMORY;
}
size_t q_start = length / 8 * 1;
size_t r_start = length / 8 * 2;
size_t s_start = length / 8 * 3;
size_t t_start = length / 8 * 4;
size_t u_start = length / 8 * 5;
size_t v_start = length / 8 * 6;
size_t w_start = length / 8 * 7;
for(i = 0; i < length / 8; i++)
{
p[i] = sequential[i];
q[i] = sequential[q_start + i];
r[i] = sequential[r_start + i];
s[i] = sequential[s_start + i];
t[i] = sequential[t_start + i];
u[i] = sequential[u_start + i];
v[i] = sequential[v_start + i];
w[i] = sequential[w_start + i];
}
memset(interleaved, 0, length);
for(i = 0; i < length; i += 8)
{
interleaved[i] += (p[i / 8] & 0x80) == 0x80 ? 0x80 : 0;
interleaved[i + 1] += (p[i / 8] & 0x40) == 0x40 ? 0x80 : 0;
interleaved[i + 2] += (p[i / 8] & 0x20) == 0x20 ? 0x80 : 0;
interleaved[i + 3] += (p[i / 8] & 0x10) == 0x10 ? 0x80 : 0;
interleaved[i + 4] += (p[i / 8] & 0x08) == 0x08 ? 0x80 : 0;
interleaved[i + 5] += (p[i / 8] & 0x04) == 0x04 ? 0x80 : 0;
interleaved[i + 6] += (p[i / 8] & 0x02) == 0x02 ? 0x80 : 0;
interleaved[i + 7] += (p[i / 8] & 0x01) == 0x01 ? 0x80 : 0;
interleaved[i] += (q[i / 8] & 0x80) == 0x80 ? 0x40 : 0;
interleaved[i + 1] += (q[i / 8] & 0x40) == 0x40 ? 0x40 : 0;
interleaved[i + 2] += (q[i / 8] & 0x20) == 0x20 ? 0x40 : 0;
interleaved[i + 3] += (q[i / 8] & 0x10) == 0x10 ? 0x40 : 0;
interleaved[i + 4] += (q[i / 8] & 0x08) == 0x08 ? 0x40 : 0;
interleaved[i + 5] += (q[i / 8] & 0x04) == 0x04 ? 0x40 : 0;
interleaved[i + 6] += (q[i / 8] & 0x02) == 0x02 ? 0x40 : 0;
interleaved[i + 7] += (q[i / 8] & 0x01) == 0x01 ? 0x40 : 0;
interleaved[i] += (r[i / 8] & 0x80) == 0x80 ? 0x20 : 0;
interleaved[i + 1] += (r[i / 8] & 0x40) == 0x40 ? 0x20 : 0;
interleaved[i + 2] += (r[i / 8] & 0x20) == 0x20 ? 0x20 : 0;
interleaved[i + 3] += (r[i / 8] & 0x10) == 0x10 ? 0x20 : 0;
interleaved[i + 4] += (r[i / 8] & 0x08) == 0x08 ? 0x20 : 0;
interleaved[i + 5] += (r[i / 8] & 0x04) == 0x04 ? 0x20 : 0;
interleaved[i + 6] += (r[i / 8] & 0x02) == 0x02 ? 0x20 : 0;
interleaved[i + 7] += (r[i / 8] & 0x01) == 0x01 ? 0x20 : 0;
interleaved[i] += (s[i / 8] & 0x80) == 0x80 ? 0x10 : 0;
interleaved[i + 1] += (s[i / 8] & 0x40) == 0x40 ? 0x10 : 0;
interleaved[i + 2] += (s[i / 8] & 0x20) == 0x20 ? 0x10 : 0;
interleaved[i + 3] += (s[i / 8] & 0x10) == 0x10 ? 0x10 : 0;
interleaved[i + 4] += (s[i / 8] & 0x08) == 0x08 ? 0x10 : 0;
interleaved[i + 5] += (s[i / 8] & 0x04) == 0x04 ? 0x10 : 0;
interleaved[i + 6] += (s[i / 8] & 0x02) == 0x02 ? 0x10 : 0;
interleaved[i + 7] += (s[i / 8] & 0x01) == 0x01 ? 0x10 : 0;
interleaved[i] += (t[i / 8] & 0x80) == 0x80 ? 0x08 : 0;
interleaved[i + 1] += (t[i / 8] & 0x40) == 0x40 ? 0x08 : 0;
interleaved[i + 2] += (t[i / 8] & 0x20) == 0x20 ? 0x08 : 0;
interleaved[i + 3] += (t[i / 8] & 0x10) == 0x10 ? 0x08 : 0;
interleaved[i + 4] += (t[i / 8] & 0x08) == 0x08 ? 0x08 : 0;
interleaved[i + 5] += (t[i / 8] & 0x04) == 0x04 ? 0x08 : 0;
interleaved[i + 6] += (t[i / 8] & 0x02) == 0x02 ? 0x08 : 0;
interleaved[i + 7] += (t[i / 8] & 0x01) == 0x01 ? 0x08 : 0;
interleaved[i] += (u[i / 8] & 0x80) == 0x80 ? 0x04 : 0;
interleaved[i + 1] += (u[i / 8] & 0x40) == 0x40 ? 0x04 : 0;
interleaved[i + 2] += (u[i / 8] & 0x20) == 0x20 ? 0x04 : 0;
interleaved[i + 3] += (u[i / 8] & 0x10) == 0x10 ? 0x04 : 0;
interleaved[i + 4] += (u[i / 8] & 0x08) == 0x08 ? 0x04 : 0;
interleaved[i + 5] += (u[i / 8] & 0x04) == 0x04 ? 0x04 : 0;
interleaved[i + 6] += (u[i / 8] & 0x02) == 0x02 ? 0x04 : 0;
interleaved[i + 7] += (u[i / 8] & 0x01) == 0x01 ? 0x04 : 0;
interleaved[i] += (v[i / 8] & 0x80) == 0x80 ? 0x02 : 0;
interleaved[i + 1] += (v[i / 8] & 0x40) == 0x40 ? 0x02 : 0;
interleaved[i + 2] += (v[i / 8] & 0x20) == 0x20 ? 0x02 : 0;
interleaved[i + 3] += (v[i / 8] & 0x10) == 0x10 ? 0x02 : 0;
interleaved[i + 4] += (v[i / 8] & 0x08) == 0x08 ? 0x02 : 0;
interleaved[i + 5] += (v[i / 8] & 0x04) == 0x04 ? 0x02 : 0;
interleaved[i + 6] += (v[i / 8] & 0x02) == 0x02 ? 0x02 : 0;
interleaved[i + 7] += (v[i / 8] & 0x01) == 0x01 ? 0x02 : 0;
interleaved[i] += (w[i / 8] & 0x80) == 0x80 ? 0x01 : 0;
interleaved[i + 1] += (w[i / 8] & 0x40) == 0x40 ? 0x01 : 0;
interleaved[i + 2] += (w[i / 8] & 0x20) == 0x20 ? 0x01 : 0;
interleaved[i + 3] += (w[i / 8] & 0x10) == 0x10 ? 0x01 : 0;
interleaved[i + 4] += (w[i / 8] & 0x08) == 0x08 ? 0x01 : 0;
interleaved[i + 5] += (w[i / 8] & 0x04) == 0x04 ? 0x01 : 0;
interleaved[i + 6] += (w[i / 8] & 0x02) == 0x02 ? 0x01 : 0;
interleaved[i + 7] += (w[i / 8] & 0x01) == 0x01 ? 0x01 : 0;
}
free(p);
free(q);
free(r);
free(s);
free(t);
free(u);
free(v);
free(w);
return AARUF_STATUS_OK;
}
aaruformat.h
aaruf_cst_untransform
int32_t aaruf_cst_untransform(const uint8_t *sequential, uint8_t *interleaved, const size_t length)
Reverses the CST (Claunia's Subchannel Transform) transformation from sequential to interleaved data.
Definition cst.c:193
aaruf_cst_transform
int32_t aaruf_cst_transform(const uint8_t *interleaved, uint8_t *sequential, const size_t length)
Transforms interleaved subchannel data to sequential format.
Definition cst.c:35
AARU_CALL
#define AARU_CALL
Definition decls.h:46
AARU_EXPORT
#define AARU_EXPORT
Definition decls.h:55
AARUF_STATUS_OK
#define AARUF_STATUS_OK
Sector present and read without uncorrectable errors.
Definition errors.h:77
AARUF_ERROR_NOT_ENOUGH_MEMORY
#define AARUF_ERROR_NOT_ENOUGH_MEMORY
Memory allocation failure (critical).
Definition errors.h:48
AARUF_ERROR_BUFFER_TOO_SMALL
#define AARUF_ERROR_BUFFER_TOO_SMALL
Caller-supplied buffer insufficient for data.
Definition errors.h:49