Files
dvdisaster/src/rs-decoder.c
Stéphane Lesimple db4d3af31d sync from upstream up to 22:14a375563e2b
This includes the following commits:

changeset:   22:14a375563e2b
summary:     chang "while" command to "type -P" in bash based configure

changeset:   21:c4bf7c0f33d2
summary:     updated codec paper for RS01 life cycle

changeset:   20:dbcaad8128aa
summary:     replaced build count with mercurial changeset

changeset:   19:fba258a6acfa
summary:     Added tag 0.79.10 for changeset 49950be5a2ef

changeset:   18:49950be5a2ef
summary:     merged some debian patches

changeset:   17:815be3929c41
summary:     merged "easy" patches from Stéphane Lesimple's version

changeset:   16:7d15f8a958cb
summary:     Made printf format strings 32/64bit safe as suggested by Stéphane;

changeset:   15:1055a53b8d6d
summary:     reorganized code for --with-gui=[yes|no] option

changeset:   14:fbe2ae12a32c
summary:     Added tag 0.79.9 for changeset f2fdd6d3a1f5

changeset:   13:f2fdd6d3a1f5
summary:     updated TODO and CHANGELOG

And other changes that were needed to resolve the (many) conflicts.
2021-10-09 15:22:57 +02:00

67 lines
1.9 KiB
C

/* dvdisaster: Additional error correction for optical media.
* Copyright (C) 2004-2017 Carsten Gnoerlich.
* Copyright (C) 2019-2021 The dvdisaster development team.
*
* Email: support@dvdisaster.org
*
* This file is part of dvdisaster.
*
* dvdisaster 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 3 of the License, or
* (at your option) any later version.
*
* dvdisaster 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 dvdisaster. If not, see <http://www.gnu.org/licenses/>.
*/
/*** src type: no GUI code ***/
#include "dvdisaster.h"
#include "galois-inlines.h"
/***
*** Reed-Solomon decoding (work in progress; incomplete)
***/
/*
* Test and report the error syndrome.
*/
int TestErrorSyndromes(ReedSolomonTables *rt, unsigned char *data)
{ int syndrome[rt->nroots];
int syn_error;
int i,j;
/*** Form the syndromes: Evaluate data(x) at roots of g(x) */
for(i=0; i<rt->nroots; i++)
syndrome[i] = data[0];
for(j=1; j<GF_FIELDMAX; j++)
for(i=0; i<rt->nroots; i++)
if(syndrome[i] == 0)
syndrome[i] = data[j];
else syndrome[i] = data[j] ^ rt->synLut[(i<<8) + syndrome[i]];
#if 0
else syndrome[i] = data[j] ^ gt->alphaTo[mod_fieldmax(gt->indexOf[syndrome[i]]
+ (rt->fcr+i)*rt->primElem)];
#endif
/*** Check for nonzero condition. */
syn_error = 0;
for(i=0; i<rt->nroots; i++)
syn_error |= syndrome[i];
/*** If the syndrome is zero, everything is fine. */
return syn_error;
}