Files
dvdisaster/endian.c
2009-11-21 16:29:02 +09:00

132 lines
4.0 KiB
C

/* dvdisaster: Additional error correction for optical media.
* Copyright (C) 2004-2009 Carsten Gnoerlich.
* Project home page: http://www.dvdisaster.com
* Email: carsten@dvdisaster.com -or- cgnoerlich@fsfe.org
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA,
* or direct your browser at http://www.gnu.org.
*/
#include "dvdisaster.h"
/***
*** Conversion between little and big endian words.
*** Only suitable for non performance critical code.
*/
/*
* Swap bytes in a 32 bit word to convert between little and big endian.
*/
guint32 SwapBytes32(guint32 in)
{
return
((in & 0xff000000) >> 24)
| ((in & 0x00ff0000) >> 8)
| ((in & 0x0000ff00) << 8)
| ((in & 0x000000ff) << 24);
}
guint64 SwapBytes64(guint64 in)
{
return
((in & 0xff00000000000000ull) >> 56)
| ((in & 0x00ff000000000000ull) >> 40)
| ((in & 0x0000ff0000000000ull) >> 24)
| ((in & 0x000000ff00000000ull) >> 8)
| ((in & 0x00000000ff000000ull) << 8)
| ((in & 0x0000000000ff0000ull) << 24)
| ((in & 0x000000000000ff00ull) << 40)
| ((in & 0x00000000000000ffull) << 56);
}
/***
*** Convert the EccHeader structure between different endians.
***/
/*
* A debugging function for printing the Ecc header.
*/
void print_hex(char *label, guint8 *values, int n)
{ PrintCLI(label);
while(n--)
PrintCLI("%02x ",*values++);
PrintCLI("\n");
}
void print_ecc_header(EccHeader *eh)
{ char buf[16];
PrintCLI("\nContents of EccHeader:\n\n");
strncpy(buf, (char*)eh->cookie, 12); buf[12] = 0;
PrintCLI("cookie %s\n",buf);
strncpy(buf, (char*)eh->method, 4); buf[4] = 0;
PrintCLI("method %s\n",buf);
print_hex("methodFlags ", (guint8*)eh->methodFlags, 4);
print_hex("mediumFP ", eh->mediumFP, 16);
print_hex("mediumSum ", eh->mediumSum, 16);
print_hex("eccSum ", eh->eccSum, 16);
print_hex("sectors ", eh->sectors, 8);
PrintCLI("sectors (native) %lld\n", uchar_to_gint64(eh->sectors));
PrintCLI("dataBytes %8x\n", eh->dataBytes);
PrintCLI("eccBytes %8x\n", eh->eccBytes);
PrintCLI("creatorVersion %8x\n", eh->creatorVersion);
PrintCLI("neededVersion %8x\n", eh->neededVersion);
PrintCLI("fpSector %8x\n", eh->fpSector);
PrintCLI("selfCRC %8x\n", eh->selfCRC);
print_hex("crcSum ", eh->crcSum, 16);
PrintCLI("inLast %8x\n", eh->inLast);
PrintCLI("\n");
}
/*
* This is the most annoying part of the endian conversions.
*/
//#define VERBOSE
void SwapEccHeaderBytes(EccHeader *eh)
{
#ifdef VERBOSE
printf("before swap:\n");
print_ecc_header(eh);
#endif
eh->dataBytes = SwapBytes32(eh->dataBytes);
eh->eccBytes = SwapBytes32(eh->eccBytes);
eh->creatorVersion = SwapBytes32(eh->creatorVersion);
eh->neededVersion = SwapBytes32(eh->neededVersion);
eh->fpSector = SwapBytes32(eh->fpSector);
eh->inLast = SwapBytes32(eh->inLast);
#ifdef VERBOSE
printf("after swap:\n");
print_ecc_header(eh);
#endif
}
void SwapDefectiveHeaderBytes(DefectiveSectorHeader *dsh)
{
dsh->lba = SwapBytes64(dsh->lba);
dsh->sectorSize = SwapBytes32(dsh->sectorSize);
dsh->properties = SwapBytes32(dsh->properties);
dsh->dshFormat = SwapBytes32(dsh->dshFormat);
dsh->nSectors = SwapBytes32(dsh->nSectors);
}