tools/gigabeat.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 by Christian Hack
  11  *
  12  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22
  23 static FILE * openinfile( const char * filename )
  24 {
  25     FILE * F = fopen( filename, "rb" );
  26     if( F == NULL )
  27     {
  28         fprintf( stderr, "Couldn't open input file %s\n", filename );
  29         perror( "Error was " );
  30         exit( -1 );
  31     };
  32     return F;
  33 };
  34
  35 static FILE * openoutfile( const char * filename )
  36 {
  37     FILE * F = fopen( filename, "wb" );
  38     if( F == NULL )
  39     {
  40         fprintf( stderr, "Couldn't open output file %s\n", filename );
  41         perror( "Error was " );
  42         exit( -1 );
  43     };
  44     return F;
  45 };
  46
  47 int gigabeat_code(char *infile, char *outfile)
  48 {
  49     FILE *in, *out;
  50     unsigned long size = 0;
  51     unsigned long bytes_read;
  52     unsigned char buf[4];
  53     unsigned long data;
  54     unsigned long key = 0x19751217;
  55
  56     in = openinfile(infile);
  57     out = openoutfile(outfile);
  58
  59     while (!feof(in)) {
  60         bytes_read = fread(buf, 1, 4, in);
  61
  62         /* Read in little-endian */
  63         data = le2int(buf);
  64
  65         data = data ^ key;
  66
  67         key = key + (key << 1);
  68         key = key + 0x19751217;
  69
  70         size += bytes_read;
  71
  72         /* Write out little-endian */
  73         int2le(data, buf);
  74
  75         fwrite(buf, 1, bytes_read, out);
  76     }
  77
  78     fprintf(stderr, "File processed successfully\n" );
  79
  80     fclose(in);
  81     fclose(out);
  82     return(0);
  83 }