1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
/*********************************************************************************
Fuji Xerox Printer Driver for Linux
(C) Fuji Xerox Co.,Ltd. 2006
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
***********************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "codec.h"
#define numof(x) (int)(sizeof(x)/sizeof(*x))
#define MAXBUFFLEN_ENCODED 32
#define MAXBUFFLEN_DECODED 24
#define FALSE 0
#define TRUE 1
typedef struct {
char before;
char after;
} CNV_T;
const CNV_T convTbl[] =
{
{0x22, 0x76},
{0x27, 0x77},
{0x2c, 0x78},
{0x3d, 0x79},
{0x5c, 0x7b}
};
static int intpow(int x, int y);
/*********************************************************************
* function : Decode
*
* input : unsigned char* encData : encoded data
* output : unsigned char* decData : decoded data
* : int* decDataLen : bytes of decoded data
*********************************************************************
*/
int
Decode (unsigned char* encData, /* encoded data */
unsigned char* decData, /* decoded data */
int* decDataLen) /* length of decode data */
{
unsigned int sum;
int ei = 0,
di = 0,
i,
j,
validEncDigits,
validDecDigits;
while (encData[ei] != 0) { /* calculate sum until NULL */
sum = 0;
validEncDigits = 0;
for (i=0 ; i<5 ; i++) {
for (j=0; j < numof(convTbl); j++) {
if (encData[ei] == convTbl[j].after) {
encData[ei] = convTbl[j].before;
break;
}
}
if ((encData[ei] >= (unsigned char) '!') && (encData[ei] <= (unsigned char) 'u')) {
sum = sum*85 + (int) encData[ei] - 33;
ei++;
validEncDigits++;
} else {
if (encData[ei] == 0) {
sum = sum*85 + 84;
} else {
return FALSE;
}
}
}
validDecDigits = validEncDigits - 1;
for (i=0 ; i < validDecDigits ; i++) { /* write data */
if (di < MAXBUFFLEN_DECODED) {
decData[di] = (unsigned char) ((sum / intpow(256, 3-i)) % 256);
di++;
} else {
return FALSE;
}
}
}
*decDataLen = di;
return TRUE;
}
static int intpow(int x, int y)
{
int ret = 1;
if (y < 0) {
return 0;
}
if (y == 0) {
return 1;
}
while (y != 0) {
ret = ret * x;
y--;
}
return ret;
}
|
