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
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
|
/*------------------------------------------------------------------------
* Copyright 2007-2010 (c) Jeff Brown <spadix@users.sourceforge.net>
*
* This file is part of the ZBar Bar Code Reader.
*
* The ZBar Bar Code Reader is free software; you can redistribute it
* and/or modify it under the terms of the GNU Lesser Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* The ZBar Bar Code Reader 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 Public License for more details.
*
* You should have received a copy of the GNU Lesser Public License
* along with the ZBar Bar Code Reader; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301 USA
*
* http://sourceforge.net/projects/zbar
*------------------------------------------------------------------------*/
#ifndef _DECODER_H_
#define _DECODER_H_
#include "config.h"
#include <limits.h>
#include <stdlib.h> /* realloc */
#include <zbar.h>
#include "debug.h"
#define NUM_CFGS (ZBAR_CFG_MAX_LEN - ZBAR_CFG_MIN_LEN + 1)
#if ENABLE_EAN == 1
#include "decoder/ean.h"
#endif
#if ENABLE_I25 == 1
#include "decoder/i25.h"
#endif
#if ENABLE_DATABAR == 1
#include "decoder/databar.h"
#endif
#if ENABLE_CODABAR == 1
#include "decoder/codabar.h"
#endif
#if ENABLE_CODE39 == 1
#include "decoder/code39.h"
#endif
#if ENABLE_CODE93 == 1
#include "decoder/code93.h"
#endif
#if ENABLE_CODE128 == 1
#include "decoder/code128.h"
#endif
#if ENABLE_PDF417 == 1
#include "decoder/pdf417.h"
#endif
#if ENABLE_QRCODE == 1
#include "decoder/qr_finder.h"
#endif
#if ENABLE_SQCODE == 1
#include "decoder/sq_finder.h"
#endif
/* size of bar width history (implementation assumes power of two) */
#ifndef DECODE_WINDOW
#define DECODE_WINDOW 16
#endif
/* initial data buffer allocation */
#ifndef BUFFER_MIN
#define BUFFER_MIN 0x20
#endif
/* maximum data buffer allocation
* (longer symbols are rejected)
*/
#ifndef BUFFER_MAX
#define BUFFER_MAX 0x100
#endif
/* buffer allocation increment */
#ifndef BUFFER_INCR
#define BUFFER_INCR 0x10
#endif
#define CFG(dcode, cfg) ((dcode).configs[(cfg)-ZBAR_CFG_MIN_LEN])
#define TEST_CFG(config, cfg) (((config) >> (cfg)) & 1)
#define MOD(mod) (1 << (mod))
/* symbology independent decoder state */
struct zbar_decoder_s {
unsigned char idx; /* current width index */
unsigned w[DECODE_WINDOW]; /* window of last N bar widths */
zbar_symbol_type_t type; /* type of last decoded data */
zbar_symbol_type_t lock; /* buffer lock */
unsigned modifiers; /* symbology modifier */
int direction; /* direction of last decoded data */
unsigned s6; /* 6-element character width */
/* everything above here is automatically reset */
unsigned buf_alloc; /* dynamic buffer allocation */
unsigned buflen; /* binary data length */
unsigned char *buf; /* decoded characters */
void *userdata; /* application data */
zbar_decoder_handler_t *handler; /* application callback */
/* symbology specific state */
#if ENABLE_EAN == 1
ean_decoder_t ean; /* EAN/UPC parallel decode attempts */
#endif
#if ENABLE_I25 == 1
i25_decoder_t i25; /* Interleaved 2 of 5 decode state */
#endif
#if ENABLE_DATABAR == 1
databar_decoder_t databar; /* DataBar decode state */
#endif
#if ENABLE_CODABAR == 1
codabar_decoder_t codabar; /* Codabar decode state */
#endif
#if ENABLE_CODE39 == 1
code39_decoder_t code39; /* Code 39 decode state */
#endif
#if ENABLE_CODE93 == 1
code93_decoder_t code93; /* Code 93 decode state */
#endif
#if ENABLE_CODE128 == 1
code128_decoder_t code128; /* Code 128 decode state */
#endif
#if ENABLE_PDF417 == 1
pdf417_decoder_t pdf417; /* PDF417 decode state */
#endif
#if ENABLE_QRCODE == 1
qr_finder_t qrf; /* QR Code finder state */
#endif
#if ENABLE_SQCODE == 1
sq_finder_t sqf; /* SQ Code finder state */
#endif
};
/* return current element color */
static inline char get_color(const zbar_decoder_t *dcode)
{
return (dcode->idx & 1);
}
/* retrieve i-th previous element width */
static inline unsigned get_width(const zbar_decoder_t *dcode,
unsigned char offset)
{
return (dcode->w[(dcode->idx - offset) & (DECODE_WINDOW - 1)]);
}
/* retrieve bar+space pair width starting at offset i */
static inline unsigned pair_width(const zbar_decoder_t *dcode,
unsigned char offset)
{
return (get_width(dcode, offset) + get_width(dcode, offset + 1));
}
/* calculate total character width "s"
* - start of character identified by context sensitive offset
* (<= DECODE_WINDOW - n)
* - size of character is n elements
*/
static inline unsigned calc_s(const zbar_decoder_t *dcode, unsigned char offset,
unsigned char n)
{
/* FIXME check that this gets unrolled for constant n */
unsigned s = 0;
while (n--)
s += get_width(dcode, offset++);
return (s);
}
/* fixed character width decode assist
* bar+space width are compared as a fraction of the reference dimension "x"
* - +/- 1/2 x tolerance
* - measured total character width (s) compared to symbology baseline (n)
* (n = 7 for EAN/UPC, 11 for Code 128)
* - bar+space *pair width* "e" is used to factor out bad "exposures"
* ("blooming" or "swelling" of dark or light areas)
* => using like-edge measurements avoids these issues
* - n should be > 3
*/
static inline int decode_e(unsigned e, unsigned s, unsigned n)
{
/* result is encoded number of units - 2
* (for use as zero based index)
* or -1 if invalid
*/
unsigned char E = ((e * n * 2 + 1) / s - 3) / 2;
return ((E >= n - 3) ? -1 : E);
}
/* sort three like-colored elements and return ordering
*/
static inline unsigned decode_sort3(zbar_decoder_t *dcode, int i0)
{
unsigned w0 = get_width(dcode, i0);
unsigned w2 = get_width(dcode, i0 + 2);
unsigned w4 = get_width(dcode, i0 + 4);
if (w0 < w2) {
if (w2 < w4)
return ((i0 << 8) | ((i0 + 2) << 4) | (i0 + 4));
if (w0 < w4)
return ((i0 << 8) | ((i0 + 4) << 4) | (i0 + 2));
return (((i0 + 4) << 8) | (i0 << 4) | (i0 + 2));
}
if (w4 < w2)
return (((i0 + 4) << 8) | ((i0 + 2) << 4) | i0);
if (w0 < w4)
return (((i0 + 2) << 8) | (i0 << 4) | (i0 + 4));
return (((i0 + 2) << 8) | ((i0 + 4) << 4) | i0);
}
/* sort N like-colored elements and return ordering
*/
static inline unsigned decode_sortn(zbar_decoder_t *dcode, int n, int i0)
{
unsigned mask = 0, sort = 0;
int i;
for (i = n - 1; i >= 0; i--) {
unsigned wmin = UINT_MAX;
int jmin = -1, j;
for (j = n - 1; j >= 0; j--) {
unsigned w;
if ((mask >> j) & 1)
continue;
w = get_width(dcode, i0 + j * 2);
if (wmin >= w) {
wmin = w;
jmin = j;
}
}
zassert(jmin >= 0, 0, "sortn(%d,%d) jmin=%d", n, i0, jmin);
sort <<= 4;
mask |= 1 << jmin;
sort |= i0 + jmin * 2;
}
return (sort);
}
/* acquire shared state lock */
static inline char acquire_lock(zbar_decoder_t *dcode, zbar_symbol_type_t req)
{
if (dcode->lock) {
dbprintf(2, " [locked %d]\n", dcode->lock);
return (1);
}
dcode->lock = req;
return (0);
}
/* check and release shared state lock */
static inline char release_lock(zbar_decoder_t *dcode, zbar_symbol_type_t req)
{
zassert(dcode->lock == req, 1, "lock=%d req=%d\n", dcode->lock, req);
dcode->lock = 0;
return (0);
}
/* ensure output buffer has sufficient allocation for request */
static inline char size_buf(zbar_decoder_t *dcode, unsigned len)
{
unsigned char *buf;
if (len <= BUFFER_MIN)
return (0);
if (len < dcode->buf_alloc)
/* FIXME size reduction heuristic? */
return (0);
if (len > BUFFER_MAX)
return (1);
if (len < dcode->buf_alloc + BUFFER_INCR) {
len = dcode->buf_alloc + BUFFER_INCR;
if (len > BUFFER_MAX)
len = BUFFER_MAX;
}
buf = realloc(dcode->buf, len);
if (!buf)
return (1);
dcode->buf = buf;
dcode->buf_alloc = len;
return (0);
}
extern const char *_zbar_decoder_buf_dump(unsigned char *buf,
unsigned int buflen);
#endif
|
