zbar-windows/zbar/decoder/code39.c
2021-10-07 16:38:06 +08:00

337 lines
10 KiB
C

/*------------------------------------------------------------------------
* Copyright 2008-2010 (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
*------------------------------------------------------------------------*/
#include "config.h"
#include <string.h> /* memmove */
#include <zbar.h>
#ifdef DEBUG_CODE39
#define DEBUG_LEVEL (DEBUG_CODE39)
#endif
#include "debug.h"
#include "decoder.h"
#define NUM_CHARS (0x2c)
static const unsigned char code39_hi[32] = {
0x80 | 0x00, /* 2 next */
0x40 | 0x02, /* 4 */
0x80 | 0x06, /* 2 next */
0xc0 | 0x08, /* 2 skip */
0x40 | 0x0a, /* 4 */
0x80 | 0x0e, /* 2 next */
0xc0 | 0x10, /* 2 skip */
0x00 | 0x12, /* direct */
0x80 | 0x13, /* 2 next */
0xc0 | 0x15, /* 2 skip */
0x80 | 0x17, /* 2 next */
0xff, 0xc0 | 0x19, /* 2 skip */
0x00 | 0x1b, /* direct */
0xff, 0xff,
0x40 | 0x1c, /* 4 */
0x80 | 0x20, /* 2 next */
0xc0 | 0x22, /* 2 skip */
0x00 | 0x24, /* direct */
0x80 | 0x25, /* 2 next */
0xff, 0x00 | 0x27, /* direct */
0xff,
0xc0 | 0x28, /* 2 skip */
0x00 | 0x2a, /* direct */
0xff, 0xff, 0x00 | 0x2b, /* direct */
0xff, 0xff, 0xff,
};
typedef struct char39_s {
unsigned char chk, rev, fwd;
} char39_t;
static const char39_t code39_encodings[NUM_CHARS] = {
{ 0x07, 0x1a, 0x20 }, /* 00 */
{ 0x0d, 0x10, 0x03 }, /* 01 */
{ 0x13, 0x17, 0x22 }, /* 02 */
{ 0x16, 0x1d, 0x23 }, /* 03 */
{ 0x19, 0x0d, 0x05 }, /* 04 */
{ 0x1c, 0x13, 0x06 }, /* 05 */
{ 0x25, 0x07, 0x0c }, /* 06 */
{ 0x2a, 0x2a, 0x27 }, /* 07 */
{ 0x31, 0x04, 0x0e }, /* 08 */
{ 0x34, 0x00, 0x0f }, /* 09 */
{ 0x43, 0x15, 0x25 }, /* 0a */
{ 0x46, 0x1c, 0x26 }, /* 0b */
{ 0x49, 0x0b, 0x08 }, /* 0c */
{ 0x4c, 0x12, 0x09 }, /* 0d */
{ 0x52, 0x19, 0x2b }, /* 0e */
{ 0x58, 0x0f, 0x00 }, /* 0f */
{ 0x61, 0x02, 0x11 }, /* 10 */
{ 0x64, 0x09, 0x12 }, /* 11 */
{ 0x70, 0x06, 0x13 }, /* 12 */
{ 0x85, 0x24, 0x16 }, /* 13 */
{ 0x8a, 0x29, 0x28 }, /* 14 */
{ 0x91, 0x21, 0x18 }, /* 15 */
{ 0x94, 0x2b, 0x19 }, /* 16 */
{ 0xa2, 0x28, 0x29 }, /* 17 */
{ 0xa8, 0x27, 0x2a }, /* 18 */
{ 0xc1, 0x1f, 0x1b }, /* 19 */
{ 0xc4, 0x26, 0x1c }, /* 1a */
{ 0xd0, 0x23, 0x1d }, /* 1b */
{ 0x03, 0x14, 0x1e }, /* 1c */
{ 0x06, 0x1b, 0x1f }, /* 1d */
{ 0x09, 0x0a, 0x01 }, /* 1e */
{ 0x0c, 0x11, 0x02 }, /* 1f */
{ 0x12, 0x18, 0x21 }, /* 20 */
{ 0x18, 0x0e, 0x04 }, /* 21 */
{ 0x21, 0x01, 0x0a }, /* 22 */
{ 0x24, 0x08, 0x0b }, /* 23 */
{ 0x30, 0x05, 0x0d }, /* 24 */
{ 0x42, 0x16, 0x24 }, /* 25 */
{ 0x48, 0x0c, 0x07 }, /* 26 */
{ 0x60, 0x03, 0x10 }, /* 27 */
{ 0x81, 0x1e, 0x14 }, /* 28 */
{ 0x84, 0x25, 0x15 }, /* 29 */
{ 0x90, 0x22, 0x17 }, /* 2a */
{ 0xc0, 0x20, 0x1a }, /* 2b */
};
static const unsigned char code39_characters[NUM_CHARS] =
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%*";
static inline unsigned char code39_decode1(unsigned char enc, unsigned e,
unsigned s)
{
unsigned char E = decode_e(e, s, 72);
if (E > 18)
return (0xff);
enc <<= 1;
if (E > 6) {
enc |= 1;
dbprintf(2, "1");
} else
dbprintf(2, "0");
return (enc);
}
static inline signed char code39_decode9(zbar_decoder_t *dcode)
{
unsigned char i, enc = 0, idx;
const char39_t *c;
code39_decoder_t *dcode39 = &dcode->code39;
if (dcode39->s9 < 9)
return (-1);
/* threshold bar width ratios */
for (i = 0; i < 5; i++) {
enc = code39_decode1(enc, get_width(dcode, i), dcode39->s9);
if (enc == 0xff)
return (-1);
}
zassert(enc < 0x20, -1, " enc=%x s9=%x\n", enc, dcode39->s9);
/* lookup first 5 encoded widths for coarse decode */
idx = code39_hi[enc];
if (idx == 0xff)
return (-1);
/* encode remaining widths (NB first encoded width is lost) */
for (; i < 9; i++) {
enc = code39_decode1(enc, get_width(dcode, i), dcode39->s9);
if (enc == 0xff)
return (-1);
}
if ((idx & 0xc0) == 0x80)
idx = (idx & 0x3f) + ((enc >> 3) & 1);
else if ((idx & 0xc0) == 0xc0)
idx = (idx & 0x3f) + ((enc >> 2) & 1);
else if (idx & 0xc0)
idx = (idx & 0x3f) + ((enc >> 2) & 3);
zassert(idx < 0x2c, -1, " idx=%x enc=%x s9=%x\n", idx, enc, dcode39->s9);
c = &code39_encodings[idx];
dbprintf(2, " i=%02x chk=%02x c=%02x/%02x", idx, c->chk, c->fwd, c->rev);
if (enc != c->chk)
return (-1);
dcode39->width = dcode39->s9;
return ((dcode39->direction) ? c->rev : c->fwd);
}
static inline signed char code39_decode_start(zbar_decoder_t *dcode)
{
signed char c;
unsigned quiet;
code39_decoder_t *dcode39 = &dcode->code39;
dbprintf(2, " s=%d ", dcode39->s9);
c = code39_decode9(dcode);
if (c != 0x19 && c != 0x2b) {
dbprintf(2, "\n");
return (ZBAR_NONE);
}
dcode39->direction ^= (c == 0x19);
/* check leading quiet zone - spec is 10x */
quiet = get_width(dcode, 9);
if (quiet && quiet < dcode39->s9 / 2) {
dbprintf(2, " [invalid quiet]\n");
return (ZBAR_NONE);
}
dcode39->element = 9;
dcode39->character = 0;
dbprintf(1, " dir=%x [valid start]\n", dcode39->direction);
return (ZBAR_PARTIAL);
}
static inline int code39_postprocess(zbar_decoder_t *dcode)
{
int i;
code39_decoder_t *dcode39 = &dcode->code39;
dcode->direction = 1 - 2 * dcode39->direction;
if (dcode39->direction) {
/* reverse buffer */
dbprintf(2, " (rev)");
for (i = 0; i < dcode39->character / 2; i++) {
unsigned j = dcode39->character - 1 - i;
char code = dcode->buf[i];
dcode->buf[i] = dcode->buf[j];
dcode->buf[j] = code;
}
}
for (i = 0; i < dcode39->character; i++)
dcode->buf[i] = ((dcode->buf[i] < 0x2b) ?
code39_characters[(unsigned)dcode->buf[i]] :
'?');
zassert(i < dcode->buf_alloc, -1, "i=%02x %s\n", i,
_zbar_decoder_buf_dump(dcode->buf, dcode39->character));
dcode->buflen = i;
dcode->buf[i] = '\0';
dcode->modifiers = 0;
return (0);
}
static inline int check_width(unsigned ref, unsigned w)
{
unsigned dref = ref;
ref *= 4;
w *= 4;
return (ref - dref <= w && w <= ref + dref);
}
zbar_symbol_type_t _zbar_decode_code39(zbar_decoder_t *dcode)
{
code39_decoder_t *dcode39 = &dcode->code39;
signed char c;
/* update latest character width */
dcode39->s9 -= get_width(dcode, 9);
dcode39->s9 += get_width(dcode, 0);
if (dcode39->character < 0) {
if (get_color(dcode) != ZBAR_BAR)
return (ZBAR_NONE);
dbprintf(2, " code39:");
return (code39_decode_start(dcode));
}
if (++dcode39->element < 9)
return (ZBAR_NONE);
dbprintf(2, " code39[%c%02d+%x]", (dcode39->direction) ? '<' : '>',
dcode39->character, dcode39->element);
if (dcode39->element == 10) {
unsigned space = get_width(dcode, 0);
if (dcode39->character &&
dcode->buf[dcode39->character - 1] == 0x2b) { /* STOP */
zbar_symbol_type_t sym;
/* trim STOP character */
dcode39->character--;
sym = ZBAR_NONE;
/* trailing quiet zone check */
if (space && space < dcode39->width / 2)
dbprintf(2, " [invalid qz]\n");
else if (dcode39->character < CFG(*dcode39, ZBAR_CFG_MIN_LEN) ||
(CFG(*dcode39, ZBAR_CFG_MAX_LEN) > 0 &&
dcode39->character > CFG(*dcode39, ZBAR_CFG_MAX_LEN)))
dbprintf(2, " [invalid len]\n");
else if (!code39_postprocess(dcode)) {
/* FIXME checksum */
dbprintf(2, " [valid end]\n");
sym = ZBAR_CODE39;
}
dcode39->character = -1;
if (!sym)
release_lock(dcode, ZBAR_CODE39);
return (sym);
}
if (space > dcode39->width / 2) {
/* inter-character space check failure */
dbprintf(2, " ics>%d [invalid ics]", dcode39->width);
if (dcode39->character)
release_lock(dcode, ZBAR_CODE39);
dcode39->character = -1;
}
dcode39->element = 0;
dbprintf(2, "\n");
return (ZBAR_NONE);
}
dbprintf(2, " s=%d ", dcode39->s9);
if (!check_width(dcode39->width, dcode39->s9)) {
dbprintf(2, " [width]\n");
if (dcode39->character)
release_lock(dcode, ZBAR_CODE39);
dcode39->character = -1;
return (ZBAR_NONE);
}
c = code39_decode9(dcode);
dbprintf(2, " c=%d", c);
/* lock shared resources */
if (!dcode39->character && acquire_lock(dcode, ZBAR_CODE39)) {
dcode39->character = -1;
return (ZBAR_PARTIAL);
}
if (c < 0 || size_buf(dcode, dcode39->character + 1)) {
dbprintf(1, (c < 0) ? " [aborted]\n" : " [overflow]\n");
release_lock(dcode, ZBAR_CODE39);
dcode39->character = -1;
return (ZBAR_NONE);
} else {
zassert(c < 0x2c, ZBAR_NONE, "c=%02x s9=%x\n", c, dcode39->s9);
dbprintf(2, "\n");
}
dcode->buf[dcode39->character++] = c;
return (ZBAR_NONE);
}