ean.c

00001 /*------------------------------------------------------------------------
00002  *  Copyright 2007-2009 (c) Jeff Brown <spadix@users.sourceforge.net>
00003  *
00004  *  This file is part of the ZBar Bar Code Reader.
00005  *
00006  *  The ZBar Bar Code Reader is free software; you can redistribute it
00007  *  and/or modify it under the terms of the GNU Lesser Public License as
00008  *  published by the Free Software Foundation; either version 2.1 of
00009  *  the License, or (at your option) any later version.
00010  *
00011  *  The ZBar Bar Code Reader is distributed in the hope that it will be
00012  *  useful, but WITHOUT ANY WARRANTY; without even the implied warranty
00013  *  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  *  GNU Lesser Public License for more details.
00015  *
00016  *  You should have received a copy of the GNU Lesser Public License
00017  *  along with the ZBar Bar Code Reader; if not, write to the Free
00018  *  Software Foundation, Inc., 51 Franklin St, Fifth Floor,
00019  *  Boston, MA  02110-1301  USA
00020  *
00021  *  http://sourceforge.net/projects/zbar
00022  *------------------------------------------------------------------------*/
00023 
00024 #include "../config.h"
00025 #include <zbar.h>
00026 #include "../decoder.h"
00027 
00028 #ifdef ENABLE_EAN
00029 
00030 #ifdef DEBUG_EAN
00031 # define DEBUG_LEVEL (DEBUG_EAN)
00032 #endif
00033 #include "../debug.h"
00034 
00035 /* partial decode symbol location */
00036 typedef enum symbol_partial_e {
00037     EAN_LEFT   = 0x0000,
00038     EAN_RIGHT  = 0x1000,
00039 } symbol_partial_t;
00040 
00041 /* convert compact encoded D2E1E2 to character (bit4 is parity) */
00042 static const unsigned char digits[] = {  /* E1   E2 */
00043     0x06, 0x10, 0x04, 0x13,              /*  2  2-5 */
00044     0x19, 0x08, 0x11, 0x05,              /*  3  2-5 (d2 <= thr) */
00045     0x09, 0x12, 0x07, 0x15,              /*  4  2-5 (d2 <= thr) */
00046     0x16, 0x00, 0x14, 0x03,              /*  5  2-5 */
00047     0x18, 0x01, 0x02, 0x17,              /* E1E2=43,44,33,34 (d2 > thr) */
00048 };
00049 
00050 static const unsigned char parity_decode[] = {
00051     0xf0, /* [xx] BBBBBB = RIGHT half EAN-13 */
00052 
00053     /* UPC-E check digit encoding */
00054     0xff,
00055     0xff,
00056     0x0f, /* [07] BBBAAA = 0 */
00057     0xff,
00058     0x1f, /* [0b] BBABAA = 1 */
00059     0x2f, /* [0d] BBAABA = 2 */
00060     0xf3, /* [0e] BBAAAB = 3 */
00061     0xff,
00062     0x4f, /* [13] BABBAA = 4 */
00063     0x7f, /* [15] BABABA = 7 */
00064     0xf8, /* [16] BABAAB = 8 */
00065     0x5f, /* [19] BAABBA = 5 */
00066     0xf9, /* [1a] BAABAB = 9 */
00067     0xf6, /* [1c] BAAABB = 6 */
00068     0xff,
00069 
00070     /* LEFT half EAN-13 leading digit */
00071     0xff,
00072     0x6f, /* [23] ABBBAA = 6 */
00073     0x9f, /* [25] ABBABA = 9 */
00074     0xf5, /* [26] ABBAAB = 5 */
00075     0x8f, /* [29] ABABBA = 8 */
00076     0xf7, /* [2a] ABABAB = 7 */
00077     0xf4, /* [2c] ABAABB = 4 */
00078     0xff,
00079     0x3f, /* [31] AABBBA = 3 */
00080     0xf2, /* [32] AABBAB = 2 */
00081     0xf1, /* [34] AABABB = 1 */
00082     0xff,
00083     0xff,
00084     0xff,
00085     0xff,
00086     0x0f, /* [3f] AAAAAA = 0 */
00087 };
00088 
00089 #ifdef DEBUG_EAN
00090 static unsigned char debug_buf[0x18];
00091 
00092 static inline const unsigned char *dsprintbuf(ean_decoder_t *ean)
00093 {
00094     int i;
00095     for(i = 0; i < 7; i++)
00096         debug_buf[i] = ((ean->buf[0] < 0 || ean->buf[i] < 0)
00097                         ? '-'
00098                         : ean->buf[i] + '0');
00099     debug_buf[i] = ' ';
00100     for(; i < 13; i++)
00101         debug_buf[i + 1] = ((ean->buf[7] < 0 || ean->buf[i] < 0)
00102                             ? '-'
00103                             : ean->buf[i] + '0');
00104     debug_buf[i + 1] = ' ';
00105     for(; i < 18; i++)
00106         debug_buf[i + 2] = ((ean->buf[13] < 0 || ean->buf[i] < 0)
00107                             ? '-'
00108                             : ean->buf[i] + '0');
00109     debug_buf[i + 2] = '\0';
00110     return(debug_buf);
00111 }
00112 #endif
00113 
00114 /* evaluate previous N (>= 2) widths as auxiliary pattern,
00115  * using preceding 4 as character width
00116  */
00117 static inline signed char aux_end (zbar_decoder_t *dcode,
00118                                    unsigned char fwd)
00119 {
00120     /* reference width from previous character */
00121     unsigned s = calc_s(dcode, 4 + fwd, 4);
00122 
00123     /* check quiet zone */
00124     unsigned qz = get_width(dcode, 0);
00125     if(!fwd && qz && qz < s * 3 / 4) {
00126         dprintf(2, " [invalid quiet]");
00127         return(-1);
00128     }
00129 
00130     dprintf(2, " (");
00131     signed char code = 0;
00132     unsigned char i;
00133     for(i = 1 - fwd; i < 3 + fwd; i++) {
00134         unsigned e = get_width(dcode, i) + get_width(dcode, i + 1);
00135         dprintf(2, " %d", e);
00136         code = (code << 2) | decode_e(e, s, 7);
00137         if(code < 0) {
00138             dprintf(2, " [invalid end guard]");
00139             return(-1);
00140         }
00141     }
00142     dprintf(2, ") s=%d aux=%x", s, code);
00143     return(code);
00144 }
00145 
00146 /* determine possible auxiliary pattern
00147  * using current 4 as possible character
00148  */
00149 static inline signed char aux_start (zbar_decoder_t *dcode)
00150 {
00151     /* FIXME NB add-on has no guard in reverse */
00152     unsigned e2 = get_width(dcode, 5) + get_width(dcode, 6);
00153     if(decode_e(e2, dcode->ean.s4, 7)) {
00154         dprintf(2, " [invalid any]");
00155         return(/*FIXME (get_color(dcode) == ZBAR_SPACE) ? STATE_ADDON : */-1);
00156     }
00157 
00158     unsigned e1 = get_width(dcode, 4) + get_width(dcode, 5);
00159     unsigned char E1 = decode_e(e1, dcode->ean.s4, 7);
00160 
00161     if(get_color(dcode) == ZBAR_BAR) {
00162         /* check for quiet-zone */
00163         unsigned qz = get_width(dcode, 7);
00164         if(!qz || qz >= dcode->ean.s4 * 3 / 4) {
00165             if(!E1) {
00166                 dprintf(2, " [valid normal]");
00167                 return(0); /* normal symbol start */
00168             }
00169             else if(E1 == 1) {
00170                 dprintf(2, " [valid add-on]");
00171                 return(STATE_ADDON); /* add-on symbol start */
00172             }
00173         }
00174         dprintf(2, " [invalid start]");
00175         return(-1);
00176     }
00177 
00178     if(!E1) {
00179         /* attempting decode from SPACE => validate center guard */
00180         unsigned e3 = get_width(dcode, 6) + get_width(dcode, 7);
00181         if(!decode_e(e3, dcode->ean.s4, 7)) {
00182             dprintf(2, " [valid center]");
00183             return(0); /* start after center guard */
00184         }
00185     }
00186     dprintf(2, " [invalid center]");
00187     return(/*STATE_ADDON*/-1);
00188 }
00189 
00190 /* attempt to decode previous 4 widths (2 bars and 2 spaces) as a character */
00191 static inline signed char decode4 (zbar_decoder_t *dcode)
00192 {
00193     /* calculate similar edge measurements */
00194     unsigned e1 = ((get_color(dcode) == ZBAR_BAR)
00195                    ? get_width(dcode, 0) + get_width(dcode, 1)
00196                    : get_width(dcode, 2) + get_width(dcode, 3));
00197     unsigned e2 = get_width(dcode, 1) + get_width(dcode, 2);
00198     dprintf(2, "\n        e1=%d e2=%d", e1, e2);
00199 
00200     /* create compacted encoding for direct lookup */
00201     signed char code = ((decode_e(e1, dcode->ean.s4, 7) << 2) |
00202                         decode_e(e2, dcode->ean.s4, 7));
00203     if(code < 0)
00204         return(-1);
00205     dprintf(2, " code=%x", code);
00206 
00207     /* 4 combinations require additional determinant (D2)
00208        E1E2 == 34 (0110)
00209        E1E2 == 43 (1001)
00210        E1E2 == 33 (0101)
00211        E1E2 == 44 (1010)
00212      */
00213     if((1 << code) & 0x0660) {
00214         /* use sum of bar widths */
00215         unsigned d2 = ((get_color(dcode) == ZBAR_BAR)
00216                        ? get_width(dcode, 0) + get_width(dcode, 2)
00217                        : get_width(dcode, 1) + get_width(dcode, 3));
00218         d2 *= 7;
00219         unsigned char mid = (((1 << code) & 0x0420)
00220                              ? 3     /* E1E2 in 33,44 */
00221                              : 4);   /* E1E2 in 34,43 */
00222         unsigned char alt = d2 > (mid * dcode->ean.s4);
00223         if(alt)
00224             code = ((code >> 1) & 3) | 0x10; /* compress code space */
00225         dprintf(2, " (d2=%d(%d) alt=%d)", d2, mid * dcode->ean.s4, alt);
00226     }
00227     dprintf(2, " char=%02x", digits[(unsigned char)code]);
00228     zassert(code < 0x14, -1, "code=%02x e1=%x e2=%x s4=%x color=%x\n",
00229             code, e1, e2, dcode->ean.s4, get_color(dcode));
00230     return(code);
00231 }
00232 
00233 static inline zbar_symbol_type_t ean_part_end4 (ean_pass_t *pass,
00234                                                 unsigned char fwd)
00235 {
00236     /* extract parity bits */
00237     unsigned char par = ((pass->raw[1] & 0x10) >> 1 |
00238                          (pass->raw[2] & 0x10) >> 2 |
00239                          (pass->raw[3] & 0x10) >> 3 |
00240                          (pass->raw[4] & 0x10) >> 4);
00241 
00242     dprintf(2, " par=%x", par);
00243     if(par && par != 0xf)
00244         /* invalid parity combination */
00245         return(ZBAR_NONE);
00246 
00247     if(!par == fwd) {
00248         /* reverse sampled digits */
00249         unsigned char tmp = pass->raw[1];
00250         pass->raw[1] = pass->raw[4];
00251         pass->raw[4] = tmp;
00252         tmp = pass->raw[2];
00253         pass->raw[2] = pass->raw[3];
00254         pass->raw[3] = tmp;
00255     }
00256 
00257     dprintf(2, "\n");
00258     dprintf(1, "decode4=%x%x%x%x\n",
00259             pass->raw[1] & 0xf, pass->raw[2] & 0xf,
00260             pass->raw[3] & 0xf, pass->raw[4] & 0xf);
00261     if(!par)
00262         return(ZBAR_EAN8 | EAN_RIGHT);
00263     return(ZBAR_EAN8 | EAN_LEFT);
00264 }
00265 
00266 static inline zbar_symbol_type_t ean_part_end7 (ean_decoder_t *ean,
00267                                                 ean_pass_t *pass,
00268                                                 unsigned char fwd)
00269 {
00270     /* calculate parity index */
00271     unsigned char par = ((fwd)
00272                          ? ((pass->raw[1] & 0x10) << 1 |
00273                             (pass->raw[2] & 0x10) |
00274                             (pass->raw[3] & 0x10) >> 1 |
00275                             (pass->raw[4] & 0x10) >> 2 |
00276                             (pass->raw[5] & 0x10) >> 3 |
00277                             (pass->raw[6] & 0x10) >> 4)
00278                          : ((pass->raw[1] & 0x10) >> 4 |
00279                             (pass->raw[2] & 0x10) >> 3 |
00280                             (pass->raw[3] & 0x10) >> 2 |
00281                             (pass->raw[4] & 0x10) >> 1 |
00282                             (pass->raw[5] & 0x10) |
00283                             (pass->raw[6] & 0x10) << 1));
00284 
00285     /* lookup parity combination */
00286     pass->raw[0] = parity_decode[par >> 1];
00287     if(par & 1)
00288         pass->raw[0] >>= 4;
00289     pass->raw[0] &= 0xf;
00290     dprintf(2, " par=%02x(%x)", par, pass->raw[0]);
00291 
00292     if(pass->raw[0] == 0xf)
00293         /* invalid parity combination */
00294         return(ZBAR_NONE);
00295 
00296     if(!par == fwd) {
00297         /* reverse sampled digits */
00298         unsigned char i;
00299         for(i = 1; i < 4; i++) {
00300             unsigned char tmp = pass->raw[i];
00301             pass->raw[i] = pass->raw[7 - i];
00302             pass->raw[7 - i] = tmp;
00303         }
00304     }
00305 
00306     dprintf(2, "\n");
00307     dprintf(1, "decode=%x%x%x%x%x%x%x(%02x)\n",
00308             pass->raw[0] & 0xf, pass->raw[1] & 0xf,
00309             pass->raw[2] & 0xf, pass->raw[3] & 0xf,
00310             pass->raw[4] & 0xf, pass->raw[5] & 0xf,
00311             pass->raw[6] & 0xf, par);
00312 
00313     if(TEST_CFG(ean->ean13_config, ZBAR_CFG_ENABLE)) {
00314         if(!par)
00315             return(ZBAR_EAN13 | EAN_RIGHT);
00316         if(par & 0x20)
00317             return(ZBAR_EAN13 | EAN_LEFT);
00318     }
00319     if(par && !(par & 0x20))
00320         return(ZBAR_UPCE);
00321 
00322     return(ZBAR_NONE);
00323 }
00324 
00325 /* update state for one of 4 parallel passes */
00326 static inline zbar_symbol_type_t decode_pass (zbar_decoder_t *dcode,
00327                                               ean_pass_t *pass)
00328 {
00329     pass->state++;
00330     unsigned char idx = pass->state & STATE_IDX;
00331     unsigned char fwd = pass->state & 1;
00332 
00333     if(get_color(dcode) == ZBAR_SPACE &&
00334        (idx == 0x10 || idx == 0x11) &&
00335        TEST_CFG(dcode->ean.ean8_config, ZBAR_CFG_ENABLE) &&
00336        !aux_end(dcode, fwd)) {
00337         dprintf(2, " fwd=%x", fwd);
00338         zbar_symbol_type_t part = ean_part_end4(pass, fwd);
00339         pass->state = -1;
00340         return(part);
00341     }
00342 
00343     if(!(idx & 0x03) && idx <= 0x14) {
00344         if(!dcode->ean.s4)
00345             return(0);
00346         /* validate guard bars before decoding first char of symbol */
00347         if(!pass->state) {
00348             pass->state = aux_start(dcode);
00349             if(pass->state < 0)
00350                 return(0);
00351             idx = pass->state & STATE_IDX;
00352         }
00353         signed char code = decode4(dcode);
00354         if(code < 0)
00355             pass->state = -1;
00356         else {
00357             dprintf(2, "\n        raw[%x]=%02x =>", idx >> 2,
00358                     digits[(unsigned char)code]);
00359             pass->raw[(idx >> 2) + 1] = digits[(unsigned char)code];
00360             dprintf(2, " raw=%d%d%d%d%d%d%d",
00361                     pass->raw[0] & 0xf, pass->raw[1] & 0xf,
00362                     pass->raw[2] & 0xf, pass->raw[3] & 0xf,
00363                     pass->raw[4] & 0xf, pass->raw[5] & 0xf,
00364                     pass->raw[6] & 0xf);
00365         }
00366     }
00367 
00368     if(get_color(dcode) == ZBAR_SPACE &&
00369        (idx == 0x18 || idx == 0x19)) {
00370         zbar_symbol_type_t part = ZBAR_NONE;
00371         dprintf(2, " fwd=%x", fwd);
00372         if(!aux_end(dcode, fwd))
00373             part = ean_part_end7(&dcode->ean, pass, fwd);
00374         pass->state = -1;
00375         return(part);
00376     }
00377     return(0);
00378 }
00379 
00380 static inline signed char ean_verify_checksum (ean_decoder_t *ean,
00381                                                int n)
00382 {
00383     unsigned char chk = 0;
00384     unsigned char i;
00385     for(i = 0; i < n; i++) {
00386         unsigned char d = ean->buf[i];
00387         zassert(d < 10, -1, "i=%x d=%x chk=%x %s\n", i, d, chk,
00388                 _zbar_decoder_buf_dump((void*)ean->buf, 18));
00389         chk += d;
00390         if((i ^ n) & 1) {
00391             chk += d << 1;
00392             if(chk >= 20)
00393                 chk -= 20;
00394         }
00395         if(chk >= 10)
00396             chk -= 10;
00397     }
00398     zassert(chk < 10, -1, "chk=%x n=%x %s", chk, n,
00399             _zbar_decoder_buf_dump((void*)ean->buf, 18));
00400     if(chk)
00401         chk = 10 - chk;
00402     unsigned char d = ean->buf[n];
00403     zassert(d < 10, -1, "n=%x d=%x chk=%x %s\n", n, d, chk,
00404             _zbar_decoder_buf_dump((void*)ean->buf, 18));
00405     if(chk != d) {
00406         dprintf(1, "\nchecksum mismatch %d != %d (%s)\n",
00407                 chk, d, dsprintbuf(ean));
00408         return(-1);
00409     }
00410     return(0);
00411 }
00412 
00413 static inline unsigned char isbn10_calc_checksum (ean_decoder_t *ean)
00414 {
00415     unsigned int chk = 0;
00416     unsigned char w;
00417     for(w = 10; w > 1; w--) {
00418         unsigned char d = ean->buf[13 - w];
00419         zassert(d < 10, '?', "w=%x d=%x chk=%x %s\n", w, d, chk,
00420                 _zbar_decoder_buf_dump((void*)ean->buf, 18));
00421         chk += d * w;
00422     }
00423     chk = chk % 11;
00424     if(!chk)
00425         return('0');
00426     chk = 11 - chk;
00427     if(chk < 10)
00428         return(chk + '0');
00429     return('X');
00430 }
00431 
00432 static inline void ean_expand_upce (ean_decoder_t *ean,
00433                                     ean_pass_t *pass)
00434 {
00435     int i = 0;
00436     /* parity encoded digit is checksum */
00437     ean->buf[12] = pass->raw[i++];
00438 
00439     unsigned char decode = pass->raw[6] & 0xf;
00440     ean->buf[0] = 0;
00441     ean->buf[1] = 0;
00442     ean->buf[2] = pass->raw[i++] & 0xf;
00443     ean->buf[3] = pass->raw[i++] & 0xf;
00444     ean->buf[4] = (decode < 3) ? decode : pass->raw[i++] & 0xf;
00445     ean->buf[5] = (decode < 4) ? 0 : pass->raw[i++] & 0xf;
00446     ean->buf[6] = (decode < 5) ? 0 : pass->raw[i++] & 0xf;
00447     ean->buf[7] = 0;
00448     ean->buf[8] = 0;
00449     ean->buf[9] = (decode < 3) ? pass->raw[i++] & 0xf : 0;
00450     ean->buf[10] = (decode < 4) ? pass->raw[i++] & 0xf : 0;
00451     ean->buf[11] = (decode < 5) ? pass->raw[i++] & 0xf : decode;
00452 }
00453 
00454 static inline zbar_symbol_type_t integrate_partial (ean_decoder_t *ean,
00455                                                     ean_pass_t *pass,
00456                                                     zbar_symbol_type_t part)
00457 {
00458     /* copy raw data into holding buffer */
00459     /* if same partial is not consistent, reset others */
00460     dprintf(2, " integrate part=%x (%s)", part, dsprintbuf(ean));
00461     signed char i, j;
00462     if(part & ZBAR_ADDON) {
00463         /* FIXME TBD */
00464         for(i = (part == ZBAR_ADDON5) ? 4 : 1; i >= 0; i--) {
00465             unsigned char digit = pass->raw[i] & 0xf;
00466             if(ean->addon && ean->buf[i + 13] != digit) {
00467                 /* partial mismatch - reset collected parts */
00468                 ean->left = ean->right = ean->addon = ZBAR_NONE;
00469             }
00470             ean->buf[i + 13] = digit;
00471         }
00472         ean->addon = part;
00473     }
00474     else {
00475         if((ean->left && ((part & ZBAR_SYMBOL) != ean->left)) ||
00476            (ean->right && ((part & ZBAR_SYMBOL) != ean->right))) {
00477             /* partial mismatch - reset collected parts */
00478             dprintf(2, " rst(type %x %x)", ean->left, ean->right);
00479             ean->left = ean->right = ean->addon = ZBAR_NONE;
00480         }
00481 
00482         if(part & EAN_RIGHT) {
00483             part &= ZBAR_SYMBOL;
00484             j = (part == ZBAR_EAN13) ? 12 : 7;
00485             for(i = (part == ZBAR_EAN13) ? 6 : 4; i; i--, j--) {
00486                 unsigned char digit = pass->raw[i] & 0xf;
00487                 if(ean->right && ean->buf[j] != digit) {
00488                     /* partial mismatch - reset collected parts */
00489                     dprintf(2, " rst(right)");
00490                     ean->left = ean->right = ean->addon = ZBAR_NONE;
00491                 }
00492                 ean->buf[j] = digit;
00493             }
00494             ean->right = part;
00495         }
00496         else if(part != ZBAR_UPCE) /* EAN_LEFT */ {
00497             j = (part == ZBAR_EAN13) ? 6 : 3;
00498             for(i = (part == ZBAR_EAN13) ? 6 : 4; j >= 0; i--, j--) {
00499                 unsigned char digit = pass->raw[i] & 0xf;
00500                 if(ean->left && ean->buf[j] != digit) {
00501                     /* partial mismatch - reset collected parts */
00502                     dprintf(2, " rst(left)");
00503                     ean->left = ean->right = ean->addon = ZBAR_NONE;
00504                 }
00505                 ean->buf[j] = digit;
00506             }
00507             ean->left = part;
00508         }
00509         else /* ZBAR_UPCE */
00510             ean_expand_upce(ean, pass);
00511     }
00512 
00513     if((part & ZBAR_SYMBOL) != ZBAR_UPCE) {
00514         part = (ean->left & ean->right);
00515         if(!part)
00516             part = ZBAR_PARTIAL;
00517     }
00518 
00519     if(((part == ZBAR_EAN13 ||
00520          part == ZBAR_UPCE) && ean_verify_checksum(ean, 12)) ||
00521        (part == ZBAR_EAN8 && ean_verify_checksum(ean, 7)))
00522         /* invalid parity */
00523         part = ZBAR_NONE;
00524 
00525     if(part == ZBAR_EAN13) {
00526         /* special case EAN-13 subsets */
00527         if(!ean->buf[0] && TEST_CFG(ean->upca_config, ZBAR_CFG_ENABLE))
00528             part = ZBAR_UPCA;
00529         else if(ean->buf[0] == 9 && ean->buf[1] == 7) {
00530             /* ISBN-10 has priority over ISBN-13(?) */
00531             if(ean->buf[2] == 8 &&
00532                TEST_CFG(ean->isbn10_config, ZBAR_CFG_ENABLE))
00533                 part = ZBAR_ISBN10;
00534             else if((ean->buf[2] == 8 || ean->buf[2] == 9) &&
00535                TEST_CFG(ean->isbn13_config, ZBAR_CFG_ENABLE))
00536                 part = ZBAR_ISBN13;
00537         }
00538     }
00539     else if(part == ZBAR_UPCE) {
00540         if(TEST_CFG(ean->upce_config, ZBAR_CFG_ENABLE)) {
00541             /* UPC-E was decompressed for checksum verification,
00542              * but user requested compressed result
00543              */
00544             ean->buf[0] = ean->buf[1] = 0;
00545             for(i = 2; i < 8; i++)
00546                 ean->buf[i] = pass->raw[i - 1] & 0xf;
00547             ean->buf[i] = pass->raw[0] & 0xf;
00548         }
00549         else if(TEST_CFG(ean->upca_config, ZBAR_CFG_ENABLE))
00550             /* UPC-E reported as UPC-A has priority over EAN-13 */
00551             part = ZBAR_UPCA;
00552         else if(TEST_CFG(ean->ean13_config, ZBAR_CFG_ENABLE))
00553             part = ZBAR_EAN13;
00554         else
00555             part = ZBAR_NONE;
00556     }
00557 
00558     if(part > ZBAR_PARTIAL)
00559         part |= ean->addon;
00560 
00561     dprintf(2, " %x/%x=%x", ean->left, ean->right, part);
00562     return(part);
00563 }
00564 
00565 /* copy result to output buffer */
00566 static inline void postprocess (zbar_decoder_t *dcode,
00567                                 zbar_symbol_type_t sym)
00568 {
00569     ean_decoder_t *ean = &dcode->ean;
00570     zbar_symbol_type_t base = sym & ZBAR_SYMBOL;
00571     int i = 0, j = 0;
00572     if(base > ZBAR_PARTIAL) {
00573         if(base == ZBAR_UPCA)
00574             i = 1;
00575         else if(base == ZBAR_UPCE) {
00576             i = 1;
00577             base--;
00578         }
00579         else if(base == ZBAR_ISBN13)
00580             base = ZBAR_EAN13;
00581         else if(base == ZBAR_ISBN10)
00582             i = 3;
00583 
00584         if(base == ZBAR_ISBN10 ||
00585            !TEST_CFG(ean_get_config(ean, sym), ZBAR_CFG_EMIT_CHECK))
00586             base--;
00587 
00588         for(; j < base && ean->buf[i] >= 0; i++, j++)
00589             dcode->buf[j] = ean->buf[i] + '0';
00590 
00591         if((sym & ZBAR_SYMBOL) == ZBAR_ISBN10 && j == 9 &&
00592            TEST_CFG(ean->isbn10_config, ZBAR_CFG_EMIT_CHECK))
00593             /* recalculate ISBN-10 check digit */
00594             dcode->buf[j++] = isbn10_calc_checksum(ean);
00595     }
00596     if(sym & ZBAR_ADDON)
00597         for(i = 13; ean->buf[i] >= 0; i++, j++)
00598             dcode->buf[j] = ean->buf[i] + '0';
00599     dcode->buflen = j;
00600     dcode->buf[j] = '\0';
00601 }
00602 
00603 zbar_symbol_type_t _zbar_decode_ean (zbar_decoder_t *dcode)
00604 {
00605     /* process upto 4 separate passes */
00606     zbar_symbol_type_t sym = ZBAR_NONE;
00607     unsigned char pass_idx = dcode->idx & 3;
00608 
00609     /* update latest character width */
00610     dcode->ean.s4 -= get_width(dcode, 4);
00611     dcode->ean.s4 += get_width(dcode, 0);
00612 
00613     unsigned char i;
00614     for(i = 0; i < 4; i++) {
00615         ean_pass_t *pass = &dcode->ean.pass[i];
00616         if(pass->state >= 0 ||
00617            i == pass_idx)
00618         {
00619             dprintf(2, "      ean[%x/%x]: idx=%x st=%d s=%d",
00620                     pass_idx, i, dcode->idx, pass->state, dcode->ean.s4);
00621             zbar_symbol_type_t part = decode_pass(dcode, pass);
00622             if(part) {
00623                 /* update accumulated data from new partial decode */
00624                 sym = integrate_partial(&dcode->ean, pass, part);
00625                 if(sym) {
00626                     /* this pass valid => _reset_ all passes */
00627                     dprintf(2, " sym=%x", sym);
00628                     dcode->ean.pass[0].state = dcode->ean.pass[1].state = -1;
00629                     dcode->ean.pass[2].state = dcode->ean.pass[3].state = -1;
00630                     if(sym > ZBAR_PARTIAL) {
00631                         if(!get_lock(dcode, ZBAR_EAN13))
00632                             postprocess(dcode, sym);
00633                         else {
00634                             dprintf(1, " [locked %d]", dcode->lock);
00635                             sym = ZBAR_PARTIAL;
00636                         }
00637                     }
00638                 }
00639             }
00640             dprintf(2, "\n");
00641         }
00642     }
00643     return(sym);
00644 }
00645 
00646 #endif