sub/subassconvert.c

   1 /*
   2  * Subtitles converter to SSA/ASS in order to allow special formatting
   3  *
   4  * This file is part of MPlayer.
   5  *
   6  * MPlayer is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * MPlayer is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <string.h>
  22 #include <stdint.h>
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25 #include <stdarg.h>
  26 #include <stdbool.h>
  27
  28 #include "mp_msg.h"
  29 #include "subassconvert.h"
  30 #include "bstr.h"
  31 #include "libavutil/common.h"
  32
  33 struct line {
  34     char *buf;
  35     int bufsize;
  36     int len;
  37 };
  38
  39 #ifdef __GNUC__
  40 static void append_text(struct line *dst, char *fmt, ...) __attribute__ ((format(printf, 2, 3)));
  41 #endif
  42
  43 static void append_text(struct line *dst, char *fmt, ...)
  44 {
  45     va_list va;
  46     va_start(va, fmt);
  47     int ret = vsnprintf(dst->buf + dst->len, dst->bufsize - dst->len, fmt, va);
  48     if (ret < 0)
  49         goto out;
  50     dst->len += ret;
  51     if (dst->len > dst->bufsize)
  52         dst->len = dst->bufsize;
  53  out:
  54     va_end(va);
  55 }
  56
  57 static int indexof(const char *s, int c)
  58 {
  59     char *f = strchr(s, c);
  60     return f ? (f - s) : -1;
  61 }
  62
  63
  64
  65 /*
  66  *      SubRip
  67  *
  68  *      Support basic tags (italic, bold, underline, strike-through)
  69  *      and font tag with size, color and face attributes.
  70  *
  71  */
  72
  73 struct font_tag {
  74     int size;
  75     uint32_t color;
  76     struct bstr face;
  77     bool has_size : 1;
  78     bool has_color : 1;
  79     bool has_face : 1;
  80 };
  81
  82 static const struct tag_conv {
  83     char *from;
  84     char *to;
  85 } subrip_basic_tags[] = {
  86     {"<i>", "{\\i1}"}, {"</i>", "{\\i0}"},
  87     {"<b>", "{\\b1}"}, {"</b>", "{\\b0}"},
  88     {"<u>", "{\\u1}"}, {"</u>", "{\\u0}"},
  89     {"<s>", "{\\s1}"}, {"</s>", "{\\s0}"},
  90     {"{", "\\{"}, {"}", "\\}"},
  91     {"\n", "\\N"}
  92 };
  93
  94 static const struct {
  95     char *s;
  96     uint32_t v;
  97 } subrip_web_colors[] = {
  98     /* 16 named HTML colors in BGR format */
  99     {"red",     0x0000ff}, {"blue",   0xff0000}, {"lime",   0x00ff00},
 100     {"aqua",    0xffff00}, {"purple", 0x800080}, {"yellow", 0x00ffff},
 101     {"fuchsia", 0xff00ff}, {"white",  0xffffff}, {"gray",   0x808080},
 102     {"maroon",  0x000080}, {"olive",  0x008080}, {"black",  0x000000},
 103     {"silver",  0xc0c0c0}, {"teal",   0x808000}, {"green",  0x008000},
 104     {"navy",    0x800000}
 105 };
 106
 107 #define SUBRIP_MAX_STACKED_FONT_TAGS    16
 108
 109 void subassconvert_subrip(const char *orig, char *dest, int dest_buffer_size)
 110 {
 111     /* line is not const to avoid warnings with strtol, etc.
 112      * orig content won't be changed */
 113     char *line = (char *)orig;
 114     struct line new_line = {
 115         .buf = dest,
 116         .bufsize = dest_buffer_size,
 117     };
 118     struct font_tag font_stack[SUBRIP_MAX_STACKED_FONT_TAGS + 1];
 119     font_stack[0] = (struct font_tag){0}; // type with all defaults
 120     int sp = 0;
 121
 122     while (*line && new_line.len < new_line.bufsize - 1) {
 123         char *orig_line = line;
 124
 125         for (int i = 0; i < FF_ARRAY_ELEMS(subrip_basic_tags); i++) {
 126             const struct tag_conv *tag = &subrip_basic_tags[i];
 127             int from_len = strlen(tag->from);
 128             if (strncmp(line, tag->from, from_len) == 0) {
 129                 append_text(&new_line, "%s", tag->to);
 130                 line += from_len;
 131             }
 132         }
 133
 134         if (strncmp(line, "</font>", 7) == 0) {
 135             /* Closing font tag */
 136             line += 7;
 137
 138             if (sp > 0) {
 139                 struct font_tag *tag = &font_stack[sp];
 140                 struct font_tag *last_tag = &tag[-1];
 141                 sp--;
 142
 143                 if (tag->has_size) {
 144                     if (!last_tag->has_size)
 145                         append_text(&new_line, "{\\fs}");
 146                     else if (last_tag->size != tag->size)
 147                         append_text(&new_line, "{\\fs%d}", last_tag->size);
 148                 }
 149
 150                 if (tag->has_color) {
 151                     if (!last_tag->has_color)
 152                         append_text(&new_line, "{\\c}");
 153                     else if (last_tag->color != tag->color)
 154                         append_text(&new_line, "{\\c&H%06X&}", last_tag->color);
 155                 }
 156
 157                 if (tag->has_face) {
 158                     if (!last_tag->has_face)
 159                         append_text(&new_line, "{\\fn}");
 160                     else if (bstrcmp(last_tag->face, tag->face) != 0)
 161                         append_text(&new_line, "{\\fn%.*s}",
 162                                     BSTR_P(last_tag->face));
 163                 }
 164             }
 165         } else if (strncmp(line, "<font ", 6) == 0
 166                    && sp + 1 < FF_ARRAY_ELEMS(font_stack)) {
 167             /* Opening font tag */
 168             char *potential_font_tag_start = line;
 169             int len_backup = new_line.len;
 170             struct font_tag *tag = &font_stack[sp + 1];
 171             bool has_valid_attr = false;
 172
 173             *tag = tag[-1]; // keep values from previous tag
 174             line += 6;
 175
 176             while (*line && *line != '>') {
 177                 if (strncmp(line, "size=\"", 6) == 0) {
 178                     line += 6;
 179                     tag->size = strtol(line, &line, 10);
 180                     if (*line != '"')
 181                         break;
 182                     append_text(&new_line, "{\\fs%d}", tag->size);
 183                     tag->has_size = true;
 184                     has_valid_attr = true;
 185                 } else if (strncmp(line, "color=\"", 7) == 0) {
 186                     line += 7;
 187                     if (*line == '#') {
 188                         // #RRGGBB format
 189                         line++;
 190                         tag->color = strtol(line, &line, 16) & 0x00ffffff;
 191                         if (*line != '"')
 192                             break;
 193                         tag->color = ((tag->color & 0xff) << 16)
 194                             | (tag->color & 0xff00)
 195                             | ((tag->color & 0xff0000) >> 16);
 196                     } else {
 197                         // Standard web colors
 198                         int len = indexof(line, '"');
 199                         if (len <= 0)
 200                             break;
 201                         for (int i = 0; i < FF_ARRAY_ELEMS(subrip_web_colors); i++) {
 202                             char *color = subrip_web_colors[i].s;
 203                             if (strlen(color) == len
 204                                 && strncasecmp(line, color, len) == 0) {
 205                                 tag->color = subrip_web_colors[i].v;
 206                                 goto foundcolor;
 207                             }
 208                         }
 209
 210                         /* We didn't find any matching color */
 211                         mp_tmsg(MSGT_SUBREADER, MSGL_WARN,
 212                                 "SubRip: unknown font color in subtitle: %s\n", orig);
 213                         append_text(&new_line, "{\\c}");
 214                         line += len + 1;
 215                         continue;
 216
 217                     foundcolor:
 218                         line += len;
 219                     }
 220                     append_text(&new_line, "{\\c&H%06X&}", tag->color);
 221                     tag->has_color = true;
 222                     has_valid_attr = true;
 223                 } else if (strncmp(line, "face=\"", 6) == 0) {
 224                     /* Font face attribute */
 225                     line += 6;
 226                     int len = indexof(line, '"');
 227                     if (len <= 0)
 228                         break;
 229                     tag->face.start = line;
 230                     tag->face.len = len;
 231                     line += len;
 232                     append_text(&new_line, "{\\fn%.*s}", BSTR_P(tag->face));
 233                     tag->has_face = true;
 234                     has_valid_attr = true;
 235                 }
 236                 line++;
 237             }
 238
 239             if (!has_valid_attr || *line != '>') { /* Not valid font tag */
 240                 line = potential_font_tag_start;
 241                 new_line.len = len_backup;
 242             } else {
 243                 sp++;
 244                 line++;
 245             }
 246         }
 247
 248         /* Tag conversion code didn't match */
 249         if (line == orig_line)
 250             new_line.buf[new_line.len++] = *line++;
 251     }
 252     new_line.buf[new_line.len] = 0;
 253 }
 254
 255
 256 /*
 257  *      MicroDVD
 258  *
 259  *      Based on the specifications found here:
 260  *      https://trac.videolan.org/vlc/ticket/1825#comment:6
 261  */
 262
 263 struct microdvd_tag {
 264     char key;
 265     int persistent;
 266     uint32_t data1;
 267     uint32_t data2;
 268     struct bstr data_string;
 269 };
 270
 271 #define MICRODVD_PERSISTENT_OFF     0
 272 #define MICRODVD_PERSISTENT_ON      1
 273 #define MICRODVD_PERSISTENT_OPENED  2
 274
 275 // Color, Font, Size, cHarset, stYle, Position, cOordinate
 276 #define MICRODVD_TAGS               "cfshyYpo"
 277
 278 static void microdvd_set_tag(struct microdvd_tag *tags, struct microdvd_tag tag)
 279 {
 280     int tag_index = indexof(MICRODVD_TAGS, tag.key);
 281
 282     if (tag_index < 0)
 283         return;
 284     memcpy(&tags[tag_index], &tag, sizeof(tag));
 285 }
 286
 287 // italic, bold, underline, strike-through
 288 #define MICRODVD_STYLES             "ibus"
 289
 290 static char *microdvd_load_tags(struct microdvd_tag *tags, char *s)
 291 {
 292     while (*s == '{') {
 293         char *start = s;
 294         char tag_char = *(s + 1);
 295         struct microdvd_tag tag = {0};
 296
 297         if (!tag_char || *(s + 2) != ':')
 298             break;
 299         s += 3;
 300
 301         switch (tag_char) {
 302
 303         /* Style */
 304         case 'Y':
 305             tag.persistent = MICRODVD_PERSISTENT_ON;
 306         case 'y':
 307             while (*s && *s != '}') {
 308                 int style_index = indexof(MICRODVD_STYLES, *s);
 309
 310                 if (style_index >= 0)
 311                     tag.data1 |= (1 << style_index);
 312                 s++;
 313             }
 314             if (*s != '}')
 315                 break;
 316             /* We must distinguish persistent and non-persistent styles
 317              * to handle this kind of style tags: {y:ib}{Y:us} */
 318             tag.key = tag_char;
 319             break;
 320
 321         /* Color */
 322         case 'C':
 323             tag.persistent = MICRODVD_PERSISTENT_ON;
 324         case 'c':
 325             tag.data1 = strtol(s, &s, 16) & 0x00ffffff;
 326             if (*s != '}')
 327                 break;
 328             tag.key = 'c';
 329             break;
 330
 331         /* Font name */
 332         case 'F':
 333             tag.persistent = MICRODVD_PERSISTENT_ON;
 334         case 'f':
 335         {
 336             int len = indexof(s, '}');
 337             if (len < 0)
 338                 break;
 339             tag.data_string.start = s;
 340             tag.data_string.len = len;
 341             s += len;
 342             tag.key = 'f';
 343             break;
 344         }
 345
 346         /* Font size */
 347         case 'S':
 348             tag.persistent = MICRODVD_PERSISTENT_ON;
 349         case 's':
 350             tag.data1 = strtol(s, &s, 10);
 351             if (*s != '}')
 352                 break;
 353             tag.key = 's';
 354             break;
 355
 356         /* Charset */
 357         case 'H':
 358         {
 359             //TODO: not yet handled, just parsed.
 360             int len = indexof(s, '}');
 361             if (len < 0)
 362                 break;
 363             tag.data_string.start = s;
 364             tag.data_string.len = len;
 365             s += len;
 366             tag.key = 'h';
 367             break;
 368         }
 369
 370         /* Position */
 371         case 'P':
 372             tag.persistent = MICRODVD_PERSISTENT_ON;
 373             tag.data1 = (*s++ == '1');
 374             if (*s != '}')
 375                 break;
 376             tag.key = 'p';
 377             break;
 378
 379         /* Coordinates */
 380         case 'o':
 381             tag.persistent = MICRODVD_PERSISTENT_ON;
 382             tag.data1 = strtol(s, &s, 10);
 383             if (*s != ',')
 384                 break;
 385             s++;
 386             tag.data2 = strtol(s, &s, 10);
 387             if (*s != '}')
 388                 break;
 389             tag.key = 'o';
 390             break;
 391
 392         default:    /* Unknown tag, we consider it to be text */
 393             break;
 394         }
 395
 396         if (tag.key == 0)
 397             return start;
 398
 399         microdvd_set_tag(tags, tag);
 400         s++;
 401     }
 402     return s;
 403 }
 404
 405 static void microdvd_open_tags(struct line *new_line, struct microdvd_tag *tags)
 406 {
 407     for (int i = 0; i < sizeof(MICRODVD_TAGS) - 1; i++) {
 408         if (tags[i].persistent == MICRODVD_PERSISTENT_OPENED)
 409             continue;
 410         switch (tags[i].key) {
 411         case 'Y':
 412         case 'y':
 413             for (int sidx = 0; sidx < sizeof(MICRODVD_STYLES) - 1; sidx++)
 414                 if (tags[i].data1 & (1 << sidx))
 415                     append_text(new_line, "{\\%c1}", MICRODVD_STYLES[sidx]);
 416             break;
 417
 418         case 'c':
 419             append_text(new_line, "{\\c&H%06X&}", tags[i].data1);
 420             break;
 421
 422         case 'f':
 423             append_text(new_line, "{\\fn%.*s}", BSTR_P(tags[i].data_string));
 424             break;
 425
 426         case 's':
 427             append_text(new_line, "{\\fs%d}", tags[i].data1);
 428             break;
 429
 430         case 'p':
 431             if (tags[i].data1 == 0)
 432                 append_text(new_line, "{\\an8}");
 433             break;
 434
 435         case 'o':
 436             append_text(new_line, "{\\pos(%d,%d)}",
 437                         tags[i].data1, tags[i].data2);
 438             break;
 439         }
 440         if (tags[i].persistent == MICRODVD_PERSISTENT_ON)
 441             tags[i].persistent = MICRODVD_PERSISTENT_OPENED;
 442     }
 443 }
 444
 445 static void microdvd_close_no_persistent_tags(struct line *new_line,
 446                                               struct microdvd_tag *tags)
 447 {
 448     int i;
 449
 450     for (i = sizeof(MICRODVD_TAGS) - 2; i; i--) {
 451         if (tags[i].persistent != MICRODVD_PERSISTENT_OFF)
 452             continue;
 453         switch (tags[i].key) {
 454
 455         case 'y':
 456             for (int sidx = sizeof(MICRODVD_STYLES) - 2; sidx >= 0; sidx--)
 457                 if (tags[i].data1 & (1 << sidx))
 458                     append_text(new_line, "{\\%c0}", MICRODVD_STYLES[sidx]);
 459             break;
 460
 461         case 'c':
 462             append_text(new_line, "{\\c}");
 463             break;
 464
 465         case 'f':
 466             append_text(new_line, "{\\fn}");
 467             break;
 468
 469         case 's':
 470             append_text(new_line, "{\\fs}");
 471             break;
 472         }
 473         tags[i].key = 0;
 474     }
 475 }
 476
 477 void subassconvert_microdvd(const char *orig, char *dest, int dest_buffer_size)
 478 {
 479     /* line is not const to avoid warnings with strtol, etc.
 480      * orig content won't be changed */
 481     char *line = (char *)orig;
 482     struct line new_line = {
 483         .buf = dest,
 484         .bufsize = dest_buffer_size,
 485     };
 486     struct microdvd_tag tags[sizeof(MICRODVD_TAGS) - 1] = {{0}};
 487
 488     while (*line) {
 489         line = microdvd_load_tags(tags, line);
 490         microdvd_open_tags(&new_line, tags);
 491
 492         while (*line && *line != '|')
 493             new_line.buf[new_line.len++] = *line++;
 494
 495         if (*line == '|') {
 496             microdvd_close_no_persistent_tags(&new_line, tags);
 497             append_text(&new_line, "\\N");
 498             line++;
 499         }
 500     }
 501     new_line.buf[new_line.len] = 0;
 502 }