ffmpeg/libavcodec/dvdsubdec.c

   1 /*
   2  * DVD subtitle decoding
   3  * Copyright (c) 2005 Fabrice Bellard
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "avcodec.h"
  23 #include "get_bits.h"
  24 #include "internal.h"
  25
  26 #include "libavutil/attributes.h"
  27 #include "libavutil/colorspace.h"
  28 #include "libavutil/opt.h"
  29 #include "libavutil/imgutils.h"
  30 #include "libavutil/avstring.h"
  31 #include "libavutil/bswap.h"
  32
  33 typedef struct DVDSubContext
  34 {
  35   AVClass *class;
  36   uint32_t palette[16];
  37   char    *palette_str;
  38   char    *ifo_str;
  39   int      has_palette;
  40   uint8_t  colormap[4];
  41   uint8_t  alpha[256];
  42   uint8_t  buf[0x10000];
  43   int      buf_size;
  44   int      forced_subs_only;
  45 #ifdef DEBUG
  46   int sub_id;
  47 #endif
  48 } DVDSubContext;
  49
  50 static void yuv_a_to_rgba(const uint8_t *ycbcr, const uint8_t *alpha, uint32_t *rgba, int num_values)
  51 {
  52     const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
  53     uint8_t r, g, b;
  54     int i, y, cb, cr;
  55     int r_add, g_add, b_add;
  56
  57     for (i = num_values; i > 0; i--) {
  58         y = *ycbcr++;
  59         cr = *ycbcr++;
  60         cb = *ycbcr++;
  61         YUV_TO_RGB1_CCIR(cb, cr);
  62         YUV_TO_RGB2_CCIR(r, g, b, y);
  63         *rgba++ = (*alpha++ << 24) | (r << 16) | (g << 8) | b;
  64     }
  65 }
  66
  67 static int decode_run_2bit(GetBitContext *gb, int *color)
  68 {
  69     unsigned int v, t;
  70
  71     v = 0;
  72     for (t = 1; v < t && t <= 0x40; t <<= 2)
  73         v = (v << 4) | get_bits(gb, 4);
  74     *color = v & 3;
  75     if (v < 4) { /* Code for fill rest of line */
  76         return INT_MAX;
  77     }
  78     return v >> 2;
  79 }
  80
  81 static int decode_run_8bit(GetBitContext *gb, int *color)
  82 {
  83     int len;
  84     int has_run = get_bits1(gb);
  85     if (get_bits1(gb))
  86         *color = get_bits(gb, 8);
  87     else
  88         *color = get_bits(gb, 2);
  89     if (has_run) {
  90         if (get_bits1(gb)) {
  91             len = get_bits(gb, 7);
  92             if (len == 0)
  93                 len = INT_MAX;
  94             else
  95                 len += 9;
  96         } else
  97             len = get_bits(gb, 3) + 2;
  98     } else
  99         len = 1;
 100     return len;
 101 }
 102
 103 static int decode_rle(uint8_t *bitmap, int linesize, int w, int h,
 104                       const uint8_t *buf, int start, int buf_size, int is_8bit)
 105 {
 106     GetBitContext gb;
 107     int bit_len;
 108     int x, y, len, color;
 109     uint8_t *d;
 110
 111     if (start >= buf_size)
 112         return -1;
 113
 114     if (w <= 0 || h <= 0)
 115         return -1;
 116
 117     bit_len = (buf_size - start) * 8;
 118     init_get_bits(&gb, buf + start, bit_len);
 119
 120     x = 0;
 121     y = 0;
 122     d = bitmap;
 123     for(;;) {
 124         if (get_bits_count(&gb) > bit_len)
 125             return -1;
 126         if (is_8bit)
 127             len = decode_run_8bit(&gb, &color);
 128         else
 129             len = decode_run_2bit(&gb, &color);
 130         len = FFMIN(len, w - x);
 131         memset(d + x, color, len);
 132         x += len;
 133         if (x >= w) {
 134             y++;
 135             if (y >= h)
 136                 break;
 137             d += linesize;
 138             x = 0;
 139             /* byte align */
 140             align_get_bits(&gb);
 141         }
 142     }
 143     return 0;
 144 }
 145
 146 static void guess_palette(DVDSubContext* ctx,
 147                           uint32_t *rgba_palette,
 148                           uint32_t subtitle_color)
 149 {
 150     static const uint8_t level_map[4][4] = {
 151         // this configuration (full range, lowest to highest) in tests
 152         // seemed most common, so assume this
 153         {0xff},
 154         {0x00, 0xff},
 155         {0x00, 0x80, 0xff},
 156         {0x00, 0x55, 0xaa, 0xff},
 157     };
 158     uint8_t color_used[16] = { 0 };
 159     int nb_opaque_colors, i, level, j, r, g, b;
 160     uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
 161
 162     if(ctx->has_palette) {
 163         for(i = 0; i < 4; i++)
 164             rgba_palette[i] = (ctx->palette[colormap[i]] & 0x00ffffff)
 165                               | ((alpha[i] * 17U) << 24);
 166         return;
 167     }
 168
 169     for(i = 0; i < 4; i++)
 170         rgba_palette[i] = 0;
 171
 172     nb_opaque_colors = 0;
 173     for(i = 0; i < 4; i++) {
 174         if (alpha[i] != 0 && !color_used[colormap[i]]) {
 175             color_used[colormap[i]] = 1;
 176             nb_opaque_colors++;
 177         }
 178     }
 179
 180     if (nb_opaque_colors == 0)
 181         return;
 182
 183     j = 0;
 184     memset(color_used, 0, 16);
 185     for(i = 0; i < 4; i++) {
 186         if (alpha[i] != 0) {
 187             if (!color_used[colormap[i]])  {
 188                 level = level_map[nb_opaque_colors][j];
 189                 r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
 190                 g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
 191                 b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
 192                 rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17) << 24);
 193                 color_used[colormap[i]] = (i + 1);
 194                 j++;
 195             } else {
 196                 rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |
 197                                     ((alpha[i] * 17) << 24);
 198             }
 199         }
 200     }
 201 }
 202
 203 static void reset_rects(AVSubtitle *sub_header)
 204 {
 205     int i;
 206
 207     if (sub_header->rects) {
 208         for (i = 0; i < sub_header->num_rects; i++) {
 209             av_freep(&sub_header->rects[i]->pict.data[0]);
 210             av_freep(&sub_header->rects[i]->pict.data[1]);
 211             av_freep(&sub_header->rects[i]);
 212         }
 213         av_freep(&sub_header->rects);
 214         sub_header->num_rects = 0;
 215     }
 216 }
 217
 218 #define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))
 219
 220 static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
 221                                 const uint8_t *buf, int buf_size)
 222 {
 223     int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
 224     int big_offsets, offset_size, is_8bit = 0;
 225     const uint8_t *yuv_palette = NULL;
 226     uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
 227     int date;
 228     int i;
 229     int is_menu = 0;
 230
 231     if (buf_size < 10)
 232         return -1;
 233
 234     if (AV_RB16(buf) == 0) {   /* HD subpicture with 4-byte offsets */
 235         big_offsets = 1;
 236         offset_size = 4;
 237         cmd_pos = 6;
 238     } else {
 239         big_offsets = 0;
 240         offset_size = 2;
 241         cmd_pos = 2;
 242     }
 243
 244     cmd_pos = READ_OFFSET(buf + cmd_pos);
 245
 246     if (cmd_pos < 0 || cmd_pos > buf_size - 2 - offset_size)
 247         return AVERROR(EAGAIN);
 248
 249     while (cmd_pos > 0 && cmd_pos < buf_size - 2 - offset_size) {
 250         date = AV_RB16(buf + cmd_pos);
 251         next_cmd_pos = READ_OFFSET(buf + cmd_pos + 2);
 252         av_dlog(NULL, "cmd_pos=0x%04x next=0x%04x date=%d\n",
 253                 cmd_pos, next_cmd_pos, date);
 254         pos = cmd_pos + 2 + offset_size;
 255         offset1 = -1;
 256         offset2 = -1;
 257         x1 = y1 = x2 = y2 = 0;
 258         while (pos < buf_size) {
 259             cmd = buf[pos++];
 260             av_dlog(NULL, "cmd=%02x\n", cmd);
 261             switch(cmd) {
 262             case 0x00:
 263                 /* menu subpicture */
 264                 is_menu = 1;
 265                 break;
 266             case 0x01:
 267                 /* set start date */
 268                 sub_header->start_display_time = (date << 10) / 90;
 269                 break;
 270             case 0x02:
 271                 /* set end date */
 272                 sub_header->end_display_time = (date << 10) / 90;
 273                 break;
 274             case 0x03:
 275                 /* set colormap */
 276                 if ((buf_size - pos) < 2)
 277                     goto fail;
 278                 colormap[3] = buf[pos] >> 4;
 279                 colormap[2] = buf[pos] & 0x0f;
 280                 colormap[1] = buf[pos + 1] >> 4;
 281                 colormap[0] = buf[pos + 1] & 0x0f;
 282                 pos += 2;
 283                 break;
 284             case 0x04:
 285                 /* set alpha */
 286                 if ((buf_size - pos) < 2)
 287                     goto fail;
 288                 alpha[3] = buf[pos] >> 4;
 289                 alpha[2] = buf[pos] & 0x0f;
 290                 alpha[1] = buf[pos + 1] >> 4;
 291                 alpha[0] = buf[pos + 1] & 0x0f;
 292                 pos += 2;
 293             av_dlog(NULL, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]);
 294                 break;
 295             case 0x05:
 296             case 0x85:
 297                 if ((buf_size - pos) < 6)
 298                     goto fail;
 299                 x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
 300                 x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
 301                 y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
 302                 y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
 303                 if (cmd & 0x80)
 304                     is_8bit = 1;
 305                 av_dlog(NULL, "x1=%d x2=%d y1=%d y2=%d\n", x1, x2, y1, y2);
 306                 pos += 6;
 307                 break;
 308             case 0x06:
 309                 if ((buf_size - pos) < 4)
 310                     goto fail;
 311                 offset1 = AV_RB16(buf + pos);
 312                 offset2 = AV_RB16(buf + pos + 2);
 313                 av_dlog(NULL, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
 314                 pos += 4;
 315                 break;
 316             case 0x86:
 317                 if ((buf_size - pos) < 8)
 318                     goto fail;
 319                 offset1 = AV_RB32(buf + pos);
 320                 offset2 = AV_RB32(buf + pos + 4);
 321                 av_dlog(NULL, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
 322                 pos += 8;
 323                 break;
 324
 325             case 0x83:
 326                 /* HD set palette */
 327                 if ((buf_size - pos) < 768)
 328                     goto fail;
 329                 yuv_palette = buf + pos;
 330                 pos += 768;
 331                 break;
 332             case 0x84:
 333                 /* HD set contrast (alpha) */
 334                 if ((buf_size - pos) < 256)
 335                     goto fail;
 336                 for (i = 0; i < 256; i++)
 337                     alpha[i] = 0xFF - buf[pos+i];
 338                 pos += 256;
 339                 break;
 340
 341             case 0xff:
 342                 goto the_end;
 343             default:
 344                 av_dlog(NULL, "unrecognised subpicture command 0x%x\n", cmd);
 345                 goto the_end;
 346             }
 347         }
 348     the_end:
 349         if (offset1 >= 0) {
 350             int w, h;
 351             uint8_t *bitmap;
 352
 353             /* decode the bitmap */
 354             w = x2 - x1 + 1;
 355             if (w < 0)
 356                 w = 0;
 357             h = y2 - y1 + 1;
 358             if (h < 0)
 359                 h = 0;
 360             if (w > 0 && h > 0) {
 361                 reset_rects(sub_header);
 362
 363                 bitmap = av_malloc(w * h);
 364                 sub_header->rects = av_mallocz(sizeof(*sub_header->rects));
 365                 sub_header->rects[0] = av_mallocz(sizeof(AVSubtitleRect));
 366                 sub_header->num_rects = 1;
 367                 sub_header->rects[0]->pict.data[0] = bitmap;
 368                 if (decode_rle(bitmap, w * 2, w, (h + 1) / 2,
 369                                buf, offset1, buf_size, is_8bit) < 0)
 370                     goto fail;
 371                 if (decode_rle(bitmap + w, w * 2, w, h / 2,
 372                                buf, offset2, buf_size, is_8bit) < 0)
 373                     goto fail;
 374                 sub_header->rects[0]->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
 375                 if (is_8bit) {
 376                     if (!yuv_palette)
 377                         goto fail;
 378                     sub_header->rects[0]->nb_colors = 256;
 379                     yuv_a_to_rgba(yuv_palette, alpha, (uint32_t*)sub_header->rects[0]->pict.data[1], 256);
 380                 } else {
 381                     sub_header->rects[0]->nb_colors = 4;
 382                     guess_palette(ctx, (uint32_t*)sub_header->rects[0]->pict.data[1],
 383                                   0xffff00);
 384                 }
 385                 sub_header->rects[0]->x = x1;
 386                 sub_header->rects[0]->y = y1;
 387                 sub_header->rects[0]->w = w;
 388                 sub_header->rects[0]->h = h;
 389                 sub_header->rects[0]->type = SUBTITLE_BITMAP;
 390                 sub_header->rects[0]->pict.linesize[0] = w;
 391                 sub_header->rects[0]->flags = is_menu ? AV_SUBTITLE_FLAG_FORCED : 0;
 392             }
 393         }
 394         if (next_cmd_pos < cmd_pos) {
 395             av_log(NULL, AV_LOG_ERROR, "Invalid command offset\n");
 396             break;
 397         }
 398         if (next_cmd_pos == cmd_pos)
 399             break;
 400         cmd_pos = next_cmd_pos;
 401     }
 402     if (sub_header->num_rects > 0)
 403         return is_menu;
 404  fail:
 405     reset_rects(sub_header);
 406     return -1;
 407 }
 408
 409 static int is_transp(const uint8_t *buf, int pitch, int n,
 410                      const uint8_t *transp_color)
 411 {
 412     int i;
 413     for(i = 0; i < n; i++) {
 414         if (!transp_color[*buf])
 415             return 0;
 416         buf += pitch;
 417     }
 418     return 1;
 419 }
 420
 421 /* return 0 if empty rectangle, 1 if non empty */
 422 static int find_smallest_bounding_rectangle(AVSubtitle *s)
 423 {
 424     uint8_t transp_color[256] = { 0 };
 425     int y1, y2, x1, x2, y, w, h, i;
 426     uint8_t *bitmap;
 427
 428     if (s->num_rects == 0 || !s->rects || s->rects[0]->w <= 0 || s->rects[0]->h <= 0)
 429         return 0;
 430
 431     for(i = 0; i < s->rects[0]->nb_colors; i++) {
 432         if ((((uint32_t*)s->rects[0]->pict.data[1])[i] >> 24) == 0)
 433             transp_color[i] = 1;
 434     }
 435     y1 = 0;
 436     while (y1 < s->rects[0]->h && is_transp(s->rects[0]->pict.data[0] + y1 * s->rects[0]->pict.linesize[0],
 437                                   1, s->rects[0]->w, transp_color))
 438         y1++;
 439     if (y1 == s->rects[0]->h) {
 440         av_freep(&s->rects[0]->pict.data[0]);
 441         s->rects[0]->w = s->rects[0]->h = 0;
 442         return 0;
 443     }
 444
 445     y2 = s->rects[0]->h - 1;
 446     while (y2 > 0 && is_transp(s->rects[0]->pict.data[0] + y2 * s->rects[0]->pict.linesize[0], 1,
 447                                s->rects[0]->w, transp_color))
 448         y2--;
 449     x1 = 0;
 450     while (x1 < (s->rects[0]->w - 1) && is_transp(s->rects[0]->pict.data[0] + x1, s->rects[0]->pict.linesize[0],
 451                                         s->rects[0]->h, transp_color))
 452         x1++;
 453     x2 = s->rects[0]->w - 1;
 454     while (x2 > 0 && is_transp(s->rects[0]->pict.data[0] + x2, s->rects[0]->pict.linesize[0], s->rects[0]->h,
 455                                   transp_color))
 456         x2--;
 457     w = x2 - x1 + 1;
 458     h = y2 - y1 + 1;
 459     bitmap = av_malloc(w * h);
 460     if (!bitmap)
 461         return 1;
 462     for(y = 0; y < h; y++) {
 463         memcpy(bitmap + w * y, s->rects[0]->pict.data[0] + x1 + (y1 + y) * s->rects[0]->pict.linesize[0], w);
 464     }
 465     av_freep(&s->rects[0]->pict.data[0]);
 466     s->rects[0]->pict.data[0] = bitmap;
 467     s->rects[0]->pict.linesize[0] = w;
 468     s->rects[0]->w = w;
 469     s->rects[0]->h = h;
 470     s->rects[0]->x += x1;
 471     s->rects[0]->y += y1;
 472     return 1;
 473 }
 474
 475 #ifdef DEBUG
 476 #define ALPHA_MIX(A,BACK,FORE) (((255-(A)) * (BACK) + (A) * (FORE)) / 255)
 477 static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,
 478                      uint32_t *rgba_palette)
 479 {
 480     int x, y, alpha;
 481     uint32_t v;
 482     int back[3] = {0, 255, 0};  /* green background */
 483     FILE *f;
 484
 485     f = fopen(filename, "w");
 486     if (!f) {
 487         perror(filename);
 488         return;
 489     }
 490     fprintf(f, "P6\n"
 491             "%d %d\n"
 492             "%d\n",
 493             w, h, 255);
 494     for(y = 0; y < h; y++) {
 495         for(x = 0; x < w; x++) {
 496             v = rgba_palette[bitmap[y * w + x]];
 497             alpha = v >> 24;
 498             putc(ALPHA_MIX(alpha, back[0], (v >> 16) & 0xff), f);
 499             putc(ALPHA_MIX(alpha, back[1], (v >> 8) & 0xff), f);
 500             putc(ALPHA_MIX(alpha, back[2], (v >> 0) & 0xff), f);
 501         }
 502     }
 503     fclose(f);
 504 }
 505 #endif
 506
 507 static int append_to_cached_buf(AVCodecContext *avctx,
 508                                 const uint8_t *buf, int buf_size)
 509 {
 510     DVDSubContext *ctx = avctx->priv_data;
 511
 512     if (ctx->buf_size >= sizeof(ctx->buf) - buf_size) {
 513         av_log(avctx, AV_LOG_WARNING, "Attempt to reconstruct "
 514                "too large SPU packets aborted.\n");
 515         return AVERROR_INVALIDDATA;
 516     }
 517     memcpy(ctx->buf + ctx->buf_size, buf, buf_size);
 518     ctx->buf_size += buf_size;
 519     return 0;
 520 }
 521
 522 static int dvdsub_decode(AVCodecContext *avctx,
 523                          void *data, int *data_size,
 524                          AVPacket *avpkt)
 525 {
 526     DVDSubContext *ctx = avctx->priv_data;
 527     const uint8_t *buf = avpkt->data;
 528     int buf_size = avpkt->size;
 529     AVSubtitle *sub = data;
 530     int is_menu;
 531
 532     if (ctx->buf_size) {
 533         int ret = append_to_cached_buf(avctx, buf, buf_size);
 534         if (ret < 0) {
 535             *data_size = 0;
 536             return ret;
 537         }
 538         buf = ctx->buf;
 539         buf_size = ctx->buf_size;
 540     }
 541
 542     is_menu = decode_dvd_subtitles(ctx, sub, buf, buf_size);
 543     if (is_menu == AVERROR(EAGAIN)) {
 544         *data_size = 0;
 545         return append_to_cached_buf(avctx, buf, buf_size);
 546     }
 547
 548     if (is_menu < 0) {
 549     no_subtitle:
 550         reset_rects(sub);
 551         *data_size = 0;
 552
 553         return buf_size;
 554     }
 555     if (!is_menu && find_smallest_bounding_rectangle(sub) == 0)
 556         goto no_subtitle;
 557
 558     if (ctx->forced_subs_only && !(sub->rects[0]->flags & AV_SUBTITLE_FLAG_FORCED))
 559         goto no_subtitle;
 560
 561 #if defined(DEBUG)
 562     {
 563     char ppm_name[32];
 564
 565     snprintf(ppm_name, sizeof(ppm_name), "/tmp/%05d.ppm", ctx->sub_id++);
 566     av_dlog(NULL, "start=%d ms end =%d ms\n",
 567             sub->start_display_time,
 568             sub->end_display_time);
 569     ppm_save(ppm_name, sub->rects[0]->pict.data[0],
 570              sub->rects[0]->w, sub->rects[0]->h, (uint32_t*) sub->rects[0]->pict.data[1]);
 571     }
 572 #endif
 573
 574     ctx->buf_size = 0;
 575     *data_size = 1;
 576     return buf_size;
 577 }
 578
 579 static void parse_palette(DVDSubContext *ctx, char *p)
 580 {
 581     int i;
 582
 583     ctx->has_palette = 1;
 584     for(i=0;i<16;i++) {
 585         ctx->palette[i] = strtoul(p, &p, 16);
 586         while(*p == ',' || av_isspace(*p))
 587             p++;
 588     }
 589 }
 590
 591 static int parse_ifo_palette(DVDSubContext *ctx, char *p)
 592 {
 593     FILE *ifo;
 594     char ifostr[12];
 595     uint32_t sp_pgci, pgci, off_pgc, pgc;
 596     uint8_t r, g, b, yuv[65], *buf;
 597     int i, y, cb, cr, r_add, g_add, b_add;
 598     int ret = 0;
 599     const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
 600
 601     ctx->has_palette = 0;
 602     if ((ifo = fopen(p, "r")) == NULL) {
 603         av_log(ctx, AV_LOG_WARNING, "Unable to open IFO file \"%s\": %s\n", p, strerror(errno));
 604         return AVERROR_EOF;
 605     }
 606     if (fread(ifostr, 12, 1, ifo) != 1 || memcmp(ifostr, "DVDVIDEO-VTS", 12)) {
 607         av_log(ctx, AV_LOG_WARNING, "\"%s\" is not a proper IFO file\n", p);
 608         ret = AVERROR_INVALIDDATA;
 609         goto end;
 610     }
 611     if (fseek(ifo, 0xCC, SEEK_SET) == -1) {
 612         ret = AVERROR(errno);
 613         goto end;
 614     }
 615     if (fread(&sp_pgci, 4, 1, ifo) == 1) {
 616         pgci = av_be2ne32(sp_pgci) * 2048;
 617         if (fseek(ifo, pgci + 0x0C, SEEK_SET) == -1) {
 618             ret = AVERROR(errno);
 619             goto end;
 620         }
 621         if (fread(&off_pgc, 4, 1, ifo) == 1) {
 622             pgc = pgci + av_be2ne32(off_pgc);
 623             if (fseek(ifo, pgc + 0xA4, SEEK_SET) == -1) {
 624                 ret = AVERROR(errno);
 625                 goto end;
 626             }
 627             if (fread(yuv, 64, 1, ifo) == 1) {
 628                 buf = yuv;
 629                 for(i=0; i<16; i++) {
 630                     y  = *++buf;
 631                     cr = *++buf;
 632                     cb = *++buf;
 633                     YUV_TO_RGB1_CCIR(cb, cr);
 634                     YUV_TO_RGB2_CCIR(r, g, b, y);
 635                     ctx->palette[i] = (r << 16) + (g << 8) + b;
 636                     buf++;
 637                 }
 638                 ctx->has_palette = 1;
 639             }
 640         }
 641     }
 642     if (ctx->has_palette == 0) {
 643         av_log(ctx, AV_LOG_WARNING, "Failed to read palette from IFO file \"%s\"\n", p);
 644         ret = AVERROR_INVALIDDATA;
 645     }
 646 end:
 647     fclose(ifo);
 648     return ret;
 649 }
 650
 651 static int dvdsub_parse_extradata(AVCodecContext *avctx)
 652 {
 653     DVDSubContext *ctx = (DVDSubContext*) avctx->priv_data;
 654     char *dataorig, *data;
 655     int ret = 1;
 656
 657     if (!avctx->extradata || !avctx->extradata_size)
 658         return 1;
 659
 660     dataorig = data = av_malloc(avctx->extradata_size+1);
 661     if (!data)
 662         return AVERROR(ENOMEM);
 663     memcpy(data, avctx->extradata, avctx->extradata_size);
 664     data[avctx->extradata_size] = '\0';
 665
 666     for(;;) {
 667         int pos = strcspn(data, "\n\r");
 668         if (pos==0 && *data==0)
 669             break;
 670
 671         if (strncmp("palette:", data, 8) == 0) {
 672             parse_palette(ctx, data + 8);
 673         } else if (strncmp("size:", data, 5) == 0) {
 674             int w, h;
 675             if (sscanf(data + 5, "%dx%d", &w, &h) == 2) {
 676                ret = ff_set_dimensions(avctx, w, h);
 677                if (ret < 0)
 678                    goto fail;
 679             }
 680         }
 681
 682         data += pos;
 683         data += strspn(data, "\n\r");
 684     }
 685
 686 fail:
 687     av_free(dataorig);
 688     return ret;
 689 }
 690
 691 static av_cold int dvdsub_init(AVCodecContext *avctx)
 692 {
 693     DVDSubContext *ctx = avctx->priv_data;
 694     int ret;
 695
 696     if ((ret = dvdsub_parse_extradata(avctx)) < 0)
 697         return ret;
 698
 699     if (ctx->ifo_str)
 700         parse_ifo_palette(ctx, ctx->ifo_str);
 701     if (ctx->palette_str)
 702         parse_palette(ctx, ctx->palette_str);
 703     if (ctx->has_palette) {
 704         int i;
 705         av_log(avctx, AV_LOG_DEBUG, "palette:");
 706         for(i=0;i<16;i++)
 707             av_log(avctx, AV_LOG_DEBUG, " 0x%06x", ctx->palette[i]);
 708         av_log(avctx, AV_LOG_DEBUG, "\n");
 709     }
 710
 711     return 1;
 712 }
 713
 714 static av_cold int dvdsub_close(AVCodecContext *avctx)
 715 {
 716     DVDSubContext *ctx = avctx->priv_data;
 717     ctx->buf_size = 0;
 718     return 0;
 719 }
 720
 721 #define OFFSET(field) offsetof(DVDSubContext, field)
 722 #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
 723 static const AVOption options[] = {
 724     { "palette", "set the global palette", OFFSET(palette_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, SD },
 725     { "ifo_palette", "obtain the global palette from .IFO file", OFFSET(ifo_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, SD },
 726     { "forced_subs_only", "Only show forced subtitles", OFFSET(forced_subs_only), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
 727     { NULL }
 728 };
 729 static const AVClass dvdsub_class = {
 730     .class_name = "dvdsubdec",
 731     .item_name  = av_default_item_name,
 732     .option     = options,
 733     .version    = LIBAVUTIL_VERSION_INT,
 734 };
 735
 736 AVCodec ff_dvdsub_decoder = {
 737     .name           = "dvdsub",
 738     .long_name      = NULL_IF_CONFIG_SMALL("DVD subtitles"),
 739     .type           = AVMEDIA_TYPE_SUBTITLE,
 740     .id             = AV_CODEC_ID_DVD_SUBTITLE,
 741     .priv_data_size = sizeof(DVDSubContext),
 742     .init           = dvdsub_init,
 743     .decode         = dvdsub_decode,
 744     .close          = dvdsub_close,
 745     .priv_class     = &dvdsub_class,
 746 };