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