1/* 2 * Teletext decoding for ffmpeg 3 * Copyright (c) 2005-2010, 2012 Wolfram Gloger 4 * Copyright (c) 2013 Marton Balint 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This library 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 GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21#include "avcodec.h" 22#include "libavcodec/ass.h" 23#include "codec_internal.h" 24#include "libavcodec/dvbtxt.h" 25#include "libavutil/opt.h" 26#include "libavutil/bprint.h" 27#include "libavutil/internal.h" 28#include "libavutil/intreadwrite.h" 29#include "libavutil/log.h" 30#include "libavutil/common.h" 31 32#include <libzvbi.h> 33 34#define TEXT_MAXSZ (25 * (56 + 1) * 4 + 2) 35#define VBI_NB_COLORS 40 36#define VBI_TRANSPARENT_BLACK 8 37#define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b)) 38#define VBI_R(rgba) (((rgba) >> 0) & 0xFF) 39#define VBI_G(rgba) (((rgba) >> 8) & 0xFF) 40#define VBI_B(rgba) (((rgba) >> 16) & 0xFF) 41#define VBI_A(rgba) (((rgba) >> 24) & 0xFF) 42#define MAX_BUFFERED_PAGES 25 43#define BITMAP_CHAR_WIDTH 12 44#define BITMAP_CHAR_HEIGHT 10 45#define MAX_SLICES 64 46 47typedef struct TeletextPage 48{ 49 AVSubtitleRect *sub_rect; 50 int pgno; 51 int subno; 52 int64_t pts; 53} TeletextPage; 54 55typedef struct TeletextContext 56{ 57 AVClass *class; 58 char *pgno; 59 int default_region; 60 int x_offset; 61 int y_offset; 62 int format_id; /* 0 = bitmap, 1 = text/ass, 2 = ass */ 63 int chop_top; 64 int sub_duration; /* in msec */ 65 int transparent_bg; 66 int opacity; 67 int chop_spaces; 68 69 int lines_processed; 70 TeletextPage *pages; 71 int nb_pages; 72 int64_t pts; 73 int handler_ret; 74 75 vbi_decoder * vbi; 76 vbi_sliced sliced[MAX_SLICES]; 77 78 int readorder; 79 uint8_t subtitle_map[2048]; 80 int last_pgno; 81 int last_p5; 82 int last_ass_alignment; 83} TeletextContext; 84 85static int my_ass_subtitle_header(AVCodecContext *avctx) 86{ 87 int ret = ff_ass_subtitle_header_default(avctx); 88 char *new_header; 89 uint8_t *event_pos; 90 91 if (ret < 0) 92 return ret; 93 94 event_pos = strstr(avctx->subtitle_header, "\r\n[Events]\r\n"); 95 if (!event_pos) 96 return AVERROR_BUG; 97 98 new_header = av_asprintf("%.*s%s%s", 99 (int)(event_pos - avctx->subtitle_header), avctx->subtitle_header, 100 "Style: " 101 "Teletext," /* Name */ 102 "Monospace,11," /* Font{name,size} */ 103 "&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */ 104 "0,0,0,0," /* Bold, Italic, Underline, StrikeOut */ 105 "160,100," /* Scale{X,Y} */ 106 "0,0," /* Spacing, Angle */ 107 "3,0.1,0," /* BorderStyle, Outline, Shadow */ 108 "5,1,1,1," /* Alignment, Margin[LRV] */ 109 "0\r\n" /* Encoding */ 110 "Style: " 111 "Subtitle," /* Name */ 112 "Monospace,16," /* Font{name,size} */ 113 "&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */ 114 "0,0,0,0," /* Bold, Italic, Underline, StrikeOut */ 115 "100,100," /* Scale{X,Y} */ 116 "0,0," /* Spacing, Angle */ 117 "1,1,1," /* BorderStyle, Outline, Shadow */ 118 "8,48,48,20," /* Alignment, Margin[LRV] */ 119 "0\r\n" /* Encoding */ 120 , event_pos); 121 122 if (!new_header) 123 return AVERROR(ENOMEM); 124 125 av_free(avctx->subtitle_header); 126 avctx->subtitle_header = new_header; 127 avctx->subtitle_header_size = strlen(new_header); 128 return 0; 129} 130 131static int chop_spaces_utf8(const unsigned char* t, int len) 132{ 133 t += len; 134 while (len > 0) { 135 if (*--t != ' ' || (len-1 > 0 && *(t-1) & 0x80)) 136 break; 137 --len; 138 } 139 return len; 140} 141 142static void subtitle_rect_free(AVSubtitleRect **sub_rect) 143{ 144 av_freep(&(*sub_rect)->data[0]); 145 av_freep(&(*sub_rect)->data[1]); 146 av_freep(&(*sub_rect)->ass); 147 av_freep(sub_rect); 148} 149 150static char *create_ass_text(TeletextContext *ctx, const char *text) 151{ 152 char *dialog; 153 AVBPrint buf; 154 155 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED); 156 ff_ass_bprint_text_event(&buf, text, strlen(text), "", 0); 157 if (!av_bprint_is_complete(&buf)) { 158 av_bprint_finalize(&buf, NULL); 159 return NULL; 160 } 161 dialog = ff_ass_get_dialog(ctx->readorder++, 0, NULL, NULL, buf.str); 162 av_bprint_finalize(&buf, NULL); 163 return dialog; 164} 165 166/* Draw a page as text */ 167static int gen_sub_text(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top) 168{ 169 const char *in; 170 AVBPrint buf; 171 char *vbi_text = av_malloc(TEXT_MAXSZ); 172 int sz; 173 174 if (!vbi_text) 175 return AVERROR(ENOMEM); 176 177 sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8", 178 /*table mode*/ TRUE, FALSE, 179 0, chop_top, 180 page->columns, page->rows-chop_top); 181 if (sz <= 0) { 182 av_log(ctx, AV_LOG_ERROR, "vbi_print error\n"); 183 av_free(vbi_text); 184 return AVERROR_EXTERNAL; 185 } 186 vbi_text[sz] = '\0'; 187 in = vbi_text; 188 av_bprint_init(&buf, 0, TEXT_MAXSZ); 189 190 if (ctx->chop_spaces) { 191 for (;;) { 192 int nl, sz; 193 194 // skip leading spaces and newlines 195 in += strspn(in, " \n"); 196 // compute end of row 197 for (nl = 0; in[nl]; ++nl) 198 if (in[nl] == '\n' && (nl==0 || !(in[nl-1] & 0x80))) 199 break; 200 if (!in[nl]) 201 break; 202 // skip trailing spaces 203 sz = chop_spaces_utf8(in, nl); 204 av_bprint_append_data(&buf, in, sz); 205 av_bprintf(&buf, "\n"); 206 in += nl; 207 } 208 } else { 209 av_bprintf(&buf, "%s\n", vbi_text); 210 } 211 av_free(vbi_text); 212 213 if (!av_bprint_is_complete(&buf)) { 214 av_bprint_finalize(&buf, NULL); 215 return AVERROR(ENOMEM); 216 } 217 218 if (buf.len) { 219 sub_rect->type = SUBTITLE_ASS; 220 sub_rect->ass = create_ass_text(ctx, buf.str); 221 222 if (!sub_rect->ass) { 223 av_bprint_finalize(&buf, NULL); 224 return AVERROR(ENOMEM); 225 } 226 av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass); 227 } else { 228 sub_rect->type = SUBTITLE_NONE; 229 } 230 av_bprint_finalize(&buf, NULL); 231 return 0; 232} 233 234static void bprint_color(const char *type, AVBPrint *buf, vbi_page *page, unsigned ci) 235{ 236 int r = VBI_R(page->color_map[ci]); 237 int g = VBI_G(page->color_map[ci]); 238 int b = VBI_B(page->color_map[ci]); 239 av_bprintf(buf, "{\\%s&H%02X%02X%02X&}", type, b, g, r); 240} 241 242#define IS_TXT_SPACE(ch) ((ch).unicode < 0x0020 || (ch).unicode >= 0xe000 || (ch).unicode == 0x00a0 ||\ 243 (ch).size > VBI_DOUBLE_SIZE || (ch).opacity == VBI_TRANSPARENT_SPACE) 244 245static void get_trim_info(vbi_page *page, vbi_char *row, int *leading, int *trailing, int *olen) 246{ 247 int i, len = 0; 248 int char_seen = 0; 249 250 *leading = 0; 251 252 for (i = 0; i < page->columns; i++) { 253 uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode; 254 255 if (out == 32 && !char_seen) 256 (*leading)++; 257 else if (out != 32) 258 char_seen = 1, len = i - (*leading) + 1; 259 } 260 261 *olen = len; 262 *trailing = len > 0 ? page->columns - *leading - len : page->columns; 263} 264 265static void decode_string(vbi_page *page, vbi_char *row, AVBPrint *buf, 266 int start, int end, vbi_color *cur_color, vbi_color *cur_back_color) 267{ 268 int i; 269 270 for (i = start; i < end; i++) { 271 uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode; 272 273 if (*cur_color != row[i].foreground) { 274 bprint_color("c", buf, page, row[i].foreground); 275 *cur_color = row[i].foreground; 276 } 277 if (*cur_back_color != row[i].background) { 278 bprint_color("3c", buf, page, row[i].background); 279 *cur_back_color = row[i].background; 280 } 281 282 if (out == 32) { 283 av_bprintf(buf, "\\h"); 284 } else if (out == '\\' || out == '{' || out == '}') { 285 av_bprintf(buf, "\\%c", (char)out); 286 } else { 287 char tmp; 288 /* convert to utf-8 */ 289 PUT_UTF8(out, tmp, av_bprint_chars(buf, tmp, 1);); 290 } 291 } 292} 293 294/* Draw a page as ass formatted text */ 295static int gen_sub_ass(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top) 296{ 297 int i; 298 int leading, trailing, len; 299 int last_trailing = -1, last_leading = -1; 300 int min_trailing = page->columns, min_leading = page->columns; 301 int alignment = 2; 302 int vertical_align = -1; 303 int can_align_left = 1, can_align_right = 1, can_align_center = 1; 304 int is_subtitle_page = ctx->subtitle_map[page->pgno & 0x7ff]; 305 int empty_lines = 0; 306 vbi_color cur_color = VBI_WHITE; 307 vbi_color cur_back_color = VBI_BLACK; 308 AVBPrint buf; 309 310 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED); 311 312 for (i = chop_top; i < page->rows; i++) { 313 vbi_char *row = page->text + i * page->columns; 314 315 get_trim_info(page, row, &leading, &trailing, &len); 316 317 if (len) { 318 if (last_leading != -1 && last_leading != leading || leading > 5) 319 can_align_left = 0; 320 if (last_trailing != -1 && last_trailing != trailing || trailing > 2) 321 can_align_right = 0; 322 if (last_trailing != -1 && (FFABS((trailing - leading) - (last_trailing - last_leading)) > 1) || trailing - leading > 4) 323 can_align_center = 0; 324 last_leading = leading; 325 last_trailing = trailing; 326 min_leading = FFMIN(leading, min_leading); 327 min_trailing = FFMIN(trailing, min_trailing); 328 } 329 } 330 331 if (!can_align_right && can_align_left && !can_align_center) { 332 ctx->last_ass_alignment = alignment = 1; 333 } else if (!can_align_right && !can_align_left && can_align_center) { 334 ctx->last_ass_alignment = alignment = 2; 335 } else if (can_align_right && !can_align_left && !can_align_center) { 336 ctx->last_ass_alignment = alignment = 3; 337 } else { 338 if (ctx->last_ass_alignment == 1 && can_align_left || 339 ctx->last_ass_alignment == 2 && can_align_center || 340 ctx->last_ass_alignment == 3 && can_align_right) 341 alignment = ctx->last_ass_alignment; 342 } 343 344 for (i = chop_top; i < page->rows; i++) { 345 int j; 346 vbi_char *row = page->text + i * page->columns; 347 int is_transparent_line; 348 349 for (j = 0; j < page->columns; j++) 350 if (row[j].opacity != VBI_TRANSPARENT_SPACE) 351 break; 352 is_transparent_line = (j == page->columns); 353 354 len = is_transparent_line ? 0 : page->columns; 355 leading = trailing = is_transparent_line ? page->columns : 0; 356 357 if (is_subtitle_page) { 358 if (!is_transparent_line) 359 get_trim_info(page, row, &leading, &trailing, &len); 360 361 if (vertical_align == -1 && len) { 362 vertical_align = (2 - (av_clip(i + 1, 0, 23) / 8)); 363 av_bprintf(&buf, "{\\an%d}", alignment + vertical_align * 3); 364 if (vertical_align != 2) 365 empty_lines = 0; 366 } 367 368 if (len && empty_lines > 1) 369 for (empty_lines /= 2; empty_lines > 0; empty_lines--) 370 av_bprintf(&buf, " \\N"); 371 372 if (alignment == 1 || alignment == 2 && !can_align_center) 373 leading = min_leading; 374 if (alignment == 3 || alignment == 2 && !can_align_center) 375 trailing = min_trailing; 376 } 377 378 if (len || !is_subtitle_page) { 379 decode_string(page, row, &buf, leading, page->columns - trailing, &cur_color, &cur_back_color); 380 av_bprintf(&buf, " \\N"); 381 empty_lines = 0; 382 } else { 383 empty_lines++; 384 } 385 } 386 387 if (vertical_align == 0) 388 for (empty_lines = (empty_lines - 1) / 2; empty_lines > 0; empty_lines--) 389 av_bprintf(&buf, " \\N"); 390 391 if (!av_bprint_is_complete(&buf)) { 392 av_bprint_finalize(&buf, NULL); 393 return AVERROR(ENOMEM); 394 } 395 396 if (buf.len) { 397 sub_rect->type = SUBTITLE_ASS; 398 sub_rect->ass = ff_ass_get_dialog(ctx->readorder++, 0, is_subtitle_page ? "Subtitle" : "Teletext", NULL, buf.str); 399 400 if (!sub_rect->ass) { 401 av_bprint_finalize(&buf, NULL); 402 return AVERROR(ENOMEM); 403 } 404 av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass); 405 } else { 406 sub_rect->type = SUBTITLE_NONE; 407 } 408 av_bprint_finalize(&buf, NULL); 409 return 0; 410} 411 412static void fix_transparency(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, 413 int chop_top, int resx, int resy) 414{ 415 int iy; 416 417 // Hack for transparency, inspired by VLC code... 418 for (iy = 0; iy < resy; iy++) { 419 uint8_t *pixel = sub_rect->data[0] + iy * sub_rect->linesize[0]; 420 vbi_char *vc = page->text + (iy / BITMAP_CHAR_HEIGHT + chop_top) * page->columns; 421 vbi_char *vcnext = vc + page->columns; 422 for (; vc < vcnext; vc++) { 423 uint8_t *pixelnext = pixel + BITMAP_CHAR_WIDTH; 424 switch (vc->opacity) { 425 case VBI_TRANSPARENT_SPACE: 426 memset(pixel, VBI_TRANSPARENT_BLACK, BITMAP_CHAR_WIDTH); 427 break; 428 case VBI_OPAQUE: 429 if (!ctx->transparent_bg) 430 break; 431 case VBI_SEMI_TRANSPARENT: 432 if (ctx->opacity > 0) { 433 if (ctx->opacity < 255) 434 for(; pixel < pixelnext; pixel++) 435 if (*pixel == vc->background) 436 *pixel += VBI_NB_COLORS; 437 break; 438 } 439 case VBI_TRANSPARENT_FULL: 440 for(; pixel < pixelnext; pixel++) 441 if (*pixel == vc->background) 442 *pixel = VBI_TRANSPARENT_BLACK; 443 break; 444 } 445 pixel = pixelnext; 446 } 447 } 448} 449 450/* Draw a page as bitmap */ 451static int gen_sub_bitmap(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top) 452{ 453 int resx = page->columns * BITMAP_CHAR_WIDTH; 454 int resy = (page->rows - chop_top) * BITMAP_CHAR_HEIGHT; 455 uint8_t ci; 456 vbi_char *vc = page->text + (chop_top * page->columns); 457 vbi_char *vcend = page->text + (page->rows * page->columns); 458 459 for (; vc < vcend; vc++) { 460 if (vc->opacity != VBI_TRANSPARENT_SPACE) 461 break; 462 } 463 464 if (vc >= vcend) { 465 av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno); 466 sub_rect->type = SUBTITLE_NONE; 467 return 0; 468 } 469 470 sub_rect->data[0] = av_mallocz(resx * resy); 471 sub_rect->linesize[0] = resx; 472 if (!sub_rect->data[0]) 473 return AVERROR(ENOMEM); 474 475 vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8, 476 sub_rect->data[0], sub_rect->linesize[0], 477 0, chop_top, page->columns, page->rows - chop_top, 478 /*reveal*/ 1, /*flash*/ 1); 479 480 fix_transparency(ctx, sub_rect, page, chop_top, resx, resy); 481 sub_rect->x = ctx->x_offset; 482 sub_rect->y = ctx->y_offset + chop_top * BITMAP_CHAR_HEIGHT; 483 sub_rect->w = resx; 484 sub_rect->h = resy; 485 sub_rect->nb_colors = ctx->opacity > 0 && ctx->opacity < 255 ? 2 * VBI_NB_COLORS : VBI_NB_COLORS; 486 sub_rect->data[1] = av_mallocz(AVPALETTE_SIZE); 487 if (!sub_rect->data[1]) { 488 av_freep(&sub_rect->data[0]); 489 return AVERROR(ENOMEM); 490 } 491 for (ci = 0; ci < VBI_NB_COLORS; ci++) { 492 int r, g, b, a; 493 494 r = VBI_R(page->color_map[ci]); 495 g = VBI_G(page->color_map[ci]); 496 b = VBI_B(page->color_map[ci]); 497 a = VBI_A(page->color_map[ci]); 498 ((uint32_t *)sub_rect->data[1])[ci] = RGBA(r, g, b, a); 499 ((uint32_t *)sub_rect->data[1])[ci + VBI_NB_COLORS] = RGBA(r, g, b, ctx->opacity); 500 ff_dlog(ctx, "palette %0x\n", ((uint32_t *)sub_rect->data[1])[ci]); 501 } 502 ((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK] = RGBA(0, 0, 0, 0); 503 ((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK + VBI_NB_COLORS] = RGBA(0, 0, 0, 0); 504 sub_rect->type = SUBTITLE_BITMAP; 505 return 0; 506} 507 508static void handler(vbi_event *ev, void *user_data) 509{ 510 TeletextContext *ctx = user_data; 511 TeletextPage *new_pages; 512 vbi_page page; 513 int res; 514 char pgno_str[12]; 515 int chop_top; 516 int is_subtitle_page = ctx->subtitle_map[ev->ev.ttx_page.pgno & 0x7ff]; 517 518 snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno); 519 av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n", 520 pgno_str, ev->ev.ttx_page.subno & 0xFF); 521 522 if (strcmp(ctx->pgno, "*") && (strcmp(ctx->pgno, "subtitle") || !is_subtitle_page) && !strstr(ctx->pgno, pgno_str)) 523 return; 524 if (ctx->handler_ret < 0) 525 return; 526 527 res = vbi_fetch_vt_page(ctx->vbi, &page, 528 ev->ev.ttx_page.pgno, 529 ev->ev.ttx_page.subno, 530 VBI_WST_LEVEL_3p5, 25, TRUE); 531 532 if (!res) 533 return; 534 535 chop_top = ctx->chop_top || ((page.rows > 1) && is_subtitle_page); 536 537 av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n", 538 page.columns, page.rows, chop_top); 539 540 if (ctx->nb_pages < MAX_BUFFERED_PAGES) { 541 if ((new_pages = av_realloc_array(ctx->pages, ctx->nb_pages + 1, sizeof(TeletextPage)))) { 542 TeletextPage *cur_page = new_pages + ctx->nb_pages; 543 ctx->pages = new_pages; 544 cur_page->sub_rect = av_mallocz(sizeof(*cur_page->sub_rect)); 545 cur_page->pts = ctx->pts; 546 cur_page->pgno = ev->ev.ttx_page.pgno; 547 cur_page->subno = ev->ev.ttx_page.subno; 548 if (cur_page->sub_rect) { 549 switch (ctx->format_id) { 550 case 0: 551 res = gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top); 552 break; 553 case 1: 554 res = gen_sub_text(ctx, cur_page->sub_rect, &page, chop_top); 555 break; 556 case 2: 557 res = gen_sub_ass(ctx, cur_page->sub_rect, &page, chop_top); 558 break; 559 default: 560 res = AVERROR_BUG; 561 break; 562 } 563 if (res < 0) { 564 av_freep(&cur_page->sub_rect); 565 ctx->handler_ret = res; 566 } else { 567 ctx->pages[ctx->nb_pages++] = *cur_page; 568 } 569 } else { 570 ctx->handler_ret = AVERROR(ENOMEM); 571 } 572 } else { 573 ctx->handler_ret = AVERROR(ENOMEM); 574 } 575 } else { 576 //TODO: If multiple packets contain more than one page, pages may got queued up, and this may happen... 577 av_log(ctx, AV_LOG_ERROR, "Buffered too many pages, dropping page %s.\n", pgno_str); 578 ctx->handler_ret = AVERROR(ENOSYS); 579 } 580 581 vbi_unref_page(&page); 582} 583 584static int slice_to_vbi_lines(TeletextContext *ctx, const uint8_t *buf, int size) 585{ 586 int lines = 0; 587 while (size >= 2 && lines < MAX_SLICES) { 588 int data_unit_id = buf[0]; 589 int data_unit_length = buf[1]; 590 if (data_unit_length + 2 > size) 591 return AVERROR_INVALIDDATA; 592 if (ff_data_unit_id_is_teletext(data_unit_id)) { 593 if (data_unit_length != 0x2c) 594 return AVERROR_INVALIDDATA; 595 else { 596 int line_offset = buf[2] & 0x1f; 597 int field_parity = buf[2] & 0x20; 598 uint8_t *p = ctx->sliced[lines].data; 599 int i, pmag; 600 ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B; 601 ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0); 602 for (i = 0; i < 42; i++) 603 p[i] = vbi_rev8(buf[4 + i]); 604 /* Unfortunately libzvbi does not expose page flags, and 605 * vbi_classify_page only checks MIP, so we have to manually 606 * decode the page flags and store the results. */ 607 pmag = vbi_unham16p(p); 608 if (pmag >= 0 && pmag >> 3 == 0) { // We found a row 0 header 609 int page = vbi_unham16p(p + 2); 610 int flags1 = vbi_unham16p(p + 6); 611 int flags2 = vbi_unham16p(p + 8); 612 if (page >= 0 && flags1 >= 0 && flags2 >= 0) { 613 int pgno = ((pmag & 7) << 8) + page; 614 // Check for disabled NEWSFLASH flag and enabled SUBTITLE and SUPRESS_HEADER flags 615 ctx->subtitle_map[pgno] = (!(flags1 & 0x40) && flags1 & 0x80 && flags2 & 0x01); 616 // Propagate ERASE_PAGE flag for repeated page headers to work around a libzvbi bug 617 if (ctx->subtitle_map[pgno] && pgno == ctx->last_pgno) { 618 int last_byte9 = vbi_unham8(ctx->last_p5); 619 if (last_byte9 >= 0 && last_byte9 & 0x8) { 620 int byte9 = vbi_unham8(p[5]); 621 if (byte9 >= 0) 622 p[5] = vbi_ham8(byte9 | 0x8); 623 } 624 } 625 ctx->last_pgno = pgno; 626 ctx->last_p5 = p[5]; 627 } 628 } 629 lines++; 630 } 631 } 632 size -= data_unit_length + 2; 633 buf += data_unit_length + 2; 634 } 635 if (size) 636 av_log(ctx, AV_LOG_WARNING, "%d bytes remained after slicing data\n", size); 637 return lines; 638} 639 640static int teletext_decode_frame(AVCodecContext *avctx, AVSubtitle *sub, 641 int *got_sub_ptr, const AVPacket *pkt) 642{ 643 TeletextContext *ctx = avctx->priv_data; 644 int ret = 0; 645 646 if (!ctx->vbi) { 647 if (!(ctx->vbi = vbi_decoder_new())) 648 return AVERROR(ENOMEM); 649 if (ctx->default_region != -1) { 650 av_log(avctx, AV_LOG_INFO, "Setting default zvbi region to %i\n", ctx->default_region); 651 vbi_teletext_set_default_region(ctx->vbi, ctx->default_region); 652 } 653 if (!vbi_event_handler_register(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) { 654 vbi_decoder_delete(ctx->vbi); 655 ctx->vbi = NULL; 656 return AVERROR(ENOMEM); 657 } 658 } 659 660 if (avctx->pkt_timebase.num && pkt->pts != AV_NOPTS_VALUE) 661 ctx->pts = av_rescale_q(pkt->pts, avctx->pkt_timebase, AV_TIME_BASE_Q); 662 663 if (pkt->size) { 664 int lines; 665 const int full_pes_size = pkt->size + 45; /* PES header is 45 bytes */ 666 667 // We allow unreasonably big packets, even if the standard only allows a max size of 1472 668 if (full_pes_size < 184 || full_pes_size > 65504 || full_pes_size % 184 != 0) 669 return AVERROR_INVALIDDATA; 670 671 ctx->handler_ret = pkt->size; 672 673 if (ff_data_identifier_is_teletext(*pkt->data)) { 674 if ((lines = slice_to_vbi_lines(ctx, pkt->data + 1, pkt->size - 1)) < 0) 675 return lines; 676 ff_dlog(avctx, "ctx=%p buf_size=%d lines=%u pkt_pts=%7.3f\n", 677 ctx, pkt->size, lines, (double)pkt->pts/90000.0); 678 if (lines > 0) { 679 vbi_decode(ctx->vbi, ctx->sliced, lines, 0.0); 680 ctx->lines_processed += lines; 681 } 682 } 683 ctx->pts = AV_NOPTS_VALUE; 684 ret = ctx->handler_ret; 685 } 686 687 if (ret < 0) 688 return ret; 689 690 // is there a subtitle to pass? 691 if (ctx->nb_pages) { 692 int i; 693 sub->format = !!ctx->format_id; 694 sub->start_display_time = 0; 695 sub->end_display_time = ctx->sub_duration; 696 sub->num_rects = 0; 697 sub->pts = ctx->pages->pts; 698 699 if (ctx->pages->sub_rect->type != SUBTITLE_NONE) { 700 sub->rects = av_malloc(sizeof(*sub->rects)); 701 if (sub->rects) { 702 sub->num_rects = 1; 703 sub->rects[0] = ctx->pages->sub_rect; 704 } else { 705 ret = AVERROR(ENOMEM); 706 } 707 } else { 708 av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n"); 709 sub->rects = NULL; 710 } 711 if (!sub->rects) // no rect was passed 712 subtitle_rect_free(&ctx->pages->sub_rect); 713 714 for (i = 0; i < ctx->nb_pages - 1; i++) 715 ctx->pages[i] = ctx->pages[i + 1]; 716 ctx->nb_pages--; 717 718 if (ret >= 0) 719 *got_sub_ptr = 1; 720 } else 721 *got_sub_ptr = 0; 722 723 return ret; 724} 725 726static int teletext_init_decoder(AVCodecContext *avctx) 727{ 728 TeletextContext *ctx = avctx->priv_data; 729 unsigned int maj, min, rev; 730 731 vbi_version(&maj, &min, &rev); 732 if (!(maj > 0 || min > 2 || min == 2 && rev >= 26)) { 733 av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n"); 734 return AVERROR_EXTERNAL; 735 } 736 737 if (ctx->format_id == 0) { 738 avctx->width = 41 * BITMAP_CHAR_WIDTH; 739 avctx->height = 25 * BITMAP_CHAR_HEIGHT; 740 } 741 742 ctx->vbi = NULL; 743 ctx->pts = AV_NOPTS_VALUE; 744 ctx->last_pgno = -1; 745 ctx->last_ass_alignment = 2; 746 747 if (ctx->opacity == -1) 748 ctx->opacity = ctx->transparent_bg ? 0 : 255; 749 750 av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno); 751 752 switch (ctx->format_id) { 753 case 0: 754 return 0; 755 case 1: 756 return ff_ass_subtitle_header_default(avctx); 757 case 2: 758 return my_ass_subtitle_header(avctx); 759 } 760 return AVERROR_BUG; 761} 762 763static int teletext_close_decoder(AVCodecContext *avctx) 764{ 765 TeletextContext *ctx = avctx->priv_data; 766 767 ff_dlog(avctx, "lines_total=%u\n", ctx->lines_processed); 768 while (ctx->nb_pages) 769 subtitle_rect_free(&ctx->pages[--ctx->nb_pages].sub_rect); 770 av_freep(&ctx->pages); 771 772 vbi_decoder_delete(ctx->vbi); 773 ctx->vbi = NULL; 774 ctx->pts = AV_NOPTS_VALUE; 775 ctx->last_pgno = -1; 776 ctx->last_ass_alignment = 2; 777 memset(ctx->subtitle_map, 0, sizeof(ctx->subtitle_map)); 778 if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP)) 779 ctx->readorder = 0; 780 return 0; 781} 782 783static void teletext_flush(AVCodecContext *avctx) 784{ 785 teletext_close_decoder(avctx); 786} 787 788#define OFFSET(x) offsetof(TeletextContext, x) 789#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM 790static const AVOption options[] = { 791 {"txt_page", "page numbers to decode, subtitle for subtitles, * for all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD}, 792 {"txt_default_region", "default G0 character set used for decoding", OFFSET(default_region), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 87, SD}, 793 {"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD}, 794 {"txt_format", "format of the subtitles (bitmap or text or ass)", OFFSET(format_id), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 2, SD, "txt_format"}, 795 {"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"}, 796 {"text", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, SD, "txt_format"}, 797 {"ass", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 0, SD, "txt_format"}, 798 {"txt_left", "x offset of generated bitmaps", OFFSET(x_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD}, 799 {"txt_top", "y offset of generated bitmaps", OFFSET(y_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD}, 800 {"txt_chop_spaces", "chops leading and trailing spaces from text", OFFSET(chop_spaces), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD}, 801 {"txt_duration", "display duration of teletext pages in msecs", OFFSET(sub_duration), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 86400000, SD}, 802 {"txt_transparent", "force transparent background of the teletext", OFFSET(transparent_bg), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD}, 803 {"txt_opacity", "set opacity of the transparent background", OFFSET(opacity), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 255, SD}, 804 { NULL }, 805}; 806 807static const AVClass teletext_class = { 808 .class_name = "libzvbi_teletextdec", 809 .item_name = av_default_item_name, 810 .option = options, 811 .version = LIBAVUTIL_VERSION_INT, 812}; 813 814const FFCodec ff_libzvbi_teletext_decoder = { 815 .p.name = "libzvbi_teletextdec", 816 .p.long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"), 817 .p.type = AVMEDIA_TYPE_SUBTITLE, 818 .p.id = AV_CODEC_ID_DVB_TELETEXT, 819 .p.capabilities = AV_CODEC_CAP_DELAY, 820 .p.priv_class = &teletext_class, 821 .p.wrapper_name = "libzvbi", 822 .priv_data_size = sizeof(TeletextContext), 823 .init = teletext_init_decoder, 824 .close = teletext_close_decoder, 825 FF_CODEC_DECODE_SUB_CB(teletext_decode_frame), 826 .flush = teletext_flush, 827}; 828