2 * Teletext decoding for ffmpeg
3 * Copyright (c) 2005-2010, 2012 Wolfram Gloger
4 * Copyright (c) 2013 Marton Balint
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.
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.
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
22 #include "libavcodec/ass.h"
23 #include "libavcodec/dvbtxt.h"
24 #include "libavutil/opt.h"
25 #include "libavutil/bprint.h"
26 #include "libavutil/internal.h"
27 #include "libavutil/intreadwrite.h"
28 #include "libavutil/log.h"
29 #include "libavutil/common.h"
33 #define TEXT_MAXSZ (25 * (56 + 1) * 4 + 2)
34 #define VBI_NB_COLORS 40
35 #define VBI_TRANSPARENT_BLACK 8
36 #define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
37 #define VBI_R(rgba) (((rgba) >> 0) & 0xFF)
38 #define VBI_G(rgba) (((rgba) >> 8) & 0xFF)
39 #define VBI_B(rgba) (((rgba) >> 16) & 0xFF)
40 #define VBI_A(rgba) (((rgba) >> 24) & 0xFF)
41 #define MAX_BUFFERED_PAGES 25
42 #define BITMAP_CHAR_WIDTH 12
43 #define BITMAP_CHAR_HEIGHT 10
46 typedef struct TeletextPage
48 AVSubtitleRect *sub_rect;
54 typedef struct TeletextContext
60 int format_id; /* 0 = bitmap, 1 = text/ass, 2 = ass */
62 int sub_duration; /* in msec */
74 vbi_sliced sliced[MAX_SLICES];
77 uint8_t subtitle_map[2048];
80 int last_ass_alignment;
83 static int my_ass_subtitle_header(AVCodecContext *avctx)
85 int ret = ff_ass_subtitle_header_default(avctx);
92 event_pos = strstr(avctx->subtitle_header, "\r\n[Events]\r\n");
96 new_header = av_asprintf("%.*s%s%s",
97 (int)(event_pos - avctx->subtitle_header), avctx->subtitle_header,
99 "Teletext," /* Name */
100 "Monospace,11," /* Font{name,size} */
101 "&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */
102 "0,0,0,0," /* Bold, Italic, Underline, StrikeOut */
103 "160,100," /* Scale{X,Y} */
104 "0,0," /* Spacing, Angle */
105 "3,0.1,0," /* BorderStyle, Outline, Shadow */
106 "5,1,1,1," /* Alignment, Margin[LRV] */
107 "0\r\n" /* Encoding */
109 "Subtitle," /* Name */
110 "Monospace,16," /* Font{name,size} */
111 "&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */
112 "0,0,0,0," /* Bold, Italic, Underline, StrikeOut */
113 "100,100," /* Scale{X,Y} */
114 "0,0," /* Spacing, Angle */
115 "1,1,1," /* BorderStyle, Outline, Shadow */
116 "8,48,48,20," /* Alignment, Margin[LRV] */
117 "0\r\n" /* Encoding */
121 return AVERROR(ENOMEM);
123 av_free(avctx->subtitle_header);
124 avctx->subtitle_header = new_header;
125 avctx->subtitle_header_size = strlen(new_header);
129 static int chop_spaces_utf8(const unsigned char* t, int len)
133 if (*--t != ' ' || (len-1 > 0 && *(t-1) & 0x80))
140 static void subtitle_rect_free(AVSubtitleRect **sub_rect)
142 av_freep(&(*sub_rect)->data[0]);
143 av_freep(&(*sub_rect)->data[1]);
144 av_freep(&(*sub_rect)->ass);
148 static char *create_ass_text(TeletextContext *ctx, const char *text)
153 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
154 ff_ass_bprint_text_event(&buf, text, strlen(text), "", 0);
155 if (!av_bprint_is_complete(&buf)) {
156 av_bprint_finalize(&buf, NULL);
159 dialog = ff_ass_get_dialog(ctx->readorder++, 0, NULL, NULL, buf.str);
160 av_bprint_finalize(&buf, NULL);
164 /* Draw a page as text */
165 static int gen_sub_text(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
169 char *vbi_text = av_malloc(TEXT_MAXSZ);
173 return AVERROR(ENOMEM);
175 sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8",
176 /*table mode*/ TRUE, FALSE,
178 page->columns, page->rows-chop_top);
180 av_log(ctx, AV_LOG_ERROR, "vbi_print error\n");
182 return AVERROR_EXTERNAL;
186 av_bprint_init(&buf, 0, TEXT_MAXSZ);
188 if (ctx->chop_spaces) {
192 // skip leading spaces and newlines
193 in += strspn(in, " \n");
194 // compute end of row
195 for (nl = 0; in[nl]; ++nl)
196 if (in[nl] == '\n' && (nl==0 || !(in[nl-1] & 0x80)))
200 // skip trailing spaces
201 sz = chop_spaces_utf8(in, nl);
202 av_bprint_append_data(&buf, in, sz);
203 av_bprintf(&buf, "\n");
207 av_bprintf(&buf, "%s\n", vbi_text);
211 if (!av_bprint_is_complete(&buf)) {
212 av_bprint_finalize(&buf, NULL);
213 return AVERROR(ENOMEM);
217 sub_rect->type = SUBTITLE_ASS;
218 sub_rect->ass = create_ass_text(ctx, buf.str);
220 if (!sub_rect->ass) {
221 av_bprint_finalize(&buf, NULL);
222 return AVERROR(ENOMEM);
224 av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
226 sub_rect->type = SUBTITLE_NONE;
228 av_bprint_finalize(&buf, NULL);
232 static void bprint_color(const char *type, AVBPrint *buf, vbi_page *page, unsigned ci)
234 int r = VBI_R(page->color_map[ci]);
235 int g = VBI_G(page->color_map[ci]);
236 int b = VBI_B(page->color_map[ci]);
237 av_bprintf(buf, "{\\%s&H%02X%02X%02X&}", type, b, g, r);
240 #define IS_TXT_SPACE(ch) ((ch).unicode < 0x0020 || (ch).unicode >= 0xe000 || (ch).unicode == 0x00a0 ||\
241 (ch).size > VBI_DOUBLE_SIZE || (ch).opacity == VBI_TRANSPARENT_SPACE)
243 static void get_trim_info(vbi_page *page, vbi_char *row, int *leading, int *trailing, int *olen)
250 for (i = 0; i < page->columns; i++) {
251 uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode;
253 if (out == 32 && !char_seen)
256 char_seen = 1, len = i - (*leading) + 1;
260 *trailing = len > 0 ? page->columns - *leading - len : page->columns;
263 static void decode_string(vbi_page *page, vbi_char *row, AVBPrint *buf,
264 int start, int end, vbi_color *cur_color, vbi_color *cur_back_color)
268 for (i = start; i < end; i++) {
269 uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode;
271 if (*cur_color != row[i].foreground) {
272 bprint_color("c", buf, page, row[i].foreground);
273 *cur_color = row[i].foreground;
275 if (*cur_back_color != row[i].background) {
276 bprint_color("3c", buf, page, row[i].background);
277 *cur_back_color = row[i].background;
281 av_bprintf(buf, "\\h");
282 } else if (out == '\\' || out == '{' || out == '}') {
283 av_bprintf(buf, "\\%c", (char)out);
286 /* convert to utf-8 */
287 PUT_UTF8(out, tmp, av_bprint_chars(buf, tmp, 1););
292 /* Draw a page as ass formatted text */
293 static int gen_sub_ass(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
296 int leading, trailing, len;
297 int last_trailing = -1, last_leading = -1;
298 int min_trailing = page->columns, min_leading = page->columns;
300 int vertical_align = -1;
301 int can_align_left = 1, can_align_right = 1, can_align_center = 1;
302 int is_subtitle_page = ctx->subtitle_map[page->pgno & 0x7ff];
304 vbi_color cur_color = VBI_WHITE;
305 vbi_color cur_back_color = VBI_BLACK;
308 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
310 for (i = chop_top; i < page->rows; i++) {
311 vbi_char *row = page->text + i * page->columns;
313 get_trim_info(page, row, &leading, &trailing, &len);
316 if (last_leading != -1 && last_leading != leading || leading > 5)
318 if (last_trailing != -1 && last_trailing != trailing || trailing > 2)
320 if (last_trailing != -1 && (FFABS((trailing - leading) - (last_trailing - last_leading)) > 1) || trailing - leading > 4)
321 can_align_center = 0;
322 last_leading = leading;
323 last_trailing = trailing;
324 min_leading = FFMIN(leading, min_leading);
325 min_trailing = FFMIN(trailing, min_trailing);
329 if (!can_align_right && can_align_left && !can_align_center) {
330 ctx->last_ass_alignment = alignment = 1;
331 } else if (!can_align_right && !can_align_left && can_align_center) {
332 ctx->last_ass_alignment = alignment = 2;
333 } else if (can_align_right && !can_align_left && !can_align_center) {
334 ctx->last_ass_alignment = alignment = 3;
336 if (ctx->last_ass_alignment == 1 && can_align_left ||
337 ctx->last_ass_alignment == 2 && can_align_center ||
338 ctx->last_ass_alignment == 3 && can_align_right)
339 alignment = ctx->last_ass_alignment;
342 for (i = chop_top; i < page->rows; i++) {
344 vbi_char *row = page->text + i * page->columns;
345 int is_transparent_line;
347 for (j = 0; j < page->columns; j++)
348 if (row[j].opacity != VBI_TRANSPARENT_SPACE)
350 is_transparent_line = (j == page->columns);
352 len = is_transparent_line ? 0 : page->columns;
353 leading = trailing = is_transparent_line ? page->columns : 0;
355 if (is_subtitle_page) {
356 if (!is_transparent_line)
357 get_trim_info(page, row, &leading, &trailing, &len);
359 if (vertical_align == -1 && len) {
360 vertical_align = (2 - (av_clip(i + 1, 0, 23) / 8));
361 av_bprintf(&buf, "{\\an%d}", alignment + vertical_align * 3);
362 if (vertical_align != 2)
366 if (len && empty_lines > 1)
367 for (empty_lines /= 2; empty_lines > 0; empty_lines--)
368 av_bprintf(&buf, " \\N");
370 if (alignment == 1 || alignment == 2 && !can_align_center)
371 leading = min_leading;
372 if (alignment == 3 || alignment == 2 && !can_align_center)
373 trailing = min_trailing;
376 if (len || !is_subtitle_page) {
377 decode_string(page, row, &buf, leading, page->columns - trailing, &cur_color, &cur_back_color);
378 av_bprintf(&buf, " \\N");
385 if (vertical_align == 0)
386 for (empty_lines = (empty_lines - 1) / 2; empty_lines > 0; empty_lines--)
387 av_bprintf(&buf, " \\N");
389 if (!av_bprint_is_complete(&buf)) {
390 av_bprint_finalize(&buf, NULL);
391 return AVERROR(ENOMEM);
395 sub_rect->type = SUBTITLE_ASS;
396 sub_rect->ass = ff_ass_get_dialog(ctx->readorder++, 0, is_subtitle_page ? "Subtitle" : "Teletext", NULL, buf.str);
398 if (!sub_rect->ass) {
399 av_bprint_finalize(&buf, NULL);
400 return AVERROR(ENOMEM);
402 av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
404 sub_rect->type = SUBTITLE_NONE;
406 av_bprint_finalize(&buf, NULL);
410 static void fix_transparency(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page,
411 int chop_top, int resx, int resy)
415 // Hack for transparency, inspired by VLC code...
416 for (iy = 0; iy < resy; iy++) {
417 uint8_t *pixel = sub_rect->data[0] + iy * sub_rect->linesize[0];
418 vbi_char *vc = page->text + (iy / BITMAP_CHAR_HEIGHT + chop_top) * page->columns;
419 vbi_char *vcnext = vc + page->columns;
420 for (; vc < vcnext; vc++) {
421 uint8_t *pixelnext = pixel + BITMAP_CHAR_WIDTH;
422 switch (vc->opacity) {
423 case VBI_TRANSPARENT_SPACE:
424 memset(pixel, VBI_TRANSPARENT_BLACK, BITMAP_CHAR_WIDTH);
427 if (!ctx->transparent_bg)
429 case VBI_SEMI_TRANSPARENT:
430 if (ctx->opacity > 0) {
431 if (ctx->opacity < 255)
432 for(; pixel < pixelnext; pixel++)
433 if (*pixel == vc->background)
434 *pixel += VBI_NB_COLORS;
437 case VBI_TRANSPARENT_FULL:
438 for(; pixel < pixelnext; pixel++)
439 if (*pixel == vc->background)
440 *pixel = VBI_TRANSPARENT_BLACK;
448 /* Draw a page as bitmap */
449 static int gen_sub_bitmap(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
451 int resx = page->columns * BITMAP_CHAR_WIDTH;
452 int resy = (page->rows - chop_top) * BITMAP_CHAR_HEIGHT;
454 vbi_char *vc = page->text + (chop_top * page->columns);
455 vbi_char *vcend = page->text + (page->rows * page->columns);
457 for (; vc < vcend; vc++) {
458 if (vc->opacity != VBI_TRANSPARENT_SPACE)
463 av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno);
464 sub_rect->type = SUBTITLE_NONE;
468 sub_rect->data[0] = av_mallocz(resx * resy);
469 sub_rect->linesize[0] = resx;
470 if (!sub_rect->data[0])
471 return AVERROR(ENOMEM);
473 vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8,
474 sub_rect->data[0], sub_rect->linesize[0],
475 0, chop_top, page->columns, page->rows - chop_top,
476 /*reveal*/ 1, /*flash*/ 1);
478 fix_transparency(ctx, sub_rect, page, chop_top, resx, resy);
479 sub_rect->x = ctx->x_offset;
480 sub_rect->y = ctx->y_offset + chop_top * BITMAP_CHAR_HEIGHT;
483 sub_rect->nb_colors = ctx->opacity > 0 && ctx->opacity < 255 ? 2 * VBI_NB_COLORS : VBI_NB_COLORS;
484 sub_rect->data[1] = av_mallocz(AVPALETTE_SIZE);
485 if (!sub_rect->data[1]) {
486 av_freep(&sub_rect->data[0]);
487 return AVERROR(ENOMEM);
489 for (ci = 0; ci < VBI_NB_COLORS; ci++) {
492 r = VBI_R(page->color_map[ci]);
493 g = VBI_G(page->color_map[ci]);
494 b = VBI_B(page->color_map[ci]);
495 a = VBI_A(page->color_map[ci]);
496 ((uint32_t *)sub_rect->data[1])[ci] = RGBA(r, g, b, a);
497 ((uint32_t *)sub_rect->data[1])[ci + VBI_NB_COLORS] = RGBA(r, g, b, ctx->opacity);
498 ff_dlog(ctx, "palette %0x\n", ((uint32_t *)sub_rect->data[1])[ci]);
500 ((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK] = RGBA(0, 0, 0, 0);
501 ((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK + VBI_NB_COLORS] = RGBA(0, 0, 0, 0);
502 sub_rect->type = SUBTITLE_BITMAP;
506 static void handler(vbi_event *ev, void *user_data)
508 TeletextContext *ctx = user_data;
509 TeletextPage *new_pages;
514 int is_subtitle_page = ctx->subtitle_map[ev->ev.ttx_page.pgno & 0x7ff];
516 snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
517 av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
518 pgno_str, ev->ev.ttx_page.subno & 0xFF);
520 if (strcmp(ctx->pgno, "*") && (strcmp(ctx->pgno, "subtitle") || !is_subtitle_page) && !strstr(ctx->pgno, pgno_str))
522 if (ctx->handler_ret < 0)
525 res = vbi_fetch_vt_page(ctx->vbi, &page,
526 ev->ev.ttx_page.pgno,
527 ev->ev.ttx_page.subno,
528 VBI_WST_LEVEL_3p5, 25, TRUE);
533 chop_top = ctx->chop_top || ((page.rows > 1) && is_subtitle_page);
535 av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
536 page.columns, page.rows, chop_top);
538 if (ctx->nb_pages < MAX_BUFFERED_PAGES) {
539 if ((new_pages = av_realloc_array(ctx->pages, ctx->nb_pages + 1, sizeof(TeletextPage)))) {
540 TeletextPage *cur_page = new_pages + ctx->nb_pages;
541 ctx->pages = new_pages;
542 cur_page->sub_rect = av_mallocz(sizeof(*cur_page->sub_rect));
543 cur_page->pts = ctx->pts;
544 cur_page->pgno = ev->ev.ttx_page.pgno;
545 cur_page->subno = ev->ev.ttx_page.subno;
546 if (cur_page->sub_rect) {
547 switch (ctx->format_id) {
549 res = gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top);
552 res = gen_sub_text(ctx, cur_page->sub_rect, &page, chop_top);
555 res = gen_sub_ass(ctx, cur_page->sub_rect, &page, chop_top);
562 av_freep(&cur_page->sub_rect);
563 ctx->handler_ret = res;
565 ctx->pages[ctx->nb_pages++] = *cur_page;
568 ctx->handler_ret = AVERROR(ENOMEM);
571 ctx->handler_ret = AVERROR(ENOMEM);
574 //TODO: If multiple packets contain more than one page, pages may got queued up, and this may happen...
575 av_log(ctx, AV_LOG_ERROR, "Buffered too many pages, dropping page %s.\n", pgno_str);
576 ctx->handler_ret = AVERROR(ENOSYS);
579 vbi_unref_page(&page);
582 static int slice_to_vbi_lines(TeletextContext *ctx, uint8_t* buf, int size)
585 while (size >= 2 && lines < MAX_SLICES) {
586 int data_unit_id = buf[0];
587 int data_unit_length = buf[1];
588 if (data_unit_length + 2 > size)
589 return AVERROR_INVALIDDATA;
590 if (ff_data_unit_id_is_teletext(data_unit_id)) {
591 if (data_unit_length != 0x2c)
592 return AVERROR_INVALIDDATA;
594 int line_offset = buf[2] & 0x1f;
595 int field_parity = buf[2] & 0x20;
596 uint8_t *p = ctx->sliced[lines].data;
598 ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B;
599 ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0);
600 for (i = 0; i < 42; i++)
601 p[i] = vbi_rev8(buf[4 + i]);
602 /* Unfortunately libzvbi does not expose page flags, and
603 * vbi_classify_page only checks MIP, so we have to manually
604 * decode the page flags and store the results. */
605 pmag = vbi_unham16p(p);
606 if (pmag >= 0 && pmag >> 3 == 0) { // We found a row 0 header
607 int page = vbi_unham16p(p + 2);
608 int flags1 = vbi_unham16p(p + 6);
609 int flags2 = vbi_unham16p(p + 8);
610 if (page >= 0 && flags1 >= 0 && flags2 >= 0) {
611 int pgno = ((pmag & 7) << 8) + page;
612 // Check for disabled NEWSFLASH flag and enabled SUBTITLE and SUPRESS_HEADER flags
613 ctx->subtitle_map[pgno] = (!(flags1 & 0x40) && flags1 & 0x80 && flags2 & 0x01);
614 // Propagate ERASE_PAGE flag for repeated page headers to work around a libzvbi bug
615 if (ctx->subtitle_map[pgno] && pgno == ctx->last_pgno) {
616 int last_byte9 = vbi_unham8(ctx->last_p5);
617 if (last_byte9 >= 0 && last_byte9 & 0x8) {
618 int byte9 = vbi_unham8(p[5]);
620 p[5] = vbi_ham8(byte9 | 0x8);
623 ctx->last_pgno = pgno;
630 size -= data_unit_length + 2;
631 buf += data_unit_length + 2;
634 av_log(ctx, AV_LOG_WARNING, "%d bytes remained after slicing data\n", size);
638 static int teletext_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *pkt)
640 TeletextContext *ctx = avctx->priv_data;
641 AVSubtitle *sub = data;
646 if (!(ctx->vbi = vbi_decoder_new()))
647 return AVERROR(ENOMEM);
648 if (!vbi_event_handler_register(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) {
649 vbi_decoder_delete(ctx->vbi);
651 return AVERROR(ENOMEM);
655 if (avctx->pkt_timebase.num && pkt->pts != AV_NOPTS_VALUE)
656 ctx->pts = av_rescale_q(pkt->pts, avctx->pkt_timebase, AV_TIME_BASE_Q);
660 const int full_pes_size = pkt->size + 45; /* PES header is 45 bytes */
662 // We allow unreasonably big packets, even if the standard only allows a max size of 1472
663 if (full_pes_size < 184 || full_pes_size > 65504 || full_pes_size % 184 != 0)
664 return AVERROR_INVALIDDATA;
666 ctx->handler_ret = pkt->size;
668 if (ff_data_identifier_is_teletext(*pkt->data)) {
669 if ((lines = slice_to_vbi_lines(ctx, pkt->data + 1, pkt->size - 1)) < 0)
671 ff_dlog(avctx, "ctx=%p buf_size=%d lines=%u pkt_pts=%7.3f\n",
672 ctx, pkt->size, lines, (double)pkt->pts/90000.0);
674 vbi_decode(ctx->vbi, ctx->sliced, lines, 0.0);
675 ctx->lines_processed += lines;
678 ctx->pts = AV_NOPTS_VALUE;
679 ret = ctx->handler_ret;
685 // is there a subtitle to pass?
688 sub->format = !!ctx->format_id;
689 sub->start_display_time = 0;
690 sub->end_display_time = ctx->sub_duration;
692 sub->pts = ctx->pages->pts;
694 if (ctx->pages->sub_rect->type != SUBTITLE_NONE) {
695 sub->rects = av_malloc(sizeof(*sub->rects));
698 sub->rects[0] = ctx->pages->sub_rect;
700 FF_DISABLE_DEPRECATION_WARNINGS
701 for (j = 0; j < 4; j++) {
702 sub->rects[0]->pict.data[j] = sub->rects[0]->data[j];
703 sub->rects[0]->pict.linesize[j] = sub->rects[0]->linesize[j];
705 FF_ENABLE_DEPRECATION_WARNINGS
708 ret = AVERROR(ENOMEM);
711 av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n");
714 if (!sub->rects) // no rect was passed
715 subtitle_rect_free(&ctx->pages->sub_rect);
717 for (i = 0; i < ctx->nb_pages - 1; i++)
718 ctx->pages[i] = ctx->pages[i + 1];
729 static int teletext_init_decoder(AVCodecContext *avctx)
731 TeletextContext *ctx = avctx->priv_data;
732 unsigned int maj, min, rev;
734 vbi_version(&maj, &min, &rev);
735 if (!(maj > 0 || min > 2 || min == 2 && rev >= 26)) {
736 av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n");
737 return AVERROR_EXTERNAL;
740 if (ctx->format_id == 0) {
741 avctx->width = 41 * BITMAP_CHAR_WIDTH;
742 avctx->height = 25 * BITMAP_CHAR_HEIGHT;
746 ctx->pts = AV_NOPTS_VALUE;
748 ctx->last_ass_alignment = 2;
750 if (ctx->opacity == -1)
751 ctx->opacity = ctx->transparent_bg ? 0 : 255;
753 av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno);
755 switch (ctx->format_id) {
759 return ff_ass_subtitle_header_default(avctx);
761 return my_ass_subtitle_header(avctx);
766 static int teletext_close_decoder(AVCodecContext *avctx)
768 TeletextContext *ctx = avctx->priv_data;
770 ff_dlog(avctx, "lines_total=%u\n", ctx->lines_processed);
771 while (ctx->nb_pages)
772 subtitle_rect_free(&ctx->pages[--ctx->nb_pages].sub_rect);
773 av_freep(&ctx->pages);
775 vbi_decoder_delete(ctx->vbi);
777 ctx->pts = AV_NOPTS_VALUE;
779 ctx->last_ass_alignment = 2;
780 memset(ctx->subtitle_map, 0, sizeof(ctx->subtitle_map));
781 if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
786 static void teletext_flush(AVCodecContext *avctx)
788 teletext_close_decoder(avctx);
791 #define OFFSET(x) offsetof(TeletextContext, x)
792 #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
793 static const AVOption options[] = {
794 {"txt_page", "page numbers to decode, subtitle for subtitles, * for all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
795 {"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
796 {"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"},
797 {"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"},
798 {"text", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, SD, "txt_format"},
799 {"ass", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 0, SD, "txt_format"},
800 {"txt_left", "x offset of generated bitmaps", OFFSET(x_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
801 {"txt_top", "y offset of generated bitmaps", OFFSET(y_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
802 {"txt_chop_spaces", "chops leading and trailing spaces from text", OFFSET(chop_spaces), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
803 {"txt_duration", "display duration of teletext pages in msecs", OFFSET(sub_duration), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 86400000, SD},
804 {"txt_transparent", "force transparent background of the teletext", OFFSET(transparent_bg), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
805 {"txt_opacity", "set opacity of the transparent background", OFFSET(opacity), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 255, SD},
809 static const AVClass teletext_class = {
810 .class_name = "libzvbi_teletextdec",
811 .item_name = av_default_item_name,
813 .version = LIBAVUTIL_VERSION_INT,
816 AVCodec ff_libzvbi_teletext_decoder = {
817 .name = "libzvbi_teletextdec",
818 .long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"),
819 .type = AVMEDIA_TYPE_SUBTITLE,
820 .id = AV_CODEC_ID_DVB_TELETEXT,
821 .priv_data_size = sizeof(TeletextContext),
822 .init = teletext_init_decoder,
823 .close = teletext_close_decoder,
824 .decode = teletext_decode_frame,
825 .capabilities = AV_CODEC_CAP_DELAY,
826 .flush = teletext_flush,
827 .priv_class= &teletext_class,
828 .wrapper_name = "libzvbi",