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 "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"
30
31 #include <libzvbi.h>
32
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
44 #define MAX_SLICES 64
45
46 typedef struct TeletextPage
47 {
48 AVSubtitleRect *sub_rect;
49 int pgno;
50 int subno;
51 int64_t pts;
52 } TeletextPage;
53
54 typedef struct TeletextContext
55 {
56 AVClass *class;
57 char *pgno;
58 int default_region;
59 int x_offset;
60 int y_offset;
61 int format_id; /* 0 = bitmap, 1 = text/ass, 2 = ass */
62 int chop_top;
63 int sub_duration; /* in msec */
64 int transparent_bg;
65 int opacity;
66 int chop_spaces;
67
68 int lines_processed;
69 TeletextPage *pages;
70 int nb_pages;
71 int64_t pts;
72 int handler_ret;
73
74 vbi_decoder * vbi;
75 vbi_sliced sliced[MAX_SLICES];
76
77 int readorder;
78 uint8_t subtitle_map[2048];
79 int last_pgno;
80 int last_p5;
81 int last_ass_alignment;
82 } TeletextContext;
83
my_ass_subtitle_header(AVCodecContext * avctx)84 static int my_ass_subtitle_header(AVCodecContext *avctx)
85 {
86 int ret = ff_ass_subtitle_header_default(avctx);
87 char *new_header;
88 uint8_t *event_pos;
89
90 if (ret < 0)
91 return ret;
92
93 event_pos = strstr(avctx->subtitle_header, "\r\n[Events]\r\n");
94 if (!event_pos)
95 return AVERROR_BUG;
96
97 new_header = av_asprintf("%.*s%s%s",
98 (int)(event_pos - avctx->subtitle_header), avctx->subtitle_header,
99 "Style: "
100 "Teletext," /* Name */
101 "Monospace,11," /* Font{name,size} */
102 "&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */
103 "0,0,0,0," /* Bold, Italic, Underline, StrikeOut */
104 "160,100," /* Scale{X,Y} */
105 "0,0," /* Spacing, Angle */
106 "3,0.1,0," /* BorderStyle, Outline, Shadow */
107 "5,1,1,1," /* Alignment, Margin[LRV] */
108 "0\r\n" /* Encoding */
109 "Style: "
110 "Subtitle," /* Name */
111 "Monospace,16," /* Font{name,size} */
112 "&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */
113 "0,0,0,0," /* Bold, Italic, Underline, StrikeOut */
114 "100,100," /* Scale{X,Y} */
115 "0,0," /* Spacing, Angle */
116 "1,1,1," /* BorderStyle, Outline, Shadow */
117 "8,48,48,20," /* Alignment, Margin[LRV] */
118 "0\r\n" /* Encoding */
119 , event_pos);
120
121 if (!new_header)
122 return AVERROR(ENOMEM);
123
124 av_free(avctx->subtitle_header);
125 avctx->subtitle_header = new_header;
126 avctx->subtitle_header_size = strlen(new_header);
127 return 0;
128 }
129
chop_spaces_utf8(const unsigned char * t,int len)130 static int chop_spaces_utf8(const unsigned char* t, int len)
131 {
132 t += len;
133 while (len > 0) {
134 if (*--t != ' ' || (len-1 > 0 && *(t-1) & 0x80))
135 break;
136 --len;
137 }
138 return len;
139 }
140
subtitle_rect_free(AVSubtitleRect ** sub_rect)141 static void subtitle_rect_free(AVSubtitleRect **sub_rect)
142 {
143 av_freep(&(*sub_rect)->data[0]);
144 av_freep(&(*sub_rect)->data[1]);
145 av_freep(&(*sub_rect)->ass);
146 av_freep(sub_rect);
147 }
148
create_ass_text(TeletextContext * ctx,const char * text)149 static char *create_ass_text(TeletextContext *ctx, const char *text)
150 {
151 char *dialog;
152 AVBPrint buf;
153
154 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
155 ff_ass_bprint_text_event(&buf, text, strlen(text), "", 0);
156 if (!av_bprint_is_complete(&buf)) {
157 av_bprint_finalize(&buf, NULL);
158 return NULL;
159 }
160 dialog = ff_ass_get_dialog(ctx->readorder++, 0, NULL, NULL, buf.str);
161 av_bprint_finalize(&buf, NULL);
162 return dialog;
163 }
164
165 /* Draw a page as text */
gen_sub_text(TeletextContext * ctx,AVSubtitleRect * sub_rect,vbi_page * page,int chop_top)166 static int gen_sub_text(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
167 {
168 const char *in;
169 AVBPrint buf;
170 char *vbi_text = av_malloc(TEXT_MAXSZ);
171 int sz;
172
173 if (!vbi_text)
174 return AVERROR(ENOMEM);
175
176 sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8",
177 /*table mode*/ TRUE, FALSE,
178 0, chop_top,
179 page->columns, page->rows-chop_top);
180 if (sz <= 0) {
181 av_log(ctx, AV_LOG_ERROR, "vbi_print error\n");
182 av_free(vbi_text);
183 return AVERROR_EXTERNAL;
184 }
185 vbi_text[sz] = '\0';
186 in = vbi_text;
187 av_bprint_init(&buf, 0, TEXT_MAXSZ);
188
189 if (ctx->chop_spaces) {
190 for (;;) {
191 int nl, sz;
192
193 // skip leading spaces and newlines
194 in += strspn(in, " \n");
195 // compute end of row
196 for (nl = 0; in[nl]; ++nl)
197 if (in[nl] == '\n' && (nl==0 || !(in[nl-1] & 0x80)))
198 break;
199 if (!in[nl])
200 break;
201 // skip trailing spaces
202 sz = chop_spaces_utf8(in, nl);
203 av_bprint_append_data(&buf, in, sz);
204 av_bprintf(&buf, "\n");
205 in += nl;
206 }
207 } else {
208 av_bprintf(&buf, "%s\n", vbi_text);
209 }
210 av_free(vbi_text);
211
212 if (!av_bprint_is_complete(&buf)) {
213 av_bprint_finalize(&buf, NULL);
214 return AVERROR(ENOMEM);
215 }
216
217 if (buf.len) {
218 sub_rect->type = SUBTITLE_ASS;
219 sub_rect->ass = create_ass_text(ctx, buf.str);
220
221 if (!sub_rect->ass) {
222 av_bprint_finalize(&buf, NULL);
223 return AVERROR(ENOMEM);
224 }
225 av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
226 } else {
227 sub_rect->type = SUBTITLE_NONE;
228 }
229 av_bprint_finalize(&buf, NULL);
230 return 0;
231 }
232
bprint_color(const char * type,AVBPrint * buf,vbi_page * page,unsigned ci)233 static void bprint_color(const char *type, AVBPrint *buf, vbi_page *page, unsigned ci)
234 {
235 int r = VBI_R(page->color_map[ci]);
236 int g = VBI_G(page->color_map[ci]);
237 int b = VBI_B(page->color_map[ci]);
238 av_bprintf(buf, "{\\%s&H%02X%02X%02X&}", type, b, g, r);
239 }
240
241 #define IS_TXT_SPACE(ch) ((ch).unicode < 0x0020 || (ch).unicode >= 0xe000 || (ch).unicode == 0x00a0 ||\
242 (ch).size > VBI_DOUBLE_SIZE || (ch).opacity == VBI_TRANSPARENT_SPACE)
243
get_trim_info(vbi_page * page,vbi_char * row,int * leading,int * trailing,int * olen)244 static void get_trim_info(vbi_page *page, vbi_char *row, int *leading, int *trailing, int *olen)
245 {
246 int i, len = 0;
247 int char_seen = 0;
248
249 *leading = 0;
250
251 for (i = 0; i < page->columns; i++) {
252 uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode;
253
254 if (out == 32 && !char_seen)
255 (*leading)++;
256 else if (out != 32)
257 char_seen = 1, len = i - (*leading) + 1;
258 }
259
260 *olen = len;
261 *trailing = len > 0 ? page->columns - *leading - len : page->columns;
262 }
263
decode_string(vbi_page * page,vbi_char * row,AVBPrint * buf,int start,int end,vbi_color * cur_color,vbi_color * cur_back_color)264 static void decode_string(vbi_page *page, vbi_char *row, AVBPrint *buf,
265 int start, int end, vbi_color *cur_color, vbi_color *cur_back_color)
266 {
267 int i;
268
269 for (i = start; i < end; i++) {
270 uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode;
271
272 if (*cur_color != row[i].foreground) {
273 bprint_color("c", buf, page, row[i].foreground);
274 *cur_color = row[i].foreground;
275 }
276 if (*cur_back_color != row[i].background) {
277 bprint_color("3c", buf, page, row[i].background);
278 *cur_back_color = row[i].background;
279 }
280
281 if (out == 32) {
282 av_bprintf(buf, "\\h");
283 } else if (out == '\\' || out == '{' || out == '}') {
284 av_bprintf(buf, "\\%c", (char)out);
285 } else {
286 char tmp;
287 /* convert to utf-8 */
288 PUT_UTF8(out, tmp, av_bprint_chars(buf, tmp, 1););
289 }
290 }
291 }
292
293 /* Draw a page as ass formatted text */
gen_sub_ass(TeletextContext * ctx,AVSubtitleRect * sub_rect,vbi_page * page,int chop_top)294 static int gen_sub_ass(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
295 {
296 int i;
297 int leading, trailing, len;
298 int last_trailing = -1, last_leading = -1;
299 int min_trailing = page->columns, min_leading = page->columns;
300 int alignment = 2;
301 int vertical_align = -1;
302 int can_align_left = 1, can_align_right = 1, can_align_center = 1;
303 int is_subtitle_page = ctx->subtitle_map[page->pgno & 0x7ff];
304 int empty_lines = 0;
305 vbi_color cur_color = VBI_WHITE;
306 vbi_color cur_back_color = VBI_BLACK;
307 AVBPrint buf;
308
309 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
310
311 for (i = chop_top; i < page->rows; i++) {
312 vbi_char *row = page->text + i * page->columns;
313
314 get_trim_info(page, row, &leading, &trailing, &len);
315
316 if (len) {
317 if (last_leading != -1 && last_leading != leading || leading > 5)
318 can_align_left = 0;
319 if (last_trailing != -1 && last_trailing != trailing || trailing > 2)
320 can_align_right = 0;
321 if (last_trailing != -1 && (FFABS((trailing - leading) - (last_trailing - last_leading)) > 1) || trailing - leading > 4)
322 can_align_center = 0;
323 last_leading = leading;
324 last_trailing = trailing;
325 min_leading = FFMIN(leading, min_leading);
326 min_trailing = FFMIN(trailing, min_trailing);
327 }
328 }
329
330 if (!can_align_right && can_align_left && !can_align_center) {
331 ctx->last_ass_alignment = alignment = 1;
332 } else if (!can_align_right && !can_align_left && can_align_center) {
333 ctx->last_ass_alignment = alignment = 2;
334 } else if (can_align_right && !can_align_left && !can_align_center) {
335 ctx->last_ass_alignment = alignment = 3;
336 } else {
337 if (ctx->last_ass_alignment == 1 && can_align_left ||
338 ctx->last_ass_alignment == 2 && can_align_center ||
339 ctx->last_ass_alignment == 3 && can_align_right)
340 alignment = ctx->last_ass_alignment;
341 }
342
343 for (i = chop_top; i < page->rows; i++) {
344 int j;
345 vbi_char *row = page->text + i * page->columns;
346 int is_transparent_line;
347
348 for (j = 0; j < page->columns; j++)
349 if (row[j].opacity != VBI_TRANSPARENT_SPACE)
350 break;
351 is_transparent_line = (j == page->columns);
352
353 len = is_transparent_line ? 0 : page->columns;
354 leading = trailing = is_transparent_line ? page->columns : 0;
355
356 if (is_subtitle_page) {
357 if (!is_transparent_line)
358 get_trim_info(page, row, &leading, &trailing, &len);
359
360 if (vertical_align == -1 && len) {
361 vertical_align = (2 - (av_clip(i + 1, 0, 23) / 8));
362 av_bprintf(&buf, "{\\an%d}", alignment + vertical_align * 3);
363 if (vertical_align != 2)
364 empty_lines = 0;
365 }
366
367 if (len && empty_lines > 1)
368 for (empty_lines /= 2; empty_lines > 0; empty_lines--)
369 av_bprintf(&buf, " \\N");
370
371 if (alignment == 1 || alignment == 2 && !can_align_center)
372 leading = min_leading;
373 if (alignment == 3 || alignment == 2 && !can_align_center)
374 trailing = min_trailing;
375 }
376
377 if (len || !is_subtitle_page) {
378 decode_string(page, row, &buf, leading, page->columns - trailing, &cur_color, &cur_back_color);
379 av_bprintf(&buf, " \\N");
380 empty_lines = 0;
381 } else {
382 empty_lines++;
383 }
384 }
385
386 if (vertical_align == 0)
387 for (empty_lines = (empty_lines - 1) / 2; empty_lines > 0; empty_lines--)
388 av_bprintf(&buf, " \\N");
389
390 if (!av_bprint_is_complete(&buf)) {
391 av_bprint_finalize(&buf, NULL);
392 return AVERROR(ENOMEM);
393 }
394
395 if (buf.len) {
396 sub_rect->type = SUBTITLE_ASS;
397 sub_rect->ass = ff_ass_get_dialog(ctx->readorder++, 0, is_subtitle_page ? "Subtitle" : "Teletext", NULL, buf.str);
398
399 if (!sub_rect->ass) {
400 av_bprint_finalize(&buf, NULL);
401 return AVERROR(ENOMEM);
402 }
403 av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
404 } else {
405 sub_rect->type = SUBTITLE_NONE;
406 }
407 av_bprint_finalize(&buf, NULL);
408 return 0;
409 }
410
fix_transparency(TeletextContext * ctx,AVSubtitleRect * sub_rect,vbi_page * page,int chop_top,int resx,int resy)411 static void fix_transparency(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page,
412 int chop_top, int resx, int resy)
413 {
414 int iy;
415
416 // Hack for transparency, inspired by VLC code...
417 for (iy = 0; iy < resy; iy++) {
418 uint8_t *pixel = sub_rect->data[0] + iy * sub_rect->linesize[0];
419 vbi_char *vc = page->text + (iy / BITMAP_CHAR_HEIGHT + chop_top) * page->columns;
420 vbi_char *vcnext = vc + page->columns;
421 for (; vc < vcnext; vc++) {
422 uint8_t *pixelnext = pixel + BITMAP_CHAR_WIDTH;
423 switch (vc->opacity) {
424 case VBI_TRANSPARENT_SPACE:
425 memset(pixel, VBI_TRANSPARENT_BLACK, BITMAP_CHAR_WIDTH);
426 break;
427 case VBI_OPAQUE:
428 if (!ctx->transparent_bg)
429 break;
430 case VBI_SEMI_TRANSPARENT:
431 if (ctx->opacity > 0) {
432 if (ctx->opacity < 255)
433 for(; pixel < pixelnext; pixel++)
434 if (*pixel == vc->background)
435 *pixel += VBI_NB_COLORS;
436 break;
437 }
438 case VBI_TRANSPARENT_FULL:
439 for(; pixel < pixelnext; pixel++)
440 if (*pixel == vc->background)
441 *pixel = VBI_TRANSPARENT_BLACK;
442 break;
443 }
444 pixel = pixelnext;
445 }
446 }
447 }
448
449 /* Draw a page as bitmap */
gen_sub_bitmap(TeletextContext * ctx,AVSubtitleRect * sub_rect,vbi_page * page,int chop_top)450 static int gen_sub_bitmap(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
451 {
452 int resx = page->columns * BITMAP_CHAR_WIDTH;
453 int resy = (page->rows - chop_top) * BITMAP_CHAR_HEIGHT;
454 uint8_t ci;
455 vbi_char *vc = page->text + (chop_top * page->columns);
456 vbi_char *vcend = page->text + (page->rows * page->columns);
457
458 for (; vc < vcend; vc++) {
459 if (vc->opacity != VBI_TRANSPARENT_SPACE)
460 break;
461 }
462
463 if (vc >= vcend) {
464 av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno);
465 sub_rect->type = SUBTITLE_NONE;
466 return 0;
467 }
468
469 sub_rect->data[0] = av_mallocz(resx * resy);
470 sub_rect->linesize[0] = resx;
471 if (!sub_rect->data[0])
472 return AVERROR(ENOMEM);
473
474 vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8,
475 sub_rect->data[0], sub_rect->linesize[0],
476 0, chop_top, page->columns, page->rows - chop_top,
477 /*reveal*/ 1, /*flash*/ 1);
478
479 fix_transparency(ctx, sub_rect, page, chop_top, resx, resy);
480 sub_rect->x = ctx->x_offset;
481 sub_rect->y = ctx->y_offset + chop_top * BITMAP_CHAR_HEIGHT;
482 sub_rect->w = resx;
483 sub_rect->h = resy;
484 sub_rect->nb_colors = ctx->opacity > 0 && ctx->opacity < 255 ? 2 * VBI_NB_COLORS : VBI_NB_COLORS;
485 sub_rect->data[1] = av_mallocz(AVPALETTE_SIZE);
486 if (!sub_rect->data[1]) {
487 av_freep(&sub_rect->data[0]);
488 return AVERROR(ENOMEM);
489 }
490 for (ci = 0; ci < VBI_NB_COLORS; ci++) {
491 int r, g, b, a;
492
493 r = VBI_R(page->color_map[ci]);
494 g = VBI_G(page->color_map[ci]);
495 b = VBI_B(page->color_map[ci]);
496 a = VBI_A(page->color_map[ci]);
497 ((uint32_t *)sub_rect->data[1])[ci] = RGBA(r, g, b, a);
498 ((uint32_t *)sub_rect->data[1])[ci + VBI_NB_COLORS] = RGBA(r, g, b, ctx->opacity);
499 ff_dlog(ctx, "palette %0x\n", ((uint32_t *)sub_rect->data[1])[ci]);
500 }
501 ((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK] = RGBA(0, 0, 0, 0);
502 ((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK + VBI_NB_COLORS] = RGBA(0, 0, 0, 0);
503 sub_rect->type = SUBTITLE_BITMAP;
504 return 0;
505 }
506
handler(vbi_event * ev,void * user_data)507 static void handler(vbi_event *ev, void *user_data)
508 {
509 TeletextContext *ctx = user_data;
510 TeletextPage *new_pages;
511 vbi_page page;
512 int res;
513 char pgno_str[12];
514 int chop_top;
515 int is_subtitle_page = ctx->subtitle_map[ev->ev.ttx_page.pgno & 0x7ff];
516
517 snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
518 av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
519 pgno_str, ev->ev.ttx_page.subno & 0xFF);
520
521 if (strcmp(ctx->pgno, "*") && (strcmp(ctx->pgno, "subtitle") || !is_subtitle_page) && !strstr(ctx->pgno, pgno_str))
522 return;
523 if (ctx->handler_ret < 0)
524 return;
525
526 res = vbi_fetch_vt_page(ctx->vbi, &page,
527 ev->ev.ttx_page.pgno,
528 ev->ev.ttx_page.subno,
529 VBI_WST_LEVEL_3p5, 25, TRUE);
530
531 if (!res)
532 return;
533
534 chop_top = ctx->chop_top || ((page.rows > 1) && is_subtitle_page);
535
536 av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
537 page.columns, page.rows, chop_top);
538
539 if (ctx->nb_pages < MAX_BUFFERED_PAGES) {
540 if ((new_pages = av_realloc_array(ctx->pages, ctx->nb_pages + 1, sizeof(TeletextPage)))) {
541 TeletextPage *cur_page = new_pages + ctx->nb_pages;
542 ctx->pages = new_pages;
543 cur_page->sub_rect = av_mallocz(sizeof(*cur_page->sub_rect));
544 cur_page->pts = ctx->pts;
545 cur_page->pgno = ev->ev.ttx_page.pgno;
546 cur_page->subno = ev->ev.ttx_page.subno;
547 if (cur_page->sub_rect) {
548 switch (ctx->format_id) {
549 case 0:
550 res = gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top);
551 break;
552 case 1:
553 res = gen_sub_text(ctx, cur_page->sub_rect, &page, chop_top);
554 break;
555 case 2:
556 res = gen_sub_ass(ctx, cur_page->sub_rect, &page, chop_top);
557 break;
558 default:
559 res = AVERROR_BUG;
560 break;
561 }
562 if (res < 0) {
563 av_freep(&cur_page->sub_rect);
564 ctx->handler_ret = res;
565 } else {
566 ctx->pages[ctx->nb_pages++] = *cur_page;
567 }
568 } else {
569 ctx->handler_ret = AVERROR(ENOMEM);
570 }
571 } else {
572 ctx->handler_ret = AVERROR(ENOMEM);
573 }
574 } else {
575 //TODO: If multiple packets contain more than one page, pages may got queued up, and this may happen...
576 av_log(ctx, AV_LOG_ERROR, "Buffered too many pages, dropping page %s.\n", pgno_str);
577 ctx->handler_ret = AVERROR(ENOSYS);
578 }
579
580 vbi_unref_page(&page);
581 }
582
slice_to_vbi_lines(TeletextContext * ctx,uint8_t * buf,int size)583 static int slice_to_vbi_lines(TeletextContext *ctx, uint8_t* buf, int size)
584 {
585 int lines = 0;
586 while (size >= 2 && lines < MAX_SLICES) {
587 int data_unit_id = buf[0];
588 int data_unit_length = buf[1];
589 if (data_unit_length + 2 > size)
590 return AVERROR_INVALIDDATA;
591 if (ff_data_unit_id_is_teletext(data_unit_id)) {
592 if (data_unit_length != 0x2c)
593 return AVERROR_INVALIDDATA;
594 else {
595 int line_offset = buf[2] & 0x1f;
596 int field_parity = buf[2] & 0x20;
597 uint8_t *p = ctx->sliced[lines].data;
598 int i, pmag;
599 ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B;
600 ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0);
601 for (i = 0; i < 42; i++)
602 p[i] = vbi_rev8(buf[4 + i]);
603 /* Unfortunately libzvbi does not expose page flags, and
604 * vbi_classify_page only checks MIP, so we have to manually
605 * decode the page flags and store the results. */
606 pmag = vbi_unham16p(p);
607 if (pmag >= 0 && pmag >> 3 == 0) { // We found a row 0 header
608 int page = vbi_unham16p(p + 2);
609 int flags1 = vbi_unham16p(p + 6);
610 int flags2 = vbi_unham16p(p + 8);
611 if (page >= 0 && flags1 >= 0 && flags2 >= 0) {
612 int pgno = ((pmag & 7) << 8) + page;
613 // Check for disabled NEWSFLASH flag and enabled SUBTITLE and SUPRESS_HEADER flags
614 ctx->subtitle_map[pgno] = (!(flags1 & 0x40) && flags1 & 0x80 && flags2 & 0x01);
615 // Propagate ERASE_PAGE flag for repeated page headers to work around a libzvbi bug
616 if (ctx->subtitle_map[pgno] && pgno == ctx->last_pgno) {
617 int last_byte9 = vbi_unham8(ctx->last_p5);
618 if (last_byte9 >= 0 && last_byte9 & 0x8) {
619 int byte9 = vbi_unham8(p[5]);
620 if (byte9 >= 0)
621 p[5] = vbi_ham8(byte9 | 0x8);
622 }
623 }
624 ctx->last_pgno = pgno;
625 ctx->last_p5 = p[5];
626 }
627 }
628 lines++;
629 }
630 }
631 size -= data_unit_length + 2;
632 buf += data_unit_length + 2;
633 }
634 if (size)
635 av_log(ctx, AV_LOG_WARNING, "%d bytes remained after slicing data\n", size);
636 return lines;
637 }
638
teletext_decode_frame(AVCodecContext * avctx,void * data,int * got_sub_ptr,AVPacket * pkt)639 static int teletext_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr, AVPacket *pkt)
640 {
641 TeletextContext *ctx = avctx->priv_data;
642 AVSubtitle *sub = data;
643 int ret = 0;
644 int j;
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 #if FF_API_AVPICTURE
705 FF_DISABLE_DEPRECATION_WARNINGS
706 for (j = 0; j < 4; j++) {
707 sub->rects[0]->pict.data[j] = sub->rects[0]->data[j];
708 sub->rects[0]->pict.linesize[j] = sub->rects[0]->linesize[j];
709 }
710 FF_ENABLE_DEPRECATION_WARNINGS
711 #endif
712 } else {
713 ret = AVERROR(ENOMEM);
714 }
715 } else {
716 av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n");
717 sub->rects = NULL;
718 }
719 if (!sub->rects) // no rect was passed
720 subtitle_rect_free(&ctx->pages->sub_rect);
721
722 for (i = 0; i < ctx->nb_pages - 1; i++)
723 ctx->pages[i] = ctx->pages[i + 1];
724 ctx->nb_pages--;
725
726 if (ret >= 0)
727 *got_sub_ptr = 1;
728 } else
729 *got_sub_ptr = 0;
730
731 return ret;
732 }
733
teletext_init_decoder(AVCodecContext * avctx)734 static int teletext_init_decoder(AVCodecContext *avctx)
735 {
736 TeletextContext *ctx = avctx->priv_data;
737 unsigned int maj, min, rev;
738
739 vbi_version(&maj, &min, &rev);
740 if (!(maj > 0 || min > 2 || min == 2 && rev >= 26)) {
741 av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n");
742 return AVERROR_EXTERNAL;
743 }
744
745 if (ctx->format_id == 0) {
746 avctx->width = 41 * BITMAP_CHAR_WIDTH;
747 avctx->height = 25 * BITMAP_CHAR_HEIGHT;
748 }
749
750 ctx->vbi = NULL;
751 ctx->pts = AV_NOPTS_VALUE;
752 ctx->last_pgno = -1;
753 ctx->last_ass_alignment = 2;
754
755 if (ctx->opacity == -1)
756 ctx->opacity = ctx->transparent_bg ? 0 : 255;
757
758 av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno);
759
760 switch (ctx->format_id) {
761 case 0:
762 return 0;
763 case 1:
764 return ff_ass_subtitle_header_default(avctx);
765 case 2:
766 return my_ass_subtitle_header(avctx);
767 }
768 return AVERROR_BUG;
769 }
770
teletext_close_decoder(AVCodecContext * avctx)771 static int teletext_close_decoder(AVCodecContext *avctx)
772 {
773 TeletextContext *ctx = avctx->priv_data;
774
775 ff_dlog(avctx, "lines_total=%u\n", ctx->lines_processed);
776 while (ctx->nb_pages)
777 subtitle_rect_free(&ctx->pages[--ctx->nb_pages].sub_rect);
778 av_freep(&ctx->pages);
779
780 vbi_decoder_delete(ctx->vbi);
781 ctx->vbi = NULL;
782 ctx->pts = AV_NOPTS_VALUE;
783 ctx->last_pgno = -1;
784 ctx->last_ass_alignment = 2;
785 memset(ctx->subtitle_map, 0, sizeof(ctx->subtitle_map));
786 if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
787 ctx->readorder = 0;
788 return 0;
789 }
790
teletext_flush(AVCodecContext * avctx)791 static void teletext_flush(AVCodecContext *avctx)
792 {
793 teletext_close_decoder(avctx);
794 }
795
796 #define OFFSET(x) offsetof(TeletextContext, x)
797 #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
798 static const AVOption options[] = {
799 {"txt_page", "page numbers to decode, subtitle for subtitles, * for all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
800 {"txt_default_region", "default G0 character set used for decoding", OFFSET(default_region), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 87, SD},
801 {"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
802 {"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"},
803 {"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"},
804 {"text", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, SD, "txt_format"},
805 {"ass", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 0, SD, "txt_format"},
806 {"txt_left", "x offset of generated bitmaps", OFFSET(x_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
807 {"txt_top", "y offset of generated bitmaps", OFFSET(y_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
808 {"txt_chop_spaces", "chops leading and trailing spaces from text", OFFSET(chop_spaces), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
809 {"txt_duration", "display duration of teletext pages in msecs", OFFSET(sub_duration), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 86400000, SD},
810 {"txt_transparent", "force transparent background of the teletext", OFFSET(transparent_bg), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
811 {"txt_opacity", "set opacity of the transparent background", OFFSET(opacity), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 255, SD},
812 { NULL },
813 };
814
815 static const AVClass teletext_class = {
816 .class_name = "libzvbi_teletextdec",
817 .item_name = av_default_item_name,
818 .option = options,
819 .version = LIBAVUTIL_VERSION_INT,
820 };
821
822 AVCodec ff_libzvbi_teletext_decoder = {
823 .name = "libzvbi_teletextdec",
824 .long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"),
825 .type = AVMEDIA_TYPE_SUBTITLE,
826 .id = AV_CODEC_ID_DVB_TELETEXT,
827 .priv_data_size = sizeof(TeletextContext),
828 .init = teletext_init_decoder,
829 .close = teletext_close_decoder,
830 .decode = teletext_decode_frame,
831 .capabilities = AV_CODEC_CAP_DELAY,
832 .flush = teletext_flush,
833 .priv_class= &teletext_class,
834 .wrapper_name = "libzvbi",
835 };
836