Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / libzvbi-teletextdec.c
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 "libavutil/opt.h"
24 #include "libavutil/bprint.h"
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/log.h"
27
28 #include <libzvbi.h>
29
30 #define TEXT_MAXSZ (25 * (56 + 1) * 4 + 2)
31 #define VBI_NB_COLORS 40
32 #define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
33 #define VBI_R(rgba) (((rgba) >> 0) & 0xFF)
34 #define VBI_G(rgba) (((rgba) >> 8) & 0xFF)
35 #define VBI_B(rgba) (((rgba) >> 16) & 0xFF)
36 #define VBI_A(rgba) (((rgba) >> 24) & 0xFF)
37 #define MAX_BUFFERED_PAGES 25
38 #define BITMAP_CHAR_WIDTH 12
39 #define BITMAP_CHAR_HEIGHT 10
40 #define MAX_SLICES 64
41
42 typedef struct TeletextPage
43 {
44 AVSubtitleRect *sub_rect;
45 int pgno;
46 int subno;
47 int64_t pts;
48 } TeletextPage;
49
50 typedef struct TeletextContext
51 {
52 AVClass *class;
53 char *pgno;
54 int x_offset;
55 int y_offset;
56 int format_id; /* 0 = bitmap, 1 = text/ass */
57 int chop_top;
58 int sub_duration; /* in msec */
59 int transparent_bg;
60 int chop_spaces;
61
62 int lines_processed;
63 TeletextPage *pages;
64 int nb_pages;
65 int64_t pts;
66 int handler_ret;
67
68 vbi_decoder * vbi;
69 #ifdef DEBUG
70 vbi_export * ex;
71 #endif
72 vbi_sliced sliced[MAX_SLICES];
73 } TeletextContext;
74
75 static int chop_spaces_utf8(const unsigned char* t, int len)
76 {
77 t += len;
78 while (len > 0) {
79 if (*--t != ' ' || (len-1 > 0 && *(t-1) & 0x80))
80 break;
81 --len;
82 }
83 return len;
84 }
85
86 static void subtitle_rect_free(AVSubtitleRect **sub_rect)
87 {
88 av_freep(&(*sub_rect)->pict.data[0]);
89 av_freep(&(*sub_rect)->pict.data[1]);
90 av_freep(&(*sub_rect)->ass);
91 av_freep(sub_rect);
92 }
93
94 static int create_ass_text(TeletextContext *ctx, const char *text, char **ass)
95 {
96 int ret;
97 AVBPrint buf, buf2;
98 const int ts_start = av_rescale_q(ctx->pts, AV_TIME_BASE_Q, (AVRational){1, 100});
99 const int ts_duration = av_rescale_q(ctx->sub_duration, (AVRational){1, 1000}, (AVRational){1, 100});
100
101 /* First we escape the plain text into buf. */
102 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
103 ff_ass_bprint_text_event(&buf, text, strlen(text), "", 0);
104 av_bprintf(&buf, "\r\n");
105
106 if (!av_bprint_is_complete(&buf)) {
107 av_bprint_finalize(&buf, NULL);
108 return AVERROR(ENOMEM);
109 }
110
111 /* Then we create the ass dialog line in buf2 from the escaped text in buf. */
112 av_bprint_init(&buf2, 0, AV_BPRINT_SIZE_UNLIMITED);
113 ff_ass_bprint_dialog(&buf2, buf.str, ts_start, ts_duration, 0);
114 av_bprint_finalize(&buf, NULL);
115
116 if (!av_bprint_is_complete(&buf2)) {
117 av_bprint_finalize(&buf2, NULL);
118 return AVERROR(ENOMEM);
119 }
120
121 if ((ret = av_bprint_finalize(&buf2, ass)) < 0)
122 return ret;
123
124 return 0;
125 }
126
127 /* Draw a page as text */
128 static int gen_sub_text(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
129 {
130 const char *in;
131 AVBPrint buf;
132 char *vbi_text = av_malloc(TEXT_MAXSZ);
133 int sz;
134
135 if (!vbi_text)
136 return AVERROR(ENOMEM);
137
138 sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8",
139 /*table mode*/ TRUE, FALSE,
140 0, chop_top,
141 page->columns, page->rows-chop_top);
142 if (sz <= 0) {
143 av_log(ctx, AV_LOG_ERROR, "vbi_print error\n");
144 av_free(vbi_text);
145 return AVERROR_EXTERNAL;
146 }
147 vbi_text[sz] = '\0';
148 in = vbi_text;
149 av_bprint_init(&buf, 0, TEXT_MAXSZ);
150
151 if (ctx->chop_spaces) {
152 for (;;) {
153 int nl, sz;
154
155 // skip leading spaces and newlines
156 in += strspn(in, " \n");
157 // compute end of row
158 for (nl = 0; in[nl]; ++nl)
159 if (in[nl] == '\n' && (nl==0 || !(in[nl-1] & 0x80)))
160 break;
161 if (!in[nl])
162 break;
163 // skip trailing spaces
164 sz = chop_spaces_utf8(in, nl);
165 av_bprint_append_data(&buf, in, sz);
166 av_bprintf(&buf, "\n");
167 in += nl;
168 }
169 } else {
170 av_bprintf(&buf, "%s\n", vbi_text);
171 }
172 av_free(vbi_text);
173
174 if (!av_bprint_is_complete(&buf)) {
175 av_bprint_finalize(&buf, NULL);
176 return AVERROR(ENOMEM);
177 }
178
179 if (buf.len) {
180 int ret;
181 sub_rect->type = SUBTITLE_ASS;
182 if ((ret = create_ass_text(ctx, buf.str, &sub_rect->ass)) < 0) {
183 av_bprint_finalize(&buf, NULL);
184 return ret;
185 }
186 av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
187 } else {
188 sub_rect->type = SUBTITLE_NONE;
189 }
190 av_bprint_finalize(&buf, NULL);
191 return 0;
192 }
193
194 static void fix_transparency(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page,
195 int chop_top, uint8_t transparent_color, int resx, int resy)
196 {
197 int iy;
198
199 // Hack for transparency, inspired by VLC code...
200 for (iy = 0; iy < resy; iy++) {
201 uint8_t *pixel = sub_rect->pict.data[0] + iy * sub_rect->pict.linesize[0];
202 vbi_char *vc = page->text + (iy / BITMAP_CHAR_HEIGHT + chop_top) * page->columns;
203 vbi_char *vcnext = vc + page->columns;
204 for (; vc < vcnext; vc++) {
205 uint8_t *pixelnext = pixel + BITMAP_CHAR_WIDTH;
206 switch (vc->opacity) {
207 case VBI_TRANSPARENT_SPACE:
208 memset(pixel, transparent_color, BITMAP_CHAR_WIDTH);
209 break;
210 case VBI_OPAQUE:
211 case VBI_SEMI_TRANSPARENT:
212 if (!ctx->transparent_bg)
213 break;
214 case VBI_TRANSPARENT_FULL:
215 for(; pixel < pixelnext; pixel++)
216 if (*pixel == vc->background)
217 *pixel = transparent_color;
218 break;
219 }
220 pixel = pixelnext;
221 }
222 }
223 }
224
225 /* Draw a page as bitmap */
226 static int gen_sub_bitmap(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
227 {
228 int resx = page->columns * BITMAP_CHAR_WIDTH;
229 int resy = (page->rows - chop_top) * BITMAP_CHAR_HEIGHT;
230 uint8_t ci, cmax = 0;
231 int ret;
232 vbi_char *vc = page->text + (chop_top * page->columns);
233 vbi_char *vcend = page->text + (page->rows * page->columns);
234
235 for (; vc < vcend; vc++) {
236 if (vc->opacity != VBI_TRANSPARENT_SPACE) {
237 cmax = VBI_NB_COLORS;
238 break;
239 }
240 }
241
242 if (cmax == 0) {
243 av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno);
244 sub_rect->type = SUBTITLE_NONE;
245 return 0;
246 }
247
248 if ((ret = avpicture_alloc(&sub_rect->pict, AV_PIX_FMT_PAL8, resx, resy)) < 0)
249 return ret;
250 // Yes, we want to allocate the palette on our own because AVSubtitle works this way
251 sub_rect->pict.data[1] = NULL;
252
253 vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8,
254 sub_rect->pict.data[0], sub_rect->pict.linesize[0],
255 0, chop_top, page->columns, page->rows - chop_top,
256 /*reveal*/ 1, /*flash*/ 1);
257
258 fix_transparency(ctx, sub_rect, page, chop_top, cmax, resx, resy);
259 sub_rect->x = ctx->x_offset;
260 sub_rect->y = ctx->y_offset + chop_top * BITMAP_CHAR_HEIGHT;
261 sub_rect->w = resx;
262 sub_rect->h = resy;
263 sub_rect->nb_colors = (int)cmax + 1;
264 sub_rect->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
265 if (!sub_rect->pict.data[1]) {
266 av_freep(&sub_rect->pict.data[0]);
267 return AVERROR(ENOMEM);
268 }
269 for (ci = 0; ci < cmax; ci++) {
270 int r, g, b, a;
271
272 r = VBI_R(page->color_map[ci]);
273 g = VBI_G(page->color_map[ci]);
274 b = VBI_B(page->color_map[ci]);
275 a = VBI_A(page->color_map[ci]);
276 ((uint32_t *)sub_rect->pict.data[1])[ci] = RGBA(r, g, b, a);
277 av_dlog(ctx, "palette %0x\n", ((uint32_t *)sub_rect->pict.data[1])[ci]);
278 }
279 ((uint32_t *)sub_rect->pict.data[1])[cmax] = RGBA(0, 0, 0, 0);
280 sub_rect->type = SUBTITLE_BITMAP;
281 return 0;
282 }
283
284 static void handler(vbi_event *ev, void *user_data)
285 {
286 TeletextContext *ctx = user_data;
287 TeletextPage *new_pages;
288 vbi_page page;
289 int res;
290 char pgno_str[12];
291 vbi_subno subno;
292 vbi_page_type vpt;
293 int chop_top;
294 char *lang;
295
296 snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
297 av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
298 pgno_str, ev->ev.ttx_page.subno & 0xFF);
299
300 if (strcmp(ctx->pgno, "*") && !strstr(ctx->pgno, pgno_str))
301 return;
302 if (ctx->handler_ret < 0)
303 return;
304
305 res = vbi_fetch_vt_page(ctx->vbi, &page,
306 ev->ev.ttx_page.pgno,
307 ev->ev.ttx_page.subno,
308 VBI_WST_LEVEL_3p5, 25, TRUE);
309
310 if (!res)
311 return;
312
313 #ifdef DEBUG
314 fprintf(stderr, "\nSaving res=%d dy0=%d dy1=%d...\n",
315 res, page.dirty.y0, page.dirty.y1);
316 fflush(stderr);
317
318 if (!vbi_export_stdio(ctx->ex, stderr, &page))
319 fprintf(stderr, "failed: %s\n", vbi_export_errstr(ctx->ex));
320 #endif
321
322 vpt = vbi_classify_page(ctx->vbi, ev->ev.ttx_page.pgno, &subno, &lang);
323 chop_top = ctx->chop_top ||
324 ((page.rows > 1) && (vpt == VBI_SUBTITLE_PAGE));
325
326 av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
327 page.columns, page.rows, chop_top);
328
329 if (ctx->nb_pages < MAX_BUFFERED_PAGES) {
330 if ((new_pages = av_realloc_array(ctx->pages, ctx->nb_pages + 1, sizeof(TeletextPage)))) {
331 TeletextPage *cur_page = new_pages + ctx->nb_pages;
332 ctx->pages = new_pages;
333 cur_page->sub_rect = av_mallocz(sizeof(*cur_page->sub_rect));
334 cur_page->pts = ctx->pts;
335 cur_page->pgno = ev->ev.ttx_page.pgno;
336 cur_page->subno = ev->ev.ttx_page.subno;
337 if (cur_page->sub_rect) {
338 res = (ctx->format_id == 0) ?
339 gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top) :
340 gen_sub_text (ctx, cur_page->sub_rect, &page, chop_top);
341 if (res < 0) {
342 av_freep(&cur_page->sub_rect);
343 ctx->handler_ret = res;
344 } else {
345 ctx->pages[ctx->nb_pages++] = *cur_page;
346 }
347 } else {
348 ctx->handler_ret = AVERROR(ENOMEM);
349 }
350 } else {
351 ctx->handler_ret = AVERROR(ENOMEM);
352 }
353 } else {
354 //TODO: If multiple packets contain more than one page, pages may got queued up, and this may happen...
355 av_log(ctx, AV_LOG_ERROR, "Buffered too many pages, dropping page %s.\n", pgno_str);
356 ctx->handler_ret = AVERROR(ENOSYS);
357 }
358
359 vbi_unref_page(&page);
360 }
361
362 static inline int data_identifier_is_teletext(int data_identifier) {
363 /* See EN 301 775 section 4.4.2. */
364 return (data_identifier >= 0x10 && data_identifier <= 0x1F ||
365 data_identifier >= 0x99 && data_identifier <= 0x9B);
366 }
367
368 static int slice_to_vbi_lines(TeletextContext *ctx, uint8_t* buf, int size)
369 {
370 int lines = 0;
371 while (size >= 2 && lines < MAX_SLICES) {
372 int data_unit_id = buf[0];
373 int data_unit_length = buf[1];
374 if (data_unit_length + 2 > size)
375 return AVERROR_INVALIDDATA;
376 if (data_unit_id == 0x02 || data_unit_id == 0x03) {
377 if (data_unit_length != 0x2c)
378 return AVERROR_INVALIDDATA;
379 else {
380 int line_offset = buf[2] & 0x1f;
381 int field_parity = buf[2] & 0x20;
382 int i;
383 ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B;
384 ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0);
385 for (i = 0; i < 42; i++)
386 ctx->sliced[lines].data[i] = vbi_rev8(buf[4 + i]);
387 lines++;
388 }
389 }
390 size -= data_unit_length + 2;
391 buf += data_unit_length + 2;
392 }
393 if (size)
394 av_log(ctx, AV_LOG_WARNING, "%d bytes remained after slicing data\n", size);
395 return lines;
396 }
397
398 static int teletext_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *pkt)
399 {
400 TeletextContext *ctx = avctx->priv_data;
401 AVSubtitle *sub = data;
402 int ret = 0;
403
404 if (!ctx->vbi) {
405 if (!(ctx->vbi = vbi_decoder_new()))
406 return AVERROR(ENOMEM);
407 if (!vbi_event_handler_add(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) {
408 vbi_decoder_delete(ctx->vbi);
409 ctx->vbi = NULL;
410 return AVERROR(ENOMEM);
411 }
412 }
413
414 if (avctx->pkt_timebase.den && pkt->pts != AV_NOPTS_VALUE)
415 ctx->pts = av_rescale_q(pkt->pts, avctx->pkt_timebase, AV_TIME_BASE_Q);
416
417 if (pkt->size) {
418 int lines;
419 const int full_pes_size = pkt->size + 45; /* PES header is 45 bytes */
420
421 // We allow unreasonably big packets, even if the standard only allows a max size of 1472
422 if (full_pes_size < 184 || full_pes_size > 65504 || full_pes_size % 184 != 0)
423 return AVERROR_INVALIDDATA;
424
425 ctx->handler_ret = pkt->size;
426
427 if (data_identifier_is_teletext(*pkt->data)) {
428 if ((lines = slice_to_vbi_lines(ctx, pkt->data + 1, pkt->size - 1)) < 0)
429 return lines;
430 av_dlog(avctx, "ctx=%p buf_size=%d lines=%u pkt_pts=%7.3f\n",
431 ctx, pkt->size, lines, (double)pkt->pts/90000.0);
432 if (lines > 0) {
433 #ifdef DEBUG
434 int i;
435 av_log(avctx, AV_LOG_DEBUG, "line numbers:");
436 for(i = 0; i < lines; i++)
437 av_log(avctx, AV_LOG_DEBUG, " %d", ctx->sliced[i].line);
438 av_log(avctx, AV_LOG_DEBUG, "\n");
439 #endif
440 vbi_decode(ctx->vbi, ctx->sliced, lines, 0.0);
441 ctx->lines_processed += lines;
442 }
443 }
444 ctx->pts = AV_NOPTS_VALUE;
445 ret = ctx->handler_ret;
446 }
447
448 if (ret < 0)
449 return ret;
450
451 // is there a subtitle to pass?
452 if (ctx->nb_pages) {
453 int i;
454 sub->format = ctx->format_id;
455 sub->start_display_time = 0;
456 sub->end_display_time = ctx->sub_duration;
457 sub->num_rects = 0;
458 sub->pts = ctx->pages->pts;
459
460 if (ctx->pages->sub_rect->type != SUBTITLE_NONE) {
461 sub->rects = av_malloc(sizeof(*sub->rects));
462 if (sub->rects) {
463 sub->num_rects = 1;
464 sub->rects[0] = ctx->pages->sub_rect;
465 } else {
466 ret = AVERROR(ENOMEM);
467 }
468 } else {
469 av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n");
470 sub->rects = NULL;
471 }
472 if (!sub->rects) // no rect was passed
473 subtitle_rect_free(&ctx->pages->sub_rect);
474
475 for (i = 0; i < ctx->nb_pages - 1; i++)
476 ctx->pages[i] = ctx->pages[i + 1];
477 ctx->nb_pages--;
478
479 if (ret >= 0)
480 *data_size = 1;
481 } else
482 *data_size = 0;
483
484 return ret;
485 }
486
487 static int teletext_init_decoder(AVCodecContext *avctx)
488 {
489 TeletextContext *ctx = avctx->priv_data;
490 unsigned int maj, min, rev;
491
492 vbi_version(&maj, &min, &rev);
493 if (!(maj > 0 || min > 2 || min == 2 && rev >= 26)) {
494 av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n");
495 return AVERROR_EXTERNAL;
496 }
497
498 if (ctx->format_id == 0) {
499 avctx->width = 41 * BITMAP_CHAR_WIDTH;
500 avctx->height = 25 * BITMAP_CHAR_HEIGHT;
501 }
502
503 ctx->vbi = NULL;
504 ctx->pts = AV_NOPTS_VALUE;
505
506 #ifdef DEBUG
507 {
508 char *t;
509 ctx->ex = vbi_export_new("text", &t);
510 }
511 #endif
512 av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno);
513 return (ctx->format_id == 1) ? ff_ass_subtitle_header_default(avctx) : 0;
514 }
515
516 static int teletext_close_decoder(AVCodecContext *avctx)
517 {
518 TeletextContext *ctx = avctx->priv_data;
519
520 av_dlog(avctx, "lines_total=%u\n", ctx->lines_processed);
521 while (ctx->nb_pages)
522 subtitle_rect_free(&ctx->pages[--ctx->nb_pages].sub_rect);
523 av_freep(&ctx->pages);
524
525 vbi_decoder_delete(ctx->vbi);
526 ctx->vbi = NULL;
527 ctx->pts = AV_NOPTS_VALUE;
528 return 0;
529 }
530
531 static void teletext_flush(AVCodecContext *avctx)
532 {
533 teletext_close_decoder(avctx);
534 }
535
536 #define OFFSET(x) offsetof(TeletextContext, x)
537 #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
538 static const AVOption options[] = {
539 {"txt_page", "list of teletext page numbers to decode, * is all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
540 {"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
541 {"txt_format", "format of the subtitles (bitmap or text)", OFFSET(format_id), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD, "txt_format"},
542 {"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"},
543 {"text", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, SD, "txt_format"},
544 {"txt_left", "x offset of generated bitmaps", OFFSET(x_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
545 {"txt_top", "y offset of generated bitmaps", OFFSET(y_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
546 {"txt_chop_spaces", "chops leading and trailing spaces from text", OFFSET(chop_spaces), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
547 {"txt_duration", "display duration of teletext pages in msecs", OFFSET(sub_duration), AV_OPT_TYPE_INT, {.i64 = 30000}, 0, 86400000, SD},
548 {"txt_transparent", "force transparent background of the teletext", OFFSET(transparent_bg), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
549 { NULL },
550 };
551
552 static const AVClass teletext_class = {
553 .class_name = "libzvbi_teletextdec",
554 .item_name = av_default_item_name,
555 .option = options,
556 .version = LIBAVUTIL_VERSION_INT,
557 };
558
559 AVCodec ff_libzvbi_teletext_decoder = {
560 .name = "libzvbi_teletextdec",
561 .long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"),
562 .type = AVMEDIA_TYPE_SUBTITLE,
563 .id = AV_CODEC_ID_DVB_TELETEXT,
564 .priv_data_size = sizeof(TeletextContext),
565 .init = teletext_init_decoder,
566 .close = teletext_close_decoder,
567 .decode = teletext_decode_frame,
568 .capabilities = CODEC_CAP_DELAY,
569 .flush = teletext_flush,
570 .priv_class= &teletext_class,
571 };