1 /*****************************************************************************
2 * telx.c : Minimalistic Teletext subtitles decoder
3 *****************************************************************************
4 * Copyright (C) 2007 Vincent Penne
5 * Some code converted from ProjectX java dvb decoder (c) 2001-2005 by dvb.matt
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
21 *****************************************************************************/
22 /*****************************************************************************
24 * information on teletext format can be found here :
25 * http://pdc.ro.nu/teletext.html
29 *****************************************************************************/
34 /* This is an ugly test so that this source compile for both 0.8.6 and current
35 * trunk version. Considere this hack to be temporary, but I need it so that
36 * I can maintain my patch for both current svn and 0.8.6 in an easy way. */
43 #include <vlc/decoder.h>
45 /* #include "vlc_es.h" */
46 /* #include "vlc_block.h" */
47 /* #include "vlc_video.h" */
48 /* #include "vlc_spu.h" */
52 #include "vlc_codec.h"
55 /* #define TELX_DEBUG */
58 # define dbg( a ) msg_Dbg a
63 /*****************************************************************************
65 *****************************************************************************/
66 static int telx_conf_cb ( vlc_object_t *, /* variable's object */
67 char const *, /* variable name */
68 vlc_value_t, /* old value */
69 vlc_value_t, /* new value */
70 void * ); /* callback data */
72 /*****************************************************************************
74 *****************************************************************************/
75 static int Open ( vlc_object_t * );
76 static void Close( vlc_object_t * );
77 static subpicture_t *Decode( decoder_t *, block_t ** );
80 #define PAGE_TEXT N_("Teletext page")
81 #define PAGE_LONGTEXT N_("Set displayed teletext page for subtitles, 0 for all pages, 888 should be a standard value. Just leave it to zero if your stream has only one language for subtitles.")
83 #define IGNORE_SUB_FLAG_TEXT N_("Ignore subtitle flag")
84 #define IGNORE_SUB_FLAG_LONGTEXT N_("Ignore the subtitle flag, try this if your subtitles don't appear.")
87 # define TELX_CFG_PREFIX "telx-"
88 set_description( _("Teletext subtitles decoder") );
89 set_shortname( "Teletext" );
90 set_capability( "decoder", 50 );
91 set_category( CAT_INPUT );
92 set_subcategory( SUBCAT_INPUT_SCODEC );
93 set_callbacks( Open, Close );
95 add_integer( "telx-page", 0, telx_conf_cb, PAGE_TEXT, PAGE_LONGTEXT,
97 add_bool( "telx-ignore-subtitle-flag", 0, telx_conf_cb,
98 IGNORE_SUB_FLAG_TEXT, IGNORE_SUB_FLAG_LONGTEXT, VLC_TRUE );
102 /****************************************************************************
104 ****************************************************************************/
109 vlc_bool_t b_is_subtitle[9];
110 char ppsz_lines[32][128];
111 char psz_prev_text[512];
114 vlc_bool_t b_erase[9];
115 uint16_t * pi_active_national_set[9];
118 /****************************************************************************
120 ****************************************************************************/
122 static int i_conf_wanted_page = 0; /* default 0 = all pages */
123 static vlc_bool_t b_ignore_sub_flag = 0;
126 * My doc only mentions 13 national characters, but experiments show there
127 * are more, in france for example I already found two more (0x9 and 0xb).
129 * Conversion is in this order :
131 * 0x23 0x24 0x40 0x5b 0x5c 0x5d 0x5e 0x5f 0x60 0x7b 0x7c 0x7d 0x7e
132 * (these are the standard ones)
133 * 0x08 0x09 0x0a 0x0b 0x0c 0x0d (apparently a control character) 0x0e 0x0f
136 static uint16_t ppi_national_subsets[][20] =
138 { 0x00a3, 0x0024, 0x0040, 0x00ab, 0x00bd, 0x00bb, 0x005e, 0x0023,
139 0x002d, 0x00bc, 0x00a6, 0x00be, 0x00f7 }, /* english ,000 */
141 { 0x00e9, 0x00ef, 0x00e0, 0x00eb, 0x00ea, 0x00f9, 0x00ee, 0x0023,
142 0x00e8, 0x00e2, 0x00f4, 0x00fb, 0x00e7, 0, 0x00eb, 0, 0x00ef }, /* french ,001 */
144 { 0x0023, 0x00a4, 0x00c9, 0x00c4, 0x00d6, 0x00c5, 0x00dc, 0x005f,
145 0x00e9, 0x00e4, 0x00f6, 0x00e5, 0x00fc }, /* swedish,finnish,hungarian ,010 */
147 { 0x0023, 0x016f, 0x010d, 0x0165, 0x017e, 0x00fd, 0x00ed, 0x0159,
148 0x00e9, 0x00e1, 0x0115, 0x00fa, 0x0161 }, /* czech,slovak ,011 */
150 { 0x0023, 0x0024, 0x00a7, 0x00c4, 0x00d6, 0x00dc, 0x005e, 0x005f,
151 0x00b0, 0x00e4, 0x00f6, 0x00fc, 0x00df }, /* german ,100 */
153 { 0x00e7, 0x0024, 0x00a1, 0x00e1, 0x00e9, 0x00ed, 0x00f3, 0x00fa,
154 0x00bf, 0x00fc, 0x00f1, 0x00e8, 0x00e0 }, /* portuguese,spanish ,101 */
156 { 0x00a3, 0x0024, 0x00e9, 0x00b0, 0x00e7, 0x00bb, 0x005e, 0x0023,
157 0x00f9, 0x00e0, 0x00f2, 0x00e8, 0x00ec }, /* italian ,110 */
159 { 0x0023, 0x00a4, 0x0162, 0x00c2, 0x015e, 0x0102, 0x00ce, 0x0131,
160 0x0163, 0x00e2, 0x015f, 0x0103, 0x00ee }, /* rumanian ,111 */
162 /* I have these tables too, but I don't know how they can be triggered */
163 { 0x0023, 0x0024, 0x0160, 0x0117, 0x0119, 0x017d, 0x010d, 0x016b,
164 0x0161, 0x0105, 0x0173, 0x017e, 0x012f }, /* lettish,lithuanian ,1000 */
166 { 0x0023, 0x0144, 0x0105, 0x005a, 0x015a, 0x0141, 0x0107, 0x00f3,
167 0x0119, 0x017c, 0x015b, 0x0142, 0x017a }, /* polish, 1001 */
169 { 0x0023, 0x00cb, 0x010c, 0x0106, 0x017d, 0x0110, 0x0160, 0x00eb,
170 0x010d, 0x0107, 0x017e, 0x0111, 0x0161 }, /* serbian,croatian,slovenian, 1010 */
172 { 0x0023, 0x00f5, 0x0160, 0x00c4, 0x00d6, 0x017e, 0x00dc, 0x00d5,
173 0x0161, 0x00e4, 0x00f6, 0x017e, 0x00fc }, /* estonian ,1011 */
175 { 0x0054, 0x011f, 0x0130, 0x015e, 0x00d6, 0x00c7, 0x00dc, 0x011e,
176 0x0131, 0x015f, 0x00f6, 0x00e7, 0x00fc }, /* turkish ,1100 */
180 /*****************************************************************************
181 * Open: probe the decoder and return score
182 *****************************************************************************
183 * Tries to launch a decoder and return score so that the interface is able
185 *****************************************************************************/
186 static int Open( vlc_object_t *p_this )
188 decoder_t *p_dec = (decoder_t *) p_this;
189 decoder_sys_t *p_sys = NULL;
193 if( p_dec->fmt_in.i_codec != VLC_FOURCC('t','e','l','x'))
198 p_dec->pf_decode_sub = Decode;
199 p_sys = p_dec->p_sys = malloc( sizeof(decoder_sys_t) );
202 msg_Err( p_dec, "out of memory" );
206 memset( p_sys, 0, sizeof(decoder_sys_t) );
209 for ( i = 0; i < 9; i++ )
210 p_sys->pi_active_national_set[i] = ppi_national_subsets[1];
212 var_Create( p_dec, "telx-page", VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
213 var_Get( p_dec, "telx-page", &val );
214 i_conf_wanted_page = val.i_int;
216 var_Create( p_dec, "telx-ignore-subtitle-flag",
217 VLC_VAR_BOOL | VLC_VAR_DOINHERIT );
218 var_Get( p_dec, "telx-ignore-subtitle-flag", &val );
219 b_ignore_sub_flag = val.b_bool;
228 /* return VLC_EGENERIC; */
231 /*****************************************************************************
233 *****************************************************************************/
234 static int telx_conf_cb ( vlc_object_t * obj, /* variable's object */
235 char const * name, /* variable name */
236 vlc_value_t oldv, /* old value */
237 vlc_value_t newv, /* new value */
238 void * data) /* callback data */
240 if ( !strcmp(name, "telx-page") )
242 i_conf_wanted_page = newv.i_int;
243 dbg((obj, "display teletext page changed to %d\n", i_conf_wanted_page));
245 else if ( !strcmp(name, "telx-ignore-subtitle-flag") )
247 b_ignore_sub_flag = newv.b_bool;
248 dbg((obj, "ignore sub flag changed to %d\n", (int) b_ignore_sub_flag));
255 /*****************************************************************************
257 *****************************************************************************/
258 static void Close( vlc_object_t *p_this )
260 decoder_t *p_dec = (decoder_t*) p_this;
261 decoder_sys_t *p_sys = p_dec->p_sys;
266 /**************************
267 * change bits endianness *
268 **************************/
269 static uint8_t bytereverse( int n )
271 n = (((n >> 1) & 0x55) | ((n << 1) & 0xaa));
272 n = (((n >> 2) & 0x33) | ((n << 2) & 0xcc));
273 n = (((n >> 4) & 0x0f) | ((n << 4) & 0xf0));
277 static int hamming_8_4( int a )
313 return -1; // decoding error , not yet corrected
318 // this is not a general function, but it's enough for what we do here
319 // the result buffer need to be at least 4 bytes long
320 static void to_utf8( char * res, uint16_t ch )
326 res[0] = (ch >> 12) | 0xE0;
327 res[1] = ((ch >> 6) & 0x3F) | 0x80;
328 res[2] = (ch & 0x3F) | 0x80;
333 res[0] = (ch >> 6) | 0xC0;
334 res[1] = (ch & 0x3F) | 0x80;
345 static void decode_string( char * res, int res_len,
346 decoder_sys_t *p_sys, int magazine,
347 uint8_t * packet, int len )
353 for ( i = 0; i < len; i++ )
355 int in = bytereverse( packet[i] ) & 0x7f;
361 /* special national characters */
363 out = p_sys->pi_active_national_set[magazine][0];
366 out = p_sys->pi_active_national_set[magazine][1];
369 out = p_sys->pi_active_national_set[magazine][2];
372 out = p_sys->pi_active_national_set[magazine][3];
375 out = p_sys->pi_active_national_set[magazine][4];
378 out = p_sys->pi_active_national_set[magazine][5];
381 out = p_sys->pi_active_national_set[magazine][6];
384 out = p_sys->pi_active_national_set[magazine][7];
387 out = p_sys->pi_active_national_set[magazine][8];
390 out = p_sys->pi_active_national_set[magazine][9];
393 out = p_sys->pi_active_national_set[magazine][10];
396 out = p_sys->pi_active_national_set[magazine][11];
399 out = p_sys->pi_active_national_set[magazine][12];
402 /* some special control characters (empirical) */
404 /* apparently this starts a sequence that ends with 0xb 0xb */
405 while ( i + 1 < len && (bytereverse( packet[i+1] ) & 0x7f) != 0x0b )
412 /* non documented national range 0x08 - 0x0f */
413 if ( in >= 0x08 && in <= 0x0f )
415 out = p_sys->pi_active_national_set[magazine][13 + in - 8];
420 if ( in > 32 && in < 0x7f )
424 /* handle undefined national characters */
428 /* convert to utf-8 */
429 to_utf8( utf8, out );
431 if ( pt + l < res + res_len - 1 )
443 /*****************************************************************************
445 *****************************************************************************/
446 static subpicture_t *Decode( decoder_t *p_dec, block_t **pp_block )
448 decoder_sys_t *p_sys = p_dec->p_sys;
450 subpicture_t *p_spu = NULL;
454 int i_wanted_magazine = i_conf_wanted_page / 100;
455 int i_wanted_page = 0x10 * ((i_conf_wanted_page % 100) / 10)
456 | (i_conf_wanted_page % 10);
457 vlc_bool_t b_update = VLC_FALSE;
458 char psz_text[512], *pt = psz_text;
462 if( pp_block == NULL || *pp_block == NULL ) return NULL;
466 dbg((p_dec, "start of telx packet with header %2x\n",
467 * (uint8_t *) p_block->p_buffer));
468 len = p_block->i_buffer;
469 for ( offset = 1; offset + 46 <= len; offset += 46 )
471 uint8_t * packet = (uint8_t *) p_block->p_buffer+offset;
472 int vbi = ((0x20 & packet[2]) != 0 ? 0 : 313) + (0x1F & packet[2]);
474 dbg((p_dec, "vbi %d header %02x %02x %02x\n", vbi, packet[0], packet[1], packet[2]));
475 if ( packet[0] == 0xFF ) continue;
477 /* if (packet[1] != 0x2C) { */
478 /* printf("wrong header\n"); */
483 int mpag = (hamming_8_4( packet[4] ) << 4) | hamming_8_4( packet[5] );
488 dbg((p_dec, "mpag hamming error\n"));
492 row = 0xFF & bytereverse(mpag);
493 magazine = (7 & row) == 0 ? 8 : (7 & row);
496 if ( i_conf_wanted_page && magazine != i_wanted_magazine ) continue;
500 /* row 0 : flags and header line */
504 for ( a = 0; a < 6; a++ )
506 flag |= (0xF & (bytereverse( hamming_8_4(packet[8 + a]) ) >> 4))
510 /* if (!b_ignore_sub_flag && !(1 & flag>>15)) */
513 p_sys->i_page[magazine] = (0xF0 & bytereverse( hamming_8_4(packet[7]) )) |
514 (0xF & (bytereverse( hamming_8_4(packet[6]) ) >> 4) );
516 decode_string( psz_line, sizeof(psz_line), p_sys, magazine,
517 packet + 14, 40 - 14 );
519 dbg((p_dec, "mag %d flags %x page %x character set %d subtitles %d", magazine, flag,
520 p_sys->i_page[magazine],
521 7 & flag>>21, 1 & flag>>15, psz_line));
523 p_sys->pi_active_national_set[magazine] =
524 ppi_national_subsets[7 & (flag >> 21)];
526 p_sys->b_is_subtitle[magazine] = b_ignore_sub_flag
527 || ( (1 & (flag >> 15))
528 && (1 & (flag>>16)) );
530 dbg(( p_dec, "FLAGS%s%s%s%s%s%s%s mag_ser %d",
531 (1 & (flag>>14))? " news" : "",
532 (1 & (flag>>15))? " subtitle" : "",
533 (1 & (flag>>7))? " erase" : "",
534 (1 & (flag>>16))? " suppressed_head" : "",
535 (1 & (flag>>17))? " update" : "",
536 (1 & (flag>>18))? " interrupt" : "",
537 (1 & (flag>>19))? " inhibit" : "",
540 if ( (i_conf_wanted_page && p_sys->i_page[magazine] != i_wanted_page)
541 || !p_sys->b_is_subtitle[magazine] )
544 p_sys->b_erase[magazine] = (1 & (flag >> 7));
546 dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts, (long int)(p_sys->prev_pts+1500000)));
548 * we ignore the erase flag if it happens less than 1.5 seconds
549 * before last caption
550 * TODO make this time configurable
551 * UPDATE the kludge seems to be no more necessary
552 * so it's commented out*/
553 if ( /*p_block->i_pts > p_sys->prev_pts + 1500000 && */
554 p_sys->b_erase[magazine] )
558 dbg((p_dec, "ERASE !\n"));
560 p_sys->b_erase[magazine] = 0;
561 for ( i = 1; i < 32; i++ )
563 if ( !p_sys->ppsz_lines[i][0] ) continue;
564 /* b_update = VLC_TRUE; */
565 p_sys->ppsz_lines[i][0] = 0;
569 /* replace the row if it's different */
570 if ( strcmp(psz_line, p_sys->ppsz_lines[row]) )
572 strncpy( p_sys->ppsz_lines[row], psz_line,
573 sizeof(p_sys->ppsz_lines[row]) - 1);
582 /* row 1-23 : normal lines */
584 if ( (i_conf_wanted_page && p_sys->i_page[magazine] != i_wanted_page)
585 || !p_sys->b_is_subtitle[magazine]
586 || (!i_conf_wanted_page && p_sys->i_page[magazine] > 0x99) )
589 decode_string( psz_line, sizeof(psz_line), p_sys, magazine,
593 /* remove starting spaces */
594 while ( *t == 32 ) t++;
596 /* remove trailing spaces */
597 for ( i = strlen(t) - 1; i >= 0 && t[i] == 32; i-- );
600 /* replace the row if it's different */
601 if ( strcmp( t, p_sys->ppsz_lines[row] ) )
603 strncpy( p_sys->ppsz_lines[row], t,
604 sizeof(p_sys->ppsz_lines[row]) - 1 );
609 p_sys->prev_pts = p_block->i_pts;
611 dbg((p_dec, "%d %d : ", magazine, row));
612 dbg((p_dec, "%s\n", t));
618 for ( i = 0; i < 40; i++ )
620 int in = bytereverse(packet[6 + i]) & 0x7f;
621 sprintf(dbg + strlen(dbg), "%02x ", in);
623 dbg((p_dec, "%s\n", dbg));
625 for ( i = 0; i < 40; i++ )
627 decode_string( psz_line, sizeof(psz_line), p_sys, magazine,
629 sprintf( dbg + strlen(dbg), "%s ", psz_line );
631 dbg((p_dec, "%s\n", dbg));
636 else if ( row == 25 )
638 /* row 25 : alternate header line */
639 if ( (i_conf_wanted_page && p_sys->i_page[magazine] != i_wanted_page)
640 || !p_sys->b_is_subtitle[magazine] )
643 decode_string( psz_line, sizeof(psz_line), p_sys, magazine,
646 /* replace the row if it's different */
647 if ( strcmp( psz_line, p_sys->ppsz_lines[0] ) )
649 strncpy( p_sys->ppsz_lines[0], psz_line,
650 sizeof(p_sys->ppsz_lines[0]) - 1 );
651 /* b_update = VLC_TRUE; */
654 /* else if (row == 26) { */
655 /* // row 26 : TV listings */
657 /* dbg((p_dec, "%d %d : %s\n", magazine, row, decode_string(p_sys, magazine, packet+6, 40))); */
664 for ( i = 1; i < 24; i++ )
666 size_t l = strlen( p_sys->ppsz_lines[i] );
668 if ( l > sizeof(psz_text) - total - 1 )
669 l = sizeof(psz_text) - total - 1;
673 memcpy( pt, p_sys->ppsz_lines[i], l );
676 if ( sizeof(psz_text) - total - 1 > 0 )
685 if ( !strcmp(psz_text, p_sys->psz_prev_text) )
688 dbg((p_dec, "UPDATE TELETEXT PICTURE\n"));
690 assert( sizeof(p_sys->psz_prev_text) >= sizeof(psz_text) );
691 strcpy( p_sys->psz_prev_text, psz_text );
693 /* Create the subpicture unit */
694 p_spu = p_dec->pf_spu_buffer_new( p_dec );
697 msg_Warn( p_dec, "can't get spu buffer" );
701 p_spu->b_pausable = VLC_TRUE;
703 /* Create a new subpicture region */
704 memset( &fmt, 0, sizeof(video_format_t) );
705 fmt.i_chroma = VLC_FOURCC('T','E','X','T');
707 fmt.i_width = fmt.i_height = 0;
708 fmt.i_x_offset = fmt.i_y_offset = 0;
709 p_spu->p_region = p_spu->pf_create_region( VLC_OBJECT(p_dec), &fmt );
710 if( p_spu->p_region == NULL )
712 msg_Err( p_dec, "cannot allocate SPU region" );
716 /* Normal text subs, easy markup */
717 p_spu->i_flags = SUBPICTURE_ALIGN_BOTTOM | p_sys->i_align;
718 p_spu->i_x = p_sys->i_align ? 20 : 0;
721 p_spu->p_region->psz_text = strdup(psz_text);
722 p_spu->i_start = p_block->i_pts;
723 p_spu->i_stop = p_block->i_pts + p_block->i_length;
724 p_spu->b_ephemer = (p_block->i_length == 0);
725 p_spu->b_absolute = VLC_FALSE;
726 dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts/100000, (long int)p_block->i_length/100000));
728 block_Release( p_block );
734 p_dec->pf_spu_buffer_del( p_dec, p_spu );
738 block_Release( p_block );