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 trunk version
35 // considere this hack to be temporary, but I need it so that I can maintain my patch
36 // 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"
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_capability( "decoder", 50 );
90 set_category( CAT_INPUT );
91 set_subcategory( SUBCAT_INPUT_SCODEC );
92 set_callbacks( Open, Close );
94 add_integer( "telx-page", 0, telx_conf_cb, PAGE_TEXT, PAGE_LONGTEXT,
96 add_bool( "telx-ignore-subtitle-flag", 0, telx_conf_cb, IGNORE_SUB_FLAG_TEXT, IGNORE_SUB_FLAG_LONGTEXT,
101 /****************************************************************************
103 ****************************************************************************/
114 uint16_t * active_national_set[9];
117 /****************************************************************************
119 ****************************************************************************/
121 static int i_wanted_page = 0; // default 0 = all pages
122 static vlc_bool_t b_ignore_sub_flag = 0;
125 // my doc only mentions 13 national characters, but experiments show there
126 // are more, in france for example I already found two more (0x9 and 0xb)
128 // convertion is in this order :
130 // 0x23 0x24 0x40 0x5b 0x5c 0x5d 0x5e 0x5f 0x60 0x7b 0x7c 0x7d 0x7e (these are the standard ones)
131 // 0x08 0x09 0x0a 0x0b 0x0c 0x0d (apparently a control character) 0x0e 0x0f
134 static uint16_t national_subsets[][20] = {
135 { 0x00a3, 0x0024, 0x0040, 0x00ab, 0x00bd, 0x00bb, 0x005e, 0x0023,
136 0x002d, 0x00bc, 0x00a6, 0x00be, 0x00f7 }, // english ,000
138 { 0x00e9, 0x00ef, 0x00e0, 0x00eb, 0x00ea, 0x00f9, 0x00ee, 0x0023,
139 0x00e8, 0x00e2, 0x00f4, 0x00fb, 0x00e7, 0, 0x00eb, 0, 0x00ef }, // french ,001
141 { 0x0023, 0x00a4, 0x00c9, 0x00c4, 0x00d6, 0x00c5, 0x00dc, 0x005f,
142 0x00e9, 0x00e4, 0x00f6, 0x00e5, 0x00fc }, // swedish,finnish,hungarian ,010
144 { 0x0023, 0x016f, 0x010d, 0x0165, 0x017e, 0x00fd, 0x00ed, 0x0159,
145 0x00e9, 0x00e1, 0x0115, 0x00fa, 0x0161 }, // czech,slovak ,011
147 { 0x0023, 0x0024, 0x00a7, 0x00c4, 0x00d6, 0x00dc, 0x005e, 0x005f,
148 0x00b0, 0x00e4, 0x00f6, 0x00fc, 0x00df }, // german ,100
150 { 0x00e7, 0x0024, 0x00a1, 0x00e1, 0x00e9, 0x00ed, 0x00f3, 0x00fa,
151 0x00bf, 0x00fc, 0x00f1, 0x00e8, 0x00e0 }, // portuguese,spanish ,101
153 { 0x00a3, 0x0024, 0x00e9, 0x00b0, 0x00e7, 0x00bb, 0x005e, 0x0023,
154 0x00f9, 0x00e0, 0x00f2, 0x00e8, 0x00ec }, // italian ,110
156 { 0x0023, 0x00a4, 0x0162, 0x00c2, 0x015e, 0x0102, 0x00ce, 0x0131,
157 0x0163, 0x00e2, 0x015f, 0x0103, 0x00ee }, // rumanian ,111
159 { 0x0023, 0x0024, 0x0160, 0x0117, 0x0119, 0x017d, 0x010d, 0x016b,
160 0x0161, 0x0105, 0x0173, 0x017e, 0x012f }, // lettish,lithuanian ,1000
162 { 0x0023, 0x0144, 0x0105, 0x005a, 0x015a, 0x0141, 0x0107, 0x00f3,
163 0x0119, 0x017c, 0x015b, 0x0142, 0x017a }, // polish, 1001
165 { 0x0023, 0x00cb, 0x010c, 0x0106, 0x017d, 0x0110, 0x0160, 0x00eb,
166 0x010d, 0x0107, 0x017e, 0x0111, 0x0161 }, // serbian,croatian,slovenian, 1010
168 { 0x0023, 0x00f5, 0x0160, 0x00c4, 0x00d6, 0x017e, 0x00dc, 0x00d5,
169 0x0161, 0x00e4, 0x00f6, 0x017e, 0x00fc }, // estonian ,1011
171 { 0x0054, 0x011f, 0x0130, 0x015e, 0x00d6, 0x00c7, 0x00dc, 0x011e,
172 0x0131, 0x015f, 0x00f6, 0x00e7, 0x00fc }, // turkish ,1100
176 /*****************************************************************************
177 * Open: probe the decoder and return score
178 *****************************************************************************
179 * Tries to launch a decoder and return score so that the interface is able
181 *****************************************************************************/
182 static int Open( vlc_object_t *p_this )
184 decoder_t *p_dec = (decoder_t *) p_this;
185 decoder_sys_t *p_sys = NULL;
189 if( p_dec->fmt_in.i_codec != VLC_FOURCC('t','e','l','x'))
194 p_dec->pf_decode_sub = Decode;
195 p_sys = p_dec->p_sys = malloc( sizeof(decoder_sys_t) );
197 msg_Err( p_dec, "out of memory" );
201 memset( p_sys, 0, sizeof(decoder_sys_t) );
205 p_sys->active_national_set[i] = national_subsets[1];
207 var_Create( p_dec, "telx-page", VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
208 var_Get( p_dec, "telx-page", &val );
209 i_wanted_page = val.i_int;
211 var_Create( p_dec, "telx-ignore-subtitle-flag", VLC_VAR_BOOL | VLC_VAR_DOINHERIT );
212 var_Get( p_dec, "telx-ignore-subtitle-flag", &val );
213 b_ignore_sub_flag = val.b_bool;
222 /* return VLC_EGENERIC; */
225 /*****************************************************************************
227 *****************************************************************************/
228 static int telx_conf_cb ( vlc_object_t * obj, /* variable's object */
229 char const * name, /* variable name */
230 vlc_value_t oldv, /* old value */
231 vlc_value_t newv, /* new value */
232 void * data) /* callback data */
234 if (!strcmp(name, "telx-page")) {
235 i_wanted_page = newv.i_int;
236 dbg((obj, "display teletext page changed to %d\n", i_wanted_page));
237 } else if (!strcmp(name, "telx-ignore-subtitle-flag")) {
238 b_ignore_sub_flag = newv.b_bool;
239 dbg((obj, "ignore sub flag changed to %d\n", (int) b_ignore_sub_flag));
246 /*****************************************************************************
248 *****************************************************************************/
249 static void Close( vlc_object_t *p_this )
251 decoder_t *p_dec = (decoder_t*) p_this;
252 decoder_sys_t *p_sys = p_dec->p_sys;
257 /**************************
258 * change bits endianness *
259 **************************/
260 static uint8_t bytereverse(int n)
262 n = (((n >> 1) & 0x55) | ((n << 1) & 0xaa));
263 n = (((n >> 2) & 0x33) | ((n << 2) & 0xcc));
264 n = (((n >> 4) & 0x0f) | ((n << 4) & 0xf0));
268 static int hamming_8_4(int a)
304 return -1; // decoding error , not yet corrected
309 // this is not a general function, but it's enough for what we do here
310 static void to_utf8(char * res, uint16_t ch)
314 res[0]=(ch>>12)|0xE0;
315 res[1]=((ch>>6)&0x3F)|0x80;
316 res[2]=(ch&0x3F)|0x80;
320 res[1]=(ch&0x3F)|0x80;
329 static void decode_string(char * res, int res_len,
330 decoder_sys_t *p_sys, int magazine,
331 uint8_t * packet, int len)
337 for (i=0; i<len; i++) {
338 int in = bytereverse(packet[i])&0x7f;
341 switch (in) { // special national characters
343 out = p_sys->active_national_set[magazine][0];
346 out = p_sys->active_national_set[magazine][1];
349 out = p_sys->active_national_set[magazine][2];
352 out = p_sys->active_national_set[magazine][3];
355 out = p_sys->active_national_set[magazine][4];
358 out = p_sys->active_national_set[magazine][5];
361 out = p_sys->active_national_set[magazine][6];
364 out = p_sys->active_national_set[magazine][7];
367 out = p_sys->active_national_set[magazine][8];
370 out = p_sys->active_national_set[magazine][9];
373 out = p_sys->active_national_set[magazine][10];
376 out = p_sys->active_national_set[magazine][11];
379 out = p_sys->active_national_set[magazine][12];
382 // some special control characters (empirical)
384 // apparently this starts a sequence that ends with 0xb 0xb
385 while (i+1<len && (bytereverse(packet[i+1])&0x7f) != 0x0b) i++;
391 // non documented national range 0x08 - 0x0f
392 if (in >= 0x08 && in <= 0x0f) {
393 out = p_sys->active_national_set[magazine][13 + in - 8];
398 if (in > 32 && in < 0x7f)
402 // handle undefined national characters
403 if (out == 0) out = 32;
408 if (pt + l < res + res_len - 1) {
419 /*****************************************************************************
421 *****************************************************************************/
422 static subpicture_t *Decode( decoder_t *p_dec, block_t **pp_block )
424 decoder_sys_t *p_sys = p_dec->p_sys;
426 subpicture_t *p_spu = NULL;
431 int wanted_magazine = i_wanted_page/100;
432 int wanted_page = 0x10*((i_wanted_page%100)/10) | (i_wanted_page%10);
434 char text[512], * pt = text;
438 if( pp_block == NULL || *pp_block == NULL ) return NULL;
442 len = p_block->i_buffer;
443 for (offset = 1; offset+46 <= len ; offset += 46) {
444 uint8_t * packet = (uint8_t *) p_block->p_buffer+offset;
446 //dbg((p_dec, "header %02x %02x %02x\n", packet[0], packet[1], packet[2]));
447 /* if (packet[1] != 0x2C) { */
448 /* printf("wrong header\n"); */
453 int mpag = (hamming_8_4(packet[4]))<<4 | hamming_8_4(packet[5]);
455 if (mpag < 0) { // decode error
456 dbg((p_dec, "mpag hamming error\n"));
460 row = 0xFF & bytereverse(mpag);
461 magazine = (7 & row) == 0 ? 8 : (7 & row);
464 if (i_wanted_page && magazine != wanted_magazine) continue;
467 // row 0 : flags and header line
472 for (a = 0; a < 6; a++)
473 flag |= (0xF & bytereverse(hamming_8_4(packet[8+a]) )>>4 ) <<(a*4);
475 dbg((p_dec, "mag %d flags %x page %x character set %d subtitles %d\n%s\n", magazine, flag,
477 (0xF0 & bytereverse(hamming_8_4(packet[7]) )) |
478 (0xF & bytereverse(hamming_8_4(packet[6]) )>>4 ),
479 7 & flag>>21, 1 & flag>>15, t));
481 /* if (!b_ignore_sub_flag && !(1 & flag>>15)) */
484 p_sys->page = (0xF0 & bytereverse(hamming_8_4(packet[7]) )) |
485 (0xF & bytereverse(hamming_8_4(packet[6]) )>>4 );
487 decode_string(line, sizeof(line), p_sys, magazine, packet+14, 40-14);
489 p_sys->active_national_set[magazine] = national_subsets[7 & flag>>21];
491 p_sys->is_subtitle[magazine] = b_ignore_sub_flag || (1 & flag>>15);
493 if ((i_wanted_page && p_sys->page != wanted_page) || !p_sys->is_subtitle[magazine])
496 p_sys->erase[magazine] = (1 & flag>>7);
498 dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts, (long int)(p_sys->prev_pts+1500000)));
500 // we ignore the erase flag if it happens less than 1.5 secondes before last caption
501 // TODO make this time configurable
502 if (p_block->i_pts > p_sys->prev_pts + 1500000 &&
503 p_sys->erase[magazine]) {
506 dbg((p_dec, "ERASE !\n"));
508 p_sys->erase[magazine] = 0;
509 for (i=1; i<32; i++) {
510 if (!p_sys->lines[i][0]) continue;
512 p_sys->lines[i][0] = 0;
516 // replace the row if it's different
517 if (strcmp(line, p_sys->lines[row])) {
518 strncpy(p_sys->lines[row], line, sizeof(p_sys->lines[row])-1);
522 } else if (row < 24) {
525 // row 1-23 : normal lines
527 if ((i_wanted_page && p_sys->page != wanted_page) || !p_sys->is_subtitle[magazine])
530 decode_string(line, sizeof(line), p_sys, magazine, packet+6, 40);
532 // remove starting spaces
533 while (*t == 32) t++;
534 // remove trailing spaces
535 for (i=strlen(t)-1; i>=0 && t[i] == 32; i--);
538 // replace the row if it's different
539 if (strcmp(t, p_sys->lines[row])) {
540 strncpy(p_sys->lines[row], t, sizeof(p_sys->lines[row])-1);
545 p_sys->prev_pts = p_block->i_pts;
547 dbg((p_dec, "%d %d : ", magazine, row));
548 dbg((p_dec, "%s\n", t));
554 for (i=0; i<40; i++) {
555 int in = bytereverse(packet[6+i]) & 0x7f;
556 sprintf(dbg+strlen(dbg), "%02x ", in);
558 dbg((p_dec, "%s\n", dbg));
560 for (i=0; i<40; i++) {
561 decode_string(line, sizeof(line), p_sys, magazine, packet+6+i, 1);
562 sprintf(dbg+strlen(dbg), "%s ", line);
564 dbg((p_dec, "%s\n", dbg));
568 } else if (row == 25) {
569 // row 25 : alternate header line
570 if ((i_wanted_page && p_sys->page != wanted_page) || !p_sys->is_subtitle[magazine])
573 decode_string(line, sizeof(line), p_sys, magazine, packet+6, 40);
574 // replace the row if it's different
575 if (strcmp(line, p_sys->lines[0])) {
576 strncpy(p_sys->lines[0], line, sizeof(p_sys->lines[0])-1);
580 /* else if (row == 26) { */
581 /* // row 26 : TV listings */
583 /* dbg((p_dec, "%d %d : %s\n", magazine, row, decode_string(p_sys, magazine, packet+6, 40))); */
590 for (i=1; i<24; i++) {
591 size_t l = strlen(p_sys->lines[i]);
592 if (l > sizeof(text)-total-1)
593 l = sizeof(text)-total-1;
595 memcpy(pt, p_sys->lines[i], l);
598 if (sizeof(text)-total-1 > 0) {
606 if (!strcmp(text, p_sys->prev_text))
609 dbg((p_dec, "UPDATE TELETEXT PICTURE\n"));
611 assert(sizeof(p_sys->prev_text)>=sizeof(text));
612 strcpy(p_sys->prev_text, text);
614 /* Create the subpicture unit */
615 p_spu = p_dec->pf_spu_buffer_new( p_dec );
617 msg_Warn( p_dec, "can't get spu buffer" );
621 p_spu->b_pausable = VLC_TRUE;
623 /* Create a new subpicture region */
624 memset( &fmt, 0, sizeof(video_format_t) );
625 fmt.i_chroma = VLC_FOURCC('T','E','X','T');
627 fmt.i_width = fmt.i_height = 0;
628 fmt.i_x_offset = fmt.i_y_offset = 0;
629 p_spu->p_region = p_spu->pf_create_region( VLC_OBJECT(p_dec), &fmt );
630 if( !p_spu->p_region ) {
631 msg_Err( p_dec, "cannot allocate SPU region" );
635 /* Normal text subs, easy markup */
636 p_spu->i_flags = SUBPICTURE_ALIGN_BOTTOM | p_sys->i_align;
637 p_spu->i_x = p_sys->i_align ? 20 : 0;
640 p_spu->p_region->psz_text = strdup(text);
641 p_spu->i_start = p_block->i_pts;
642 p_spu->i_stop = p_block->i_pts + p_block->i_length;
643 p_spu->b_ephemer = (p_block->i_length == 0);
644 p_spu->b_absolute = VLC_FALSE;
645 dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts/100000, (long int)p_block->i_length/100000));
650 if (error && p_spu) {
651 p_dec->pf_spu_buffer_del( p_dec, p_spu );
655 block_Release( p_block );