/***************************************************************************** * telx.c : Minimalistic Teletext subtitles decoder ***************************************************************************** * Copyright (C) 2007 Vincent Penne * Some code converted from ProjectX java dvb decoder (c) 2001-2005 by dvb.matt * $Id: 95fa9dafd09550736ccb6049c6f306262311ac78 $ * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************/ /***************************************************************************** * * information on teletext format can be found here : * http://pdc.ro.nu/teletext.html * *****************************************************************************/ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #include #include /* #define TELX_DEBUG */ #ifdef TELX_DEBUG # define dbg( a ) msg_Dbg a #else # define dbg( a ) #endif /***************************************************************************** * Module descriptor. *****************************************************************************/ static int Open ( vlc_object_t * ); static void Close( vlc_object_t * ); static subpicture_t *Decode( decoder_t *, block_t ** ); #define OVERRIDE_PAGE_TEXT N_("Override page") #define OVERRIDE_PAGE_LONGTEXT N_("Override the indicated page, try this if " \ "your subtitles don't appear (-1 = autodetect from TS, " \ "0 = autodetect from teletext, " \ ">0 = actual page number, usually 888 or 889).") #define IGNORE_SUB_FLAG_TEXT N_("Ignore subtitle flag") #define IGNORE_SUB_FLAG_LONGTEXT N_("Ignore the subtitle flag, try this if " \ "your subtitles don't appear.") #define FRENCH_WORKAROUND_TEXT N_("Workaround for France") #define FRENCH_WORKAROUND_LONGTEXT N_("Some French channels do not flag " \ "their subtitling pages correctly due to a historical " \ "interpretation mistake. Try using this wrong interpretation if " \ "your subtitles don't appear.") vlc_module_begin () set_description( N_("Teletext subtitles decoder") ) set_shortname( "Teletext" ) set_capability( "decoder", 50 ) set_category( CAT_INPUT ) set_subcategory( SUBCAT_INPUT_SCODEC ) set_callbacks( Open, Close ) add_integer( "telx-override-page", -1, OVERRIDE_PAGE_TEXT, OVERRIDE_PAGE_LONGTEXT, true ) add_bool( "telx-ignore-subtitle-flag", false, IGNORE_SUB_FLAG_TEXT, IGNORE_SUB_FLAG_LONGTEXT, true ) add_bool( "telx-french-workaround", false, FRENCH_WORKAROUND_TEXT, FRENCH_WORKAROUND_LONGTEXT, true ) vlc_module_end () /**************************************************************************** * Local structures ****************************************************************************/ struct decoder_sys_t { int i_align; bool b_is_subtitle[9]; char ppsz_lines[32][128]; char psz_prev_text[512]; mtime_t prev_pts; int i_page[9]; bool b_erase[9]; const uint16_t * pi_active_national_set[9]; int i_wanted_page, i_wanted_magazine; bool b_ignore_sub_flag; }; /**************************************************************************** * Local data ****************************************************************************/ /* * My doc only mentions 13 national characters, but experiments show there * are more, in france for example I already found two more (0x9 and 0xb). * * Conversion is in this order : * * 0x23 0x24 0x40 0x5b 0x5c 0x5d 0x5e 0x5f 0x60 0x7b 0x7c 0x7d 0x7e * (these are the standard ones) * 0x08 0x09 0x0a 0x0b 0x0c 0x0d (apparently a control character) 0x0e 0x0f */ static const uint16_t ppi_national_subsets[][20] = { { 0x00a3, 0x0024, 0x0040, 0x00ab, 0x00bd, 0x00bb, 0x005e, 0x0023, 0x002d, 0x00bc, 0x00a6, 0x00be, 0x00f7 }, /* english ,000 */ { 0x00e9, 0x00ef, 0x00e0, 0x00eb, 0x00ea, 0x00f9, 0x00ee, 0x0023, 0x00e8, 0x00e2, 0x00f4, 0x00fb, 0x00e7, 0, 0x00eb, 0, 0x00ef }, /* french ,001 */ { 0x0023, 0x00a4, 0x00c9, 0x00c4, 0x00d6, 0x00c5, 0x00dc, 0x005f, 0x00e9, 0x00e4, 0x00f6, 0x00e5, 0x00fc }, /* swedish,finnish,hungarian ,010 */ { 0x0023, 0x016f, 0x010d, 0x0165, 0x017e, 0x00fd, 0x00ed, 0x0159, 0x00e9, 0x00e1, 0x011b, 0x00fa, 0x0161 }, /* czech,slovak ,011 */ { 0x0023, 0x0024, 0x00a7, 0x00c4, 0x00d6, 0x00dc, 0x005e, 0x005f, 0x00b0, 0x00e4, 0x00f6, 0x00fc, 0x00df }, /* german ,100 */ { 0x00e7, 0x0024, 0x00a1, 0x00e1, 0x00e9, 0x00ed, 0x00f3, 0x00fa, 0x00bf, 0x00fc, 0x00f1, 0x00e8, 0x00e0 }, /* portuguese,spanish ,101 */ { 0x00a3, 0x0024, 0x00e9, 0x00b0, 0x00e7, 0x00bb, 0x005e, 0x0023, 0x00f9, 0x00e0, 0x00f2, 0x00e8, 0x00ec }, /* italian ,110 */ { 0x0023, 0x00a4, 0x0162, 0x00c2, 0x015e, 0x0102, 0x00ce, 0x0131, 0x0163, 0x00e2, 0x015f, 0x0103, 0x00ee }, /* rumanian ,111 */ /* I have these tables too, but I don't know how they can be triggered */ { 0x0023, 0x0024, 0x0160, 0x0117, 0x0119, 0x017d, 0x010d, 0x016b, 0x0161, 0x0105, 0x0173, 0x017e, 0x012f }, /* lettish,lithuanian ,1000 */ { 0x0023, 0x0144, 0x0105, 0x005a, 0x015a, 0x0141, 0x0107, 0x00f3, 0x0119, 0x017c, 0x015b, 0x0142, 0x017a }, /* polish, 1001 */ { 0x0023, 0x00cb, 0x010c, 0x0106, 0x017d, 0x0110, 0x0160, 0x00eb, 0x010d, 0x0107, 0x017e, 0x0111, 0x0161 }, /* serbian,croatian,slovenian, 1010 */ { 0x0023, 0x00f5, 0x0160, 0x00c4, 0x00d6, 0x017e, 0x00dc, 0x00d5, 0x0161, 0x00e4, 0x00f6, 0x017e, 0x00fc }, /* estonian ,1011 */ { 0x0054, 0x011f, 0x0130, 0x015e, 0x00d6, 0x00c7, 0x00dc, 0x011e, 0x0131, 0x015f, 0x00f6, 0x00e7, 0x00fc }, /* turkish ,1100 */ }; /***************************************************************************** * Open: probe the decoder and return score ***************************************************************************** * Tries to launch a decoder and return score so that the interface is able * to chose. *****************************************************************************/ static int Open( vlc_object_t *p_this ) { decoder_t *p_dec = (decoder_t *) p_this; decoder_sys_t *p_sys = NULL; int i_val; if( p_dec->fmt_in.i_codec != VLC_CODEC_TELETEXT) { return VLC_EGENERIC; } p_dec->pf_decode_sub = Decode; p_sys = p_dec->p_sys = calloc( 1, sizeof(*p_sys) ); if( p_sys == NULL ) return VLC_ENOMEM; p_dec->fmt_out.i_cat = SPU_ES; p_dec->fmt_out.i_codec = 0; p_sys->i_align = 0; for ( int i = 0; i < 9; i++ ) p_sys->pi_active_national_set[i] = ppi_national_subsets[1]; i_val = var_CreateGetInteger( p_dec, "telx-override-page" ); if( i_val == -1 && p_dec->fmt_in.subs.teletext.i_magazine != -1 && ( p_dec->fmt_in.subs.teletext.i_magazine != 1 || p_dec->fmt_in.subs.teletext.i_page != 0 ) ) /* ignore if TS demux wants page 100 (unlikely to be sub) */ { bool b_val; p_sys->i_wanted_magazine = p_dec->fmt_in.subs.teletext.i_magazine; p_sys->i_wanted_page = p_dec->fmt_in.subs.teletext.i_page; b_val = var_CreateGetBool( p_dec, "telx-french-workaround" ); if( p_sys->i_wanted_page < 100 && (b_val || (p_sys->i_wanted_page % 16) >= 10)) { /* See http://www.nada.kth.se/~ragge/vdr/ttxtsubs/TROUBLESHOOTING.txt * paragraph about French channels - they mix up decimal and * hexadecimal */ p_sys->i_wanted_page = (p_sys->i_wanted_page / 10) * 16 + (p_sys->i_wanted_page % 10); } } else if( i_val <= 0 ) { p_sys->i_wanted_magazine = -1; p_sys->i_wanted_page = -1; } else { p_sys->i_wanted_magazine = i_val / 100; p_sys->i_wanted_page = (((i_val % 100) / 10) << 4) |((i_val % 100) % 10); } p_sys->b_ignore_sub_flag = var_CreateGetBool( p_dec, "telx-ignore-subtitle-flag" ); msg_Dbg( p_dec, "starting telx on magazine %d page %02x flag %d", p_sys->i_wanted_magazine, p_sys->i_wanted_page, p_sys->b_ignore_sub_flag ); return VLC_SUCCESS; /* error: */ /* if (p_sys) { */ /* free(p_sys); */ /* p_sys = NULL; */ /* } */ /* return VLC_EGENERIC; */ } /***************************************************************************** * Close: *****************************************************************************/ static void Close( vlc_object_t *p_this ) { decoder_t *p_dec = (decoder_t*) p_this; decoder_sys_t *p_sys = p_dec->p_sys; free( p_sys ); } /************************** * change bits endianness * **************************/ static uint8_t bytereverse( int n ) { n = (((n >> 1) & 0x55) | ((n << 1) & 0xaa)); n = (((n >> 2) & 0x33) | ((n << 2) & 0xcc)); n = (((n >> 4) & 0x0f) | ((n << 4) & 0xf0)); return n; } static int hamming_8_4( int a ) { switch (a) { case 0xA8: return 0; case 0x0B: return 1; case 0x26: return 2; case 0x85: return 3; case 0x92: return 4; case 0x31: return 5; case 0x1C: return 6; case 0xBF: return 7; case 0x40: return 8; case 0xE3: return 9; case 0xCE: return 10; case 0x6D: return 11; case 0x7A: return 12; case 0xD9: return 13; case 0xF4: return 14; case 0x57: return 15; default: return -1; // decoding error , not yet corrected } } // utc-2 --> utf-8 // this is not a general function, but it's enough for what we do here // the result buffer need to be at least 4 bytes long static void to_utf8( char * res, uint16_t ch ) { if( ch >= 0x80 ) { if( ch >= 0x800 ) { res[0] = (ch >> 12) | 0xE0; res[1] = ((ch >> 6) & 0x3F) | 0x80; res[2] = (ch & 0x3F) | 0x80; res[3] = 0; } else { res[0] = (ch >> 6) | 0xC0; res[1] = (ch & 0x3F) | 0x80; res[2] = 0; } } else { res[0] = ch; res[1] = 0; } } static void decode_string( char * res, int res_len, decoder_sys_t *p_sys, int magazine, uint8_t * packet, int len ) { char utf8[7]; char * pt = res; int i; for ( i = 0; i < len; i++ ) { int in = bytereverse( packet[i] ) & 0x7f; uint16_t out = 32; size_t l; switch ( in ) { /* special national characters */ case 0x23: out = p_sys->pi_active_national_set[magazine][0]; break; case 0x24: out = p_sys->pi_active_national_set[magazine][1]; break; case 0x40: out = p_sys->pi_active_national_set[magazine][2]; break; case 0x5b: out = p_sys->pi_active_national_set[magazine][3]; break; case 0x5c: out = p_sys->pi_active_national_set[magazine][4]; break; case 0x5d: out = p_sys->pi_active_national_set[magazine][5]; break; case 0x5e: out = p_sys->pi_active_national_set[magazine][6]; break; case 0x5f: out = p_sys->pi_active_national_set[magazine][7]; break; case 0x60: out = p_sys->pi_active_national_set[magazine][8]; break; case 0x7b: out = p_sys->pi_active_national_set[magazine][9]; break; case 0x7c: out = p_sys->pi_active_national_set[magazine][10]; break; case 0x7d: out = p_sys->pi_active_national_set[magazine][11]; break; case 0x7e: out = p_sys->pi_active_national_set[magazine][12]; break; /* some special control characters (empirical) */ case 0x0d: /* apparently this starts a sequence that ends with 0xb 0xb */ while ( i + 1 < len && (bytereverse( packet[i+1] ) & 0x7f) != 0x0b ) i++; i += 2; break; /* goto skip; */ default: /* non documented national range 0x08 - 0x0f */ if ( in >= 0x08 && in <= 0x0f ) { out = p_sys->pi_active_national_set[magazine][13 + in - 8]; break; } /* normal ascii */ if ( in > 32 && in < 0x7f ) out = in; } /* handle undefined national characters */ if ( out == 0 ) out = 32; /* convert to utf-8 */ to_utf8( utf8, out ); l = strlen( utf8 ); if ( pt + l < res + res_len - 1 ) { strcpy(pt, utf8); pt += l; } /* skip: ; */ } /* end: */ *pt++ = 0; } /***************************************************************************** * Decode: *****************************************************************************/ static subpicture_t *Decode( decoder_t *p_dec, block_t **pp_block ) { decoder_sys_t *p_sys = p_dec->p_sys; block_t *p_block; subpicture_t *p_spu = NULL; video_format_t fmt; /* int erase = 0; */ int len, offset; #if 0 int i_wanted_magazine = i_conf_wanted_page / 100; int i_wanted_page = 0x10 * ((i_conf_wanted_page % 100) / 10) | (i_conf_wanted_page % 10); #endif bool b_update = false; char psz_text[512], *pt = psz_text; char psz_line[256]; int i, total; if( pp_block == NULL || *pp_block == NULL ) return NULL; p_block = *pp_block; *pp_block = NULL; dbg((p_dec, "start of telx packet with header %2x\n", * (uint8_t *) p_block->p_buffer)); len = p_block->i_buffer; for ( offset = 1; offset + 46 <= len; offset += 46 ) { uint8_t * packet = (uint8_t *) p_block->p_buffer+offset; // int vbi = ((0x20 & packet[2]) != 0 ? 0 : 313) + (0x1F & packet[2]); // dbg((p_dec, "vbi %d header %02x %02x %02x\n", vbi, packet[0], packet[1], packet[2])); if ( packet[0] == 0xFF ) continue; /* if (packet[1] != 0x2C) { */ /* printf("wrong header\n"); */ /* //goto error; */ /* continue; */ /* } */ int mpag = (hamming_8_4( packet[4] ) << 4) | hamming_8_4( packet[5] ); int row, magazine; if ( mpag < 0 ) { /* decode error */ dbg((p_dec, "mpag hamming error\n")); continue; } row = 0xFF & bytereverse(mpag); magazine = (7 & row) == 0 ? 8 : (7 & row); row >>= 3; if ( p_sys->i_wanted_page != -1 && magazine != p_sys->i_wanted_magazine ) continue; if ( row == 0 ) { /* row 0 : flags and header line */ int flag = 0; int a; for ( a = 0; a < 6; a++ ) { flag |= (0xF & (bytereverse( hamming_8_4(packet[8 + a]) ) >> 4)) << (a * 4); } /* if (!p_sys->b_ignore_sub_flag && !(1 & flag>>15)) */ /* continue; */ p_sys->i_page[magazine] = (0xF0 & bytereverse( hamming_8_4(packet[7]) )) | (0xF & (bytereverse( hamming_8_4(packet[6]) ) >> 4) ); decode_string( psz_line, sizeof(psz_line), p_sys, magazine, packet + 14, 40 - 14 ); dbg((p_dec, "mag %d flags %x page %x character set %d subtitles %d", magazine, flag, p_sys->i_page[magazine], 7 & flag>>21, 1 & flag>>15, psz_line)); p_sys->pi_active_national_set[magazine] = ppi_national_subsets[7 & (flag >> 21)]; p_sys->b_is_subtitle[magazine] = p_sys->b_ignore_sub_flag || ( (1 & (flag >> 15)) && (1 & (flag>>16)) ); dbg(( p_dec, "FLAGS%s%s%s%s%s%s%s mag_ser %d", (1 & (flag>>14))? " news" : "", (1 & (flag>>15))? " subtitle" : "", (1 & (flag>>7))? " erase" : "", (1 & (flag>>16))? " suppressed_head" : "", (1 & (flag>>17))? " update" : "", (1 & (flag>>18))? " interrupt" : "", (1 & (flag>>19))? " inhibit" : "", (1 & (flag>>20)) )); if ( (p_sys->i_wanted_page != -1 && p_sys->i_page[magazine] != p_sys->i_wanted_page) || !p_sys->b_is_subtitle[magazine] ) continue; p_sys->b_erase[magazine] = (1 & (flag >> 7)); dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts, (long int)(p_sys->prev_pts+1500000))); /* kludge here : * we ignore the erase flag if it happens less than 1.5 seconds * before last caption * TODO make this time configurable * UPDATE the kludge seems to be no more necessary * so it's commented out*/ if ( /*p_block->i_pts > p_sys->prev_pts + 1500000 && */ p_sys->b_erase[magazine] ) { int i; dbg((p_dec, "ERASE !\n")); p_sys->b_erase[magazine] = 0; for ( i = 1; i < 32; i++ ) { if ( !p_sys->ppsz_lines[i][0] ) continue; /* b_update = true; */ p_sys->ppsz_lines[i][0] = 0; } } /* replace the row if it's different */ if ( strcmp(psz_line, p_sys->ppsz_lines[row]) ) { strncpy( p_sys->ppsz_lines[row], psz_line, sizeof(p_sys->ppsz_lines[row]) - 1); } b_update = true; } else if ( row < 24 ) { char * t; int i; /* row 1-23 : normal lines */ if ( (p_sys->i_wanted_page != -1 && p_sys->i_page[magazine] != p_sys->i_wanted_page) || !p_sys->b_is_subtitle[magazine] || (p_sys->i_wanted_page == -1 && p_sys->i_page[magazine] > 0x99) ) continue; decode_string( psz_line, sizeof(psz_line), p_sys, magazine, packet + 6, 40 ); t = psz_line; /* remove starting spaces */ while ( *t == 32 ) t++; /* remove trailing spaces */ for ( i = strlen(t) - 1; i >= 0 && t[i] == 32; i-- ); t[i + 1] = 0; /* replace the row if it's different */ if ( strcmp( t, p_sys->ppsz_lines[row] ) ) { strncpy( p_sys->ppsz_lines[row], t, sizeof(p_sys->ppsz_lines[row]) - 1 ); b_update = true; } if (t[0]) p_sys->prev_pts = p_block->i_pts; dbg((p_dec, "%d %d : ", magazine, row)); dbg((p_dec, "%s\n", t)); #ifdef TELX_DEBUG { char dbg[256]; dbg[0] = 0; for ( i = 0; i < 40; i++ ) { int in = bytereverse(packet[6 + i]) & 0x7f; sprintf(dbg + strlen(dbg), "%02x ", in); } dbg((p_dec, "%s\n", dbg)); dbg[0] = 0; for ( i = 0; i < 40; i++ ) { decode_string( psz_line, sizeof(psz_line), p_sys, magazine, packet + 6 + i, 1 ); sprintf( dbg + strlen(dbg), "%s ", psz_line ); } dbg((p_dec, "%s\n", dbg)); } #endif } else if ( row == 25 ) { /* row 25 : alternate header line */ if ( (p_sys->i_wanted_page != -1 && p_sys->i_page[magazine] != p_sys->i_wanted_page) || !p_sys->b_is_subtitle[magazine] ) continue; decode_string( psz_line, sizeof(psz_line), p_sys, magazine, packet + 6, 40 ); /* replace the row if it's different */ if ( strcmp( psz_line, p_sys->ppsz_lines[0] ) ) { strncpy( p_sys->ppsz_lines[0], psz_line, sizeof(p_sys->ppsz_lines[0]) - 1 ); /* b_update = true; */ } } /* else if (row == 26) { */ /* // row 26 : TV listings */ /* } else */ /* dbg((p_dec, "%d %d : %s\n", magazine, row, decode_string(p_sys, magazine, packet+6, 40))); */ } if ( !b_update ) goto error; total = 0; for ( i = 1; i < 24; i++ ) { size_t l = strlen( p_sys->ppsz_lines[i] ); if ( l > sizeof(psz_text) - total - 1 ) l = sizeof(psz_text) - total - 1; if ( l > 0 ) { memcpy( pt, p_sys->ppsz_lines[i], l ); total += l; pt += l; if ( sizeof(psz_text) - total - 1 > 0 ) { *pt++ = '\n'; total++; } } } *pt = 0; if ( !strcmp(psz_text, p_sys->psz_prev_text) ) goto error; dbg((p_dec, "UPDATE TELETEXT PICTURE\n")); assert( sizeof(p_sys->psz_prev_text) >= sizeof(psz_text) ); strcpy( p_sys->psz_prev_text, psz_text ); /* Create the subpicture unit */ p_spu = decoder_NewSubpicture( p_dec, NULL ); if( !p_spu ) { msg_Warn( p_dec, "can't get spu buffer" ); goto error; } /* Create a new subpicture region */ memset( &fmt, 0, sizeof(video_format_t) ); fmt.i_chroma = VLC_CODEC_TEXT; fmt.i_width = fmt.i_height = 0; fmt.i_x_offset = fmt.i_y_offset = 0; p_spu->p_region = subpicture_region_New( &fmt ); if( p_spu->p_region == NULL ) { msg_Err( p_dec, "cannot allocate SPU region" ); goto error; } /* Normal text subs, easy markup */ p_spu->p_region->i_align = SUBPICTURE_ALIGN_BOTTOM | p_sys->i_align; p_spu->p_region->i_x = p_sys->i_align ? 20 : 0; p_spu->p_region->i_y = 10; p_spu->p_region->psz_text = strdup(psz_text); p_spu->i_start = p_block->i_pts; p_spu->i_stop = p_block->i_pts + p_block->i_length; p_spu->b_ephemer = (p_block->i_length == 0); p_spu->b_absolute = false; dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts/100000, (long int)p_block->i_length/100000)); block_Release( p_block ); return p_spu; error: if ( p_spu != NULL ) { decoder_DeleteSubpicture( p_dec, p_spu ); p_spu = NULL; } block_Release( p_block ); return NULL; }