1 /*****************************************************************************
2 * langfromtelx.c: dynamic language setting from telx
3 *****************************************************************************
4 * Copyright © 2009-2011 VLC authors and VideoLAN
7 * Authors: Christophe Massiot <massiot@via.ecp.fr>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU Lesser General Public License as published by
11 * the Free Software Foundation; either version 2.1 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public License
20 * along with this program; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
33 #include <vlc_common.h>
34 #include <vlc_plugin.h>
36 #include <vlc_block.h>
38 /*****************************************************************************
40 *****************************************************************************/
42 #define ID_TEXT N_("Elementary Stream ID")
43 #define ID_LONGTEXT N_( \
44 "Specify an identifier integer for this elementary stream to change" )
45 #define MAGAZINE_TEXT N_("Magazine")
46 #define MAGAZINE_LONGTEXT N_( \
47 "Specify the magazine containing the language page" )
48 #define PAGE_TEXT N_("Page")
49 #define PAGE_LONGTEXT N_( \
50 "Specify the page containing the language" )
51 #define ROW_TEXT N_("Row")
52 #define ROW_LONGTEXT N_( \
53 "Specify the row containing the language" )
55 static int Open ( vlc_object_t * );
56 static void Close ( vlc_object_t * );
58 #define SOUT_CFG_PREFIX "sout-langfromtelx-"
61 set_shortname( N_("Lang From Telx"))
62 set_description( N_("Dynamic language setting from teletext"))
63 set_capability( "sout stream", 50 )
64 add_shortcut( "langfromtelx" )
65 set_category( CAT_SOUT )
66 set_subcategory( SUBCAT_SOUT_STREAM )
68 set_callbacks( Open, Close )
69 add_integer( SOUT_CFG_PREFIX "id", 0, ID_TEXT, ID_LONGTEXT,
71 add_integer( SOUT_CFG_PREFIX "magazine", 7, MAGAZINE_TEXT,
72 MAGAZINE_LONGTEXT, false )
73 add_integer( SOUT_CFG_PREFIX "page", 0x99, PAGE_TEXT, PAGE_LONGTEXT,
75 add_integer( SOUT_CFG_PREFIX "row", 1, ROW_TEXT, ROW_LONGTEXT,
80 /*****************************************************************************
82 *****************************************************************************/
83 static const char *ppsz_sout_options[] = {
84 "id", "magazine", "page", "row", NULL
87 static sout_stream_id_t *Add ( sout_stream_t *, es_format_t * );
88 static int Del ( sout_stream_t *, sout_stream_id_t * );
89 static int Send ( sout_stream_t *, sout_stream_id_t *, block_t * );
91 struct sout_stream_sys_t
93 int i_id, i_magazine, i_page, i_row;
94 char *psz_language, *psz_old_language;
95 sout_stream_id_t *p_id, *p_telx;
99 /*****************************************************************************
101 *****************************************************************************/
102 static int Open( vlc_object_t *p_this )
104 sout_stream_t *p_stream = (sout_stream_t*)p_this;
105 sout_stream_sys_t *p_sys;
107 if( !p_stream->p_next )
109 msg_Err( p_stream, "cannot create chain" );
113 p_sys = malloc( sizeof( sout_stream_sys_t ) );
114 if( unlikely( !p_sys ) )
117 config_ChainParse( p_stream, SOUT_CFG_PREFIX, ppsz_sout_options,
120 p_sys->i_id = var_GetInteger( p_stream, SOUT_CFG_PREFIX "id" );
121 p_sys->i_magazine = var_GetInteger( p_stream, SOUT_CFG_PREFIX "magazine" );
122 p_sys->i_page = var_GetInteger( p_stream, SOUT_CFG_PREFIX "page" );
123 p_sys->i_row = var_GetInteger( p_stream, SOUT_CFG_PREFIX "row" );
125 p_stream->pf_add = Add;
126 p_stream->pf_del = Del;
127 p_stream->pf_send = Send;
129 p_stream->p_sys = p_sys;
134 /*****************************************************************************
136 *****************************************************************************/
137 static void Close( vlc_object_t * p_this )
139 sout_stream_t *p_stream = (sout_stream_t*)p_this;
140 sout_stream_sys_t *p_sys = (sout_stream_sys_t *)p_stream->p_sys;
142 free( p_sys->psz_old_language );
146 static sout_stream_id_t * Add( sout_stream_t *p_stream, es_format_t *p_fmt )
148 sout_stream_sys_t *p_sys = (sout_stream_sys_t *)p_stream->p_sys;
150 if ( p_fmt->i_id == p_sys->i_id )
152 p_sys->psz_old_language = p_fmt->psz_language;
154 "changing language of ID %d (magazine %d page %x row %d)",
155 p_sys->i_id, p_sys->i_magazine, p_sys->i_page, p_sys->i_row );
156 p_sys->psz_language = p_fmt->psz_language = malloc(4);
157 if ( p_sys->psz_old_language != NULL )
158 strncpy( p_fmt->psz_language, p_sys->psz_old_language, 3 );
160 strcpy( p_fmt->psz_language, "unk" );
161 p_fmt->psz_language[3] = '\0';
163 p_sys->p_id = p_stream->p_next->pf_add( p_stream->p_next, p_fmt );
167 if ( p_fmt->i_codec == VLC_CODEC_TELETEXT )
169 p_sys->p_telx = p_stream->p_next->pf_add( p_stream->p_next, p_fmt );
170 return p_sys->p_telx;
173 return p_stream->p_next->pf_add( p_stream->p_next, p_fmt );
176 static int Del( sout_stream_t *p_stream, sout_stream_id_t *id )
178 sout_stream_sys_t *p_sys = (sout_stream_sys_t *)p_stream->p_sys;
180 if ( id == p_sys->p_id ) p_sys->p_id = NULL;
181 if ( id == p_sys->p_telx ) p_sys->p_telx = NULL;
183 return p_stream->p_next->pf_del( p_stream->p_next, id );
186 static void SetLanguage( sout_stream_t *p_stream, char *psz_language )
188 sout_stream_sys_t *p_sys = (sout_stream_sys_t *)p_stream->p_sys;
190 if ( strncmp( p_sys->psz_language, psz_language, 3 ) )
191 msg_Dbg( p_stream, "changing language to %s", psz_language );
193 strncpy( p_sys->psz_language, (const char *)psz_language, 3 );
196 /*****************************************************************************
198 *****************************************************************************/
199 static uint8_t bytereverse( int n )
201 n = (((n >> 1) & 0x55) | ((n << 1) & 0xaa));
202 n = (((n >> 2) & 0x33) | ((n << 2) & 0xcc));
203 n = (((n >> 4) & 0x0f) | ((n << 4) & 0xf0));
207 static int hamming_8_4( int a )
243 return -1; // decoding error , not yet corrected
247 static void decode_string( char *res, uint8_t *packet, int len )
249 for ( int i = 0; i < len; i++ )
250 res[i] = bytereverse( packet[i] ) & 0x7f;
255 static void HandleTelx( sout_stream_t *p_stream, block_t *p_block )
257 sout_stream_sys_t *p_sys = (sout_stream_sys_t *)p_stream->p_sys;
258 int len = p_block->i_buffer;
260 for ( int offset = 1; offset + 46 <= len; offset += 46 )
262 uint8_t * packet = (uint8_t *) p_block->p_buffer+offset;
263 if ( packet[0] == 0xFF )
266 int mpag = (hamming_8_4( packet[4] ) << 4) | hamming_8_4( packet[5] );
267 int i_row, i_magazine;
274 i_row = 0xFF & bytereverse(mpag);
275 i_magazine = (7 & i_row) == 0 ? 8 : (7 & i_row);
278 if ( i_magazine != p_sys->i_magazine )
283 /* row 0 : flags and header line */
284 p_sys->i_current_page =
285 (0xF0 & bytereverse( hamming_8_4(packet[7]) )) |
286 (0xF & (bytereverse( hamming_8_4(packet[6]) ) >> 4) );
288 if ( p_sys->i_current_page != p_sys->i_page ) continue;
289 if ( i_row == p_sys->i_row )
291 /* row 1-23 : normal lines */
293 decode_string( psz_line, packet + 6, 40 );
294 psz_line[0] = tolower(psz_line[0]);
295 psz_line[1] = tolower(psz_line[1]);
296 psz_line[2] = tolower(psz_line[2]);
298 SetLanguage( p_stream, psz_line );
303 /*****************************************************************************
305 *****************************************************************************/
306 static int Send( sout_stream_t *p_stream, sout_stream_id_t *id,
309 sout_stream_sys_t *p_sys = (sout_stream_sys_t *)p_stream->p_sys;
311 if ( id == p_sys->p_telx )
312 HandleTelx( p_stream, p_buffer );
314 return p_stream->p_next->pf_send( p_stream->p_next, id, p_buffer );