modules/demux/ttml.c

   1 /*****************************************************************************
   2  * ttml.c : TTML subtitles demux
   3  *****************************************************************************
   4  * Copyright (C) 2015-2017 VLC authors and VideoLAN
   5  *
   6  * Authors: Hugo Beauzée-Luyssen <hugo@beauzee.fr>
   7  *          Sushma Reddy <sushma.reddy@research.iiit.ac.in>
   8  *
   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.
  13  *
  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.
  18  *
  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  *****************************************************************************/
  23
  24 #ifdef HAVE_CONFIG_H
  25 # include "config.h"
  26 #endif
  27
  28 #include <vlc_common.h>
  29 #include <vlc_demux.h>
  30 #include <vlc_xml.h>
  31 #include <vlc_strings.h>
  32 #include <vlc_memory.h>
  33 #include <vlc_memstream.h>
  34 #include <vlc_es_out.h>
  35 #include <vlc_charset.h>          /* FromCharset */
  36
  37 #include <assert.h>
  38 #include <stdlib.h>
  39
  40 #include "../codec/ttml/ttml.h"
  41
  42 //#define TTML_DEMUX_DEBUG
  43
  44 struct demux_sys_t
  45 {
  46     xml_t*          p_xml;
  47     xml_reader_t*   p_reader;
  48     es_out_id_t*    p_es;
  49     int64_t         i_next_demux_time;
  50     bool            b_slave;
  51     bool            b_first_time;
  52
  53     tt_node_t         *p_rootnode;
  54
  55     tt_timings_t    temporal_extent;
  56
  57     /*
  58      * All timings are stored unique and ordered.
  59      * Being begin or end times of sub sequence,
  60      * we use them as 'point of change' for output filtering.
  61     */
  62     struct
  63     {
  64         tt_time_t *p_array;
  65         size_t   i_count;
  66         size_t   i_current;
  67     } times;
  68 };
  69
  70 static char *tt_genTiming( tt_time_t t )
  71 {
  72     if( !tt_time_Valid( &t ) )
  73         t.base = 0;
  74     unsigned f = t.base % CLOCK_FREQ;
  75     t.base /= CLOCK_FREQ;
  76     unsigned h = t.base / 3600;
  77     unsigned m = t.base % 3600 / 60;
  78     unsigned s = t.base % 60;
  79
  80     int i_ret;
  81     char *psz;
  82     if( f )
  83     {
  84         const char *lz = "000000";
  85         const char *psz_lz = &lz[6];
  86         /* add leading zeroes */
  87         for( unsigned i=10*f; i<CLOCK_FREQ; i *= 10 )
  88             psz_lz--;
  89         /* strip trailing zeroes */
  90         for( ; f > 0 && (f % 10) == 0; f /= 10 );
  91         i_ret = asprintf( &psz, "%02u:%02u:%02u.%s%u",
  92                                  h, m, s, psz_lz, f );
  93     }
  94     else if( t.frames )
  95     {
  96         i_ret = asprintf( &psz, "%02u:%02u:%02u:%s%u",
  97                                  h, m, s, t.frames < 10 ? "0" : "", t.frames );
  98     }
  99     else
 100     {
 101         i_ret = asprintf( &psz, "%02u:%02u:%02u",
 102                                  h, m, s );
 103     }
 104
 105     return i_ret < 0 ? NULL : psz;
 106 }
 107
 108 static void tt_node_AttributesToText( struct vlc_memstream *p_stream, const tt_node_t* p_node )
 109 {
 110     bool b_timed_node = false;
 111     const vlc_dictionary_t* p_attr_dict = &p_node->attr_dict;
 112     for( int i = 0; i < p_attr_dict->i_size; ++i )
 113     {
 114         for ( vlc_dictionary_entry_t* p_entry = p_attr_dict->p_entries[i];
 115                                       p_entry != NULL; p_entry = p_entry->p_next )
 116         {
 117             const char *psz_value = NULL;
 118
 119             if( !strcmp(p_entry->psz_key, "begin") ||
 120                 !strcmp(p_entry->psz_key, "end") ||
 121                 !strcmp(p_entry->psz_key, "dur") )
 122             {
 123                 b_timed_node = true;
 124                 /* will remove duration */
 125                 continue;
 126             }
 127             else if( !strcmp(p_entry->psz_key, "timeContainer") )
 128             {
 129                 /* also remove sequential timings info (all abs now) */
 130                 continue;
 131             }
 132             else
 133             {
 134                 psz_value = (char const*)p_entry->p_value;
 135             }
 136
 137             if( psz_value == NULL )
 138                 continue;
 139
 140             vlc_memstream_printf( p_stream, " %s=\"%s\"",
 141                                   p_entry->psz_key, psz_value );
 142         }
 143     }
 144
 145     if( b_timed_node )
 146     {
 147         if( tt_time_Valid( &p_node->timings.begin ) )
 148         {
 149             char *psz = tt_genTiming( p_node->timings.begin );
 150             vlc_memstream_printf( p_stream, " begin=\"%s\"", psz );
 151             free( psz );
 152         }
 153
 154         if( tt_time_Valid( &p_node->timings.end ) )
 155         {
 156             char *psz = tt_genTiming( p_node->timings.end );
 157             vlc_memstream_printf( p_stream, " end=\"%s\"", psz );
 158             free( psz );
 159         }
 160     }
 161 }
 162
 163 static void tt_node_ToText( struct vlc_memstream *p_stream, const tt_basenode_t *p_basenode,
 164                             const tt_time_t *playbacktime )
 165 {
 166     if( p_basenode->i_type == TT_NODE_TYPE_ELEMENT )
 167     {
 168         const tt_node_t *p_node = (const tt_node_t *) p_basenode;
 169
 170         if( tt_time_Valid( playbacktime ) &&
 171            !tt_timings_Contains( &p_node->timings, playbacktime ) )
 172             return;
 173
 174         vlc_memstream_putc( p_stream, '<' );
 175         vlc_memstream_puts( p_stream, p_node->psz_node_name );
 176
 177         tt_node_AttributesToText( p_stream, p_node );
 178
 179         if( tt_node_HasChild( p_node ) )
 180         {
 181             vlc_memstream_putc( p_stream, '>' );
 182
 183 #ifdef TTML_DEMUX_DEBUG
 184             vlc_memstream_printf( p_stream, "<!-- starts %ld ends %ld -->",
 185                                   tt_time_Convert( &p_node->timings.begin ),
 186                                   tt_time_Convert( &p_node->timings.end ) );
 187 #endif
 188
 189             for( const tt_basenode_t *p_child = p_node->p_child;
 190                                    p_child; p_child = p_child->p_next )
 191             {
 192                 tt_node_ToText( p_stream, p_child, playbacktime );
 193             }
 194
 195             vlc_memstream_printf( p_stream, "</%s>", p_node->psz_node_name );
 196         }
 197         else
 198             vlc_memstream_puts( p_stream, "/>" );
 199     }
 200     else
 201     {
 202         const tt_textnode_t *p_textnode = (const tt_textnode_t *) p_basenode;
 203         vlc_memstream_puts( p_stream, p_textnode->psz_text );
 204     }
 205 }
 206
 207 static int Control( demux_t* p_demux, int i_query, va_list args )
 208 {
 209     demux_sys_t *p_sys = p_demux->p_sys;
 210     int64_t *pi64, i64;
 211     double *pf, f;
 212     bool b;
 213
 214     switch( i_query )
 215     {
 216         case DEMUX_CAN_SEEK:
 217             *va_arg( args, bool * ) = true;
 218             return VLC_SUCCESS;
 219         case DEMUX_GET_TIME:
 220             pi64 = va_arg( args, int64_t * );
 221             *pi64 = p_sys->i_next_demux_time;
 222             return VLC_SUCCESS;
 223         case DEMUX_SET_TIME:
 224             i64 = va_arg( args, int64_t );
 225             if( p_sys->times.i_count )
 226             {
 227                 tt_time_t t = tt_time_Create( i64 - VLC_TS_0 );
 228                 size_t i_index = tt_timings_FindLowerIndex( p_sys->times.p_array,
 229                                                             p_sys->times.i_count, t, &b );
 230                 p_sys->times.i_current = i_index;
 231                 p_sys->b_first_time = true;
 232                 return VLC_SUCCESS;
 233             }
 234             break;
 235         case DEMUX_SET_NEXT_DEMUX_TIME:
 236             i64 = va_arg( args, int64_t );
 237             p_sys->i_next_demux_time = i64;
 238             p_sys->b_slave = true;
 239             return VLC_SUCCESS;
 240         case DEMUX_GET_LENGTH:
 241             pi64 = va_arg( args, int64_t * );
 242             if( p_sys->times.i_count )
 243             {
 244                 tt_time_t t = tt_time_Sub( p_sys->times.p_array[p_sys->times.i_count - 1],
 245                                            p_sys->temporal_extent.begin );
 246                 *pi64 = tt_time_Convert( &t );
 247                 return VLC_SUCCESS;
 248             }
 249             break;
 250         case DEMUX_GET_POSITION:
 251             pf = va_arg( args, double * );
 252             if( p_sys->times.i_current >= p_sys->times.i_count )
 253             {
 254                 *pf = 1.0;
 255             }
 256             else if( p_sys->times.i_count > 0 )
 257             {
 258                 i64 = tt_time_Convert( &p_sys->times.p_array[p_sys->times.i_count - 1] );
 259                 *pf = (double) p_sys->i_next_demux_time / (i64 + 0.5);
 260             }
 261             else
 262             {
 263                 *pf = 0.0;
 264             }
 265             return VLC_SUCCESS;
 266         case DEMUX_SET_POSITION:
 267             f = va_arg( args, double );
 268             if( p_sys->times.i_count )
 269             {
 270                 i64 = f * tt_time_Convert( &p_sys->times.p_array[p_sys->times.i_count - 1] );
 271                 tt_time_t t = tt_time_Create( i64 );
 272                 size_t i_index = tt_timings_FindLowerIndex( p_sys->times.p_array,
 273                                                             p_sys->times.i_count, t, &b );
 274                 p_sys->times.i_current = i_index;
 275                 p_sys->b_first_time = true;
 276                 return VLC_SUCCESS;
 277             }
 278             break;
 279         case DEMUX_GET_PTS_DELAY:
 280         case DEMUX_GET_FPS:
 281         case DEMUX_GET_META:
 282         case DEMUX_GET_ATTACHMENTS:
 283         case DEMUX_GET_TITLE_INFO:
 284         case DEMUX_HAS_UNSUPPORTED_META:
 285         case DEMUX_CAN_RECORD:
 286         default:
 287             break;
 288     }
 289
 290     return VLC_EGENERIC;
 291 }
 292
 293 static int ReadTTML( demux_t* p_demux )
 294 {
 295     demux_sys_t* p_sys = p_demux->p_sys;
 296     const char* psz_node_name;
 297
 298     do
 299     {
 300         int i_type = xml_ReaderNextNode( p_sys->p_reader, &psz_node_name );
 301         bool b_empty = xml_ReaderIsEmptyElement( p_sys->p_reader );
 302
 303         if( i_type <= XML_READER_NONE )
 304             break;
 305
 306         switch(i_type)
 307         {
 308             default:
 309                 break;
 310
 311             case XML_READER_STARTELEM:
 312                 if( tt_node_NameCompare( psz_node_name, "tt" ) ||
 313                     p_sys->p_rootnode != NULL )
 314                     return VLC_EGENERIC;
 315
 316                 p_sys->p_rootnode = tt_node_New( p_sys->p_reader, NULL, psz_node_name );
 317                 if( b_empty )
 318                     break;
 319                 if( !p_sys->p_rootnode ||
 320                     tt_nodes_Read( p_sys->p_reader, p_sys->p_rootnode ) != VLC_SUCCESS )
 321                     return VLC_EGENERIC;
 322                 break;
 323
 324             case XML_READER_ENDELEM:
 325                 if( !p_sys->p_rootnode ||
 326                     tt_node_NameCompare( psz_node_name, p_sys->p_rootnode->psz_node_name ) )
 327                     return VLC_EGENERIC;
 328                 break;
 329         }
 330
 331     } while( 1 );
 332
 333     if( p_sys->p_rootnode == NULL )
 334         return VLC_EGENERIC;
 335
 336     return VLC_SUCCESS;
 337 }
 338
 339 static int Demux( demux_t* p_demux )
 340 {
 341     demux_sys_t* p_sys = p_demux->p_sys;
 342
 343     /* Last one must be an end time */
 344     while( p_sys->times.i_current + 1 < p_sys->times.i_count &&
 345            tt_time_Convert( &p_sys->times.p_array[p_sys->times.i_current] ) <= p_sys->i_next_demux_time )
 346     {
 347         const int64_t i_playbacktime =
 348                 tt_time_Convert( &p_sys->times.p_array[p_sys->times.i_current] );
 349         const int64_t i_playbackendtime =
 350                 tt_time_Convert( &p_sys->times.p_array[p_sys->times.i_current + 1] ) - 1;
 351
 352         if ( !p_sys->b_slave && p_sys->b_first_time )
 353         {
 354             es_out_SetPCR( p_demux->out, VLC_TS_0 + i_playbacktime );
 355             p_sys->b_first_time = false;
 356         }
 357
 358         struct vlc_memstream stream;
 359
 360         if( vlc_memstream_open( &stream ) )
 361             return VLC_DEMUXER_EGENERIC;
 362
 363         tt_node_ToText( &stream, (tt_basenode_t *) p_sys->p_rootnode,
 364                         &p_sys->times.p_array[p_sys->times.i_current] );
 365
 366         if( vlc_memstream_close( &stream ) == VLC_SUCCESS )
 367         {
 368             block_t* p_block = block_heap_Alloc( stream.ptr, stream.length );
 369             if( p_block )
 370             {
 371                 p_block->i_dts =
 372                     p_block->i_pts = VLC_TS_0 + i_playbacktime;
 373                 p_block->i_length = i_playbackendtime - i_playbacktime;
 374
 375                 es_out_Send( p_demux->out, p_sys->p_es, p_block );
 376             }
 377         }
 378
 379         p_sys->times.i_current++;
 380     }
 381
 382     if ( !p_sys->b_slave )
 383     {
 384         es_out_SetPCR( p_demux->out, VLC_TS_0 + p_sys->i_next_demux_time );
 385         p_sys->i_next_demux_time += CLOCK_FREQ / 8;
 386     }
 387
 388     if( p_sys->times.i_current + 1 >= p_sys->times.i_count )
 389         return VLC_DEMUXER_EOF;
 390
 391     return VLC_DEMUXER_SUCCESS;
 392 }
 393
 394 int tt_OpenDemux( vlc_object_t* p_this )
 395 {
 396     demux_t     *p_demux = (demux_t*)p_this;
 397     demux_sys_t *p_sys;
 398
 399     const uint8_t *p_peek;
 400     ssize_t i_peek = vlc_stream_Peek( p_demux->s, &p_peek, 2048 );
 401     if( unlikely( i_peek <= 32 ) )
 402         return VLC_EGENERIC;
 403
 404     const char *psz_xml = (const char *) p_peek;
 405     size_t i_xml  = i_peek;
 406
 407     /* Try to probe without xml module/loading the full document */
 408     char *psz_alloc = NULL;
 409     switch( GetQWBE(p_peek) )
 410     {
 411         /* See RFC 3023 Part 4 */
 412         case UINT64_C(0xFFFE3C003F007800): /* UTF16 BOM<? */
 413         case UINT64_C(0xFFFE3C003F007400): /* UTF16 BOM<t */
 414         case UINT64_C(0xFEFF003C003F0078): /* UTF16 BOM<? */
 415         case UINT64_C(0xFEFF003C003F0074): /* UTF16 BOM<t */
 416             psz_alloc = FromCharset( "UTF-16", p_peek, i_peek );
 417             break;
 418         case UINT64_C(0x3C003F0078006D00): /* UTF16-LE <?xm */
 419         case UINT64_C(0x3C003F0074007400): /* UTF16-LE <tt */
 420             psz_alloc = FromCharset( "UTF-16LE", p_peek, i_peek );
 421             break;
 422         case UINT64_C(0x003C003F0078006D): /* UTF16-BE <?xm */
 423         case UINT64_C(0x003C003F00740074): /* UTF16-BE <tt */
 424             psz_alloc = FromCharset( "UTF-16BE", p_peek, i_peek );
 425             break;
 426         case UINT64_C(0xEFBBBF3C3F786D6C): /* UTF8 BOM<?xml */
 427         case UINT64_C(0x3C3F786D6C207665): /* UTF8 <?xml ve */
 428         case UINT64_C(0xEFBBBF3C74742078): /* UTF8 BOM<tt x*/
 429             break;
 430         default:
 431             if(GetDWBE(p_peek) != UINT32_C(0x3C747420)) /* tt node without xml document marker */
 432                 return VLC_EGENERIC;
 433     }
 434
 435     if( psz_alloc )
 436     {
 437         psz_xml = psz_alloc;
 438         i_xml = strlen( psz_alloc );
 439     }
 440
 441     /* Simplified probing. Valid TTML must have a namespace declaration */
 442     const char *psz_tt = strnstr( psz_xml, "tt ", i_xml );
 443     if( !psz_tt || psz_tt == psz_xml ||
 444         (psz_tt[-1] != ':' && psz_tt[-1] != '<') )
 445     {
 446         free( psz_alloc );
 447         return VLC_EGENERIC;
 448     }
 449     else
 450     {
 451         const char * const rgsz[] =
 452         {
 453             "=\"http://www.w3.org/ns/ttml\"",
 454             "=\"http://www.w3.org/2004/11/ttaf1\"",
 455             "=\"http://www.w3.org/2006/04/ttaf1\"",
 456             "=\"http://www.w3.org/2006/10/ttaf1\"",
 457         };
 458         const char *psz_ns = NULL;
 459         for( size_t i=0; i<ARRAY_SIZE(rgsz) && !psz_ns; i++ )
 460         {
 461             psz_ns = strnstr( psz_xml, rgsz[i],
 462                               i_xml - (psz_tt - psz_xml) );
 463         }
 464         free( psz_alloc );
 465         if( !psz_ns )
 466             return VLC_EGENERIC;
 467     }
 468
 469     p_demux->p_sys = p_sys = calloc( 1, sizeof( *p_sys ) );
 470     if( unlikely( p_sys == NULL ) )
 471         return VLC_ENOMEM;
 472
 473     p_sys->b_first_time = true;
 474     p_sys->temporal_extent.i_type = TT_TIMINGS_PARALLEL;
 475     tt_time_Init( &p_sys->temporal_extent.begin );
 476     tt_time_Init( &p_sys->temporal_extent.end );
 477     tt_time_Init( &p_sys->temporal_extent.dur );
 478     p_sys->temporal_extent.begin.base = 0;
 479
 480     p_sys->p_xml = xml_Create( p_demux );
 481     if( !p_sys->p_xml )
 482         goto error;
 483
 484     p_sys->p_reader = xml_ReaderCreate( p_sys->p_xml, p_demux->s );
 485     if( !p_sys->p_reader )
 486         goto error;
 487
 488 #ifndef TTML_DEMUX_DEBUG
 489     p_sys->p_reader->obj.flags |= OBJECT_FLAGS_QUIET;
 490 #endif
 491
 492     if( ReadTTML( p_demux ) != VLC_SUCCESS )
 493         goto error;
 494
 495     tt_timings_Resolve( (tt_basenode_t *) p_sys->p_rootnode, &p_sys->temporal_extent,
 496                         &p_sys->times.p_array, &p_sys->times.i_count );
 497
 498 #ifdef TTML_DEMUX_DEBUG
 499     {
 500         struct vlc_memstream stream;
 501
 502         if( vlc_memstream_open( &stream ) )
 503             goto error;
 504
 505         tt_time_t t;
 506         tt_time_Init( &t );
 507         tt_node_ToText( &stream, (tt_basenode_t*)p_sys->p_rootnode, &t /* invalid */ );
 508
 509         vlc_memstream_putc( &stream, '\0' );
 510
 511         if( vlc_memstream_close( &stream ) == VLC_SUCCESS )
 512         {
 513             msg_Dbg( p_demux, "%s", stream.ptr );
 514             free( stream.ptr );
 515         }
 516     }
 517 #endif
 518
 519     p_demux->pf_demux = Demux;
 520     p_demux->pf_control = Control;
 521
 522     es_format_t fmt;
 523     es_format_Init( &fmt, SPU_ES, VLC_CODEC_TTML );
 524     p_sys->p_es = es_out_Add( p_demux->out, &fmt );
 525     if( !p_sys->p_es )
 526         goto error;
 527
 528     es_format_Clean( &fmt );
 529
 530     return VLC_SUCCESS;
 531
 532 error:
 533     tt_CloseDemux( p_demux );
 534
 535     return VLC_EGENERIC;
 536 }
 537
 538 void tt_CloseDemux( demux_t* p_demux )
 539 {
 540     demux_sys_t* p_sys = p_demux->p_sys;
 541
 542     if( p_sys->p_rootnode )
 543         tt_node_RecursiveDelete( p_sys->p_rootnode );
 544
 545     if( p_sys->p_es )
 546         es_out_Del( p_demux->out, p_sys->p_es );
 547
 548     if( p_sys->p_reader )
 549         xml_ReaderDelete( p_sys->p_reader );
 550
 551     if( p_sys->p_xml )
 552         xml_Delete( p_sys->p_xml );
 553
 554     free( p_sys->times.p_array );
 555
 556     free( p_sys );
 557 }