git.sesse.net Git - vlc/blob - modules/demux/ps.c

   1 /*****************************************************************************
   2  * ps.c: Program Stream demux module for VLC.
   3  *****************************************************************************
   4  * Copyright (C) 2004-2009 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   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 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_demux.h>
  35
  36 #include "ps.h"
  37
  38 /* TODO:
  39  *  - re-add pre-scanning.
  40  *  - ...
  41  */
  42
  43 #define TIME_TEXT N_("Trust MPEG timestamps")
  44 #define TIME_LONGTEXT N_("Normally we use the timestamps of the MPEG files " \
  45     "to calculate position and duration. However sometimes this might not " \
  46     "be usable. Disable this option to calculate from the bitrate instead." )
  47
  48 /*****************************************************************************
  49  * Module descriptor
  50  *****************************************************************************/
  51 static int  OpenForce( vlc_object_t * );
  52 static int  Open   ( vlc_object_t * );
  53 static void Close  ( vlc_object_t * );
  54
  55 vlc_module_begin ()
  56     set_description( N_("MPEG-PS demuxer") )
  57     set_shortname( N_("PS") )
  58     set_category( CAT_INPUT )
  59     set_subcategory( SUBCAT_INPUT_DEMUX )
  60     set_capability( "demux", 1 )
  61     set_callbacks( OpenForce, Close )
  62     add_shortcut( "ps" )
  63
  64     add_bool( "ps-trust-timestamps", true, TIME_TEXT,
  65                  TIME_LONGTEXT, true )
  66         change_safe ()
  67
  68     add_submodule ()
  69     set_description( N_("MPEG-PS demuxer") )
  70     set_capability( "demux", 8 )
  71     set_callbacks( Open, Close )
  72     add_shortcut( "ps" )
  73 vlc_module_end ()
  74
  75 /*****************************************************************************
  76  * Local prototypes
  77  *****************************************************************************/
  78
  79 struct demux_sys_t
  80 {
  81     ps_psm_t    psm;
  82     ps_track_t  tk[PS_TK_COUNT];
  83
  84     int64_t     i_scr;
  85     int64_t     i_last_scr;
  86     int         i_mux_rate;
  87     int64_t     i_length;
  88     int         i_time_track;
  89     int64_t     i_current_pts;
  90
  91     int         i_aob_mlp_count;
  92
  93     bool  b_lost_sync;
  94     bool  b_have_pack;
  95     bool  b_seekable;
  96 };
  97
  98 static int Demux  ( demux_t *p_demux );
  99 static int Control( demux_t *p_demux, int i_query, va_list args );
 100
 101 static int      ps_pkt_resynch( stream_t *, uint32_t *pi_code );
 102 static block_t *ps_pkt_read   ( stream_t *, uint32_t i_code );
 103
 104 /*****************************************************************************
 105  * Open
 106  *****************************************************************************/
 107 static int OpenCommon( vlc_object_t *p_this, bool b_force )
 108 {
 109     demux_t     *p_demux = (demux_t*)p_this;
 110     demux_sys_t *p_sys;
 111
 112     const uint8_t *p_peek;
 113
 114     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 115     {
 116         msg_Err( p_demux, "cannot peek" );
 117         return VLC_EGENERIC;
 118     }
 119
 120     if( memcmp( p_peek, "\x00\x00\x01", 3 ) || ( p_peek[3] < 0xb9 ) )
 121     {
 122         if( !b_force )
 123             return VLC_EGENERIC;
 124
 125         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
 126                   "continuing anyway" );
 127     }
 128
 129     /* Fill p_demux field */
 130     p_demux->pf_demux = Demux;
 131     p_demux->pf_control = Control;
 132     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
 133     if( !p_sys ) return VLC_ENOMEM;
 134
 135     /* Init p_sys */
 136     p_sys->i_mux_rate = 0;
 137     p_sys->i_scr      = -1;
 138     p_sys->i_last_scr = -1;
 139     p_sys->i_length   = -1;
 140     p_sys->i_current_pts = (mtime_t) 0;
 141     p_sys->i_time_track = -1;
 142     p_sys->i_aob_mlp_count = 0;
 143
 144     p_sys->b_lost_sync = false;
 145     p_sys->b_have_pack = false;
 146     p_sys->b_seekable  = false;
 147
 148     stream_Control( p_demux->s, STREAM_CAN_SEEK, &p_sys->b_seekable );
 149
 150     ps_psm_init( &p_sys->psm );
 151     ps_track_init( p_sys->tk );
 152
 153     /* TODO prescanning of ES */
 154
 155     return VLC_SUCCESS;
 156 }
 157
 158 static int OpenForce( vlc_object_t *p_this )
 159 {
 160     return OpenCommon( p_this, true );
 161 }
 162
 163 static int Open( vlc_object_t *p_this )
 164 {
 165     return OpenCommon( p_this, ((demux_t *)p_this)->b_force );
 166 }
 167
 168 /*****************************************************************************
 169  * Close
 170  *****************************************************************************/
 171 static void Close( vlc_object_t *p_this )
 172 {
 173     demux_t     *p_demux = (demux_t*)p_this;
 174     demux_sys_t *p_sys = p_demux->p_sys;
 175     int i;
 176
 177     for( i = 0; i < PS_TK_COUNT; i++ )
 178     {
 179         ps_track_t *tk = &p_sys->tk[i];
 180         if( tk->b_seen )
 181         {
 182             es_format_Clean( &tk->fmt );
 183             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 184         }
 185     }
 186
 187     ps_psm_destroy( &p_sys->psm );
 188
 189     free( p_sys );
 190 }
 191
 192 static int Demux2( demux_t *p_demux, bool b_end )
 193 {
 194     demux_sys_t *p_sys = p_demux->p_sys;
 195     int i_ret, i_id;
 196     uint32_t i_code;
 197     block_t *p_pkt;
 198
 199     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 200     if( i_ret < 0 )
 201     {
 202         return 0;
 203     }
 204     else if( i_ret == 0 )
 205     {
 206         if( !p_sys->b_lost_sync )
 207             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 208
 209         p_sys->b_lost_sync = true;
 210         return 1;
 211     }
 212
 213     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 214     p_sys->b_lost_sync = false;
 215
 216     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 217     {
 218         return 0;
 219     }
 220     if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 221     {
 222         ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 223         if( !ps_pkt_parse_pes( p_pkt, tk->i_skip ) && p_pkt->i_pts > VLC_TS_INVALID )
 224         {
 225             if( b_end && p_pkt->i_pts > tk->i_last_pts )
 226             {
 227                 tk->i_last_pts = p_pkt->i_pts;
 228             }
 229             else if ( tk->i_first_pts == -1 )
 230             {
 231                 tk->i_first_pts = p_pkt->i_pts;
 232             }
 233         }
 234     }
 235     block_Release( p_pkt );
 236     return 1;
 237 }
 238
 239 static void FindLength( demux_t *p_demux )
 240 {
 241     demux_sys_t *p_sys = p_demux->p_sys;
 242     int64_t i_current_pos = -1, i_size = 0, i_end = 0;
 243
 244     if( !var_CreateGetBool( p_demux, "ps-trust-timestamps" ) )
 245         return;
 246
 247     if( p_sys->i_length == -1 ) /* First time */
 248     {
 249         p_sys->i_length = 0;
 250         /* Check beginning */
 251         int i = 0;
 252         i_current_pos = stream_Tell( p_demux->s );
 253         while( vlc_object_alive (p_demux) && i < 40 && Demux2( p_demux, false ) > 0 ) i++;
 254
 255         /* Check end */
 256         i_size = stream_Size( p_demux->s );
 257         i_end = VLC_CLIP( i_size, 0, 200000 );
 258         stream_Seek( p_demux->s, i_size - i_end );
 259
 260         i = 0;
 261         while( vlc_object_alive (p_demux) && i < 40 && Demux2( p_demux, true ) > 0 ) i++;
 262         if( i_current_pos >= 0 ) stream_Seek( p_demux->s, i_current_pos );
 263     }
 264
 265     /* Find the longest track */
 266     for( int i = 0; i < PS_TK_COUNT; i++ )
 267     {
 268         ps_track_t *tk = &p_sys->tk[i];
 269         if( tk->i_first_pts >= 0 && tk->i_last_pts > 0 &&
 270             tk->i_last_pts > tk->i_first_pts )
 271         {
 272             int64_t i_length = (int64_t)tk->i_last_pts - tk->i_first_pts;
 273             if( i_length > p_sys->i_length )
 274             {
 275                 p_sys->i_length = i_length;
 276                 p_sys->i_time_track = i;
 277                 msg_Dbg( p_demux, "we found a length of: %"PRId64, p_sys->i_length );
 278             }
 279         }
 280     }
 281 }
 282
 283 /*****************************************************************************
 284  * Demux:
 285  *****************************************************************************/
 286 static int Demux( demux_t *p_demux )
 287 {
 288     demux_sys_t *p_sys = p_demux->p_sys;
 289     int i_ret, i_id, i_mux_rate;
 290     uint32_t i_code;
 291     block_t *p_pkt;
 292
 293     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 294     if( i_ret < 0 )
 295     {
 296         return 0;
 297     }
 298     else if( i_ret == 0 )
 299     {
 300         if( !p_sys->b_lost_sync )
 301             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 302
 303         p_sys->b_lost_sync = true;
 304         return 1;
 305     }
 306
 307     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 308     p_sys->b_lost_sync = false;
 309
 310     if( p_sys->i_length < 0 && p_sys->b_seekable )
 311         FindLength( p_demux );
 312
 313     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 314     {
 315         return 0;
 316     }
 317
 318     switch( i_code )
 319     {
 320     case 0x1b9:
 321         block_Release( p_pkt );
 322         break;
 323
 324     case 0x1ba:
 325         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 326         {
 327             p_sys->i_last_scr = p_sys->i_scr;
 328             if( !p_sys->b_have_pack ) p_sys->b_have_pack = true;
 329             /* done later on to work around bad vcd/svcd streams */
 330             /* es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr ); */
 331             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 332         }
 333         block_Release( p_pkt );
 334         break;
 335
 336     case 0x1bb:
 337         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 338         {
 339             int i;
 340             for( i = 0; i < PS_TK_COUNT; i++ )
 341             {
 342                 ps_track_t *tk = &p_sys->tk[i];
 343
 344                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 345                 {
 346                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 347                 }
 348             }
 349         }
 350         block_Release( p_pkt );
 351         break;
 352
 353     case 0x1bc:
 354         if( p_sys->psm.i_version == 0xFFFF )
 355             msg_Dbg( p_demux, "contains a PSM");
 356
 357         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 358         block_Release( p_pkt );
 359         break;
 360
 361     default:
 362         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 363         {
 364             /* Small heuristic to improve MLP detection from AOB */
 365             if( i_id == 0xa001 &&
 366                 p_sys->i_aob_mlp_count < 500 )
 367             {
 368                 p_sys->i_aob_mlp_count++;
 369             }
 370             else if( i_id == 0xbda1 &&
 371                      p_sys->i_aob_mlp_count > 0 )
 372             {
 373                 p_sys->i_aob_mlp_count--;
 374                 i_id = 0xa001;
 375             }
 376
 377             bool b_new = false;
 378             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 379
 380             if( !tk->b_seen )
 381             {
 382                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 383                 {
 384                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 385                     b_new = true;
 386                 }
 387                 else
 388                 {
 389                     msg_Dbg( p_demux, "es id=0x%x format unknown", i_id );
 390                 }
 391                 tk->b_seen = true;
 392             }
 393
 394             /* The popular VCD/SVCD subtitling WinSubMux does not
 395              * renumber the SCRs when merging subtitles into the PES */
 396             if( tk->b_seen &&
 397                 ( tk->fmt.i_codec == VLC_CODEC_OGT ||
 398                   tk->fmt.i_codec == VLC_CODEC_CVD ) )
 399             {
 400                 p_sys->i_scr = -1;
 401                 p_sys->i_last_scr = -1;
 402             }
 403
 404             if( p_sys->i_scr >= 0 )
 405                 es_out_Control( p_demux->out, ES_OUT_SET_PCR, VLC_TS_0 + p_sys->i_scr );
 406
 407             p_sys->i_scr = -1;
 408
 409             if( tk->b_seen && tk->es &&
 410                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 411             {
 412                 if( !b_new && !p_sys->b_have_pack &&
 413                     (tk->fmt.i_cat == AUDIO_ES) &&
 414                     (p_pkt->i_pts > VLC_TS_INVALID) )
 415                 {
 416                     /* A hack to sync the A/V on PES files. */
 417                     msg_Dbg( p_demux, "force SCR: %"PRId64, p_pkt->i_pts );
 418                     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_pkt->i_pts );
 419                 }
 420                 if( tk->fmt.i_codec == VLC_CODEC_TELETEXT &&
 421                     p_pkt->i_pts <= VLC_TS_INVALID && p_sys->i_last_scr >= 0 )
 422                 {
 423                     /* Teletext may have missing PTS (ETSI EN 300 472 Annexe A)
 424                      * In this case use the last SCR + 40ms */
 425                     p_pkt->i_pts = VLC_TS_0 + p_sys->i_last_scr + 40000;
 426                 }
 427
 428                 if( (int64_t)p_pkt->i_pts > p_sys->i_current_pts )
 429                 {
 430                     p_sys->i_current_pts = (int64_t)p_pkt->i_pts;
 431                 }
 432
 433                 es_out_Send( p_demux->out, tk->es, p_pkt );
 434             }
 435             else
 436             {
 437                 block_Release( p_pkt );
 438             }
 439         }
 440         else
 441         {
 442             block_Release( p_pkt );
 443         }
 444         break;
 445     }
 446
 447     return 1;
 448 }
 449
 450 /*****************************************************************************
 451  * Control:
 452  *****************************************************************************/
 453 static int Control( demux_t *p_demux, int i_query, va_list args )
 454 {
 455     demux_sys_t *p_sys = p_demux->p_sys;
 456     double f, *pf;
 457     int64_t i64, *pi64;
 458
 459     switch( i_query )
 460     {
 461         case DEMUX_GET_POSITION:
 462             pf = (double*) va_arg( args, double* );
 463             i64 = stream_Size( p_demux->s );
 464             if( i64 > 0 )
 465             {
 466                 double current = stream_Tell( p_demux->s );
 467                 *pf = current / (double)i64;
 468             }
 469             else
 470             {
 471                 *pf = 0.0;
 472             }
 473             return VLC_SUCCESS;
 474
 475         case DEMUX_SET_POSITION:
 476             f = (double) va_arg( args, double );
 477             i64 = stream_Size( p_demux->s );
 478             p_sys->i_current_pts = 0;
 479             p_sys->i_last_scr = -1;
 480
 481             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 482
 483         case DEMUX_GET_TIME:
 484             pi64 = (int64_t*)va_arg( args, int64_t * );
 485             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 486             {
 487                 *pi64 = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 488                 return VLC_SUCCESS;
 489             }
 490             if( p_sys->i_mux_rate > 0 )
 491             {
 492                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 493                     p_sys->i_mux_rate;
 494                 return VLC_SUCCESS;
 495             }
 496             *pi64 = 0;
 497             return VLC_EGENERIC;
 498
 499         case DEMUX_GET_LENGTH:
 500             pi64 = (int64_t*)va_arg( args, int64_t * );
 501             if( p_sys->i_length > 0 )
 502             {
 503                 *pi64 = p_sys->i_length;
 504                 return VLC_SUCCESS;
 505             }
 506             else if( p_sys->i_mux_rate > 0 )
 507             {
 508                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 509                     p_sys->i_mux_rate;
 510                 return VLC_SUCCESS;
 511             }
 512             *pi64 = 0;
 513             return VLC_EGENERIC;
 514
 515         case DEMUX_SET_TIME:
 516             i64 = (int64_t)va_arg( args, int64_t );
 517             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 518             {
 519                 int64_t i_now = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 520                 int64_t i_pos = stream_Tell( p_demux->s );
 521
 522                 if( !i_now )
 523                     return i64 ? VLC_EGENERIC : VLC_SUCCESS;
 524
 525                 p_sys->i_current_pts = 0;
 526                 p_sys->i_last_scr = -1;
 527                 i_pos *= (float)i64 / (float)i_now;
 528                 stream_Seek( p_demux->s, i_pos );
 529                 return VLC_SUCCESS;
 530             }
 531             return VLC_EGENERIC;
 532
 533         case DEMUX_GET_FPS:
 534         default:
 535             return VLC_EGENERIC;
 536     }
 537 }
 538
 539 /*****************************************************************************
 540  * Divers:
 541  *****************************************************************************/
 542
 543 /* PSResynch: resynch on a system startcode
 544  *  It doesn't skip more than 512 bytes
 545  *  -1 -> error, 0 -> not synch, 1 -> ok
 546  */
 547 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 548 {
 549     const uint8_t *p_peek;
 550     int     i_peek;
 551     int     i_skip;
 552
 553     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 554     {
 555         return -1;
 556     }
 557     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 558         p_peek[3] >= 0xb9 )
 559     {
 560         *pi_code = 0x100 | p_peek[3];
 561         return 1;
 562     }
 563
 564     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 565     {
 566         return -1;
 567     }
 568     i_skip = 0;
 569
 570     for( ;; )
 571     {
 572         if( i_peek < 4 )
 573         {
 574             break;
 575         }
 576         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 577             p_peek[3] >= 0xb9 )
 578         {
 579             *pi_code = 0x100 | p_peek[3];
 580             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 581         }
 582
 583         p_peek++;
 584         i_peek--;
 585         i_skip++;
 586     }
 587     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 588 }
 589
 590 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 591 {
 592     const uint8_t *p_peek;
 593     int i_peek = stream_Peek( s, &p_peek, 14 );
 594     if( i_peek < 4 )
 595         return NULL;
 596
 597     int i_size = ps_pkt_size( p_peek, i_peek );
 598     if( i_size <= 6 && p_peek[3] > 0xba )
 599     {
 600         /* Special case, search the next start code */
 601         i_size = 6;
 602         for( ;; )
 603         {
 604             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 605             if( i_peek <= i_size + 4 )
 606             {
 607                 return NULL;
 608             }
 609             while( i_size <= i_peek - 4 )
 610             {
 611                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 612                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 613                 {
 614                     return stream_Block( s, i_size );
 615                 }
 616                 i_size++;
 617             }
 618         }
 619     }
 620     else
 621     {
 622         /* Normal case */
 623         return stream_Block( s, i_size );
 624     }
 625
 626     VLC_UNUSED(i_code);
 627     return NULL;
 628 }