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 the VideoLAN team
   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
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <stdlib.h>                                      /* malloc(), free() */
  28
  29 #include <vlc/vlc.h>
  30 #include <vlc_demux.h>
  31
  32 #include "ps.h"
  33
  34 /* TODO:
  35  *  - re-add pre-scanning.
  36  *  - ...
  37  */
  38
  39 #define TIME_TEXT N_("Trust MPEG timestamps")
  40 #define TIME_LONGTEXT N_("Normally we use the timestamps of the MPEG files " \
  41     "to calculate position and duration. However sometimes this might not " \
  42     "be usable. Disable this option to calculate from the bitrate instead." )
  43
  44 /*****************************************************************************
  45  * Module descriptor
  46  *****************************************************************************/
  47 static int  OpenForce( vlc_object_t * );
  48 static int  Open   ( vlc_object_t * );
  49 static void Close  ( vlc_object_t * );
  50
  51 vlc_module_begin();
  52     set_description( _("MPEG-PS demuxer") );
  53     set_category( CAT_INPUT );
  54     set_subcategory( SUBCAT_INPUT_DEMUX );
  55     set_capability( "demux2", 1 );
  56     set_callbacks( OpenForce, Close );
  57     add_shortcut( "ps" );
  58
  59     add_bool( "ps-trust-timestamps", VLC_TRUE, NULL, TIME_TEXT,
  60                  TIME_LONGTEXT, VLC_TRUE );
  61
  62     add_submodule();
  63     set_description( _("MPEG-PS demuxer") );
  64     set_capability( "demux2", 9 );
  65     set_callbacks( Open, Close );
  66 vlc_module_end();
  67
  68 /*****************************************************************************
  69  * Local prototypes
  70  *****************************************************************************/
  71
  72 struct demux_sys_t
  73 {
  74     ps_psm_t    psm;
  75     ps_track_t  tk[PS_TK_COUNT];
  76
  77     int64_t     i_scr;
  78     int         i_mux_rate;
  79     int64_t     i_length;
  80     int         i_time_track;
  81     int64_t     i_current_pts;
  82
  83     vlc_bool_t  b_lost_sync;
  84     vlc_bool_t  b_have_pack;
  85     vlc_bool_t  b_seekable;
  86 };
  87
  88 static int Demux  ( demux_t *p_demux );
  89 static int Control( demux_t *p_demux, int i_query, va_list args );
  90
  91 static int      ps_pkt_resynch( stream_t *, uint32_t *pi_code );
  92 static block_t *ps_pkt_read   ( stream_t *, uint32_t i_code );
  93
  94 /*****************************************************************************
  95  * Open
  96  *****************************************************************************/
  97 static int OpenCommon( vlc_object_t *p_this, vlc_bool_t b_force )
  98 {
  99     demux_t     *p_demux = (demux_t*)p_this;
 100     demux_sys_t *p_sys;
 101
 102     uint8_t     *p_peek;
 103
 104     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 105     {
 106         msg_Err( p_demux, "cannot peek" );
 107         return VLC_EGENERIC;
 108     }
 109
 110     if( memcmp( p_peek, "\x00\x00\x01", 3 ) || ( p_peek[3] < 0xb9 ) )
 111     {
 112         if( !b_force )
 113             return VLC_EGENERIC;
 114
 115         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
 116                   "continuing anyway" );
 117     }
 118
 119     /* Fill p_demux field */
 120     p_demux->pf_demux = Demux;
 121     p_demux->pf_control = Control;
 122     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
 123
 124     /* Init p_sys */
 125     p_sys->i_mux_rate = 0;
 126     p_sys->i_scr      = -1;
 127     p_sys->i_length   = -1;
 128     p_sys->i_current_pts = (mtime_t) 0;
 129     p_sys->i_time_track = -1;
 130
 131     p_sys->b_lost_sync = VLC_FALSE;
 132     p_sys->b_have_pack = VLC_FALSE;
 133     p_sys->b_seekable  = VLC_FALSE;
 134
 135     stream_Control( p_demux->s, STREAM_CAN_SEEK, &p_sys->b_seekable );
 136
 137     ps_psm_init( &p_sys->psm );
 138     ps_track_init( p_sys->tk );
 139
 140     /* TODO prescanning of ES */
 141
 142     return VLC_SUCCESS;
 143 }
 144
 145 static int OpenForce( vlc_object_t *p_this )
 146 {
 147     return OpenCommon( p_this, VLC_TRUE );
 148 }
 149
 150 static int Open( vlc_object_t *p_this )
 151 {
 152     return OpenCommon( p_this, ((demux_t *)p_this)->b_force );
 153 }
 154
 155 /*****************************************************************************
 156  * Close
 157  *****************************************************************************/
 158 static void Close( vlc_object_t *p_this )
 159 {
 160     demux_t     *p_demux = (demux_t*)p_this;
 161     demux_sys_t *p_sys = p_demux->p_sys;
 162     int i;
 163
 164     for( i = 0; i < PS_TK_COUNT; i++ )
 165     {
 166         ps_track_t *tk = &p_sys->tk[i];
 167         if( tk->b_seen )
 168         {
 169             es_format_Clean( &tk->fmt );
 170             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 171         }
 172     }
 173
 174     ps_psm_destroy( &p_sys->psm );
 175
 176     free( p_sys );
 177 }
 178
 179 static int Demux2( demux_t *p_demux, vlc_bool_t b_end )
 180 {
 181     demux_sys_t *p_sys = p_demux->p_sys;
 182     int i_ret, i_id;
 183     uint32_t i_code;
 184     block_t *p_pkt;
 185
 186     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 187     if( i_ret < 0 )
 188     {
 189         return 0;
 190     }
 191     else if( i_ret == 0 )
 192     {
 193         if( !p_sys->b_lost_sync )
 194             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 195
 196         p_sys->b_lost_sync = VLC_TRUE;
 197         return 1;
 198     }
 199
 200     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 201     p_sys->b_lost_sync = VLC_FALSE;
 202
 203     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 204     {
 205         return 0;
 206     }
 207     if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 208     {
 209         ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 210         if( !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 211         {
 212             if( b_end && p_pkt->i_pts > tk->i_last_pts )
 213             {
 214                 tk->i_last_pts = p_pkt->i_pts;
 215             }
 216             else if ( tk->i_first_pts == -1 )
 217             {
 218                 tk->i_first_pts = p_pkt->i_pts;
 219             }
 220         }
 221     }
 222     block_Release( p_pkt );
 223     return 1;
 224 }
 225
 226 static void FindLength( demux_t *p_demux )
 227 {
 228     demux_sys_t *p_sys = p_demux->p_sys;
 229     int64_t i_current_pos = -1, i_size = 0, i_end = 0;
 230     int i;
 231
 232     if( !var_CreateGetInteger( p_demux, "ps-trust-timestamps" ) )
 233         return;
 234
 235     if( p_sys->i_length == -1 ) /* First time */
 236     {
 237         p_sys->i_length = 0;
 238         /* Check beginning */
 239         i = 0;
 240         i_current_pos = stream_Tell( p_demux->s );
 241         while( !p_demux->b_die && i < 40 && Demux2( p_demux, VLC_FALSE ) > 0 ) i++;
 242
 243         /* Check end */
 244         i_size = stream_Size( p_demux->s );
 245         i_end = __MAX( 0, __MIN( 200000, i_size ) );
 246         stream_Seek( p_demux->s, i_size - i_end );
 247
 248         while( !p_demux->b_die && Demux2( p_demux, VLC_TRUE ) > 0 );
 249         if( i_current_pos >= 0 ) stream_Seek( p_demux->s, i_current_pos );
 250     }
 251
 252     for( i = 0; i < PS_TK_COUNT; i++ )
 253     {
 254         ps_track_t *tk = &p_sys->tk[i];
 255         if( tk->i_first_pts >= 0 && tk->i_last_pts > 0 )
 256             if( tk->i_last_pts > tk->i_first_pts )
 257             {
 258                 int64_t i_length = (int64_t)tk->i_last_pts - tk->i_first_pts;
 259                 if( i_length > p_sys->i_length )
 260                 {
 261                     p_sys->i_length = i_length;
 262                     p_sys->i_time_track = i;
 263                     msg_Dbg( p_demux, "we found a length of: %lld", p_sys->i_length );
 264                 }
 265             }
 266     }
 267 }
 268
 269 /*****************************************************************************
 270  * Demux:
 271  *****************************************************************************/
 272 static int Demux( demux_t *p_demux )
 273 {
 274     demux_sys_t *p_sys = p_demux->p_sys;
 275     int i_ret, i_id, i_mux_rate;
 276     uint32_t i_code;
 277     block_t *p_pkt;
 278
 279     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 280     if( i_ret < 0 )
 281     {
 282         return 0;
 283     }
 284     else if( i_ret == 0 )
 285     {
 286         if( !p_sys->b_lost_sync )
 287             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 288
 289         p_sys->b_lost_sync = VLC_TRUE;
 290         return 1;
 291     }
 292
 293     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 294     p_sys->b_lost_sync = VLC_FALSE;
 295
 296     if( p_sys->i_length < 0 && p_sys->b_seekable )
 297         FindLength( p_demux );
 298
 299     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 300     {
 301         return 0;
 302     }
 303
 304     switch( i_code )
 305     {
 306     case 0x1b9:
 307         block_Release( p_pkt );
 308         break;
 309
 310     case 0x1ba:
 311         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 312         {
 313             if( !p_sys->b_have_pack ) p_sys->b_have_pack = VLC_TRUE;
 314             /* done later on to work around bad vcd/svcd streams */
 315             /* es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr ); */
 316             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 317         }
 318         block_Release( p_pkt );
 319         break;
 320
 321     case 0x1bb:
 322         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 323         {
 324             int i;
 325             for( i = 0; i < PS_TK_COUNT; i++ )
 326             {
 327                 ps_track_t *tk = &p_sys->tk[i];
 328
 329                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 330                 {
 331                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 332                 }
 333             }
 334         }
 335         block_Release( p_pkt );
 336         break;
 337
 338     case 0x1bc:
 339         if( p_sys->psm.i_version == 0xFFFF )
 340             msg_Dbg( p_demux, "contains a PSM");
 341
 342         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 343         block_Release( p_pkt );
 344         break;
 345
 346     default:
 347         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 348         {
 349             vlc_bool_t b_new = VLC_FALSE;
 350             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 351
 352             if( !tk->b_seen )
 353             {
 354                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 355                 {
 356                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 357                     b_new = VLC_TRUE;
 358                 }
 359                 else
 360                 {
 361                     msg_Dbg( p_demux, "es id=0x%x format unknown", i_id );
 362                 }
 363                 tk->b_seen = VLC_TRUE;
 364             }
 365
 366             /* The popular VCD/SVCD subtitling WinSubMux does not
 367              * renumber the SCRs when merging subtitles into the PES */
 368             if( tk->b_seen &&
 369                 ( tk->fmt.i_codec == VLC_FOURCC('o','g','t',' ') ||
 370                   tk->fmt.i_codec == VLC_FOURCC('c','v','d',' ') ) )
 371             {
 372                 p_sys->i_scr = -1;
 373             }
 374
 375             if( p_sys->i_scr > 0 )
 376                 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 377
 378             p_sys->i_scr = -1;
 379
 380             if( tk->b_seen && tk->es &&
 381                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 382             {
 383                 if( !b_new && !p_sys->b_have_pack && tk->fmt.i_cat == AUDIO_ES && p_pkt->i_pts > 0 )
 384                 {
 385                     /* A hack to sync the A/V on PES files. */
 386                     msg_Dbg( p_demux, "force SCR: %lld", p_pkt->i_pts );
 387                     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_pkt->i_pts );
 388                 }
 389
 390                 if( (int64_t)p_pkt->i_pts > p_sys->i_current_pts )
 391                 {
 392                     p_sys->i_current_pts = (int64_t)p_pkt->i_pts;
 393                 }
 394
 395                 es_out_Send( p_demux->out, tk->es, p_pkt );
 396             }
 397             else
 398             {
 399                 block_Release( p_pkt );
 400             }
 401         }
 402         else
 403         {
 404             block_Release( p_pkt );
 405         }
 406         break;
 407     }
 408
 409     return 1;
 410 }
 411
 412 /*****************************************************************************
 413  * Control:
 414  *****************************************************************************/
 415 static int Control( demux_t *p_demux, int i_query, va_list args )
 416 {
 417     demux_sys_t *p_sys = p_demux->p_sys;
 418     double f, *pf;
 419     int64_t i64, *pi64;
 420
 421     switch( i_query )
 422     {
 423         case DEMUX_GET_POSITION:
 424             pf = (double*) va_arg( args, double* );
 425             i64 = stream_Size( p_demux->s );
 426             if( i64 > 0 )
 427             {
 428                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 429             }
 430             else
 431             {
 432                 *pf = 0.0;
 433             }
 434             return VLC_SUCCESS;
 435
 436         case DEMUX_SET_POSITION:
 437             f = (double) va_arg( args, double );
 438             i64 = stream_Size( p_demux->s );
 439             p_sys->i_current_pts = 0;
 440             es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 441
 442             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 443
 444         case DEMUX_GET_TIME:
 445             pi64 = (int64_t*)va_arg( args, int64_t * );
 446             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 447             {
 448                 *pi64 = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 449                 return VLC_SUCCESS;
 450             }
 451             if( p_sys->i_mux_rate > 0 )
 452             {
 453                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 454                     p_sys->i_mux_rate;
 455                 return VLC_SUCCESS;
 456             }
 457             *pi64 = 0;
 458             return VLC_EGENERIC;
 459
 460         case DEMUX_GET_LENGTH:
 461             pi64 = (int64_t*)va_arg( args, int64_t * );
 462             if( p_sys->i_length > 0 )
 463             {
 464                 *pi64 = p_sys->i_length;
 465                 return VLC_SUCCESS;
 466             }
 467             else if( p_sys->i_mux_rate > 0 )
 468             {
 469                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 470                     p_sys->i_mux_rate;
 471                 return VLC_SUCCESS;
 472             }
 473             *pi64 = 0;
 474             return VLC_EGENERIC;
 475
 476         case DEMUX_SET_TIME:
 477             i64 = (int64_t)va_arg( args, int64_t );
 478             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 479             {
 480                 int64_t i_now = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 481                 int64_t i_pos = stream_Tell( p_demux->s );
 482                 int64_t i_offset = i_pos / (i_now / 1000000) * ((i64 - i_now) / 1000000);
 483                 stream_Seek( p_demux->s, i_pos + i_offset);
 484
 485                 es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 486                 return VLC_SUCCESS;
 487             }
 488             return VLC_EGENERIC;
 489
 490         case DEMUX_GET_FPS:
 491         default:
 492             return VLC_EGENERIC;
 493     }
 494 }
 495
 496 /*****************************************************************************
 497  * Divers:
 498  *****************************************************************************/
 499
 500 /* PSResynch: resynch on a system startcode
 501  *  It doesn't skip more than 512 bytes
 502  *  -1 -> error, 0 -> not synch, 1 -> ok
 503  */
 504 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 505 {
 506     uint8_t *p_peek;
 507     int     i_peek;
 508     int     i_skip;
 509
 510     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 511     {
 512         return -1;
 513     }
 514     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 515         p_peek[3] >= 0xb9 )
 516     {
 517         *pi_code = 0x100 | p_peek[3];
 518         return 1;
 519     }
 520
 521     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 522     {
 523         return -1;
 524     }
 525     i_skip = 0;
 526
 527     for( ;; )
 528     {
 529         if( i_peek < 4 )
 530         {
 531             break;
 532         }
 533         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 534             p_peek[3] >= 0xb9 )
 535         {
 536             *pi_code = 0x100 | p_peek[3];
 537             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 538         }
 539
 540         p_peek++;
 541         i_peek--;
 542         i_skip++;
 543     }
 544     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 545 }
 546
 547 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 548 {
 549     uint8_t *p_peek;
 550     int      i_peek = stream_Peek( s, &p_peek, 14 );
 551     int      i_size = ps_pkt_size( p_peek, i_peek );
 552
 553     if( i_size <= 6 && p_peek[3] > 0xba )
 554     {
 555         /* Special case, search the next start code */
 556         i_size = 6;
 557         for( ;; )
 558         {
 559             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 560             if( i_peek <= i_size + 4 )
 561             {
 562                 return NULL;
 563             }
 564             while( i_size <= i_peek - 4 )
 565             {
 566                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 567                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 568                 {
 569                     return stream_Block( s, i_size );
 570                 }
 571                 i_size++;
 572             }
 573         }
 574     }
 575     else
 576     {
 577         /* Normal case */
 578         return stream_Block( s, i_size );
 579     }
 580
 581     return NULL;
 582 }