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
  28 #include <vlc/vlc.h>
  29 #include <vlc_demux.h>
  30
  31 #include "ps.h"
  32
  33 /* TODO:
  34  *  - re-add pre-scanning.
  35  *  - ...
  36  */
  37
  38 #define TIME_TEXT N_("Trust MPEG timestamps")
  39 #define TIME_LONGTEXT N_("Normally we use the timestamps of the MPEG files " \
  40     "to calculate position and duration. However sometimes this might not " \
  41     "be usable. Disable this option to calculate from the bitrate instead." )
  42
  43 /*****************************************************************************
  44  * Module descriptor
  45  *****************************************************************************/
  46 static int  OpenForce( vlc_object_t * );
  47 static int  Open   ( vlc_object_t * );
  48 static void Close  ( vlc_object_t * );
  49
  50 vlc_module_begin();
  51     set_description( _("MPEG-PS demuxer") );
  52     set_category( CAT_INPUT );
  53     set_subcategory( SUBCAT_INPUT_DEMUX );
  54     set_capability( "demux2", 1 );
  55     set_callbacks( OpenForce, Close );
  56     add_shortcut( "ps" );
  57
  58     add_bool( "ps-trust-timestamps", VLC_TRUE, NULL, TIME_TEXT,
  59                  TIME_LONGTEXT, VLC_TRUE );
  60
  61     add_submodule();
  62     set_description( _("MPEG-PS demuxer") );
  63     set_capability( "demux2", 8 );
  64     set_callbacks( Open, Close );
  65 vlc_module_end();
  66
  67 /*****************************************************************************
  68  * Local prototypes
  69  *****************************************************************************/
  70
  71 struct demux_sys_t
  72 {
  73     ps_psm_t    psm;
  74     ps_track_t  tk[PS_TK_COUNT];
  75
  76     int64_t     i_scr;
  77     int         i_mux_rate;
  78     int64_t     i_length;
  79     int         i_time_track;
  80     int64_t     i_current_pts;
  81
  82     vlc_bool_t  b_lost_sync;
  83     vlc_bool_t  b_have_pack;
  84     vlc_bool_t  b_seekable;
  85 };
  86
  87 static int Demux  ( demux_t *p_demux );
  88 static int Control( demux_t *p_demux, int i_query, va_list args );
  89
  90 static int      ps_pkt_resynch( stream_t *, uint32_t *pi_code );
  91 static block_t *ps_pkt_read   ( stream_t *, uint32_t i_code );
  92
  93 /*****************************************************************************
  94  * Open
  95  *****************************************************************************/
  96 static int OpenCommon( vlc_object_t *p_this, vlc_bool_t b_force )
  97 {
  98     demux_t     *p_demux = (demux_t*)p_this;
  99     demux_sys_t *p_sys;
 100
 101     const uint8_t *p_peek;
 102
 103     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 104     {
 105         msg_Err( p_demux, "cannot peek" );
 106         return VLC_EGENERIC;
 107     }
 108
 109     if( memcmp( p_peek, "\x00\x00\x01", 3 ) || ( p_peek[3] < 0xb9 ) )
 110     {
 111         if( !b_force )
 112             return VLC_EGENERIC;
 113
 114         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
 115                   "continuing anyway" );
 116     }
 117
 118     /* Fill p_demux field */
 119     p_demux->pf_demux = Demux;
 120     p_demux->pf_control = Control;
 121     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
 122
 123     /* Init p_sys */
 124     p_sys->i_mux_rate = 0;
 125     p_sys->i_scr      = -1;
 126     p_sys->i_length   = -1;
 127     p_sys->i_current_pts = (mtime_t) 0;
 128     p_sys->i_time_track = -1;
 129
 130     p_sys->b_lost_sync = VLC_FALSE;
 131     p_sys->b_have_pack = VLC_FALSE;
 132     p_sys->b_seekable  = VLC_FALSE;
 133
 134     stream_Control( p_demux->s, STREAM_CAN_SEEK, &p_sys->b_seekable );
 135
 136     ps_psm_init( &p_sys->psm );
 137     ps_track_init( p_sys->tk );
 138
 139     /* TODO prescanning of ES */
 140
 141     return VLC_SUCCESS;
 142 }
 143
 144 static int OpenForce( vlc_object_t *p_this )
 145 {
 146     return OpenCommon( p_this, VLC_TRUE );
 147 }
 148
 149 static int Open( vlc_object_t *p_this )
 150 {
 151     return OpenCommon( p_this, ((demux_t *)p_this)->b_force );
 152 }
 153
 154 /*****************************************************************************
 155  * Close
 156  *****************************************************************************/
 157 static void Close( vlc_object_t *p_this )
 158 {
 159     demux_t     *p_demux = (demux_t*)p_this;
 160     demux_sys_t *p_sys = p_demux->p_sys;
 161     int i;
 162
 163     for( i = 0; i < PS_TK_COUNT; i++ )
 164     {
 165         ps_track_t *tk = &p_sys->tk[i];
 166         if( tk->b_seen )
 167         {
 168             es_format_Clean( &tk->fmt );
 169             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 170         }
 171     }
 172
 173     ps_psm_destroy( &p_sys->psm );
 174
 175     free( p_sys );
 176 }
 177
 178 static int Demux2( demux_t *p_demux, vlc_bool_t b_end )
 179 {
 180     demux_sys_t *p_sys = p_demux->p_sys;
 181     int i_ret, i_id;
 182     uint32_t i_code;
 183     block_t *p_pkt;
 184
 185     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 186     if( i_ret < 0 )
 187     {
 188         return 0;
 189     }
 190     else if( i_ret == 0 )
 191     {
 192         if( !p_sys->b_lost_sync )
 193             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 194
 195         p_sys->b_lost_sync = VLC_TRUE;
 196         return 1;
 197     }
 198
 199     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 200     p_sys->b_lost_sync = VLC_FALSE;
 201
 202     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 203     {
 204         return 0;
 205     }
 206     if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 207     {
 208         ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 209         if( !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 210         {
 211             if( b_end && p_pkt->i_pts > tk->i_last_pts )
 212             {
 213                 tk->i_last_pts = p_pkt->i_pts;
 214             }
 215             else if ( tk->i_first_pts == -1 )
 216             {
 217                 tk->i_first_pts = p_pkt->i_pts;
 218             }
 219         }
 220     }
 221     block_Release( p_pkt );
 222     return 1;
 223 }
 224
 225 static void FindLength( demux_t *p_demux )
 226 {
 227     demux_sys_t *p_sys = p_demux->p_sys;
 228     int64_t i_current_pos = -1, i_size = 0, i_end = 0;
 229     int i;
 230
 231     if( !var_CreateGetInteger( p_demux, "ps-trust-timestamps" ) )
 232         return;
 233
 234     if( p_sys->i_length == -1 ) /* First time */
 235     {
 236         p_sys->i_length = 0;
 237         /* Check beginning */
 238         i = 0;
 239         i_current_pos = stream_Tell( p_demux->s );
 240         while( !p_demux->b_die && i < 40 && Demux2( p_demux, VLC_FALSE ) > 0 ) i++;
 241
 242         /* Check end */
 243         i_size = stream_Size( p_demux->s );
 244         i_end = __MAX( 0, __MIN( 200000, i_size ) );
 245         stream_Seek( p_demux->s, i_size - i_end );
 246
 247         while( !p_demux->b_die && Demux2( p_demux, VLC_TRUE ) > 0 );
 248         if( i_current_pos >= 0 ) stream_Seek( p_demux->s, i_current_pos );
 249     }
 250
 251     for( i = 0; i < PS_TK_COUNT; i++ )
 252     {
 253         ps_track_t *tk = &p_sys->tk[i];
 254         if( tk->i_first_pts >= 0 && tk->i_last_pts > 0 )
 255             if( tk->i_last_pts > tk->i_first_pts )
 256             {
 257                 int64_t i_length = (int64_t)tk->i_last_pts - tk->i_first_pts;
 258                 if( i_length > p_sys->i_length )
 259                 {
 260                     p_sys->i_length = i_length;
 261                     p_sys->i_time_track = i;
 262                     msg_Dbg( p_demux, "we found a length of: "I64Fd, p_sys->i_length );
 263                 }
 264             }
 265     }
 266 }
 267
 268 /*****************************************************************************
 269  * Demux:
 270  *****************************************************************************/
 271 static int Demux( demux_t *p_demux )
 272 {
 273     demux_sys_t *p_sys = p_demux->p_sys;
 274     int i_ret, i_id, i_mux_rate;
 275     uint32_t i_code;
 276     block_t *p_pkt;
 277
 278     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 279     if( i_ret < 0 )
 280     {
 281         return 0;
 282     }
 283     else if( i_ret == 0 )
 284     {
 285         if( !p_sys->b_lost_sync )
 286             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 287
 288         p_sys->b_lost_sync = VLC_TRUE;
 289         return 1;
 290     }
 291
 292     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 293     p_sys->b_lost_sync = VLC_FALSE;
 294
 295     if( p_sys->i_length < 0 && p_sys->b_seekable )
 296         FindLength( p_demux );
 297
 298     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 299     {
 300         return 0;
 301     }
 302
 303     switch( i_code )
 304     {
 305     case 0x1b9:
 306         block_Release( p_pkt );
 307         break;
 308
 309     case 0x1ba:
 310         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 311         {
 312             if( !p_sys->b_have_pack ) p_sys->b_have_pack = VLC_TRUE;
 313             /* done later on to work around bad vcd/svcd streams */
 314             /* es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr ); */
 315             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 316         }
 317         block_Release( p_pkt );
 318         break;
 319
 320     case 0x1bb:
 321         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 322         {
 323             int i;
 324             for( i = 0; i < PS_TK_COUNT; i++ )
 325             {
 326                 ps_track_t *tk = &p_sys->tk[i];
 327
 328                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 329                 {
 330                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 331                 }
 332             }
 333         }
 334         block_Release( p_pkt );
 335         break;
 336
 337     case 0x1bc:
 338         if( p_sys->psm.i_version == 0xFFFF )
 339             msg_Dbg( p_demux, "contains a PSM");
 340
 341         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 342         block_Release( p_pkt );
 343         break;
 344
 345     default:
 346         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 347         {
 348             vlc_bool_t b_new = VLC_FALSE;
 349             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 350
 351             if( !tk->b_seen )
 352             {
 353                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 354                 {
 355                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 356                     b_new = VLC_TRUE;
 357                 }
 358                 else
 359                 {
 360                     msg_Dbg( p_demux, "es id=0x%x format unknown", i_id );
 361                 }
 362                 tk->b_seen = VLC_TRUE;
 363             }
 364
 365             /* The popular VCD/SVCD subtitling WinSubMux does not
 366              * renumber the SCRs when merging subtitles into the PES */
 367             if( tk->b_seen &&
 368                 ( tk->fmt.i_codec == VLC_FOURCC('o','g','t',' ') ||
 369                   tk->fmt.i_codec == VLC_FOURCC('c','v','d',' ') ) )
 370             {
 371                 p_sys->i_scr = -1;
 372             }
 373
 374             if( p_sys->i_scr > 0 )
 375                 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 376
 377             p_sys->i_scr = -1;
 378
 379             if( tk->b_seen && tk->es &&
 380                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 381             {
 382                 if( !b_new && !p_sys->b_have_pack && tk->fmt.i_cat == AUDIO_ES && p_pkt->i_pts > 0 )
 383                 {
 384                     /* A hack to sync the A/V on PES files. */
 385                     msg_Dbg( p_demux, "force SCR: "I64Fd, p_pkt->i_pts );
 386                     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_pkt->i_pts );
 387                 }
 388
 389                 if( (int64_t)p_pkt->i_pts > p_sys->i_current_pts )
 390                 {
 391                     p_sys->i_current_pts = (int64_t)p_pkt->i_pts;
 392                 }
 393
 394                 es_out_Send( p_demux->out, tk->es, p_pkt );
 395             }
 396             else
 397             {
 398                 block_Release( p_pkt );
 399             }
 400         }
 401         else
 402         {
 403             block_Release( p_pkt );
 404         }
 405         break;
 406     }
 407
 408     return 1;
 409 }
 410
 411 /*****************************************************************************
 412  * Control:
 413  *****************************************************************************/
 414 static int Control( demux_t *p_demux, int i_query, va_list args )
 415 {
 416     demux_sys_t *p_sys = p_demux->p_sys;
 417     double f, *pf;
 418     int64_t i64, *pi64;
 419
 420     switch( i_query )
 421     {
 422         case DEMUX_GET_POSITION:
 423             pf = (double*) va_arg( args, double* );
 424             i64 = stream_Size( p_demux->s );
 425             if( i64 > 0 )
 426             {
 427                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 428             }
 429             else
 430             {
 431                 *pf = 0.0;
 432             }
 433             return VLC_SUCCESS;
 434
 435         case DEMUX_SET_POSITION:
 436             f = (double) va_arg( args, double );
 437             i64 = stream_Size( p_demux->s );
 438             p_sys->i_current_pts = 0;
 439             es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 440
 441             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 442
 443         case DEMUX_GET_TIME:
 444             pi64 = (int64_t*)va_arg( args, int64_t * );
 445             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 446             {
 447                 *pi64 = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 448                 return VLC_SUCCESS;
 449             }
 450             if( p_sys->i_mux_rate > 0 )
 451             {
 452                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 453                     p_sys->i_mux_rate;
 454                 return VLC_SUCCESS;
 455             }
 456             *pi64 = 0;
 457             return VLC_EGENERIC;
 458
 459         case DEMUX_GET_LENGTH:
 460             pi64 = (int64_t*)va_arg( args, int64_t * );
 461             if( p_sys->i_length > 0 )
 462             {
 463                 *pi64 = p_sys->i_length;
 464                 return VLC_SUCCESS;
 465             }
 466             else if( p_sys->i_mux_rate > 0 )
 467             {
 468                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 469                     p_sys->i_mux_rate;
 470                 return VLC_SUCCESS;
 471             }
 472             *pi64 = 0;
 473             return VLC_EGENERIC;
 474
 475         case DEMUX_SET_TIME:
 476             i64 = (int64_t)va_arg( args, int64_t );
 477             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 478             {
 479                 int64_t i_now = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 480                 int64_t i_pos = stream_Tell( p_demux->s );
 481                 int64_t i_offset = i_pos / (i_now / 1000000) * ((i64 - i_now) / 1000000);
 482                 stream_Seek( p_demux->s, i_pos + i_offset);
 483
 484                 es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 485                 return VLC_SUCCESS;
 486             }
 487             return VLC_EGENERIC;
 488
 489         case DEMUX_GET_FPS:
 490         default:
 491             return VLC_EGENERIC;
 492     }
 493 }
 494
 495 /*****************************************************************************
 496  * Divers:
 497  *****************************************************************************/
 498
 499 /* PSResynch: resynch on a system startcode
 500  *  It doesn't skip more than 512 bytes
 501  *  -1 -> error, 0 -> not synch, 1 -> ok
 502  */
 503 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 504 {
 505     const uint8_t *p_peek;
 506     int     i_peek;
 507     int     i_skip;
 508
 509     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 510     {
 511         return -1;
 512     }
 513     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 514         p_peek[3] >= 0xb9 )
 515     {
 516         *pi_code = 0x100 | p_peek[3];
 517         return 1;
 518     }
 519
 520     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 521     {
 522         return -1;
 523     }
 524     i_skip = 0;
 525
 526     for( ;; )
 527     {
 528         if( i_peek < 4 )
 529         {
 530             break;
 531         }
 532         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 533             p_peek[3] >= 0xb9 )
 534         {
 535             *pi_code = 0x100 | p_peek[3];
 536             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 537         }
 538
 539         p_peek++;
 540         i_peek--;
 541         i_skip++;
 542     }
 543     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 544 }
 545
 546 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 547 {
 548     const uint8_t *p_peek;
 549     int      i_peek = stream_Peek( s, &p_peek, 14 );
 550     int      i_size = ps_pkt_size( p_peek, i_peek );
 551
 552     if( i_size <= 6 && p_peek[3] > 0xba )
 553     {
 554         /* Special case, search the next start code */
 555         i_size = 6;
 556         for( ;; )
 557         {
 558             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 559             if( i_peek <= i_size + 4 )
 560             {
 561                 return NULL;
 562             }
 563             while( i_size <= i_peek - 4 )
 564             {
 565                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 566                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 567                 {
 568                     return stream_Block( s, i_size );
 569                 }
 570                 i_size++;
 571             }
 572         }
 573     }
 574     else
 575     {
 576         /* Normal case */
 577         return stream_Block( s, i_size );
 578     }
 579
 580     return NULL;
 581 }