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