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/input.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  Open   ( vlc_object_t * );
  48 static int  OpenAlt( 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( Open, 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( OpenAlt, 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 Open( vlc_object_t *p_this )
  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( p_peek[0] != 0 || p_peek[1] != 0 ||
 111         p_peek[2] != 1 || p_peek[3] < 0xb9 )
 112     {
 113         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
 114                   "continuing anyway" );
 115     }
 116
 117     /* Fill p_demux field */
 118     p_demux->pf_demux = Demux;
 119     p_demux->pf_control = Control;
 120     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
 121
 122     /* Init p_sys */
 123     p_sys->i_mux_rate = 0;
 124     p_sys->i_scr      = -1;
 125     p_sys->i_length   = -1;
 126     p_sys->i_current_pts = (mtime_t) 0;
 127     p_sys->i_time_track = -1;
 128
 129     p_sys->b_lost_sync = VLC_FALSE;
 130     p_sys->b_have_pack = VLC_FALSE;
 131     p_sys->b_seekable  = VLC_FALSE;
 132
 133     stream_Control( p_demux->s, STREAM_CAN_SEEK, &p_sys->b_seekable );
 134
 135     ps_psm_init( &p_sys->psm );
 136     ps_track_init( p_sys->tk );
 137
 138     /* TODO prescanning of ES */
 139
 140     return VLC_SUCCESS;
 141 }
 142
 143 static int OpenAlt( vlc_object_t *p_this )
 144 {
 145     demux_t *p_demux = (demux_t*)p_this;
 146     uint8_t *p_peek;
 147
 148     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 149     {
 150         msg_Err( p_demux, "cannot peek" );
 151         return VLC_EGENERIC;
 152     }
 153
 154     if( p_peek[0] != 0 || p_peek[1] != 0 ||
 155         p_peek[2] != 1 || p_peek[3] < 0xb9 )
 156     {
 157         if( !p_demux->b_force ) return VLC_EGENERIC;
 158     }
 159
 160     return Open( p_this );
 161 }
 162
 163 /*****************************************************************************
 164  * Close
 165  *****************************************************************************/
 166 static void Close( vlc_object_t *p_this )
 167 {
 168     demux_t     *p_demux = (demux_t*)p_this;
 169     demux_sys_t *p_sys = p_demux->p_sys;
 170     int i;
 171
 172     for( i = 0; i < PS_TK_COUNT; i++ )
 173     {
 174         ps_track_t *tk = &p_sys->tk[i];
 175         if( tk->b_seen )
 176         {
 177             es_format_Clean( &tk->fmt );
 178             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 179         }
 180     }
 181
 182     ps_psm_destroy( &p_sys->psm );
 183
 184     free( p_sys );
 185 }
 186
 187 static int Demux2( demux_t *p_demux, vlc_bool_t b_end )
 188 {
 189     demux_sys_t *p_sys = p_demux->p_sys;
 190     int i_ret, i_id;
 191     uint32_t i_code;
 192     block_t *p_pkt;
 193
 194     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 195     if( i_ret < 0 )
 196     {
 197         return 0;
 198     }
 199     else if( i_ret == 0 )
 200     {
 201         if( !p_sys->b_lost_sync )
 202             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 203
 204         p_sys->b_lost_sync = VLC_TRUE;
 205         return 1;
 206     }
 207
 208     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 209     p_sys->b_lost_sync = VLC_FALSE;
 210
 211     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 212     {
 213         return 0;
 214     }
 215     if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 216     {
 217         ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 218         if( !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 219         {
 220             if( b_end && p_pkt->i_pts > tk->i_last_pts )
 221             {
 222                 tk->i_last_pts = p_pkt->i_pts;
 223             }
 224             else if ( tk->i_first_pts == -1 )
 225             {
 226                 tk->i_first_pts = p_pkt->i_pts;
 227             }
 228         }
 229     }
 230     block_Release( p_pkt );
 231     return 1;
 232 }
 233
 234 static void FindLength( demux_t *p_demux )
 235 {
 236     demux_sys_t *p_sys = p_demux->p_sys;
 237     int64_t i_current_pos = -1, i_size = 0, i_end = 0;
 238     int i;
 239
 240     if( !var_CreateGetInteger( p_demux, "ps-trust-timestamps" ) )
 241         return;
 242
 243     if( p_sys->i_length == -1 ) /* First time */
 244     {
 245         p_sys->i_length = 0;
 246         /* Check beginning */
 247         i = 0;
 248         i_current_pos = stream_Tell( p_demux->s );
 249         while( !p_demux->b_die && i < 40 && Demux2( p_demux, VLC_FALSE ) > 0 ) i++;
 250
 251         /* Check end */
 252         i_size = stream_Size( p_demux->s );
 253         i_end = __MAX( 0, __MIN( 200000, i_size ) );
 254         stream_Seek( p_demux->s, i_size - i_end );
 255
 256         while( !p_demux->b_die && Demux2( p_demux, VLC_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: %lld", 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 = VLC_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 = VLC_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 = VLC_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             vlc_bool_t b_new = VLC_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 = VLC_TRUE;
 366                 }
 367                 else
 368                 {
 369                     msg_Dbg( p_demux, "es id=0x%x format unknown", i_id );
 370                 }
 371                 tk->b_seen = VLC_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                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 390             {
 391                 if( !b_new && !p_sys->b_have_pack && tk->fmt.i_cat == AUDIO_ES && p_pkt->i_pts > 0 )
 392                 {
 393                     /* A hack to sync the A/V on PES files. */
 394                     msg_Dbg( p_demux, "force SCR: %lld", p_pkt->i_pts );
 395                     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_pkt->i_pts );
 396                 }
 397
 398                 if( (int64_t)p_pkt->i_pts > p_sys->i_current_pts )
 399                 {
 400                     p_sys->i_current_pts = (int64_t)p_pkt->i_pts;
 401                 }
 402
 403                 es_out_Send( p_demux->out, tk->es, p_pkt );
 404             }
 405             else
 406             {
 407                 block_Release( p_pkt );
 408             }
 409         }
 410         else
 411         {
 412             block_Release( p_pkt );
 413         }
 414         break;
 415     }
 416
 417     return 1;
 418 }
 419
 420 /*****************************************************************************
 421  * Control:
 422  *****************************************************************************/
 423 static int Control( demux_t *p_demux, int i_query, va_list args )
 424 {
 425     demux_sys_t *p_sys = p_demux->p_sys;
 426     double f, *pf;
 427     int64_t i64, *pi64;
 428
 429     switch( i_query )
 430     {
 431         case DEMUX_GET_POSITION:
 432             pf = (double*) va_arg( args, double* );
 433             i64 = stream_Size( p_demux->s );
 434             if( i64 > 0 )
 435             {
 436                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 437             }
 438             else
 439             {
 440                 *pf = 0.0;
 441             }
 442             return VLC_SUCCESS;
 443
 444         case DEMUX_SET_POSITION:
 445             f = (double) va_arg( args, double );
 446             i64 = stream_Size( p_demux->s );
 447             p_sys->i_current_pts = 0;
 448             es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 449
 450             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 451
 452         case DEMUX_GET_TIME:
 453             pi64 = (int64_t*)va_arg( args, int64_t * );
 454             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 455             {
 456                 *pi64 = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 457                 return VLC_SUCCESS;
 458             }
 459             if( p_sys->i_mux_rate > 0 )
 460             {
 461                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 462                     p_sys->i_mux_rate;
 463                 return VLC_SUCCESS;
 464             }
 465             *pi64 = 0;
 466             return VLC_EGENERIC;
 467
 468         case DEMUX_GET_LENGTH:
 469             pi64 = (int64_t*)va_arg( args, int64_t * );
 470             if( p_sys->i_length > 0 )
 471             {
 472                 *pi64 = p_sys->i_length;
 473                 return VLC_SUCCESS;
 474             }
 475             else if( p_sys->i_mux_rate > 0 )
 476             {
 477                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 478                     p_sys->i_mux_rate;
 479                 return VLC_SUCCESS;
 480             }
 481             *pi64 = 0;
 482             return VLC_EGENERIC;
 483
 484         case DEMUX_SET_TIME:
 485         case DEMUX_GET_FPS:
 486         default:
 487             return VLC_EGENERIC;
 488     }
 489 }
 490
 491 /*****************************************************************************
 492  * Divers:
 493  *****************************************************************************/
 494
 495 /* PSResynch: resynch on a system starcode
 496  *  It doesn't skip more than 512 bytes
 497  *  -1 -> error, 0 -> not synch, 1 -> ok
 498  */
 499 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 500 {
 501     uint8_t *p_peek;
 502     int     i_peek;
 503     int     i_skip;
 504
 505     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 506     {
 507         return -1;
 508     }
 509     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 510         p_peek[3] >= 0xb9 )
 511     {
 512         *pi_code = 0x100 | p_peek[3];
 513         return 1;
 514     }
 515
 516     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 517     {
 518         return -1;
 519     }
 520     i_skip = 0;
 521
 522     for( ;; )
 523     {
 524         if( i_peek < 4 )
 525         {
 526             break;
 527         }
 528         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 529             p_peek[3] >= 0xb9 )
 530         {
 531             *pi_code = 0x100 | p_peek[3];
 532             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 533         }
 534
 535         p_peek++;
 536         i_peek--;
 537         i_skip++;
 538     }
 539     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 540 }
 541
 542 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 543 {
 544     uint8_t *p_peek;
 545     int      i_peek = stream_Peek( s, &p_peek, 14 );
 546     int      i_size = ps_pkt_size( p_peek, i_peek );
 547
 548     if( i_size <= 6 && p_peek[3] > 0xba )
 549     {
 550         /* Special case, search the next start code */
 551         i_size = 6;
 552         for( ;; )
 553         {
 554             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 555             if( i_peek <= i_size + 4 )
 556             {
 557                 return NULL;
 558             }
 559             while( i_size <= i_peek - 4 )
 560             {
 561                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 562                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 563                 {
 564                     return stream_Block( s, i_size );
 565                 }
 566                 i_size++;
 567             }
 568         }
 569     }
 570     else
 571     {
 572         /* Normal case */
 573         return stream_Block( s, i_size );
 574     }
 575
 576     return NULL;
 577 }