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_integer( "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
 128     p_sys->b_lost_sync = VLC_FALSE;
 129     p_sys->b_have_pack = VLC_FALSE;
 130     p_sys->b_seekable  = VLC_FALSE;
 131
 132     stream_Control( p_demux->s, STREAM_CAN_SEEK, &p_sys->b_seekable );
 133
 134     ps_psm_init( &p_sys->psm );
 135     ps_track_init( p_sys->tk );
 136
 137     /* TODO prescanning of ES */
 138
 139     return VLC_SUCCESS;
 140 }
 141
 142 static int OpenAlt( vlc_object_t *p_this )
 143 {
 144     demux_t *p_demux = (demux_t*)p_this;
 145     uint8_t *p_peek;
 146
 147     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 148     {
 149         msg_Err( p_demux, "cannot peek" );
 150         return VLC_EGENERIC;
 151     }
 152
 153     if( p_peek[0] != 0 || p_peek[1] != 0 ||
 154         p_peek[2] != 1 || p_peek[3] < 0xb9 )
 155     {
 156         if( !p_demux->b_force ) return VLC_EGENERIC;
 157     }
 158
 159     return Open( p_this );
 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 )
 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 = VLC_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 = VLC_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             tk->i_last_pts = p_pkt->i_pts;
 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         i_current_pos = stream_Tell( p_demux->s );
 238         i_size = stream_Size( p_demux->s );
 239         i_end = __MAX( 0, __MIN( 100000, i_size ) );
 240         stream_Seek( p_demux->s, stream_Size( p_demux->s ) - i_end );
 241
 242         while( Demux2( p_demux ) > 0 && !p_demux->b_die ) ;
 243     }
 244
 245     for( i = 0; i < PS_TK_COUNT; i++ )
 246     {
 247         ps_track_t *tk = &p_sys->tk[i];
 248         if( tk->b_seen && tk->i_first_pts > 0 && tk->i_last_pts > 0 )
 249             if( tk->i_last_pts > tk->i_first_pts )
 250             {
 251                 int64_t i_length = (int64_t)tk->i_last_pts - tk->i_first_pts;
 252                 if( i_length > p_sys->i_length )
 253                 {
 254                     p_sys->i_length = i_length;
 255                     p_sys->i_time_track = i;
 256                 }
 257             }
 258     }
 259     if( i_current_pos >= 0 ) stream_Seek( p_demux->s, i_current_pos );
 260 }
 261
 262 /*****************************************************************************
 263  * Demux:
 264  *****************************************************************************/
 265 static int Demux( demux_t *p_demux )
 266 {
 267     demux_sys_t *p_sys = p_demux->p_sys;
 268     int i_ret, i_id, i_mux_rate;
 269     uint32_t i_code;
 270     block_t *p_pkt;
 271
 272     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 273     if( i_ret < 0 )
 274     {
 275         return 0;
 276     }
 277     else if( i_ret == 0 )
 278     {
 279         if( !p_sys->b_lost_sync )
 280             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 281
 282         p_sys->b_lost_sync = VLC_TRUE;
 283         return 1;
 284     }
 285
 286     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 287     p_sys->b_lost_sync = VLC_FALSE;
 288
 289     if( p_sys->b_seekable && p_sys->i_length <= 0 )
 290         FindLength( p_demux );
 291
 292     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 293     {
 294         return 0;
 295     }
 296
 297     switch( i_code )
 298     {
 299     case 0x1b9:
 300         block_Release( p_pkt );
 301         break;
 302
 303     case 0x1ba:
 304         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 305         {
 306             if( !p_sys->b_have_pack ) p_sys->b_have_pack = VLC_TRUE;
 307             /* done later on to work around bad vcd/svcd streams */
 308             /* es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr ); */
 309             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 310         }
 311         block_Release( p_pkt );
 312         break;
 313
 314     case 0x1bb:
 315         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 316         {
 317             int i;
 318             for( i = 0; i < PS_TK_COUNT; i++ )
 319             {
 320                 ps_track_t *tk = &p_sys->tk[i];
 321
 322                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 323                 {
 324                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 325                 }
 326             }
 327         }
 328         block_Release( p_pkt );
 329         break;
 330
 331     case 0x1bc:
 332         if( p_sys->psm.i_version == 0xFFFF )
 333             msg_Dbg( p_demux, "contains a PSM");
 334
 335         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 336         block_Release( p_pkt );
 337         break;
 338
 339     default:
 340         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 341         {
 342             vlc_bool_t b_new = VLC_FALSE;
 343             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 344
 345             if( !tk->b_seen )
 346             {
 347                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 348                 {
 349                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 350                     b_new = VLC_TRUE;
 351                 }
 352                 else
 353                 {
 354                     msg_Dbg( p_demux, "es id=0x%x format unknown", i_id );
 355                 }
 356                 tk->b_seen = VLC_TRUE;
 357             }
 358
 359             /* The popular VCD/SVCD subtitling WinSubMux does not
 360              * renumber the SCRs when merging subtitles into the PES */
 361             if( tk->b_seen &&
 362                 ( tk->fmt.i_codec == VLC_FOURCC('o','g','t',' ') ||
 363                   tk->fmt.i_codec == VLC_FOURCC('c','v','d',' ') ) )
 364             {
 365                 p_sys->i_scr = -1;
 366             }
 367
 368             if( p_sys->i_scr > 0 )
 369                 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 370
 371             p_sys->i_scr = -1;
 372
 373             if( tk->b_seen && tk->es &&
 374                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 375             {
 376                 if( !b_new && !p_sys->b_have_pack && tk->fmt.i_cat == AUDIO_ES && p_pkt->i_pts > 0 )
 377                 {
 378                     /* A hack to sync the A/V on PES files. */
 379                     msg_Dbg( p_demux, "force SCR: %lld", p_pkt->i_pts );
 380                     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_pkt->i_pts );
 381                 }
 382
 383                 if( !tk->i_first_pts && p_pkt->i_pts > 0 )
 384                 {
 385                     tk->i_first_pts = p_pkt->i_pts;
 386                     p_sys->i_length = 0;
 387                 }
 388                 if( (int64_t)p_pkt->i_pts > p_sys->i_current_pts )
 389                 {
 390                     p_sys->i_current_pts = (int64_t)p_pkt->i_pts;
 391                 }
 392
 393                 es_out_Send( p_demux->out, tk->es, p_pkt );
 394             }
 395             else
 396             {
 397                 block_Release( p_pkt );
 398             }
 399         }
 400         else
 401         {
 402             block_Release( p_pkt );
 403         }
 404         break;
 405     }
 406
 407     return 1;
 408 }
 409
 410 /*****************************************************************************
 411  * Control:
 412  *****************************************************************************/
 413 static int Control( demux_t *p_demux, int i_query, va_list args )
 414 {
 415     demux_sys_t *p_sys = p_demux->p_sys;
 416     double f, *pf;
 417     int64_t i64, *pi64;
 418
 419     switch( i_query )
 420     {
 421         case DEMUX_GET_POSITION:
 422             pf = (double*) va_arg( args, double* );
 423             i64 = stream_Size( p_demux->s );
 424             if( i64 > 0 )
 425             {
 426                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 427             }
 428             else
 429             {
 430                 *pf = 0.0;
 431             }
 432             return VLC_SUCCESS;
 433
 434         case DEMUX_SET_POSITION:
 435             f = (double) va_arg( args, double );
 436             i64 = stream_Size( p_demux->s );
 437             p_sys->i_current_pts = 0;
 438             es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 439
 440             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 441
 442         case DEMUX_GET_TIME:
 443             pi64 = (int64_t*)va_arg( args, int64_t * );
 444             if( p_sys->i_current_pts > 0 )
 445             {
 446                 *pi64 = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 447                 return VLC_SUCCESS;
 448             }
 449             if( p_sys->i_mux_rate > 0 )
 450             {
 451                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 452                     p_sys->i_mux_rate;
 453                 return VLC_SUCCESS;
 454             }
 455             *pi64 = 0;
 456             return VLC_EGENERIC;
 457
 458         case DEMUX_GET_LENGTH:
 459             pi64 = (int64_t*)va_arg( args, int64_t * );
 460             if( p_sys->i_length > 0 )
 461             {
 462                 *pi64 = p_sys->i_length;
 463                 return VLC_SUCCESS;
 464             }
 465             else if( p_sys->i_mux_rate > 0 )
 466             {
 467                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 468                     p_sys->i_mux_rate;
 469                 return VLC_SUCCESS;
 470             }
 471             *pi64 = 0;
 472             return VLC_EGENERIC;
 473
 474         case DEMUX_SET_TIME:
 475         case DEMUX_GET_FPS:
 476         default:
 477             return VLC_EGENERIC;
 478     }
 479 }
 480
 481 /*****************************************************************************
 482  * Divers:
 483  *****************************************************************************/
 484
 485 /* PSResynch: resynch on a system starcode
 486  *  It doesn't skip more than 512 bytes
 487  *  -1 -> error, 0 -> not synch, 1 -> ok
 488  */
 489 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 490 {
 491     uint8_t *p_peek;
 492     int     i_peek;
 493     int     i_skip;
 494
 495     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 496     {
 497         return -1;
 498     }
 499     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 500         p_peek[3] >= 0xb9 )
 501     {
 502         *pi_code = 0x100 | p_peek[3];
 503         return 1;
 504     }
 505
 506     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 507     {
 508         return -1;
 509     }
 510     i_skip = 0;
 511
 512     for( ;; )
 513     {
 514         if( i_peek < 4 )
 515         {
 516             break;
 517         }
 518         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 519             p_peek[3] >= 0xb9 )
 520         {
 521             *pi_code = 0x100 | p_peek[3];
 522             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 523         }
 524
 525         p_peek++;
 526         i_peek--;
 527         i_skip++;
 528     }
 529     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 530 }
 531
 532 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 533 {
 534     uint8_t *p_peek;
 535     int      i_peek = stream_Peek( s, &p_peek, 14 );
 536     int      i_size = ps_pkt_size( p_peek, i_peek );
 537
 538     if( i_size <= 6 && p_peek[3] > 0xba )
 539     {
 540         /* Special case, search the next start code */
 541         i_size = 6;
 542         for( ;; )
 543         {
 544             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 545             if( i_peek <= i_size + 4 )
 546             {
 547                 return NULL;
 548             }
 549             while( i_size <= i_peek - 4 )
 550             {
 551                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 552                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 553                 {
 554                     return stream_Block( s, i_size );
 555                 }
 556                 i_size++;
 557             }
 558         }
 559     }
 560     else
 561     {
 562         /* Normal case */
 563         return stream_Block( s, i_size );
 564     }
 565
 566     return NULL;
 567 }