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         change_safe ()
  67
  68     add_submodule ()
  69     set_description( N_("MPEG-PS demuxer") )
  70     set_capability( "demux", 8 )
  71     set_callbacks( Open, Close )
  72     add_shortcut( "ps" )
  73 vlc_module_end ()
  74
  75 /*****************************************************************************
  76  * Local prototypes
  77  *****************************************************************************/
  78
  79 struct demux_sys_t
  80 {
  81     ps_psm_t    psm;
  82     ps_track_t  tk[PS_TK_COUNT];
  83
  84     int64_t     i_scr;
  85     int         i_mux_rate;
  86     int64_t     i_length;
  87     int         i_time_track;
  88     int64_t     i_current_pts;
  89
  90     bool  b_lost_sync;
  91     bool  b_have_pack;
  92     bool  b_seekable;
  93 };
  94
  95 static int Demux  ( demux_t *p_demux );
  96 static int Control( demux_t *p_demux, int i_query, va_list args );
  97
  98 static int      ps_pkt_resynch( stream_t *, uint32_t *pi_code );
  99 static block_t *ps_pkt_read   ( stream_t *, uint32_t i_code );
 100
 101 /*****************************************************************************
 102  * Open
 103  *****************************************************************************/
 104 static int OpenCommon( vlc_object_t *p_this, bool b_force )
 105 {
 106     demux_t     *p_demux = (demux_t*)p_this;
 107     demux_sys_t *p_sys;
 108
 109     const uint8_t *p_peek;
 110
 111     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 112     {
 113         msg_Err( p_demux, "cannot peek" );
 114         return VLC_EGENERIC;
 115     }
 116
 117     if( memcmp( p_peek, "\x00\x00\x01", 3 ) || ( p_peek[3] < 0xb9 ) )
 118     {
 119         if( !b_force )
 120             return VLC_EGENERIC;
 121
 122         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
 123                   "continuing anyway" );
 124     }
 125
 126     /* Fill p_demux field */
 127     p_demux->pf_demux = Demux;
 128     p_demux->pf_control = Control;
 129     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
 130     if( !p_sys ) return VLC_ENOMEM;
 131
 132     /* Init p_sys */
 133     p_sys->i_mux_rate = 0;
 134     p_sys->i_scr      = -1;
 135     p_sys->i_length   = -1;
 136     p_sys->i_current_pts = (mtime_t) 0;
 137     p_sys->i_time_track = -1;
 138
 139     p_sys->b_lost_sync = false;
 140     p_sys->b_have_pack = false;
 141     p_sys->b_seekable  = false;
 142
 143     stream_Control( p_demux->s, STREAM_CAN_SEEK, &p_sys->b_seekable );
 144
 145     ps_psm_init( &p_sys->psm );
 146     ps_track_init( p_sys->tk );
 147
 148     /* TODO prescanning of ES */
 149
 150     return VLC_SUCCESS;
 151 }
 152
 153 static int OpenForce( vlc_object_t *p_this )
 154 {
 155     return OpenCommon( p_this, true );
 156 }
 157
 158 static int Open( vlc_object_t *p_this )
 159 {
 160     return OpenCommon( p_this, ((demux_t *)p_this)->b_force );
 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, bool 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 = 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 = 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( vlc_object_alive (p_demux) && i < 40 && Demux2( p_demux, 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         i = 0;
 256
 257         while( vlc_object_alive (p_demux) && i < 40 && Demux2( p_demux, true ) > 0 );
 258         if( i_current_pos >= 0 ) stream_Seek( p_demux->s, i_current_pos );
 259     }
 260
 261     for( i = 0; i < PS_TK_COUNT; i++ )
 262     {
 263         ps_track_t *tk = &p_sys->tk[i];
 264         if( tk->i_first_pts >= 0 && tk->i_last_pts > 0 )
 265             if( tk->i_last_pts > tk->i_first_pts )
 266             {
 267                 int64_t i_length = (int64_t)tk->i_last_pts - tk->i_first_pts;
 268                 if( i_length > p_sys->i_length )
 269                 {
 270                     p_sys->i_length = i_length;
 271                     p_sys->i_time_track = i;
 272                     msg_Dbg( p_demux, "we found a length of: %"PRId64, p_sys->i_length );
 273                 }
 274             }
 275     }
 276 }
 277
 278 /*****************************************************************************
 279  * Demux:
 280  *****************************************************************************/
 281 static int Demux( demux_t *p_demux )
 282 {
 283     demux_sys_t *p_sys = p_demux->p_sys;
 284     int i_ret, i_id, i_mux_rate;
 285     uint32_t i_code;
 286     block_t *p_pkt;
 287
 288     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 289     if( i_ret < 0 )
 290     {
 291         return 0;
 292     }
 293     else if( i_ret == 0 )
 294     {
 295         if( !p_sys->b_lost_sync )
 296             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 297
 298         p_sys->b_lost_sync = true;
 299         return 1;
 300     }
 301
 302     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 303     p_sys->b_lost_sync = false;
 304
 305     if( p_sys->i_length < 0 && p_sys->b_seekable )
 306         FindLength( p_demux );
 307
 308     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 309     {
 310         return 0;
 311     }
 312
 313     switch( i_code )
 314     {
 315     case 0x1b9:
 316         block_Release( p_pkt );
 317         break;
 318
 319     case 0x1ba:
 320         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 321         {
 322             if( !p_sys->b_have_pack ) p_sys->b_have_pack = true;
 323             /* done later on to work around bad vcd/svcd streams */
 324             /* es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr ); */
 325             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 326         }
 327         block_Release( p_pkt );
 328         break;
 329
 330     case 0x1bb:
 331         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 332         {
 333             int i;
 334             for( i = 0; i < PS_TK_COUNT; i++ )
 335             {
 336                 ps_track_t *tk = &p_sys->tk[i];
 337
 338                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 339                 {
 340                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 341                 }
 342             }
 343         }
 344         block_Release( p_pkt );
 345         break;
 346
 347     case 0x1bc:
 348         if( p_sys->psm.i_version == 0xFFFF )
 349             msg_Dbg( p_demux, "contains a PSM");
 350
 351         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 352         block_Release( p_pkt );
 353         break;
 354
 355     default:
 356         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 357         {
 358             bool b_new = false;
 359             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 360
 361             if( !tk->b_seen )
 362             {
 363                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 364                 {
 365                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 366                     b_new = true;
 367                 }
 368                 else
 369                 {
 370                     msg_Dbg( p_demux, "es id=0x%x format unknown", i_id );
 371                 }
 372                 tk->b_seen = true;
 373             }
 374
 375             /* The popular VCD/SVCD subtitling WinSubMux does not
 376              * renumber the SCRs when merging subtitles into the PES */
 377             if( tk->b_seen &&
 378                 ( tk->fmt.i_codec == VLC_FOURCC('o','g','t',' ') ||
 379                   tk->fmt.i_codec == VLC_FOURCC('c','v','d',' ') ) )
 380             {
 381                 p_sys->i_scr = -1;
 382             }
 383
 384             if( p_sys->i_scr > 0 )
 385                 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 386
 387             p_sys->i_scr = -1;
 388
 389             if( tk->b_seen && tk->es &&
 390                 (
 391 #ifdef ZVBI_COMPILED /* FIXME!! */
 392                 tk->fmt.i_codec == VLC_CODEC_TELETEXT ||
 393 #endif
 394                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) ) )
 395             {
 396                 if( !b_new && !p_sys->b_have_pack &&
 397                     (tk->fmt.i_cat == AUDIO_ES) &&
 398                     (p_pkt->i_pts > 0) )
 399                 {
 400                     /* A hack to sync the A/V on PES files. */
 401                     msg_Dbg( p_demux, "force SCR: %"PRId64, p_pkt->i_pts );
 402                     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_pkt->i_pts );
 403                 }
 404
 405                 if( (int64_t)p_pkt->i_pts > p_sys->i_current_pts )
 406                 {
 407                     p_sys->i_current_pts = (int64_t)p_pkt->i_pts;
 408                 }
 409
 410                 es_out_Send( p_demux->out, tk->es, p_pkt );
 411             }
 412             else
 413             {
 414                 block_Release( p_pkt );
 415             }
 416         }
 417         else
 418         {
 419             block_Release( p_pkt );
 420         }
 421         break;
 422     }
 423
 424     return 1;
 425 }
 426
 427 /*****************************************************************************
 428  * Control:
 429  *****************************************************************************/
 430 static int Control( demux_t *p_demux, int i_query, va_list args )
 431 {
 432     demux_sys_t *p_sys = p_demux->p_sys;
 433     double f, *pf;
 434     int64_t i64, *pi64;
 435
 436     switch( i_query )
 437     {
 438         case DEMUX_GET_POSITION:
 439             pf = (double*) va_arg( args, double* );
 440             i64 = stream_Size( p_demux->s );
 441             if( i64 > 0 )
 442             {
 443                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 444             }
 445             else
 446             {
 447                 *pf = 0.0;
 448             }
 449             return VLC_SUCCESS;
 450
 451         case DEMUX_SET_POSITION:
 452             f = (double) va_arg( args, double );
 453             i64 = stream_Size( p_demux->s );
 454             p_sys->i_current_pts = 0;
 455
 456             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 457
 458         case DEMUX_GET_TIME:
 459             pi64 = (int64_t*)va_arg( args, int64_t * );
 460             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 461             {
 462                 *pi64 = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 463                 return VLC_SUCCESS;
 464             }
 465             if( p_sys->i_mux_rate > 0 )
 466             {
 467                 *pi64 = (int64_t)1000000 * ( stream_Tell( 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_GET_LENGTH:
 475             pi64 = (int64_t*)va_arg( args, int64_t * );
 476             if( p_sys->i_length > 0 )
 477             {
 478                 *pi64 = p_sys->i_length;
 479                 return VLC_SUCCESS;
 480             }
 481             else if( p_sys->i_mux_rate > 0 )
 482             {
 483                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 484                     p_sys->i_mux_rate;
 485                 return VLC_SUCCESS;
 486             }
 487             *pi64 = 0;
 488             return VLC_EGENERIC;
 489
 490         case DEMUX_SET_TIME:
 491             i64 = (int64_t)va_arg( args, int64_t );
 492             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 493             {
 494                 int64_t i_now = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 495                 int64_t i_pos = stream_Tell( p_demux->s );
 496
 497                 if( !i_now )
 498                     return i64 ? VLC_EGENERIC : VLC_SUCCESS;
 499
 500                 i_pos *= (float)i64 / (float)i_now;
 501                 stream_Seek( p_demux->s, i_pos );
 502                 return VLC_SUCCESS;
 503             }
 504             return VLC_EGENERIC;
 505
 506         case DEMUX_GET_FPS:
 507         default:
 508             return VLC_EGENERIC;
 509     }
 510 }
 511
 512 /*****************************************************************************
 513  * Divers:
 514  *****************************************************************************/
 515
 516 /* PSResynch: resynch on a system startcode
 517  *  It doesn't skip more than 512 bytes
 518  *  -1 -> error, 0 -> not synch, 1 -> ok
 519  */
 520 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 521 {
 522     const uint8_t *p_peek;
 523     int     i_peek;
 524     int     i_skip;
 525
 526     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 527     {
 528         return -1;
 529     }
 530     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 531         p_peek[3] >= 0xb9 )
 532     {
 533         *pi_code = 0x100 | p_peek[3];
 534         return 1;
 535     }
 536
 537     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 538     {
 539         return -1;
 540     }
 541     i_skip = 0;
 542
 543     for( ;; )
 544     {
 545         if( i_peek < 4 )
 546         {
 547             break;
 548         }
 549         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 550             p_peek[3] >= 0xb9 )
 551         {
 552             *pi_code = 0x100 | p_peek[3];
 553             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 554         }
 555
 556         p_peek++;
 557         i_peek--;
 558         i_skip++;
 559     }
 560     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 561 }
 562
 563 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 564 {
 565     const uint8_t *p_peek;
 566     int      i_peek = stream_Peek( s, &p_peek, 14 );
 567     int      i_size;
 568     VLC_UNUSED(i_code);
 569
 570     /* Smallest valid packet */
 571     if( i_peek < 6 ) return NULL;
 572
 573     i_size = ps_pkt_size( p_peek, i_peek );
 574
 575     if( i_size < 0 || ( i_size <= 6 && p_peek[3] > 0xba ) )
 576     {
 577         /* Special case, search the next start code */
 578         i_size = 6;
 579         for( ;; )
 580         {
 581             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 582             if( i_peek <= i_size + 4 )
 583             {
 584                 return NULL;
 585             }
 586             while( i_size <= i_peek - 4 )
 587             {
 588                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 589                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 590                 {
 591                     return stream_Block( s, i_size );
 592                 }
 593                 i_size++;
 594             }
 595         }
 596     }
 597     else
 598     {
 599         /* Normal case */
 600         return stream_Block( s, i_size );
 601     }
 602
 603     return NULL;
 604 }