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