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/vlc.h>
  33 #include <vlc_demux.h>
  34
  35 #include "ps.h"
  36
  37 /* TODO:
  38  *  - re-add pre-scanning.
  39  *  - ...
  40  */
  41
  42 #define TIME_TEXT N_("Trust MPEG timestamps")
  43 #define TIME_LONGTEXT N_("Normally we use the timestamps of the MPEG files " \
  44     "to calculate position and duration. However sometimes this might not " \
  45     "be usable. Disable this option to calculate from the bitrate instead." )
  46
  47 /*****************************************************************************
  48  * Module descriptor
  49  *****************************************************************************/
  50 static int  OpenForce( vlc_object_t * );
  51 static int  Open   ( vlc_object_t * );
  52 static void Close  ( vlc_object_t * );
  53
  54 vlc_module_begin();
  55     set_description( _("MPEG-PS demuxer") );
  56     set_category( CAT_INPUT );
  57     set_subcategory( SUBCAT_INPUT_DEMUX );
  58     set_capability( "demux", 1 );
  59     set_callbacks( OpenForce, Close );
  60     add_shortcut( "ps" );
  61
  62     add_bool( "ps-trust-timestamps", true, NULL, TIME_TEXT,
  63                  TIME_LONGTEXT, true );
  64
  65     add_submodule();
  66     set_description( _("MPEG-PS demuxer") );
  67     set_capability( "demux", 8 );
  68     set_callbacks( Open, Close );
  69 vlc_module_end();
  70
  71 /*****************************************************************************
  72  * Local prototypes
  73  *****************************************************************************/
  74
  75 struct demux_sys_t
  76 {
  77     ps_psm_t    psm;
  78     ps_track_t  tk[PS_TK_COUNT];
  79
  80     int64_t     i_scr;
  81     int         i_mux_rate;
  82     int64_t     i_length;
  83     int         i_time_track;
  84     int64_t     i_current_pts;
  85
  86     bool  b_lost_sync;
  87     bool  b_have_pack;
  88     bool  b_seekable;
  89 };
  90
  91 static int Demux  ( demux_t *p_demux );
  92 static int Control( demux_t *p_demux, int i_query, va_list args );
  93
  94 static int      ps_pkt_resynch( stream_t *, uint32_t *pi_code );
  95 static block_t *ps_pkt_read   ( stream_t *, uint32_t i_code );
  96
  97 /*****************************************************************************
  98  * Open
  99  *****************************************************************************/
 100 static int OpenCommon( vlc_object_t *p_this, bool b_force )
 101 {
 102     demux_t     *p_demux = (demux_t*)p_this;
 103     demux_sys_t *p_sys;
 104
 105     const uint8_t *p_peek;
 106
 107     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 108     {
 109         msg_Err( p_demux, "cannot peek" );
 110         return VLC_EGENERIC;
 111     }
 112
 113     if( memcmp( p_peek, "\x00\x00\x01", 3 ) || ( p_peek[3] < 0xb9 ) )
 114     {
 115         if( !b_force )
 116             return VLC_EGENERIC;
 117
 118         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
 119                   "continuing anyway" );
 120     }
 121
 122     /* Fill p_demux field */
 123     p_demux->pf_demux = Demux;
 124     p_demux->pf_control = Control;
 125     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
 126
 127     /* Init p_sys */
 128     p_sys->i_mux_rate = 0;
 129     p_sys->i_scr      = -1;
 130     p_sys->i_length   = -1;
 131     p_sys->i_current_pts = (mtime_t) 0;
 132     p_sys->i_time_track = -1;
 133
 134     p_sys->b_lost_sync = false;
 135     p_sys->b_have_pack = false;
 136     p_sys->b_seekable  = false;
 137
 138     stream_Control( p_demux->s, STREAM_CAN_SEEK, &p_sys->b_seekable );
 139
 140     ps_psm_init( &p_sys->psm );
 141     ps_track_init( p_sys->tk );
 142
 143     /* TODO prescanning of ES */
 144
 145     return VLC_SUCCESS;
 146 }
 147
 148 static int OpenForce( vlc_object_t *p_this )
 149 {
 150     return OpenCommon( p_this, true );
 151 }
 152
 153 static int Open( vlc_object_t *p_this )
 154 {
 155     return OpenCommon( p_this, ((demux_t *)p_this)->b_force );
 156 }
 157
 158 /*****************************************************************************
 159  * Close
 160  *****************************************************************************/
 161 static void Close( vlc_object_t *p_this )
 162 {
 163     demux_t     *p_demux = (demux_t*)p_this;
 164     demux_sys_t *p_sys = p_demux->p_sys;
 165     int i;
 166
 167     for( i = 0; i < PS_TK_COUNT; i++ )
 168     {
 169         ps_track_t *tk = &p_sys->tk[i];
 170         if( tk->b_seen )
 171         {
 172             es_format_Clean( &tk->fmt );
 173             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 174         }
 175     }
 176
 177     ps_psm_destroy( &p_sys->psm );
 178
 179     free( p_sys );
 180 }
 181
 182 static int Demux2( demux_t *p_demux, bool b_end )
 183 {
 184     demux_sys_t *p_sys = p_demux->p_sys;
 185     int i_ret, i_id;
 186     uint32_t i_code;
 187     block_t *p_pkt;
 188
 189     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 190     if( i_ret < 0 )
 191     {
 192         return 0;
 193     }
 194     else if( i_ret == 0 )
 195     {
 196         if( !p_sys->b_lost_sync )
 197             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 198
 199         p_sys->b_lost_sync = true;
 200         return 1;
 201     }
 202
 203     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 204     p_sys->b_lost_sync = false;
 205
 206     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 207     {
 208         return 0;
 209     }
 210     if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 211     {
 212         ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 213         if( !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 214         {
 215             if( b_end && p_pkt->i_pts > tk->i_last_pts )
 216             {
 217                 tk->i_last_pts = p_pkt->i_pts;
 218             }
 219             else if ( tk->i_first_pts == -1 )
 220             {
 221                 tk->i_first_pts = p_pkt->i_pts;
 222             }
 223         }
 224     }
 225     block_Release( p_pkt );
 226     return 1;
 227 }
 228
 229 static void FindLength( demux_t *p_demux )
 230 {
 231     demux_sys_t *p_sys = p_demux->p_sys;
 232     int64_t i_current_pos = -1, i_size = 0, i_end = 0;
 233     int i;
 234
 235     if( !var_CreateGetInteger( p_demux, "ps-trust-timestamps" ) )
 236         return;
 237
 238     if( p_sys->i_length == -1 ) /* First time */
 239     {
 240         p_sys->i_length = 0;
 241         /* Check beginning */
 242         i = 0;
 243         i_current_pos = stream_Tell( p_demux->s );
 244         while( !p_demux->b_die && i < 40 && Demux2( p_demux, false ) > 0 ) i++;
 245
 246         /* Check end */
 247         i_size = stream_Size( p_demux->s );
 248         i_end = __MAX( 0, __MIN( 200000, i_size ) );
 249         stream_Seek( p_demux->s, i_size - i_end );
 250
 251         while( !p_demux->b_die && Demux2( p_demux, true ) > 0 );
 252         if( i_current_pos >= 0 ) stream_Seek( p_demux->s, i_current_pos );
 253     }
 254
 255     for( i = 0; i < PS_TK_COUNT; i++ )
 256     {
 257         ps_track_t *tk = &p_sys->tk[i];
 258         if( tk->i_first_pts >= 0 && tk->i_last_pts > 0 )
 259             if( tk->i_last_pts > tk->i_first_pts )
 260             {
 261                 int64_t i_length = (int64_t)tk->i_last_pts - tk->i_first_pts;
 262                 if( i_length > p_sys->i_length )
 263                 {
 264                     p_sys->i_length = i_length;
 265                     p_sys->i_time_track = i;
 266                     msg_Dbg( p_demux, "we found a length of: "I64Fd, p_sys->i_length );
 267                 }
 268             }
 269     }
 270 }
 271
 272 /*****************************************************************************
 273  * Demux:
 274  *****************************************************************************/
 275 static int Demux( demux_t *p_demux )
 276 {
 277     demux_sys_t *p_sys = p_demux->p_sys;
 278     int i_ret, i_id, i_mux_rate;
 279     uint32_t i_code;
 280     block_t *p_pkt;
 281
 282     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 283     if( i_ret < 0 )
 284     {
 285         return 0;
 286     }
 287     else if( i_ret == 0 )
 288     {
 289         if( !p_sys->b_lost_sync )
 290             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 291
 292         p_sys->b_lost_sync = true;
 293         return 1;
 294     }
 295
 296     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 297     p_sys->b_lost_sync = false;
 298
 299     if( p_sys->i_length < 0 && p_sys->b_seekable )
 300         FindLength( p_demux );
 301
 302     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 303     {
 304         return 0;
 305     }
 306
 307     switch( i_code )
 308     {
 309     case 0x1b9:
 310         block_Release( p_pkt );
 311         break;
 312
 313     case 0x1ba:
 314         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 315         {
 316             if( !p_sys->b_have_pack ) p_sys->b_have_pack = true;
 317             /* done later on to work around bad vcd/svcd streams */
 318             /* es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr ); */
 319             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 320         }
 321         block_Release( p_pkt );
 322         break;
 323
 324     case 0x1bb:
 325         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 326         {
 327             int i;
 328             for( i = 0; i < PS_TK_COUNT; i++ )
 329             {
 330                 ps_track_t *tk = &p_sys->tk[i];
 331
 332                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 333                 {
 334                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 335                 }
 336             }
 337         }
 338         block_Release( p_pkt );
 339         break;
 340
 341     case 0x1bc:
 342         if( p_sys->psm.i_version == 0xFFFF )
 343             msg_Dbg( p_demux, "contains a PSM");
 344
 345         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 346         block_Release( p_pkt );
 347         break;
 348
 349     default:
 350         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 351         {
 352             bool b_new = false;
 353             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 354
 355             if( !tk->b_seen )
 356             {
 357                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 358                 {
 359                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 360                     b_new = true;
 361                 }
 362                 else
 363                 {
 364                     msg_Dbg( p_demux, "es id=0x%x format unknown", i_id );
 365                 }
 366                 tk->b_seen = true;
 367             }
 368
 369             /* The popular VCD/SVCD subtitling WinSubMux does not
 370              * renumber the SCRs when merging subtitles into the PES */
 371             if( tk->b_seen &&
 372                 ( tk->fmt.i_codec == VLC_FOURCC('o','g','t',' ') ||
 373                   tk->fmt.i_codec == VLC_FOURCC('c','v','d',' ') ) )
 374             {
 375                 p_sys->i_scr = -1;
 376             }
 377
 378             if( p_sys->i_scr > 0 )
 379                 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 380
 381             p_sys->i_scr = -1;
 382
 383             if( tk->b_seen && tk->es &&
 384                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 385             {
 386                 if( !b_new && !p_sys->b_have_pack && tk->fmt.i_cat == AUDIO_ES && p_pkt->i_pts > 0 )
 387                 {
 388                     /* A hack to sync the A/V on PES files. */
 389                     msg_Dbg( p_demux, "force SCR: "I64Fd, p_pkt->i_pts );
 390                     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_pkt->i_pts );
 391                 }
 392
 393                 if( (int64_t)p_pkt->i_pts > p_sys->i_current_pts )
 394                 {
 395                     p_sys->i_current_pts = (int64_t)p_pkt->i_pts;
 396                 }
 397
 398                 es_out_Send( p_demux->out, tk->es, p_pkt );
 399             }
 400             else
 401             {
 402                 block_Release( p_pkt );
 403             }
 404         }
 405         else
 406         {
 407             block_Release( p_pkt );
 408         }
 409         break;
 410     }
 411
 412     return 1;
 413 }
 414
 415 /*****************************************************************************
 416  * Control:
 417  *****************************************************************************/
 418 static int Control( demux_t *p_demux, int i_query, va_list args )
 419 {
 420     demux_sys_t *p_sys = p_demux->p_sys;
 421     double f, *pf;
 422     int64_t i64, *pi64;
 423
 424     switch( i_query )
 425     {
 426         case DEMUX_GET_POSITION:
 427             pf = (double*) va_arg( args, double* );
 428             i64 = stream_Size( p_demux->s );
 429             if( i64 > 0 )
 430             {
 431                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 432             }
 433             else
 434             {
 435                 *pf = 0.0;
 436             }
 437             return VLC_SUCCESS;
 438
 439         case DEMUX_SET_POSITION:
 440             f = (double) va_arg( args, double );
 441             i64 = stream_Size( p_demux->s );
 442             p_sys->i_current_pts = 0;
 443             es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 444
 445             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 446
 447         case DEMUX_GET_TIME:
 448             pi64 = (int64_t*)va_arg( args, int64_t * );
 449             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 450             {
 451                 *pi64 = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 452                 return VLC_SUCCESS;
 453             }
 454             if( p_sys->i_mux_rate > 0 )
 455             {
 456                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 457                     p_sys->i_mux_rate;
 458                 return VLC_SUCCESS;
 459             }
 460             *pi64 = 0;
 461             return VLC_EGENERIC;
 462
 463         case DEMUX_GET_LENGTH:
 464             pi64 = (int64_t*)va_arg( args, int64_t * );
 465             if( p_sys->i_length > 0 )
 466             {
 467                 *pi64 = p_sys->i_length;
 468                 return VLC_SUCCESS;
 469             }
 470             else if( p_sys->i_mux_rate > 0 )
 471             {
 472                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 473                     p_sys->i_mux_rate;
 474                 return VLC_SUCCESS;
 475             }
 476             *pi64 = 0;
 477             return VLC_EGENERIC;
 478
 479         case DEMUX_SET_TIME:
 480             i64 = (int64_t)va_arg( args, int64_t );
 481             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 482             {
 483                 int64_t i_now = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 484                 int64_t i_pos = stream_Tell( p_demux->s );
 485                 int64_t i_offset = i_pos / (i_now / 1000000) * ((i64 - i_now) / 1000000);
 486                 stream_Seek( p_demux->s, i_pos + i_offset);
 487
 488                 es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 489                 return VLC_SUCCESS;
 490             }
 491             return VLC_EGENERIC;
 492
 493         case DEMUX_GET_FPS:
 494         default:
 495             return VLC_EGENERIC;
 496     }
 497 }
 498
 499 /*****************************************************************************
 500  * Divers:
 501  *****************************************************************************/
 502
 503 /* PSResynch: resynch on a system startcode
 504  *  It doesn't skip more than 512 bytes
 505  *  -1 -> error, 0 -> not synch, 1 -> ok
 506  */
 507 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 508 {
 509     const uint8_t *p_peek;
 510     int     i_peek;
 511     int     i_skip;
 512
 513     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 514     {
 515         return -1;
 516     }
 517     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 518         p_peek[3] >= 0xb9 )
 519     {
 520         *pi_code = 0x100 | p_peek[3];
 521         return 1;
 522     }
 523
 524     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 525     {
 526         return -1;
 527     }
 528     i_skip = 0;
 529
 530     for( ;; )
 531     {
 532         if( i_peek < 4 )
 533         {
 534             break;
 535         }
 536         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 537             p_peek[3] >= 0xb9 )
 538         {
 539             *pi_code = 0x100 | p_peek[3];
 540             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 541         }
 542
 543         p_peek++;
 544         i_peek--;
 545         i_skip++;
 546     }
 547     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 548 }
 549
 550 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 551 {
 552     const uint8_t *p_peek;
 553     int      i_peek = stream_Peek( s, &p_peek, 14 );
 554     int      i_size = ps_pkt_size( p_peek, i_peek );
 555
 556     if( i_size <= 6 && p_peek[3] > 0xba )
 557     {
 558         /* Special case, search the next start code */
 559         i_size = 6;
 560         for( ;; )
 561         {
 562             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 563             if( i_peek <= i_size + 4 )
 564             {
 565                 return NULL;
 566             }
 567             while( i_size <= i_peek - 4 )
 568             {
 569                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 570                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 571                 {
 572                     return stream_Block( s, i_size );
 573                 }
 574                 i_size++;
 575             }
 576         }
 577     }
 578     else
 579     {
 580         /* Normal case */
 581         return stream_Block( s, i_size );
 582     }
 583
 584     return NULL;
 585 }