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_category( CAT_INPUT );
  58     set_subcategory( SUBCAT_INPUT_DEMUX );
  59     set_capability( "demux", 1 );
  60     set_callbacks( OpenForce, Close );
  61     add_shortcut( "ps" );
  62
  63     add_bool( "ps-trust-timestamps", true, NULL, TIME_TEXT,
  64                  TIME_LONGTEXT, true );
  65
  66     add_submodule();
  67     set_description( N_("MPEG-PS demuxer") );
  68     set_capability( "demux", 8 );
  69     set_callbacks( Open, Close );
  70 vlc_module_end();
  71
  72 /*****************************************************************************
  73  * Local prototypes
  74  *****************************************************************************/
  75
  76 struct demux_sys_t
  77 {
  78     ps_psm_t    psm;
  79     ps_track_t  tk[PS_TK_COUNT];
  80
  81     int64_t     i_scr;
  82     int         i_mux_rate;
  83     int64_t     i_length;
  84     int         i_time_track;
  85     int64_t     i_current_pts;
  86
  87     bool  b_lost_sync;
  88     bool  b_have_pack;
  89     bool  b_seekable;
  90 };
  91
  92 static int Demux  ( demux_t *p_demux );
  93 static int Control( demux_t *p_demux, int i_query, va_list args );
  94
  95 static int      ps_pkt_resynch( stream_t *, uint32_t *pi_code );
  96 static block_t *ps_pkt_read   ( stream_t *, uint32_t i_code );
  97
  98 /*****************************************************************************
  99  * Open
 100  *****************************************************************************/
 101 static int OpenCommon( vlc_object_t *p_this, bool b_force )
 102 {
 103     demux_t     *p_demux = (demux_t*)p_this;
 104     demux_sys_t *p_sys;
 105
 106     const uint8_t *p_peek;
 107
 108     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 109     {
 110         msg_Err( p_demux, "cannot peek" );
 111         return VLC_EGENERIC;
 112     }
 113
 114     if( memcmp( p_peek, "\x00\x00\x01", 3 ) || ( p_peek[3] < 0xb9 ) )
 115     {
 116         if( !b_force )
 117             return VLC_EGENERIC;
 118
 119         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
 120                   "continuing anyway" );
 121     }
 122
 123     /* Fill p_demux field */
 124     p_demux->pf_demux = Demux;
 125     p_demux->pf_control = Control;
 126     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
 127
 128     /* Init p_sys */
 129     p_sys->i_mux_rate = 0;
 130     p_sys->i_scr      = -1;
 131     p_sys->i_length   = -1;
 132     p_sys->i_current_pts = (mtime_t) 0;
 133     p_sys->i_time_track = -1;
 134
 135     p_sys->b_lost_sync = false;
 136     p_sys->b_have_pack = false;
 137     p_sys->b_seekable  = false;
 138
 139     stream_Control( p_demux->s, STREAM_CAN_SEEK, &p_sys->b_seekable );
 140
 141     ps_psm_init( &p_sys->psm );
 142     ps_track_init( p_sys->tk );
 143
 144     /* TODO prescanning of ES */
 145
 146     return VLC_SUCCESS;
 147 }
 148
 149 static int OpenForce( vlc_object_t *p_this )
 150 {
 151     return OpenCommon( p_this, true );
 152 }
 153
 154 static int Open( vlc_object_t *p_this )
 155 {
 156     return OpenCommon( p_this, ((demux_t *)p_this)->b_force );
 157 }
 158
 159 /*****************************************************************************
 160  * Close
 161  *****************************************************************************/
 162 static void Close( vlc_object_t *p_this )
 163 {
 164     demux_t     *p_demux = (demux_t*)p_this;
 165     demux_sys_t *p_sys = p_demux->p_sys;
 166     int i;
 167
 168     for( i = 0; i < PS_TK_COUNT; i++ )
 169     {
 170         ps_track_t *tk = &p_sys->tk[i];
 171         if( tk->b_seen )
 172         {
 173             es_format_Clean( &tk->fmt );
 174             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 175         }
 176     }
 177
 178     ps_psm_destroy( &p_sys->psm );
 179
 180     free( p_sys );
 181 }
 182
 183 static int Demux2( demux_t *p_demux, bool b_end )
 184 {
 185     demux_sys_t *p_sys = p_demux->p_sys;
 186     int i_ret, i_id;
 187     uint32_t i_code;
 188     block_t *p_pkt;
 189
 190     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 191     if( i_ret < 0 )
 192     {
 193         return 0;
 194     }
 195     else if( i_ret == 0 )
 196     {
 197         if( !p_sys->b_lost_sync )
 198             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 199
 200         p_sys->b_lost_sync = true;
 201         return 1;
 202     }
 203
 204     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 205     p_sys->b_lost_sync = false;
 206
 207     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 208     {
 209         return 0;
 210     }
 211     if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 212     {
 213         ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 214         if( !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 215         {
 216             if( b_end && p_pkt->i_pts > tk->i_last_pts )
 217             {
 218                 tk->i_last_pts = p_pkt->i_pts;
 219             }
 220             else if ( tk->i_first_pts == -1 )
 221             {
 222                 tk->i_first_pts = p_pkt->i_pts;
 223             }
 224         }
 225     }
 226     block_Release( p_pkt );
 227     return 1;
 228 }
 229
 230 static void FindLength( demux_t *p_demux )
 231 {
 232     demux_sys_t *p_sys = p_demux->p_sys;
 233     int64_t i_current_pos = -1, i_size = 0, i_end = 0;
 234     int i;
 235
 236     if( !var_CreateGetInteger( p_demux, "ps-trust-timestamps" ) )
 237         return;
 238
 239     if( p_sys->i_length == -1 ) /* First time */
 240     {
 241         p_sys->i_length = 0;
 242         /* Check beginning */
 243         i = 0;
 244         i_current_pos = stream_Tell( p_demux->s );
 245         while( !p_demux->b_die && i < 40 && Demux2( p_demux, false ) > 0 ) i++;
 246
 247         /* Check end */
 248         i_size = stream_Size( p_demux->s );
 249         i_end = __MAX( 0, __MIN( 200000, i_size ) );
 250         stream_Seek( p_demux->s, i_size - i_end );
 251
 252         while( !p_demux->b_die && Demux2( p_demux, true ) > 0 );
 253         if( i_current_pos >= 0 ) stream_Seek( p_demux->s, i_current_pos );
 254     }
 255
 256     for( i = 0; i < PS_TK_COUNT; i++ )
 257     {
 258         ps_track_t *tk = &p_sys->tk[i];
 259         if( tk->i_first_pts >= 0 && tk->i_last_pts > 0 )
 260             if( tk->i_last_pts > tk->i_first_pts )
 261             {
 262                 int64_t i_length = (int64_t)tk->i_last_pts - tk->i_first_pts;
 263                 if( i_length > p_sys->i_length )
 264                 {
 265                     p_sys->i_length = i_length;
 266                     p_sys->i_time_track = i;
 267                     msg_Dbg( p_demux, "we found a length of: %"PRId64, p_sys->i_length );
 268                 }
 269             }
 270     }
 271 }
 272
 273 /*****************************************************************************
 274  * Demux:
 275  *****************************************************************************/
 276 static int Demux( demux_t *p_demux )
 277 {
 278     demux_sys_t *p_sys = p_demux->p_sys;
 279     int i_ret, i_id, i_mux_rate;
 280     uint32_t i_code;
 281     block_t *p_pkt;
 282
 283     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 284     if( i_ret < 0 )
 285     {
 286         return 0;
 287     }
 288     else if( i_ret == 0 )
 289     {
 290         if( !p_sys->b_lost_sync )
 291             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 292
 293         p_sys->b_lost_sync = true;
 294         return 1;
 295     }
 296
 297     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 298     p_sys->b_lost_sync = false;
 299
 300     if( p_sys->i_length < 0 && p_sys->b_seekable )
 301         FindLength( p_demux );
 302
 303     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 304     {
 305         return 0;
 306     }
 307
 308     switch( i_code )
 309     {
 310     case 0x1b9:
 311         block_Release( p_pkt );
 312         break;
 313
 314     case 0x1ba:
 315         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 316         {
 317             if( !p_sys->b_have_pack ) p_sys->b_have_pack = true;
 318             /* done later on to work around bad vcd/svcd streams */
 319             /* es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr ); */
 320             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 321         }
 322         block_Release( p_pkt );
 323         break;
 324
 325     case 0x1bb:
 326         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 327         {
 328             int i;
 329             for( i = 0; i < PS_TK_COUNT; i++ )
 330             {
 331                 ps_track_t *tk = &p_sys->tk[i];
 332
 333                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 334                 {
 335                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 336                 }
 337             }
 338         }
 339         block_Release( p_pkt );
 340         break;
 341
 342     case 0x1bc:
 343         if( p_sys->psm.i_version == 0xFFFF )
 344             msg_Dbg( p_demux, "contains a PSM");
 345
 346         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 347         block_Release( p_pkt );
 348         break;
 349
 350     default:
 351         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 352         {
 353             bool b_new = false;
 354             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 355
 356             if( !tk->b_seen )
 357             {
 358                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 359                 {
 360                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 361                     b_new = true;
 362                 }
 363                 else
 364                 {
 365                     msg_Dbg( p_demux, "es id=0x%x format unknown", i_id );
 366                 }
 367                 tk->b_seen = true;
 368             }
 369
 370             /* The popular VCD/SVCD subtitling WinSubMux does not
 371              * renumber the SCRs when merging subtitles into the PES */
 372             if( tk->b_seen &&
 373                 ( tk->fmt.i_codec == VLC_FOURCC('o','g','t',' ') ||
 374                   tk->fmt.i_codec == VLC_FOURCC('c','v','d',' ') ) )
 375             {
 376                 p_sys->i_scr = -1;
 377             }
 378
 379             if( p_sys->i_scr > 0 )
 380                 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 381
 382             p_sys->i_scr = -1;
 383
 384             if( tk->b_seen && tk->es &&
 385                 (
 386 #ifdef ZVBI_COMPILED /* FIXME!! */
 387                 tk->fmt.i_codec == VLC_FOURCC('t','e','l','x') ||
 388 #endif
 389                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) ) )
 390             {
 391                 if( !b_new && !p_sys->b_have_pack &&
 392                     (tk->fmt.i_cat == AUDIO_ES) &&
 393                     (p_pkt->i_pts > 0) )
 394                 {
 395                     /* A hack to sync the A/V on PES files. */
 396                     msg_Dbg( p_demux, "force SCR: %"PRId64, p_pkt->i_pts );
 397                     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_pkt->i_pts );
 398                 }
 399
 400                 if( (int64_t)p_pkt->i_pts > p_sys->i_current_pts )
 401                 {
 402                     p_sys->i_current_pts = (int64_t)p_pkt->i_pts;
 403                 }
 404
 405                 es_out_Send( p_demux->out, tk->es, p_pkt );
 406             }
 407             else
 408             {
 409                 block_Release( p_pkt );
 410             }
 411         }
 412         else
 413         {
 414             block_Release( p_pkt );
 415         }
 416         break;
 417     }
 418
 419     return 1;
 420 }
 421
 422 /*****************************************************************************
 423  * Control:
 424  *****************************************************************************/
 425 static int Control( demux_t *p_demux, int i_query, va_list args )
 426 {
 427     demux_sys_t *p_sys = p_demux->p_sys;
 428     double f, *pf;
 429     int64_t i64, *pi64;
 430
 431     switch( i_query )
 432     {
 433         case DEMUX_GET_POSITION:
 434             pf = (double*) va_arg( args, double* );
 435             i64 = stream_Size( p_demux->s );
 436             if( i64 > 0 )
 437             {
 438                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 439             }
 440             else
 441             {
 442                 *pf = 0.0;
 443             }
 444             return VLC_SUCCESS;
 445
 446         case DEMUX_SET_POSITION:
 447             f = (double) va_arg( args, double );
 448             i64 = stream_Size( p_demux->s );
 449             p_sys->i_current_pts = 0;
 450             es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 451
 452             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 453
 454         case DEMUX_GET_TIME:
 455             pi64 = (int64_t*)va_arg( args, int64_t * );
 456             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 457             {
 458                 *pi64 = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 459                 return VLC_SUCCESS;
 460             }
 461             if( p_sys->i_mux_rate > 0 )
 462             {
 463                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 464                     p_sys->i_mux_rate;
 465                 return VLC_SUCCESS;
 466             }
 467             *pi64 = 0;
 468             return VLC_EGENERIC;
 469
 470         case DEMUX_GET_LENGTH:
 471             pi64 = (int64_t*)va_arg( args, int64_t * );
 472             if( p_sys->i_length > 0 )
 473             {
 474                 *pi64 = p_sys->i_length;
 475                 return VLC_SUCCESS;
 476             }
 477             else if( p_sys->i_mux_rate > 0 )
 478             {
 479                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 480                     p_sys->i_mux_rate;
 481                 return VLC_SUCCESS;
 482             }
 483             *pi64 = 0;
 484             return VLC_EGENERIC;
 485
 486         case DEMUX_SET_TIME:
 487             i64 = (int64_t)va_arg( args, int64_t );
 488             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 489             {
 490                 int64_t i_now = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 491                 int64_t i_pos = stream_Tell( p_demux->s );
 492                 int64_t i_offset = i_pos / (i_now / 1000000) * ((i64 - i_now) / 1000000);
 493                 stream_Seek( p_demux->s, i_pos + i_offset);
 494
 495                 es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 496                 return VLC_SUCCESS;
 497             }
 498             return VLC_EGENERIC;
 499
 500         case DEMUX_GET_FPS:
 501         default:
 502             return VLC_EGENERIC;
 503     }
 504 }
 505
 506 /*****************************************************************************
 507  * Divers:
 508  *****************************************************************************/
 509
 510 /* PSResynch: resynch on a system startcode
 511  *  It doesn't skip more than 512 bytes
 512  *  -1 -> error, 0 -> not synch, 1 -> ok
 513  */
 514 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 515 {
 516     const uint8_t *p_peek;
 517     int     i_peek;
 518     int     i_skip;
 519
 520     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 521     {
 522         return -1;
 523     }
 524     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 525         p_peek[3] >= 0xb9 )
 526     {
 527         *pi_code = 0x100 | p_peek[3];
 528         return 1;
 529     }
 530
 531     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 532     {
 533         return -1;
 534     }
 535     i_skip = 0;
 536
 537     for( ;; )
 538     {
 539         if( i_peek < 4 )
 540         {
 541             break;
 542         }
 543         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 544             p_peek[3] >= 0xb9 )
 545         {
 546             *pi_code = 0x100 | p_peek[3];
 547             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 548         }
 549
 550         p_peek++;
 551         i_peek--;
 552         i_skip++;
 553     }
 554     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 555 }
 556
 557 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 558 {
 559     const uint8_t *p_peek;
 560     int      i_peek = stream_Peek( s, &p_peek, 14 );
 561     int      i_size = ps_pkt_size( p_peek, i_peek );
 562
 563     if( i_size <= 6 && p_peek[3] > 0xba )
 564     {
 565         /* Special case, search the next start code */
 566         i_size = 6;
 567         for( ;; )
 568         {
 569             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 570             if( i_peek <= i_size + 4 )
 571             {
 572                 return NULL;
 573             }
 574             while( i_size <= i_peek - 4 )
 575             {
 576                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 577                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 578                 {
 579                     return stream_Block( s, i_size );
 580                 }
 581                 i_size++;
 582             }
 583         }
 584     }
 585     else
 586     {
 587         /* Normal case */
 588         return stream_Block( s, i_size );
 589     }
 590
 591     return NULL;
 592 }