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     if( !p_sys ) return VLC_ENOMEM;
 128
 129     /* Init p_sys */
 130     p_sys->i_mux_rate = 0;
 131     p_sys->i_scr      = -1;
 132     p_sys->i_length   = -1;
 133     p_sys->i_current_pts = (mtime_t) 0;
 134     p_sys->i_time_track = -1;
 135
 136     p_sys->b_lost_sync = false;
 137     p_sys->b_have_pack = false;
 138     p_sys->b_seekable  = false;
 139
 140     stream_Control( p_demux->s, STREAM_CAN_SEEK, &p_sys->b_seekable );
 141
 142     ps_psm_init( &p_sys->psm );
 143     ps_track_init( p_sys->tk );
 144
 145     /* TODO prescanning of ES */
 146
 147     return VLC_SUCCESS;
 148 }
 149
 150 static int OpenForce( vlc_object_t *p_this )
 151 {
 152     return OpenCommon( p_this, true );
 153 }
 154
 155 static int Open( vlc_object_t *p_this )
 156 {
 157     return OpenCommon( p_this, ((demux_t *)p_this)->b_force );
 158 }
 159
 160 /*****************************************************************************
 161  * Close
 162  *****************************************************************************/
 163 static void Close( vlc_object_t *p_this )
 164 {
 165     demux_t     *p_demux = (demux_t*)p_this;
 166     demux_sys_t *p_sys = p_demux->p_sys;
 167     int i;
 168
 169     for( i = 0; i < PS_TK_COUNT; i++ )
 170     {
 171         ps_track_t *tk = &p_sys->tk[i];
 172         if( tk->b_seen )
 173         {
 174             es_format_Clean( &tk->fmt );
 175             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 176         }
 177     }
 178
 179     ps_psm_destroy( &p_sys->psm );
 180
 181     free( p_sys );
 182 }
 183
 184 static int Demux2( demux_t *p_demux, bool b_end )
 185 {
 186     demux_sys_t *p_sys = p_demux->p_sys;
 187     int i_ret, i_id;
 188     uint32_t i_code;
 189     block_t *p_pkt;
 190
 191     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 192     if( i_ret < 0 )
 193     {
 194         return 0;
 195     }
 196     else if( i_ret == 0 )
 197     {
 198         if( !p_sys->b_lost_sync )
 199             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 200
 201         p_sys->b_lost_sync = true;
 202         return 1;
 203     }
 204
 205     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 206     p_sys->b_lost_sync = false;
 207
 208     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 209     {
 210         return 0;
 211     }
 212     if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 213     {
 214         ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 215         if( !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 216         {
 217             if( b_end && p_pkt->i_pts > tk->i_last_pts )
 218             {
 219                 tk->i_last_pts = p_pkt->i_pts;
 220             }
 221             else if ( tk->i_first_pts == -1 )
 222             {
 223                 tk->i_first_pts = p_pkt->i_pts;
 224             }
 225         }
 226     }
 227     block_Release( p_pkt );
 228     return 1;
 229 }
 230
 231 static void FindLength( demux_t *p_demux )
 232 {
 233     demux_sys_t *p_sys = p_demux->p_sys;
 234     int64_t i_current_pos = -1, i_size = 0, i_end = 0;
 235     int i;
 236
 237     if( !var_CreateGetInteger( p_demux, "ps-trust-timestamps" ) )
 238         return;
 239
 240     if( p_sys->i_length == -1 ) /* First time */
 241     {
 242         p_sys->i_length = 0;
 243         /* Check beginning */
 244         i = 0;
 245         i_current_pos = stream_Tell( p_demux->s );
 246         while( vlc_object_alive (p_demux) && i < 40 && Demux2( p_demux, false ) > 0 ) i++;
 247
 248         /* Check end */
 249         i_size = stream_Size( p_demux->s );
 250         i_end = __MAX( 0, __MIN( 200000, i_size ) );
 251         stream_Seek( p_demux->s, i_size - i_end );
 252         i = 0;
 253
 254         while( vlc_object_alive (p_demux) && i < 40 && Demux2( p_demux, true ) > 0 );
 255         if( i_current_pos >= 0 ) stream_Seek( p_demux->s, i_current_pos );
 256     }
 257
 258     for( i = 0; i < PS_TK_COUNT; i++ )
 259     {
 260         ps_track_t *tk = &p_sys->tk[i];
 261         if( tk->i_first_pts >= 0 && tk->i_last_pts > 0 )
 262             if( tk->i_last_pts > tk->i_first_pts )
 263             {
 264                 int64_t i_length = (int64_t)tk->i_last_pts - tk->i_first_pts;
 265                 if( i_length > p_sys->i_length )
 266                 {
 267                     p_sys->i_length = i_length;
 268                     p_sys->i_time_track = i;
 269                     msg_Dbg( p_demux, "we found a length of: %"PRId64, p_sys->i_length );
 270                 }
 271             }
 272     }
 273 }
 274
 275 /*****************************************************************************
 276  * Demux:
 277  *****************************************************************************/
 278 static int Demux( demux_t *p_demux )
 279 {
 280     demux_sys_t *p_sys = p_demux->p_sys;
 281     int i_ret, i_id, i_mux_rate;
 282     uint32_t i_code;
 283     block_t *p_pkt;
 284
 285     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 286     if( i_ret < 0 )
 287     {
 288         return 0;
 289     }
 290     else if( i_ret == 0 )
 291     {
 292         if( !p_sys->b_lost_sync )
 293             msg_Warn( p_demux, "garbage at input, trying to resync..." );
 294
 295         p_sys->b_lost_sync = true;
 296         return 1;
 297     }
 298
 299     if( p_sys->b_lost_sync ) msg_Warn( p_demux, "found sync code" );
 300     p_sys->b_lost_sync = false;
 301
 302     if( p_sys->i_length < 0 && p_sys->b_seekable )
 303         FindLength( p_demux );
 304
 305     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 306     {
 307         return 0;
 308     }
 309
 310     switch( i_code )
 311     {
 312     case 0x1b9:
 313         block_Release( p_pkt );
 314         break;
 315
 316     case 0x1ba:
 317         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 318         {
 319             if( !p_sys->b_have_pack ) p_sys->b_have_pack = true;
 320             /* done later on to work around bad vcd/svcd streams */
 321             /* es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr ); */
 322             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 323         }
 324         block_Release( p_pkt );
 325         break;
 326
 327     case 0x1bb:
 328         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 329         {
 330             int i;
 331             for( i = 0; i < PS_TK_COUNT; i++ )
 332             {
 333                 ps_track_t *tk = &p_sys->tk[i];
 334
 335                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 336                 {
 337                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 338                 }
 339             }
 340         }
 341         block_Release( p_pkt );
 342         break;
 343
 344     case 0x1bc:
 345         if( p_sys->psm.i_version == 0xFFFF )
 346             msg_Dbg( p_demux, "contains a PSM");
 347
 348         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 349         block_Release( p_pkt );
 350         break;
 351
 352     default:
 353         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 354         {
 355             bool b_new = false;
 356             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 357
 358             if( !tk->b_seen )
 359             {
 360                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 361                 {
 362                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 363                     b_new = true;
 364                 }
 365                 else
 366                 {
 367                     msg_Dbg( p_demux, "es id=0x%x format unknown", i_id );
 368                 }
 369                 tk->b_seen = true;
 370             }
 371
 372             /* The popular VCD/SVCD subtitling WinSubMux does not
 373              * renumber the SCRs when merging subtitles into the PES */
 374             if( tk->b_seen &&
 375                 ( tk->fmt.i_codec == VLC_FOURCC('o','g','t',' ') ||
 376                   tk->fmt.i_codec == VLC_FOURCC('c','v','d',' ') ) )
 377             {
 378                 p_sys->i_scr = -1;
 379             }
 380
 381             if( p_sys->i_scr > 0 )
 382                 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 383
 384             p_sys->i_scr = -1;
 385
 386             if( tk->b_seen && tk->es &&
 387                 (
 388 #ifdef ZVBI_COMPILED /* FIXME!! */
 389                 tk->fmt.i_codec == VLC_FOURCC('t','e','l','x') ||
 390 #endif
 391                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) ) )
 392             {
 393                 if( !b_new && !p_sys->b_have_pack &&
 394                     (tk->fmt.i_cat == AUDIO_ES) &&
 395                     (p_pkt->i_pts > 0) )
 396                 {
 397                     /* A hack to sync the A/V on PES files. */
 398                     msg_Dbg( p_demux, "force SCR: %"PRId64, p_pkt->i_pts );
 399                     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_pkt->i_pts );
 400                 }
 401
 402                 if( (int64_t)p_pkt->i_pts > p_sys->i_current_pts )
 403                 {
 404                     p_sys->i_current_pts = (int64_t)p_pkt->i_pts;
 405                 }
 406
 407                 es_out_Send( p_demux->out, tk->es, p_pkt );
 408             }
 409             else
 410             {
 411                 block_Release( p_pkt );
 412             }
 413         }
 414         else
 415         {
 416             block_Release( p_pkt );
 417         }
 418         break;
 419     }
 420
 421     return 1;
 422 }
 423
 424 /*****************************************************************************
 425  * Control:
 426  *****************************************************************************/
 427 static int Control( demux_t *p_demux, int i_query, va_list args )
 428 {
 429     demux_sys_t *p_sys = p_demux->p_sys;
 430     double f, *pf;
 431     int64_t i64, *pi64;
 432
 433     switch( i_query )
 434     {
 435         case DEMUX_GET_POSITION:
 436             pf = (double*) va_arg( args, double* );
 437             i64 = stream_Size( p_demux->s );
 438             if( i64 > 0 )
 439             {
 440                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 441             }
 442             else
 443             {
 444                 *pf = 0.0;
 445             }
 446             return VLC_SUCCESS;
 447
 448         case DEMUX_SET_POSITION:
 449             f = (double) va_arg( args, double );
 450             i64 = stream_Size( p_demux->s );
 451             p_sys->i_current_pts = 0;
 452
 453             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 454
 455         case DEMUX_GET_TIME:
 456             pi64 = (int64_t*)va_arg( args, int64_t * );
 457             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 458             {
 459                 *pi64 = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 460                 return VLC_SUCCESS;
 461             }
 462             if( p_sys->i_mux_rate > 0 )
 463             {
 464                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 465                     p_sys->i_mux_rate;
 466                 return VLC_SUCCESS;
 467             }
 468             *pi64 = 0;
 469             return VLC_EGENERIC;
 470
 471         case DEMUX_GET_LENGTH:
 472             pi64 = (int64_t*)va_arg( args, int64_t * );
 473             if( p_sys->i_length > 0 )
 474             {
 475                 *pi64 = p_sys->i_length;
 476                 return VLC_SUCCESS;
 477             }
 478             else if( p_sys->i_mux_rate > 0 )
 479             {
 480                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 481                     p_sys->i_mux_rate;
 482                 return VLC_SUCCESS;
 483             }
 484             *pi64 = 0;
 485             return VLC_EGENERIC;
 486
 487         case DEMUX_SET_TIME:
 488             i64 = (int64_t)va_arg( args, int64_t );
 489             if( p_sys->i_time_track >= 0 && p_sys->i_current_pts > 0 )
 490             {
 491                 int64_t i_now = p_sys->i_current_pts - p_sys->tk[p_sys->i_time_track].i_first_pts;
 492                 int64_t i_pos = stream_Tell( p_demux->s );
 493                 int64_t i_offset = i_pos / (i_now / 1000000) * ((i64 - i_now) / 1000000);
 494                 stream_Seek( p_demux->s, i_pos + i_offset);
 495
 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;
 562     VLC_UNUSED(i_code);
 563
 564     /* Smallest valid packet */
 565     if( i_peek < 6 ) return NULL;
 566
 567     i_size = ps_pkt_size( p_peek, i_peek );
 568
 569     if( i_size < 0 || ( i_size <= 6 && p_peek[3] > 0xba ) )
 570     {
 571         /* Special case, search the next start code */
 572         i_size = 6;
 573         for( ;; )
 574         {
 575             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 576             if( i_peek <= i_size + 4 )
 577             {
 578                 return NULL;
 579             }
 580             while( i_size <= i_peek - 4 )
 581             {
 582                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 583                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 584                 {
 585                     return stream_Block( s, i_size );
 586                 }
 587                 i_size++;
 588             }
 589         }
 590     }
 591     else
 592     {
 593         /* Normal case */
 594         return stream_Block( s, i_size );
 595     }
 596
 597     return NULL;
 598 }