git.sesse.net Git - vlc/blob - modules/demux/ogg.c

   1 /*****************************************************************************
   2  * ogg.c : ogg stream input module for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2001 VideoLAN
   5  * $Id: ogg.c,v 1.5 2002/11/03 13:22:44 gbazin Exp $
   6  *
   7  * Authors: Gildas Bazin <gbazin@netcourrier.com>
   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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <stdlib.h>                                      /* malloc(), free() */
  28 #include <string.h>
  29
  30 #include <vlc/vlc.h>
  31 #include <vlc/input.h>
  32
  33 #include <sys/types.h>
  34
  35 #include <ogg/ogg.h>
  36
  37 #define OGG_BLOCK_SIZE 4096
  38 #define PAGES_READ_ONCE 1
  39
  40 /*****************************************************************************
  41  * Definitions of structures and functions used by this plugins
  42  *****************************************************************************/
  43 typedef struct logical_stream_s
  44 {
  45     ogg_stream_state os;                        /* logical stream of packets */
  46
  47     int              i_serial_no;
  48     int              i_cat;                            /* AUDIO_ES, VIDEO_ES */
  49     int              i_activated;
  50     vlc_fourcc_t     i_fourcc;
  51     vlc_fourcc_t     i_codec;
  52
  53     es_descriptor_t  *p_es;
  54     int              b_selected;                           /* newly selected */
  55
  56     /* the header of some logical streams (eg vorbis) contain essential
  57      * data for the decoder. We back them up here in case we need to re-feed
  58      * them to the decoder. */
  59     int              b_force_backup;
  60     int              i_packets_backup;
  61     ogg_packet       *p_packets_backup;
  62
  63     /* program clock reference (in units of 90kHz) derived from the previous
  64      * granulepos */
  65     mtime_t i_pcr;
  66
  67     /* info from logical streams */
  68     int i_rate;
  69     int i_bitrate;
  70     int b_reinit;
  71
  72 } logical_stream_t;
  73
  74 struct demux_sys_t
  75 {
  76     ogg_sync_state oy;        /* sync and verify incoming physical bitstream */
  77
  78     int i_streams;                           /* number of logical bitstreams */
  79     logical_stream_t **pp_stream;  /* pointer to an array of logical streams */
  80
  81     /* current audio and video es */
  82     logical_stream_t *p_stream_video;
  83     logical_stream_t *p_stream_audio;
  84
  85     /* stream we use as a time reference for demux reading speed */
  86     logical_stream_t *p_stream_timeref;
  87
  88     /* program clock reference (in units of 90kHz) derived from the pcr of
  89      * one of the sub-streams (p_stream_timeref) */
  90     mtime_t i_pcr;
  91
  92     mtime_t i_length;
  93     int     b_seekable;
  94 };
  95
  96 /*****************************************************************************
  97  * Local prototypes
  98  *****************************************************************************/
  99 static int  Activate  ( vlc_object_t * );
 100 static void Deactivate( vlc_object_t * );
 101 static int  Demux     ( input_thread_t * );
 102
 103 /* Stream managment */
 104 static int  Ogg_StreamStart  ( input_thread_t *, demux_sys_t *, int );
 105 static int  Ogg_StreamSeek   ( input_thread_t *, demux_sys_t *, int, mtime_t );
 106 static void Ogg_StreamStop   ( input_thread_t *, demux_sys_t *, int );
 107
 108 /* Bitstream manipulation */
 109 static int  Ogg_Check        ( input_thread_t *p_input );
 110 static int  Ogg_ReadPage     ( input_thread_t *, demux_sys_t *, ogg_page * );
 111 static void Ogg_DecodePacket ( input_thread_t *p_input,
 112                                logical_stream_t *p_stream,
 113                                ogg_packet *p_oggpacket );
 114 static int  Ogg_FindLogicalStreams( input_thread_t *p_input,
 115                                     demux_sys_t *p_ogg );
 116
 117 /*****************************************************************************
 118  * Module descriptor
 119  *****************************************************************************/
 120 vlc_module_begin();
 121     set_description( _("ogg stream demux" ) );
 122     set_capability( "demux", 50 );
 123     set_callbacks( Activate, Deactivate );
 124     add_shortcut( "ogg" );
 125 vlc_module_end();
 126
 127 /*****************************************************************************
 128  * Stream managment
 129  *****************************************************************************/
 130 static int Ogg_StreamStart( input_thread_t *p_input,
 131                             demux_sys_t *p_ogg, int i_stream )
 132 {
 133 #define p_stream p_ogg->pp_stream[i_stream]
 134     if( !p_stream->p_es )
 135     {
 136         msg_Warn( p_input, "stream[%d] unselectable", i_stream );
 137         return( 0 );
 138     }
 139     if( p_stream->i_activated )
 140     {
 141         msg_Warn( p_input, "stream[%d] already selected", i_stream );
 142         return( 1 );
 143     }
 144
 145     if( !p_stream->p_es->p_decoder_fifo )
 146     {
 147         vlc_mutex_lock( &p_input->stream.stream_lock );
 148         input_SelectES( p_input, p_stream->p_es );
 149         vlc_mutex_unlock( &p_input->stream.stream_lock );
 150     }
 151     p_stream->i_activated = p_stream->p_es->p_decoder_fifo ? 1 : 0;
 152
 153     /* Feed the backup header to the decoder */
 154     if( !p_stream->b_force_backup )
 155     {
 156         int i;
 157         for( i = 0; i < p_stream->i_packets_backup; i++ )
 158         {
 159             Ogg_DecodePacket( p_input, p_stream,
 160                               &p_stream->p_packets_backup[i] );
 161         }
 162     }
 163
 164     //Ogg_StreamSeek( p_input, p_ogg, i_stream, p_ogg->i_time );
 165
 166     return( p_stream->i_activated );
 167 #undef  p_stream
 168 }
 169
 170 static void Ogg_StreamStop( input_thread_t *p_input,
 171                             demux_sys_t *p_ogg, int i_stream )
 172 {
 173 #define p_stream    p_ogg->pp_stream[i_stream]
 174
 175     if( !p_stream->i_activated )
 176     {
 177         msg_Warn( p_input, "stream[%d] already unselected", i_stream );
 178         return;
 179     }
 180
 181     if( p_stream->p_es->p_decoder_fifo )
 182     {
 183         vlc_mutex_lock( &p_input->stream.stream_lock );
 184         input_UnselectES( p_input, p_stream->p_es );
 185         vlc_mutex_unlock( &p_input->stream.stream_lock );
 186     }
 187
 188     p_stream->i_activated = 0;
 189
 190 #undef  p_stream
 191 }
 192
 193 static int Ogg_StreamSeek( input_thread_t *p_input, demux_sys_t  *p_ogg,
 194                            int i_stream, mtime_t i_date )
 195 {
 196 #define p_stream    p_ogg->pp_stream[i_stream]
 197
 198     /* FIXME: todo */
 199
 200     return 1;
 201 #undef p_stream
 202 }
 203
 204 /****************************************************************************
 205  * Ogg_Check: Check we are dealing with an ogg stream.
 206  ****************************************************************************/
 207 static int Ogg_Check( input_thread_t *p_input )
 208 {
 209     u8 *p_peek;
 210     int i_size = input_Peek( p_input, &p_peek, 4 );
 211
 212     /* Check for the Ogg capture pattern */
 213     if( !(i_size>3) || !(p_peek[0] == 'O') || !(p_peek[1] == 'g') ||
 214         !(p_peek[2] == 'g') || !(p_peek[3] == 'S') )
 215         return VLC_EGENERIC;
 216
 217     /* FIXME: Capture pattern might not be enough so we can also check for the
 218      * the first complete page */
 219
 220     return VLC_SUCCESS;
 221 }
 222
 223 /****************************************************************************
 224  * Ogg_ReadPage: Read a full Ogg page from the physical bitstream.
 225  ****************************************************************************
 226  * Returns VLC_SUCCESS if a page has been read. An error might happen if we
 227  * are at the end of stream.
 228  ****************************************************************************/
 229 static int Ogg_ReadPage( input_thread_t *p_input, demux_sys_t *p_ogg,
 230                          ogg_page *p_oggpage )
 231 {
 232     int i_read = 0;
 233     data_packet_t *p_data;
 234     byte_t *p_buffer;
 235
 236     while( ogg_sync_pageout( &p_ogg->oy, p_oggpage ) != 1 )
 237     {
 238         i_read = input_SplitBuffer( p_input, &p_data, OGG_BLOCK_SIZE );
 239         if( i_read <= 0 )
 240             return VLC_EGENERIC;
 241
 242         p_buffer = ogg_sync_buffer( &p_ogg->oy, i_read );
 243         p_input->p_vlc->pf_memcpy( p_buffer, p_data->p_payload_start, i_read );
 244         ogg_sync_wrote( &p_ogg->oy, i_read );
 245         input_DeletePacket( p_input->p_method_data, p_data );
 246     }
 247
 248     return VLC_SUCCESS;
 249 }
 250
 251 /****************************************************************************
 252  * Ogg_DecodePacket: Decode an Ogg packet.
 253  ****************************************************************************/
 254 static void Ogg_DecodePacket( input_thread_t *p_input,
 255                               logical_stream_t *p_stream,
 256                               ogg_packet *p_oggpacket )
 257 {
 258     pes_packet_t  *p_pes;
 259     data_packet_t *p_data;
 260     demux_sys_t *p_ogg = p_input->p_demux_data;
 261
 262     if( p_stream->b_force_backup )
 263     {
 264         /* Backup the ogg packet (likely an header) */
 265         ogg_packet *p_packet_backup;
 266         p_stream->i_packets_backup++;
 267         p_stream->p_packets_backup =
 268             realloc( p_stream->p_packets_backup, p_stream->i_packets_backup *
 269                      sizeof(ogg_packet) );
 270
 271         p_packet_backup =
 272             &p_stream->p_packets_backup[p_stream->i_packets_backup - 1];
 273
 274         p_packet_backup->bytes = p_oggpacket->bytes;
 275         p_packet_backup->granulepos = p_oggpacket->granulepos;
 276         p_packet_backup->packet = malloc( p_oggpacket->bytes );
 277         if( !p_packet_backup->packet ) return;
 278         memcpy( p_packet_backup->packet, p_oggpacket->packet,
 279                 p_oggpacket->bytes );
 280
 281         switch( p_stream->i_fourcc )
 282         {
 283         case VLC_FOURCC( 'v','o','r','b' ):
 284           if( p_stream->i_packets_backup == 3 ) p_stream->b_force_backup = 0;
 285           break;
 286
 287         default:
 288           p_stream->b_force_backup = 0;
 289           break;
 290         }
 291     }
 292
 293     if( !p_stream->p_es->p_decoder_fifo )
 294     {
 295         /* This stream isn't currently selected so we don't need to decode it,
 296          * but we do need to store its pcr as it might be selected later on. */
 297
 298         /* Convert the next granule into a pcr */
 299         p_stream->i_pcr = ( p_oggpacket->granulepos < 0 ) ?
 300             p_stream->i_pcr + ( p_oggpacket->bytes * 90000
 301                 / p_stream->i_bitrate / 8 ):
 302             p_oggpacket->granulepos * 90000 / p_stream->i_rate;
 303
 304         return;
 305     }
 306
 307     if( !( p_pes = input_NewPES( p_input->p_method_data ) ) )
 308     {
 309         return;
 310     }
 311     if( !( p_data = input_NewPacket( p_input->p_method_data,
 312                                      p_oggpacket->bytes ) ) )
 313     {
 314         input_DeletePES( p_input->p_method_data, p_pes );
 315         return;
 316     }
 317
 318     p_pes->p_first = p_pes->p_last = p_data;
 319     p_pes->i_nb_data = 1;
 320     p_pes->i_pes_size = p_oggpacket->bytes;
 321     p_pes->i_dts = p_oggpacket->granulepos;
 322
 323     /* Convert the pcr into a pts */
 324     p_pes->i_pts = ( p_stream->i_pcr < 0 ) ? 0 :
 325         input_ClockGetTS( p_input, p_input->stream.p_selected_program,
 326                           p_stream->i_pcr );
 327
 328     /* Convert the next granule into a pcr */
 329     p_stream->i_pcr = ( p_oggpacket->granulepos < 0 ) ? -1 :
 330                         p_oggpacket->granulepos * 90000 / p_stream->i_rate;
 331
 332     /* Update the main pcr */
 333     if( p_stream == p_ogg->p_stream_timeref )
 334     {
 335         if( p_ogg->p_stream_timeref->i_pcr >= 0 )
 336         {
 337             p_ogg->i_pcr = p_ogg->p_stream_timeref->i_pcr;
 338         }
 339         else
 340         {
 341             p_ogg->i_pcr += ( p_oggpacket->bytes * 90000
 342                               / p_stream->i_bitrate / 8 );
 343         }
 344     }
 345
 346     memcpy( p_data->p_payload_start, p_oggpacket->packet, p_oggpacket->bytes );
 347
 348     input_DecodePES( p_stream->p_es->p_decoder_fifo, p_pes );
 349 }
 350
 351 /****************************************************************************
 352  * Ogg_FindLogicalStreams: Find the logical streams embedded in the physical
 353  *                         stream and fill p_ogg.
 354  *****************************************************************************
 355  * The initial page of a logical stream is marked as a 'bos' page.
 356  * Furthermore, the Ogg specification mandates that grouped bitstreams begin
 357  * together and all of the initial pages must appear before any data pages.
 358  *
 359  * On success this function returns VLC_SUCCESS.
 360  ****************************************************************************/
 361 static int Ogg_FindLogicalStreams( input_thread_t *p_input, demux_sys_t *p_ogg)
 362 {
 363     ogg_packet oggpacket;
 364     ogg_page oggpage;
 365     int i_stream;
 366
 367     while( Ogg_ReadPage( p_input, p_ogg, &oggpage ) == VLC_SUCCESS )
 368     {
 369         if( ogg_page_bos( &oggpage ) )
 370         {
 371
 372             /* All is wonderful in our fine fine little world.
 373              * We found the beginning of our first logical stream. */
 374             while( ogg_page_bos( &oggpage ) )
 375             {
 376                 p_ogg->i_streams++;
 377                 p_ogg->pp_stream =
 378                     realloc( p_ogg->pp_stream, p_ogg->i_streams *
 379                              sizeof(logical_stream_t *) );
 380
 381 #define p_stream p_ogg->pp_stream[p_ogg->i_streams - 1]
 382
 383                 p_stream = malloc( sizeof(logical_stream_t) );
 384                 memset( p_stream, 0, sizeof(logical_stream_t) );
 385
 386                 /* Setup the logical stream */
 387                 p_stream->i_serial_no = ogg_page_serialno( &oggpage );
 388                 ogg_stream_init( &p_stream->os, p_stream->i_serial_no );
 389
 390                 /* The first stream we find is our timeref (might be changed
 391                  * later on) */
 392                 p_ogg->p_stream_timeref = p_stream;
 393
 394                 /* Extract the initial header from the first page and verify
 395                  * the codec type of tis Ogg bitstream */
 396                 if( ogg_stream_pagein( &p_stream->os, &oggpage ) < 0 )
 397                 {
 398                     /* error. stream version mismatch perhaps */
 399                     msg_Err( p_input, "Error reading first page of "
 400                              "Ogg bitstream data" );
 401                     return VLC_EGENERIC;
 402                 }
 403
 404                 /* FIXME: check return value */
 405                 ogg_stream_packetpeek( &p_stream->os, &oggpacket );
 406
 407                 /* Check for Vorbis header */
 408                 if( oggpacket.bytes >= 7 &&
 409                     ! strncmp( &oggpacket.packet[1], "vorbis", 6 ) )
 410                 {
 411                     oggpack_buffer opb;
 412
 413                     msg_Dbg( p_input, "found vorbis header" );
 414                     p_stream->i_cat = AUDIO_ES;
 415                     p_stream->i_fourcc = VLC_FOURCC( 'v','o','r','b' );
 416
 417                     /* Signal that we want to keep a backup of the vorbis
 418                      * stream headers. They will be used when switching between
 419                      * audio streams. */
 420                     p_stream->b_force_backup = 1;
 421
 422                     /* Cheat and get additionnal info ;) */
 423                     oggpack_readinit( &opb, oggpacket.packet, oggpacket.bytes);
 424                     oggpack_adv( &opb, 96 );
 425                     p_stream->i_rate = oggpack_read( &opb, 32 );
 426                     oggpack_adv( &opb, 32 );
 427                     p_stream->i_bitrate = oggpack_read( &opb, 32 );
 428                 }
 429                 else
 430                 {
 431                     msg_Dbg( p_input, "found unknown codec" );
 432                     free( p_stream );
 433                     p_ogg->i_streams--;
 434                 }
 435
 436 #undef p_stream
 437
 438                 if( Ogg_ReadPage( p_input, p_ogg, &oggpage ) != VLC_SUCCESS )
 439                     return VLC_EGENERIC;
 440             }
 441
 442             /* This is the first data page, which means we are now finished
 443              * with the initial pages. We just need to store it in the relevant
 444              * bitstream. */
 445             for( i_stream = 0; i_stream < p_ogg->i_streams; i_stream++ )
 446             {
 447                 if( ogg_stream_pagein( &p_ogg->pp_stream[i_stream]->os,
 448                                        &oggpage ) == 0 )
 449                 {
 450                     break;
 451                 }
 452             }
 453             return VLC_SUCCESS;
 454         }
 455     }
 456     return VLC_EGENERIC;
 457 }
 458
 459 /*****************************************************************************
 460  * Activate: initializes ogg demux structures
 461  *****************************************************************************/
 462 static int Activate( vlc_object_t * p_this )
 463 {
 464     int i_stream, b_forced;
 465     demux_sys_t    *p_ogg;
 466     input_thread_t *p_input = (input_thread_t *)p_this;
 467
 468     p_input->p_demux_data = NULL;
 469     b_forced = ( ( *p_input->psz_demux )&&
 470                  ( !strncmp( p_input->psz_demux, "ogg", 10 ) ) ) ? 1 : 0;
 471
 472     /* Check if we are dealing with an ogg stream */
 473     if( !b_forced && ( Ogg_Check( p_input ) != VLC_SUCCESS ) )
 474         return -1;
 475
 476     /* Allocate p_ogg */
 477     if( !( p_ogg = malloc( sizeof( demux_sys_t ) ) ) )
 478     {
 479         msg_Err( p_input, "out of memory" );
 480         goto error;
 481     }
 482     memset( p_ogg, 0, sizeof( demux_sys_t ) );
 483     p_input->p_demux_data = p_ogg;
 484
 485     p_ogg->i_pcr  = 0;
 486     p_ogg->p_stream_timeref = NULL;
 487     p_ogg->b_seekable = ( ( p_input->stream.b_seekable )
 488                         &&( p_input->stream.i_method == INPUT_METHOD_FILE ) );
 489
 490     /* Initialize the Ogg physical bitstream parser */
 491     ogg_sync_init( &p_ogg->oy );
 492
 493     /* Find the logical streams embedded in the physical stream and
 494      * initialize our p_ogg structure. */
 495     if( Ogg_FindLogicalStreams( p_input, p_ogg ) != VLC_SUCCESS )
 496     {
 497         msg_Err( p_input, "couldn't find an ogg logical stream" );
 498         goto error;
 499     }
 500
 501     /* Set the demux function */
 502     p_input->pf_demux = Demux;
 503
 504     /* Initialize access plug-in structures. */
 505     if( p_input->i_mtu == 0 )
 506     {
 507         /* Improve speed. */
 508         p_input->i_bufsize = INPUT_DEFAULT_BUFSIZE;
 509     }
 510
 511     /* Create one program */
 512     vlc_mutex_lock( &p_input->stream.stream_lock );
 513     if( input_InitStream( p_input, 0 ) == -1)
 514     {
 515         vlc_mutex_unlock( &p_input->stream.stream_lock );
 516         msg_Err( p_input, "cannot init stream" );
 517         goto error;
 518     }
 519     if( input_AddProgram( p_input, 0, 0) == NULL )
 520     {
 521         vlc_mutex_unlock( &p_input->stream.stream_lock );
 522         msg_Err( p_input, "cannot add program" );
 523         goto error;
 524     }
 525     p_input->stream.p_selected_program = p_input->stream.pp_programs[0];
 526     p_input->stream.i_mux_rate = 0;
 527     vlc_mutex_unlock( &p_input->stream.stream_lock );
 528
 529     for( i_stream = 0 ; i_stream < p_ogg->i_streams; i_stream++ )
 530     {
 531 #define p_stream p_ogg->pp_stream[i_stream]
 532         vlc_mutex_lock( &p_input->stream.stream_lock );
 533         p_stream->p_es = input_AddES( p_input,
 534                                       p_input->stream.p_selected_program,
 535                                       p_ogg->i_streams + 1, 0 );
 536         p_input->stream.i_mux_rate += (p_stream->i_bitrate / ( 8 * 50 ));
 537         vlc_mutex_unlock( &p_input->stream.stream_lock );
 538         p_stream->p_es->i_stream_id = i_stream;
 539         p_stream->p_es->i_fourcc = p_stream->i_fourcc;
 540         p_stream->p_es->i_cat = p_stream->i_cat;
 541 #undef p_stream
 542     }
 543
 544     for( i_stream = 0; i_stream < p_ogg->i_streams; i_stream++ )
 545     {
 546 #define p_stream  p_ogg->pp_stream[i_stream]
 547         switch( p_stream->p_es->i_cat )
 548         {
 549             case( VIDEO_ES ):
 550
 551                 if( (p_ogg->p_stream_video == NULL) )
 552                 {
 553                     p_ogg->p_stream_video = p_stream;
 554                     /* TODO add test to see if a decoder has been found */
 555                     Ogg_StreamStart( p_input, p_ogg, i_stream );
 556                 }
 557                 break;
 558
 559             case( AUDIO_ES ):
 560                 if( (p_ogg->p_stream_audio == NULL) )
 561                 {
 562                     p_ogg->p_stream_audio = p_stream;
 563                     p_ogg->p_stream_timeref = p_stream;
 564                     Ogg_StreamStart( p_input, p_ogg, i_stream );
 565                 }
 566                 break;
 567
 568             default:
 569                 break;
 570         }
 571 #undef p_stream
 572     }
 573
 574     /* we select the first audio and video ES */
 575     vlc_mutex_lock( &p_input->stream.stream_lock );
 576     if( !p_ogg->p_stream_video )
 577     {
 578         msg_Warn( p_input, "no video stream found" );
 579     }
 580     if( !p_ogg->p_stream_audio )
 581     {
 582         msg_Warn( p_input, "no audio stream found!" );
 583     }
 584     p_input->stream.p_selected_program->b_is_ok = 1;
 585     vlc_mutex_unlock( &p_input->stream.stream_lock );
 586
 587     /* Call the pace control */
 588     input_ClockManageRef( p_input,
 589                           p_input->stream.p_selected_program,
 590                           p_ogg->i_pcr );
 591
 592     return 0;
 593
 594  error:
 595     Deactivate( (vlc_object_t *)p_input );
 596     return -1;
 597
 598 }
 599
 600 /*****************************************************************************
 601  * Deactivate: frees unused data
 602  *****************************************************************************/
 603 static void Deactivate( vlc_object_t *p_this )
 604 {
 605     input_thread_t *p_input = (input_thread_t *)p_this;
 606     demux_sys_t *p_ogg = (demux_sys_t *)p_input->p_demux_data  ;
 607     int i, j;
 608
 609     if( p_ogg )
 610     {
 611         /* Cleanup the bitstream parser */
 612         ogg_sync_clear( &p_ogg->oy );
 613
 614         for( i = 0; i < p_ogg->i_streams; i++ )
 615         {
 616             ogg_stream_clear( &p_ogg->pp_stream[i]->os );
 617             for( j = 0; j < p_ogg->pp_stream[i]->i_packets_backup; j++ )
 618             {
 619                 free( p_ogg->pp_stream[i]->p_packets_backup[j].packet );
 620             }
 621             free( p_ogg->pp_stream[i]->p_packets_backup );
 622             free( p_ogg->pp_stream[i] );
 623         }
 624         if( p_ogg->pp_stream ) free( p_ogg->pp_stream );
 625
 626         free( p_ogg );
 627     }
 628 }
 629
 630 /*****************************************************************************
 631  * Demux: reads and demuxes data packets
 632  *****************************************************************************
 633  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 634  *****************************************************************************/
 635 static int Demux( input_thread_t * p_input )
 636 {
 637     int i, i_stream, b_eos = 0;
 638     ogg_page    oggpage;
 639     ogg_packet  oggpacket;
 640     demux_sys_t *p_ogg  = (demux_sys_t *)p_input->p_demux_data;
 641
 642 #define p_stream p_ogg->pp_stream[i_stream]
 643     /* detect new selected/unselected streams */
 644     for( i_stream = 0; i_stream < p_ogg->i_streams; i_stream++ )
 645     {
 646         if( p_stream->p_es )
 647         {
 648             if( p_stream->p_es->p_decoder_fifo &&
 649                 !p_stream->i_activated )
 650             {
 651                 Ogg_StreamStart( p_input, p_ogg, i_stream );
 652             }
 653             else
 654             if( !p_stream->p_es->p_decoder_fifo &&
 655                 p_stream->i_activated )
 656             {
 657                 Ogg_StreamStop( p_input, p_ogg, i_stream );
 658             }
 659         }
 660     }
 661
 662     /* search for new video and audio stream to select
 663      * if current have been unselected */
 664     if( ( !p_ogg->p_stream_video )
 665             || ( !p_ogg->p_stream_video->p_es->p_decoder_fifo ) )
 666     {
 667         p_ogg->p_stream_video = NULL;
 668         for( i_stream = 0; i_stream < p_ogg->i_streams; i_stream++ )
 669         {
 670             if( ( p_stream->i_cat == VIDEO_ES )
 671                   &&( p_stream->p_es->p_decoder_fifo ) )
 672             {
 673                 p_ogg->p_stream_video = p_stream;
 674                 break;
 675             }
 676         }
 677     }
 678     if( ( !p_ogg->p_stream_audio )
 679             ||( !p_ogg->p_stream_audio->p_es->p_decoder_fifo ) )
 680     {
 681         p_ogg->p_stream_audio = NULL;
 682         for( i_stream = 0; i_stream < p_ogg->i_streams; i_stream++ )
 683         {
 684             if( ( p_stream->i_cat == AUDIO_ES )
 685                   &&( p_stream->p_es->p_decoder_fifo ) )
 686             {
 687                 p_ogg->p_stream_audio = p_stream;
 688                 p_ogg->p_stream_timeref = p_stream;
 689                 break;
 690             }
 691         }
 692     }
 693
 694     if( p_input->stream.p_selected_program->i_synchro_state == SYNCHRO_REINIT )
 695     {
 696         msg_Warn( p_input, "synchro reinit" );
 697
 698         /* An ogg packet does only contain the starting date of the next
 699          * packet, not its own starting date.
 700          * As a quick work around, we just skip an oggpage */
 701
 702         for( i_stream = 0; i_stream < p_ogg->i_streams; i_stream++ )
 703         {
 704             /* we'll trash all the data until we find the next pcr */
 705             p_stream->b_reinit = 1;
 706             p_ogg->i_pcr = 0;
 707         }
 708     }
 709
 710
 711     /* Demux ogg pages from the stream */
 712     for( i = 0; (i < PAGES_READ_ONCE) || p_ogg->p_stream_timeref->b_reinit;
 713          i++ )
 714     {
 715         if( Ogg_ReadPage( p_input, p_ogg, &oggpage ) != VLC_SUCCESS )
 716         {
 717             b_eos = 1;
 718             break;
 719         }
 720
 721         for( i_stream = 0; i_stream < p_ogg->i_streams; i_stream++ )
 722         {
 723             if( ogg_stream_pagein( &p_stream->os, &oggpage ) != 0 )
 724                 continue;
 725
 726             while( ogg_stream_packetout( &p_stream->os, &oggpacket ) > 0 )
 727             {
 728                 if( !p_stream->p_es )
 729                 {
 730                     break;
 731                 }
 732
 733                 if( p_stream->b_reinit )
 734                 {
 735                     if( oggpacket.granulepos >= 0 )
 736                     {
 737                         p_stream->b_reinit = 0;
 738                         p_stream->i_pcr = oggpacket.granulepos
 739                             * 90000 / p_stream->i_rate;
 740
 741                         if( !p_ogg->i_pcr ||
 742                             (p_stream == p_ogg->p_stream_timeref) )
 743                         {
 744                             /* Call the pace control to reinitialize
 745                              * the system clock */
 746                             p_ogg->i_pcr = p_stream->i_pcr;
 747                             input_ClockManageRef( p_input,
 748                                p_input->stream.p_selected_program,
 749                                p_ogg->i_pcr );
 750                         }
 751                     }
 752                     continue;
 753                 }
 754
 755                 Ogg_DecodePacket( p_input, p_stream, &oggpacket );
 756
 757             }
 758         }
 759 #undef p_stream
 760     }
 761
 762     /* Call the pace control */
 763     if( !b_eos ) input_ClockManageRef( p_input,
 764                                        p_input->stream.p_selected_program,
 765                                        p_ogg->i_pcr );
 766
 767     /* Did we reach the end of stream ? */
 768     return( b_eos ? 0 : 1 );
 769 }