git.sesse.net Git - vlc/blob - src/input/mpeg_system.c

   1 /*****************************************************************************
   2  * mpeg_system.c: TS, PS and PES management
   3  *****************************************************************************
   4  * Copyright (C) 1998, 1999, 2000 VideoLAN
   5  * $Id: mpeg_system.c,v 1.10 2000/12/20 16:04:31 massiot Exp $
   6  *
   7  * Authors:
   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 "defs.h"
  28
  29 #include <stdlib.h>
  30 #include <netinet/in.h>
  31
  32 #include "config.h"
  33 #include "common.h"
  34 #include "threads.h"
  35 #include "mtime.h"
  36
  37 #include "intf_msg.h"
  38
  39 #include "stream_control.h"
  40 #include "input_ext-intf.h"
  41 #include "input_ext-dec.h"
  42
  43 #include "input.h"
  44
  45 #include "mpeg_system.h"
  46
  47 /*****************************************************************************
  48  * Local prototypes
  49  *****************************************************************************/
  50
  51
  52 /*
  53  * PES Packet management
  54  */
  55
  56 /*****************************************************************************
  57  * input_DecodePES
  58  *****************************************************************************
  59  * Put a PES in the decoder's fifo.
  60  *****************************************************************************/
  61 void input_DecodePES( input_thread_t * p_input, es_descriptor_t * p_es )
  62 {
  63 #define p_pes (p_es->p_pes)
  64
  65     if( p_es->p_decoder_fifo != NULL )
  66     {
  67         vlc_mutex_lock( &p_es->p_decoder_fifo->data_lock );
  68
  69 #if 0
  70         if( p_input->stream.b_pace_control )
  71         {
  72             /* FIXME : normally we shouldn't need this... */
  73             while( DECODER_FIFO_ISFULL( *p_es->p_decoder_fifo ) )
  74             {
  75                 vlc_mutex_unlock( &p_es->p_decoder_fifo->data_lock );
  76                 msleep( 20000 );
  77                 vlc_mutex_lock( &p_es->p_decoder_fifo->data_lock );
  78             }
  79         }
  80 #endif
  81
  82         if( !DECODER_FIFO_ISFULL( *p_es->p_decoder_fifo ) )
  83         {
  84             //intf_DbgMsg("Putting %p into fifo %p/%d\n",
  85             //            p_pes, p_fifo, p_fifo->i_end);
  86             p_es->p_decoder_fifo->buffer[p_es->p_decoder_fifo->i_end] = p_pes;
  87             DECODER_FIFO_INCEND( *p_es->p_decoder_fifo );
  88
  89             /* Warn the decoder that it's got work to do. */
  90             vlc_cond_signal( &p_es->p_decoder_fifo->data_wait );
  91         }
  92         else
  93         {
  94             /* The FIFO is full !!! This should not happen. */
  95             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
  96             intf_ErrMsg( "PES trashed - fifo full ! (%d, %d)",
  97                        p_es->i_id, p_es->i_type);
  98         }
  99         vlc_mutex_unlock( &p_es->p_decoder_fifo->data_lock );
 100     }
 101     else
 102     {
 103         intf_ErrMsg("No fifo to receive PES %p (who wrote this damn code ?)",
 104                     p_pes);
 105         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 106     }
 107     p_pes = NULL;
 108
 109 #undef p_pes
 110 }
 111
 112 /*****************************************************************************
 113  * input_ParsePES
 114  *****************************************************************************
 115  * Parse a finished PES packet and analyze its header.
 116  *****************************************************************************/
 117 #define PES_HEADER_SIZE     14
 118 void input_ParsePES( input_thread_t * p_input, es_descriptor_t * p_es )
 119 {
 120     data_packet_t * p_header_data;
 121     byte_t          p_header[PES_HEADER_SIZE];
 122     int             i_done, i_todo;
 123
 124 #define p_pes (p_es->p_pes)
 125
 126     //intf_DbgMsg("End of PES packet %p\n", p_pes);
 127
 128     /* Parse the header. The header has a variable length, but in order
 129      * to improve the algorithm, we will read the 14 bytes we may be
 130      * interested in */
 131     p_header_data = p_pes->p_first;
 132     i_done = 0;
 133
 134     for( ; ; )
 135     {
 136         i_todo = p_header_data->p_payload_end
 137                      - p_header_data->p_payload_start;
 138         if( i_todo > PES_HEADER_SIZE - i_done )
 139             i_todo = PES_HEADER_SIZE - i_done;
 140
 141         memcpy( p_header + i_done, p_header_data->p_payload_start,
 142                 i_todo );
 143         i_done += i_todo;
 144
 145         if( i_done < PES_HEADER_SIZE && p_header_data->p_next != NULL )
 146         {
 147             p_header_data = p_header_data->p_next;
 148         }
 149         else
 150         {
 151             break;
 152         }
 153     }
 154
 155     if( i_done != PES_HEADER_SIZE )
 156     {
 157         intf_WarnMsg( 3, "PES packet too short to have a header" );
 158         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 159         p_pes = NULL;
 160         return;
 161     }
 162
 163     /* Get the PES size if defined */
 164     p_es->i_pes_real_size = U16_AT(p_header + 4) + 6;
 165
 166     /* First read the 6 header bytes common to all PES packets:
 167      * use them to test the PES validity */
 168     if( (p_header[0] || p_header[1] || (p_header[2] != 1)) )
 169     {
 170         /* packet_start_code_prefix != 0x000001 */
 171         intf_ErrMsg( "PES packet doesn't start with 0x000001 : data loss" );
 172         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 173         p_pes = NULL;
 174     }
 175     else
 176     {
 177         int i_pes_header_size, i_payload_size;
 178
 179         if ( p_es->i_pes_real_size &&
 180              (p_es->i_pes_real_size != p_pes->i_pes_size) )
 181         {
 182             /* PES_packet_length is set and != total received payload */
 183             /* Warn the decoder that the data may be corrupt. */
 184             intf_WarnMsg( 3, "PES sizes do not match : packet corrupted" );
 185             p_pes->b_messed_up = 1;
 186         }
 187
 188         switch( p_es->i_stream_id )
 189         {
 190         case 0xBC:  /* Program stream map */
 191         case 0xBE:  /* Padding */
 192         case 0xBF:  /* Private stream 2 */
 193         case 0xB0:  /* ECM */
 194         case 0xB1:  /* EMM */
 195         case 0xFF:  /* Program stream directory */
 196         case 0xF2:  /* DSMCC stream */
 197         case 0xF8:  /* ITU-T H.222.1 type E stream */
 198             /* The payload begins immediately after the 6 bytes header, so
 199              * we have finished with the parsing */
 200             i_pes_header_size = 6;
 201             break;
 202
 203         default:
 204             if( (p_header[6] & 0xC0) == 0x80 )
 205             {
 206                 /* MPEG-2 : the PES header contains at least 3 more bytes. */
 207                 p_pes->b_data_alignment = p_header[6] & 0x04;
 208                 p_pes->b_has_pts = p_header[7] & 0x80;
 209                 i_pes_header_size = p_header[8] + 9;
 210
 211                 /* Now parse the optional header extensions (in the limit of
 212                  * the 14 bytes). */
 213                 if( p_pes->b_has_pts )
 214                 {
 215                     p_pes->i_pts =
 216                       ( ((mtime_t)(p_header[9] & 0x0E) << 29) |
 217                         (((mtime_t)U16_AT(p_header + 10) << 14) - (1 << 14)) |
 218                         ((mtime_t)U16_AT(p_header + 12) >> 1) ) * 300;
 219                     p_pes->i_pts /= 27;
 220                 }
 221             }
 222             else
 223             {
 224                 /* Probably MPEG-1 */
 225                 byte_t *        p_byte;
 226                 data_packet_t * p_data;
 227
 228                 i_pes_header_size = 6;
 229                 p_data = p_pes->p_first;
 230                 p_byte = p_data->p_buffer + 6;
 231                 while( *p_byte == 0xFF && i_pes_header_size < 22 )
 232                 {
 233                     i_pes_header_size++;
 234                     p_byte++;
 235                     if( p_byte >= p_data->p_payload_end )
 236                     {
 237                         p_data = p_data->p_next;
 238                         if( p_data == NULL )
 239                         {
 240                             intf_ErrMsg( "MPEG-1 packet too short for header" );
 241                             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 242                             p_pes = NULL;
 243                             return;
 244                         }
 245                         p_byte = p_data->p_payload_start;
 246                     }
 247                 }
 248                 if( i_pes_header_size == 22 )
 249                 {
 250                     intf_ErrMsg( "Too much MPEG-1 stuffing" );
 251                     p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 252                     p_pes = NULL;
 253                     return;
 254                 }
 255
 256                 if( (*p_byte & 0xC0) == 0x40 )
 257                 {
 258                     /* Don't ask why... --Meuuh */
 259                     p_byte += 2;
 260                     i_pes_header_size += 2;
 261                     if( p_byte >= p_data->p_payload_end )
 262                     {
 263                         int i_plus = p_byte - p_data->p_payload_end;
 264                         p_data = p_data->p_next;
 265                         if( p_data == NULL )
 266                         {
 267                             intf_ErrMsg( "MPEG-1 packet too short for header" );
 268                             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 269                             p_pes = NULL;
 270                             return;
 271                         }
 272                         p_byte = p_data->p_payload_start + i_plus;
 273                     }
 274                 }
 275
 276                 i_pes_header_size++;
 277                 p_pes->b_has_pts = *p_byte & 0x20;
 278
 279                 if( *p_byte & 0x10 )
 280                 {
 281                     /* DTS */
 282                     i_pes_header_size += 5;
 283                 }
 284                 if( *p_byte & 0x20 )
 285                 {
 286                     /* PTS */
 287                     byte_t      p_pts[5];
 288                     int         i;
 289
 290                     i_pes_header_size += 4;
 291                     p_pts[0] = *p_byte;
 292                     for( i = 1; i < 5; i++ )
 293                     {
 294                         p_byte++;
 295                         if( p_byte >= p_data->p_payload_end )
 296                         {
 297                             p_data = p_data->p_next;
 298                             if( p_data == NULL )
 299                             {
 300                                 intf_ErrMsg( "MPEG-1 packet too short for header" );
 301                                 p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 302                                 p_pes = NULL;
 303                                 return;
 304                             }
 305                             p_byte = p_data->p_payload_start;
 306                         }
 307
 308                         p_pts[i] = *p_byte;
 309                     }
 310                     p_pes->i_pts =
 311                       ( ((mtime_t)(p_pts[0] & 0x0E) << 29) |
 312                         (((mtime_t)U16_AT(p_pts + 1) << 14) - (1 << 14)) |
 313                         ((mtime_t)U16_AT(p_pts + 3) >> 1) ) * 300;
 314                     p_pes->i_pts /= 27;
 315                 }
 316             }
 317
 318             /* PTS management */
 319             if( p_pes->b_has_pts )
 320             {
 321                 //intf_Msg("%lld\n", p_pes->i_pts);
 322                 switch( p_es->p_pgrm->i_synchro_state )
 323                 {
 324                 case SYNCHRO_NOT_STARTED:
 325                 case SYNCHRO_START:
 326                     p_pes->b_has_pts = 0;
 327                     break;
 328
 329                 case SYNCHRO_REINIT: /* We skip a PES | Why ?? --Meuuh */
 330                     p_pes->b_has_pts = 0;
 331                     p_es->p_pgrm->i_synchro_state = SYNCHRO_START;
 332                     break;
 333
 334                 case SYNCHRO_OK:
 335                     p_pes->i_pts += p_es->p_pgrm->delta_cr
 336                                          + p_es->p_pgrm->delta_absolute
 337                                          + DEFAULT_PTS_DELAY;
 338                     break;
 339                 }
 340             }
 341             break;
 342         }
 343
 344         if( p_es->i_stream_id == 0xBC )
 345         {
 346             /* With private stream 1, the first byte of the payload
 347              * is a stream_private_id, so skip it. */
 348             i_pes_header_size++;
 349         }
 350
 351         /* Now we've parsed the header, we just have to indicate in some
 352          * specific data packets where the PES payload begins (renumber
 353          * p_payload_start), so that the decoders can find the beginning
 354          * of their data right out of the box. */
 355         p_header_data = p_pes->p_first;
 356         i_payload_size = p_header_data->p_payload_end
 357                                  - p_header_data->p_payload_start;
 358         while( i_pes_header_size > i_payload_size )
 359         {
 360             /* These packets are entirely filled by the PES header. */
 361             i_pes_header_size -= i_payload_size;
 362             p_header_data->p_payload_start = p_header_data->p_payload_end;
 363             /* Go to the next data packet. */
 364             if( (p_header_data = p_header_data->p_next) == NULL )
 365             {
 366                 intf_ErrMsg( "PES header bigger than payload" );
 367                 p_input->p_plugin->pf_delete_pes( p_input->p_method_data,
 368                                                   p_pes );
 369                 p_pes = NULL;
 370                 return;
 371             }
 372             i_payload_size = p_header_data->p_payload_end
 373                                  - p_header_data->p_payload_start;
 374         }
 375         /* This last packet is partly header, partly payload. */
 376         if( i_payload_size < i_pes_header_size )
 377         {
 378             intf_ErrMsg( "PES header bigger than payload" );
 379             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 380             p_pes = NULL;
 381             return;
 382         }
 383         p_header_data->p_payload_start += i_pes_header_size;
 384
 385         /* Now we can eventually put the PES packet in the decoder's
 386          * PES fifo */
 387         input_DecodePES( p_input, p_es );
 388     }
 389 #undef p_pes
 390 }
 391
 392 /*****************************************************************************
 393  * input_GatherPES:
 394  *****************************************************************************
 395  * Gather a PES packet.
 396  *****************************************************************************/
 397 void input_GatherPES( input_thread_t * p_input, data_packet_t * p_data,
 398                       es_descriptor_t * p_es,
 399                       boolean_t b_unit_start, boolean_t b_packet_lost )
 400 {
 401 #define p_pes (p_es->p_pes)
 402
 403     //intf_DbgMsg("PES-demultiplexing %p (%p)\n", p_ts_packet, p_pes);
 404
 405     /* If we lost data, insert an NULL data packet (philosophy : 0 is quite
 406      * often an escape sequence in decoders, so that should make them wait
 407      * for the next start code). */
 408     if( b_packet_lost || p_es->b_discontinuity )
 409     {
 410         data_packet_t *             p_pad_data;
 411
 412         if( (p_pad_data = p_input->p_plugin->pf_new_packet(
 413                                             p_input->p_method_data,
 414                                             PADDING_PACKET_SIZE )) == NULL )
 415         {
 416             intf_ErrMsg("Out of memory\n");
 417             p_input->b_error = 1;
 418             return;
 419         }
 420         memset( p_data->p_buffer, 0, PADDING_PACKET_SIZE );
 421         p_pad_data->b_discard_payload = 1;
 422
 423         if( p_pes != NULL )
 424         {
 425             p_pes->b_messed_up = p_pes->b_discontinuity = 1;
 426             input_GatherPES( p_input, p_pad_data, p_es, 0, 0 );
 427         }
 428         else
 429         {
 430             if( (p_pes = p_input->p_plugin->pf_new_pes(
 431                                             p_input->p_method_data )) == NULL )
 432             {
 433                 intf_ErrMsg("Out of memory\n");
 434                 p_input->b_error = 1;
 435                 return;
 436             }
 437
 438             p_pes->p_first = p_pad_data;
 439             p_pes->b_messed_up = p_pes->b_discontinuity = 1;
 440             input_DecodePES( p_input, p_es );
 441         }
 442
 443         p_es->b_discontinuity = 0;
 444     }
 445
 446     if( b_unit_start && p_pes != NULL )
 447     {
 448         /* If the TS packet contains the begining of a new PES packet, and
 449          * if we were reassembling a PES packet, then the PES should be
 450          * complete now, so parse its header and give it to the decoders. */
 451         input_ParsePES( p_input, p_es );
 452     }
 453
 454     if( !b_unit_start && p_pes == NULL )
 455     {
 456         /* Random access... */
 457         p_input->p_plugin->pf_delete_packet( p_input->p_method_data, p_data );
 458     }
 459     else
 460     {
 461         if( b_unit_start )
 462         {
 463             /* If we are at the beginning of a new PES packet, we must fetch
 464              * a new PES buffer to begin with the reassembly of this PES
 465              * packet. This is also here that we can synchronize with the
 466              * stream if we lost packets or if the decoder has just
 467              * started. */
 468             if( (p_pes = p_input->p_plugin->pf_new_pes( p_input->p_method_data ) ) == NULL )
 469             {
 470                 intf_ErrMsg("Out of memory");
 471                 p_input->b_error = 1;
 472                 return;
 473             }
 474             //intf_DbgMsg("New PES packet %p (first data: %p)\n", p_pes, p_data);
 475             p_pes->p_first = p_data;
 476
 477             /* If the PES header fits in the first data packet, we can
 478              * already set p_gather->i_pes_real_size. */
 479             if( p_data->p_payload_end - p_data->p_payload_start
 480                     >= PES_HEADER_SIZE )
 481             {
 482                 p_es->i_pes_real_size =
 483                                 U16_AT(p_data->p_payload_start + 4) + 6;
 484             }
 485             else
 486             {
 487                 p_es->i_pes_real_size = 0;
 488             }
 489         }
 490         else
 491         {
 492             /* Update the relations between the data packets */
 493             p_es->p_last->p_next = p_data;
 494         }
 495
 496         p_data->p_next = NULL;
 497         p_es->p_last = p_data;
 498
 499         /* Size of the payload carried in the data packet */
 500         p_pes->i_pes_size += (p_data->p_payload_end
 501                                  - p_data->p_payload_start);
 502
 503         /* We can check if the packet is finished */
 504         if( p_pes->i_pes_size == p_es->i_pes_real_size )
 505         {
 506             /* The packet is finished, parse it */
 507             input_ParsePES( p_input, p_es );
 508         }
 509     }
 510 #undef p_pes
 511 }
 512
 513
 514 /*
 515  * Pace control
 516  */
 517
 518 /*
 519  *   DISCUSSION : SYNCHRONIZATION METHOD
 520  *
 521  *   In some cases we can impose the pace of reading (when reading from a
 522  *   file or a pipe), and for the synchronization we simply sleep() until
 523  *   it is time to deliver the packet to the decoders. When reading from
 524  *   the network, we must be read at the same pace as the server writes,
 525  *   otherwise the kernel's buffer will trash packets. The risk is now to
 526  *   overflow the input buffers in case the server goes too fast, that is
 527  *   why we do these calculations :
 528  *
 529  *   We compute an average for the pcr because we want to eliminate the
 530  *   network jitter and keep the low frequency variations. The average is
 531  *   in fact a low pass filter and the jitter is a high frequency signal
 532  *   that is why it is eliminated by the filter/average.
 533  *
 534  *   The low frequency variations enable us to synchronize the client clock
 535  *   with the server clock because they represent the time variation between
 536  *   the 2 clocks. Those variations (ie the filtered pcr) are used to compute
 537  *   the presentation dates for the audio and video frames. With those dates
 538  *   we can decode (or trash) the MPEG2 stream at "exactly" the same rate
 539  *   as it is sent by the server and so we keep the synchronization between
 540  *   the server and the client.
 541  *
 542  *   It is a very important matter if you want to avoid underflow or overflow
 543  *   in all the FIFOs, but it may be not enough.
 544  */
 545
 546 /*****************************************************************************
 547  * Constants
 548  *****************************************************************************/
 549
 550 /* Maximum number of samples used to compute the dynamic average value,
 551  * it is also the maximum of c_average_count in pgrm_ts_data_t.
 552  * We use the following formula :
 553  * new_average = (old_average * c_average + new_sample_value) / (c_average +1) */
 554 #define CR_MAX_AVERAGE_COUNTER 40
 555
 556 /* Maximum gap allowed between two CRs. */
 557 #define CR_MAX_GAP 1000000
 558
 559 /*****************************************************************************
 560  * CRReInit : Reinitialize the clock reference
 561  *****************************************************************************/
 562 static void CRReInit( pgrm_descriptor_t * p_pgrm )
 563 {
 564     p_pgrm->delta_cr        = 0;
 565     p_pgrm->last_cr         = 0;
 566     p_pgrm->c_average_count = 0;
 567 }
 568
 569 /* FIXME: find a better name */
 570 /*****************************************************************************
 571  * CRDecode : Decode a clock reference
 572  *****************************************************************************/
 573 static void CRDecode( input_thread_t * p_input, pgrm_descriptor_t * p_pgrm,
 574                       mtime_t cr_time )
 575 {
 576     if( p_pgrm->i_synchro_state != SYNCHRO_OK )
 577     {
 578         switch( p_pgrm->i_synchro_state )
 579         {
 580         case SYNCHRO_START:
 581             p_pgrm->delta_absolute = mdate() - cr_time;
 582             p_pgrm->i_synchro_state = SYNCHRO_OK;
 583             break;
 584
 585         case SYNCHRO_NOT_STARTED:
 586             p_pgrm->i_synchro_state = SYNCHRO_START;
 587             break;
 588
 589         default:
 590             break;
 591         }
 592     }
 593     else
 594     {
 595         if( p_pgrm->b_discontinuity ||
 596             ( p_pgrm->last_cr != 0 &&
 597                   (    (p_pgrm->last_cr - cr_time) > CR_MAX_GAP
 598                     || (p_pgrm->last_cr - cr_time) < - CR_MAX_GAP ) ) )
 599         {
 600             int i_es;
 601
 602             /* Stream discontinuity. */
 603             intf_WarnMsg( 3, "CR re-initialiazed" );
 604             CRReInit( p_pgrm );
 605             p_pgrm->i_synchro_state = SYNCHRO_REINIT;
 606             p_pgrm->b_discontinuity = 0;
 607
 608             /* Warn all the elementary streams */
 609             for( i_es = 0; i_es < p_pgrm->i_es_number; i_es++ )
 610             {
 611                 p_pgrm->pp_es[i_es]->b_discontinuity = 1;
 612             }
 613         }
 614         p_pgrm->last_cr = cr_time;
 615
 616         if( p_input->stream.b_pace_control )
 617         {
 618             /* Wait a while before delivering the packets to the decoder. */
 619             mwait( cr_time + p_pgrm->delta_absolute );
 620         }
 621         else
 622         {
 623             mtime_t                 sys_time, delta_cr;
 624
 625             sys_time = mdate();
 626             delta_cr = sys_time - cr_time;
 627
 628             if( p_pgrm->c_average_count == CR_MAX_AVERAGE_COUNTER )
 629             {
 630                 p_pgrm->delta_cr = ( delta_cr + (p_pgrm->delta_cr
 631                                               * (CR_MAX_AVERAGE_COUNTER - 1)) )
 632                                      / CR_MAX_AVERAGE_COUNTER;
 633             }
 634             else
 635             {
 636                 p_pgrm->delta_cr = ( delta_cr + (p_pgrm->delta_cr
 637                                               * p_pgrm->c_average_count) )
 638                                      / ( p_pgrm->c_average_count + 1 );
 639                 p_pgrm->c_average_count++;
 640             }
 641         }
 642     }
 643 }
 644
 645
 646 /*
 647  * PS Demultiplexing
 648  */
 649
 650 /*****************************************************************************
 651  * GetID: Get the ID of a stream
 652  *****************************************************************************/
 653 static u16 GetID( data_packet_t * p_data )
 654 {
 655     u16         i_id;
 656
 657     i_id = p_data->p_buffer[3];                                 /* stream_id */
 658     if( i_id == 0xBD )
 659     {
 660         /* stream_private_id */
 661         i_id |= p_data->p_buffer[ 9 + p_data->p_buffer[8] ] << 8;
 662     }
 663     return( i_id );
 664 }
 665
 666 /*****************************************************************************
 667  * DecodePSM: Decode the Program Stream Map information
 668  *****************************************************************************/
 669 static void DecodePSM( input_thread_t * p_input, data_packet_t * p_data )
 670 {
 671     stream_ps_data_t *  p_demux =
 672                  (stream_ps_data_t *)p_input->stream.p_demux_data;
 673
 674     if( !p_demux->b_is_PSM_complete )
 675     {
 676         byte_t *    p_byte;
 677         byte_t *    p_end;
 678         int         i_es = 0;
 679
 680         intf_DbgMsg( "Building PSM" );
 681         if( p_data->p_payload_start + 10 > p_data->p_payload_end )
 682         {
 683             intf_ErrMsg( "PSM too short : packet corrupt" );
 684             return;
 685         }
 686         /* Go to elementary_stream_map_length, jumping over
 687          * program_stream_info. */
 688         p_byte = p_data->p_payload_start + 10
 689                   + U16_AT(&p_data->p_payload_start[8]);
 690         if( p_byte > p_data->p_payload_end )
 691         {
 692             intf_ErrMsg( "PSM too short : packet corrupt" );
 693             return;
 694         }
 695         /* This is the full size of the elementary_stream_map.
 696          * 2 == elementary_stream_map_length
 697          * 4 == CRC_32 */
 698         p_end = p_byte + 2 + U16_AT(p_byte) - 4;
 699         p_byte += 2;
 700         if( p_end > p_data->p_payload_end )
 701         {
 702             intf_ErrMsg( "PSM too short : packet corrupt" );
 703             return;
 704         }
 705
 706         vlc_mutex_lock( &p_input->stream.stream_lock );
 707
 708         /* 4 == minimum useful size of a section */
 709         while( p_byte + 4 <= p_end )
 710         {
 711             p_input->p_es[i_es].i_id
 712                 = p_input->p_es[i_es].i_stream_id
 713                 = p_byte[1];
 714             p_input->p_es[i_es].i_type = p_byte[0];
 715             p_input->p_es[i_es].p_pgrm = p_input->stream.pp_programs[0];
 716             p_input->p_es[i_es].p_pes = NULL;
 717             p_byte += 4 + U16_AT(&p_byte[2]);
 718
 719 #ifdef AUTO_SPAWN
 720             switch( p_input->p_es[i_es].i_type )
 721             {
 722                 case MPEG1_AUDIO_ES:
 723                 case MPEG2_AUDIO_ES:
 724                     /* Spawn audio thread. */
 725                     intf_DbgMsg( "Starting an MPEG-audio decoder" );
 726                     break;
 727
 728                 case MPEG1_VIDEO_ES:
 729                 case MPEG2_VIDEO_ES:
 730                     /* Spawn video thread. */
 731                     intf_DbgMsg( "Starting an MPEG-video decoder" );
 732                     break;
 733             }
 734 #endif
 735
 736             i_es++;
 737         }
 738
 739         vlc_mutex_unlock( &p_input->stream.stream_lock );
 740         p_demux->i_PSM_version = p_data->p_buffer[6] & 0x1F;
 741         p_demux->b_is_PSM_complete = 1;
 742     }
 743     else if( p_demux->i_PSM_version != (p_data->p_buffer[6] & 0x1F) )
 744     {
 745         /* FIXME */
 746         intf_ErrMsg( "PSM changed, this is not supported yet !" );
 747         p_demux->i_PSM_version = p_data->p_buffer[6] & 0x1F;
 748     }
 749 }
 750
 751 /*****************************************************************************
 752  * input_ParsePS: read the PS header
 753  *****************************************************************************/
 754 es_descriptor_t * input_ParsePS( input_thread_t * p_input,
 755                                  data_packet_t * p_data )
 756 {
 757     u32                 i_code;
 758     es_descriptor_t *   p_es = NULL;
 759
 760     i_code = U32_AT( p_data->p_buffer );
 761     if( i_code > 0x1BC ) /* ES start code */
 762     {
 763         u16                 i_id;
 764         int                 i_dummy;
 765
 766         /* This is a PES packet. Find out if we want it or not. */
 767         i_id = GetID( p_data );
 768
 769         vlc_mutex_lock( &p_input->stream.stream_lock );
 770         if( p_input->stream.pp_programs[0]->b_is_ok )
 771         {
 772             /* Look only at the selected ES. */
 773             for( i_dummy = 0; i_dummy < INPUT_MAX_SELECTED_ES; i_dummy++ )
 774             {
 775                 if( p_input->pp_selected_es[i_dummy] != NULL
 776                     && p_input->pp_selected_es[i_dummy]->i_id == i_id )
 777                 {
 778                     p_es = p_input->pp_selected_es[i_dummy];
 779                     break;
 780                 }
 781             }
 782         }
 783         else
 784         {
 785             /* Search all ES ; if not found -> AddES */
 786             for( i_dummy = 0; i_dummy < INPUT_MAX_ES; i_dummy++ )
 787             {
 788                 if( p_input->p_es[i_dummy].i_id != EMPTY_ID
 789                     && p_input->p_es[i_dummy].i_id == i_id )
 790                 {
 791                     p_es = &p_input->p_es[i_dummy];
 792                     break;
 793                 }
 794             }
 795
 796             if( p_es == NULL )
 797             {
 798                 p_es = input_AddES( p_input, p_input->stream.pp_programs[0],
 799                                     i_id, 0 );
 800                 if( p_es != NULL )
 801                 {
 802                     p_es->i_stream_id = p_data->p_buffer[3];
 803
 804                     /* Set stream type and auto-spawn. */
 805                     if( (i_id & 0xF0) == 0xE0 )
 806                     {
 807                         /* MPEG video */
 808                         p_es->i_type = MPEG2_VIDEO_ES;
 809 #ifdef AUTO_SPAWN
 810                         input_SelectES( p_input, p_es );
 811 #endif
 812                     }
 813                     else if( (i_id & 0xE0) == 0xC0 )
 814                     {
 815                         /* MPEG audio */
 816                         p_es->i_type = MPEG2_AUDIO_ES;
 817 #ifdef AUTO_SPAWN
 818                         input_SelectES( p_input, p_es );
 819 #endif
 820                     }
 821                     else if( (i_id & 0xF0FF) == 0x80BD )
 822                     {
 823                         /* AC3 audio */
 824                         p_es->i_type = AC3_AUDIO_ES;
 825 #ifdef AUTO_SPAWN
 826                         input_SelectES( p_input, p_es );
 827 #endif
 828                     }
 829                     else if( (i_id & 0xF0FF) == 0x20BD )
 830                     {
 831                         /* Subtitles video */
 832                         p_es->i_type = DVD_SPU_ES;
 833 #ifdef AUTO_SPAWN
 834                         input_SelectES( p_input, p_es );
 835 #endif
 836                     }
 837                     else
 838                     {
 839                         p_es->i_type = UNKNOWN_ES;
 840                     }
 841                 }
 842             }
 843         } /* stream.b_is_ok */
 844         vlc_mutex_unlock( &p_input->stream.stream_lock );
 845     } /* i_code > 0xBC */
 846
 847     return( p_es );
 848 }
 849
 850 /*****************************************************************************
 851  * input_DemuxPS: first step of demultiplexing: the PS header
 852  *****************************************************************************/
 853 void input_DemuxPS( input_thread_t * p_input, data_packet_t * p_data )
 854 {
 855     u32                 i_code;
 856     boolean_t           b_trash = 0;
 857     es_descriptor_t *   p_es = NULL;
 858
 859     i_code = U32_AT( p_data->p_buffer );
 860     if( i_code <= 0x1BC )
 861     {
 862         switch( i_code )
 863         {
 864         case 0x1BA: /* PACK_START_CODE */
 865             {
 866                 /* Convert the SCR in microseconds. */
 867                 mtime_t         scr_time;
 868
 869                 if( (p_data->p_buffer[4] & 0xC0) == 0x40 )
 870                 {
 871                     /* MPEG-2 */
 872                     scr_time =
 873                       (( ((mtime_t)(p_data->p_buffer[4] & 0x38) << 27) |
 874                          ((mtime_t)(U32_AT(p_data->p_buffer + 4) & 0x03FFF800)
 875                                         << 4) |
 876                          ((mtime_t)(U32_AT(p_data->p_buffer + 6) & 0x03FFF800)
 877                                         >> 11)
 878                       ) * 300) / 27;
 879                 }
 880                 else
 881                 {
 882                     /* MPEG-1 SCR is like PTS */
 883                     scr_time =
 884                       (( ((mtime_t)(p_data->p_buffer[4] & 0x0E) << 29) |
 885                          (((mtime_t)U16_AT(p_data->p_buffer + 5) << 14)
 886                            - (1 << 14)) |
 887                          ((mtime_t)U16_AT(p_data->p_buffer + 7) >> 1)
 888                       ) * 300) / 27;
 889                 }
 890                 /* Call the pace control. */
 891                 //intf_Msg("+%lld\n", scr_time);
 892                 CRDecode( p_input, p_input->stream.pp_programs[0],
 893                           scr_time );
 894                 b_trash = 1;
 895             }
 896             break;
 897
 898         case 0x1BB: /* SYSTEM_START_CODE */
 899             b_trash = 1;                              /* Nothing interesting */
 900             break;
 901
 902         case 0x1BC: /* PROGRAM_STREAM_MAP_CODE */
 903             intf_ErrMsg("meuuuuh\n");
 904             DecodePSM( p_input, p_data );
 905             b_trash = 1;
 906             break;
 907
 908         case 0x1B9: /* PROGRAM_END_CODE */
 909             b_trash = 1;
 910             break;
 911
 912         default:
 913             /* This should not happen */
 914             b_trash = 1;
 915             intf_WarnMsg( 1, "Unwanted packet received with start code %x",
 916                           i_code );
 917         }
 918     }
 919     else
 920     {
 921         p_es = input_ParsePS( p_input, p_data );
 922
 923         if( p_es != NULL && p_es->p_decoder_fifo != NULL && !b_trash )
 924         {
 925 #ifdef STATS
 926             p_es->c_packets++;
 927 #endif
 928             input_GatherPES( p_input, p_data, p_es, 1, 0 );
 929         }
 930     }
 931
 932     /* Trash the packet if it has no payload or if it isn't selected */
 933     if( b_trash )
 934     {
 935         p_input->p_plugin->pf_delete_packet( p_input, p_data );
 936 #ifdef STATS
 937         p_input->c_packets_trashed++;
 938 #endif
 939     }
 940 }
 941
 942
 943 /*
 944  * TS Demultiplexing
 945  */
 946
 947 /*****************************************************************************
 948  * input_DemuxTS: first step of demultiplexing: the TS header
 949  *****************************************************************************/
 950 void input_DemuxTS( input_thread_t * p_input, data_packet_t * p_data )
 951 {
 952     int                 i_pid, i_dummy;
 953     boolean_t           b_adaptation;         /* Adaptation field is present */
 954     boolean_t           b_payload;                 /* Packet carries payload */
 955     boolean_t           b_unit_start;  /* A PSI or a PES start in the packet */
 956     boolean_t           b_trash = 0;             /* Is the packet unuseful ? */
 957     boolean_t           b_lost = 0;             /* Was there a packet loss ? */
 958     es_descriptor_t *   p_es = NULL;
 959     es_ts_data_t *      p_es_demux = NULL;
 960     pgrm_ts_data_t *    p_pgrm_demux = NULL;
 961
 962 #define p (p_data->p_buffer)
 963
 964     //intf_DbgMsg("input debug: TS-demultiplexing packet %p, pid %d\n",
 965     //            p_ts_packet, U16_AT(&p[1]) & 0x1fff);
 966
 967     /* Extract flags values from TS common header. */
 968     i_pid = U16_AT(&p[1]) & 0x1fff;
 969     b_unit_start = (p[1] & 0x40);
 970     b_adaptation = (p[3] & 0x20);
 971     b_payload = (p[3] & 0x10);
 972
 973     /* Find out the elementary stream. */
 974     vlc_mutex_lock( &p_input->stream.stream_lock );
 975     for( i_dummy = 0; i_dummy < INPUT_MAX_ES; i_dummy++ )
 976     {
 977         if( p_input->p_es[i_dummy].i_id != EMPTY_ID )
 978         {
 979             if( p_input->p_es[i_dummy].i_id == i_pid )
 980             {
 981                 p_es = &p_input->p_es[i_dummy];
 982                 p_es_demux = (es_ts_data_t *)p_es->p_demux_data;
 983                 p_pgrm_demux = (pgrm_ts_data_t *)p_es->p_pgrm->p_demux_data;
 984                 break;
 985             }
 986         }
 987     }
 988     vlc_mutex_unlock( &p_input->stream.stream_lock );
 989
 990 #ifdef STATS
 991     p_es->c_packets++;
 992 #endif
 993
 994     if( p_es->p_decoder_fifo == NULL )
 995     {
 996         /* Not selected. Just read the adaptation field for a PCR. */
 997         b_trash = 1;
 998     }
 999
1000     if( (p_es->p_decoder_fifo != NULL) || (p_pgrm_demux->i_pcr_pid == i_pid) )
1001     {
1002         /* Extract adaptation field information if any */
1003         if( !b_adaptation )
1004         {
1005             /* We don't have any adaptation_field, so payload starts
1006              * immediately after the 4 byte TS header */
1007             p_data->p_payload_start += 4;
1008         }
1009         else
1010         {
1011             /* p[4] is adaptation_field_length minus one */
1012             p_data->p_payload_start += 5 + p[4];
1013
1014             /* The adaptation field can be limited to the
1015              * adaptation_field_length byte, so that there is nothing to do:
1016              * skip this possibility */
1017             if( p[4] )
1018             {
1019                 /* If the packet has both adaptation_field and payload,
1020                  * adaptation_field cannot be more than 182 bytes long; if
1021                  * there is only an adaptation_field, it must fill the next
1022                  * 183 bytes. */
1023                 if( b_payload ? (p[4] > 182) : (p[4] != 183) )
1024                 {
1025                     intf_WarnMsg( 2,
1026                         "invalid TS adaptation field (%p)",
1027                         p_data );
1028                     p_data->b_discard_payload = 1;
1029 #ifdef STATS
1030                     p_es->c_invalid_packets++;
1031 #endif
1032                 }
1033
1034                 /* Now we are sure that the byte containing flags is present:
1035                  * read it */
1036                 else
1037                 {
1038                     /* discontinuity_indicator */
1039                     if( p[5] & 0x80 )
1040                     {
1041                         intf_WarnMsg( 2,
1042                             "discontinuity_indicator"                       \
1043                             " encountered by TS demux (position read: %d,"  \
1044                             " saved: %d)",
1045                             p[5] & 0x80, p_es_demux->i_continuity_counter );
1046
1047                         /* If the PID carries the PCR, there will be a system
1048                          * time-based discontinuity. We let the PCR decoder
1049                          * handle that. */
1050                         p_es->p_pgrm->b_discontinuity = 1;
1051
1052                         /* There also may be a continuity_counter
1053                          * discontinuity: resynchronise our counter with
1054                          * the one of the stream. */
1055                         p_es_demux->i_continuity_counter = (p[3] & 0x0f) - 1;
1056                     }
1057
1058                     /* If this is a PCR_PID, and this TS packet contains a
1059                      * PCR, we pass it along to the PCR decoder. */
1060                     if( (p_pgrm_demux->i_pcr_pid == i_pid) && (p[5] & 0x10) )
1061                     {
1062                         /* There should be a PCR field in the packet, check
1063                          * if the adaptation field is long enough to carry
1064                          * it. */
1065                         if( p[4] >= 7 )
1066                         {
1067                             /* Convert the PCR in microseconds.
1068                              * WARNING: do not remove the casts in the
1069                              * following calculation ! */
1070                             mtime_t     pcr_time;
1071                             pcr_time =
1072                                     ( (( (mtime_t)U32_AT((u32*)&p[6]) << 1 )
1073                                       | ( p[10] >> 7 )) * 300 ) / 27;
1074                             /* Call the pace control. */
1075                             CRDecode( p_input, p_es->p_pgrm, pcr_time );
1076                         }
1077                     } /* PCR ? */
1078                 } /* valid TS adaptation field ? */
1079             } /* length > 0 */
1080         } /* has adaptation field */
1081
1082         /* Check the continuity of the stream. */
1083         i_dummy = ((p[3] & 0x0f) - p_es_demux->i_continuity_counter) & 0x0f;
1084         if( i_dummy == 1 )
1085         {
1086             /* Everything is ok, just increase our counter */
1087             p_es_demux->i_continuity_counter++;
1088         }
1089         else
1090         {
1091             if( !b_payload && i_dummy == 0 )
1092             {
1093                 /* This is a packet without payload, this is allowed by the draft.
1094                  * As there is nothing interesting in this packet (except PCR that
1095                  * have already been handled), we can trash the packet. */
1096                 intf_WarnMsg( 1,
1097                               "Packet without payload received by TS demux" );
1098                 b_trash = 1;
1099             }
1100             else if( i_dummy <= 0 )
1101             {
1102                 /* FIXME: this can never happen, can it ? --Meuuh */
1103                 /* Duplicate packet: mark it as being to be trashed. */
1104                 intf_WarnMsg( 1, "Duplicate packet received by TS demux" );
1105                 b_trash = 1;
1106             }
1107             else if( p_es_demux->i_continuity_counter == 0xFF )
1108             {
1109                 /* This means that the packet is the first one we receive for this
1110                  * ES since the continuity counter ranges between 0 and 0x0F
1111                  * excepts when it has been initialized by the input: Init the
1112                  * counter to the correct value. */
1113                 intf_DbgMsg( "First packet for PID %d received by TS demux",
1114                              p_es->i_id );
1115                 p_es_demux->i_continuity_counter = (p[3] & 0x0f);
1116             }
1117             else
1118             {
1119                 /* This can indicate that we missed a packet or that the
1120                  * continuity_counter wrapped and we received a dup packet: as we
1121                  * don't know, do as if we missed a packet to be sure to recover
1122                  * from this situation */
1123                 intf_WarnMsg( 2,
1124                            "Packet lost by TS demux: current %d, packet %d\n",
1125                            p_es_demux->i_continuity_counter & 0x0f,
1126                            p[3] & 0x0f );
1127                 b_lost = 1;
1128                 p_es_demux->i_continuity_counter = p[3] & 0x0f;
1129             } /* not continuous */
1130         } /* continuity */
1131     } /* if selected or PCR */
1132
1133     /* Trash the packet if it has no payload or if it isn't selected */
1134     if( b_trash )
1135     {
1136         p_input->p_plugin->pf_delete_packet( p_input, p_data );
1137 #ifdef STATS
1138         p_input->c_packets_trashed++;
1139 #endif
1140     }
1141     else
1142     {
1143         if( p_es_demux->b_psi )
1144         {
1145             /* The payload contains PSI tables */
1146 #if 0
1147             input_DemuxPSI( p_input, p_data, p_es,
1148                             b_unit_start, b_lost );
1149 #endif
1150         }
1151         else
1152         {
1153             /* The payload carries a PES stream */
1154             if( b_unit_start )
1155             input_GatherPES( p_input, p_data, p_es, b_unit_start, b_lost );
1156         }
1157     }
1158
1159 #undef p
1160 }