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 1.19 2000/12/26 19:14:47 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 #include "mpeg_system.h"
  45 #include "input_dec.h"
  46
  47 #include "main.h"                           /* AC3/MPEG channel, SPU channel */
  48
  49 /*****************************************************************************
  50  * Local prototypes
  51  *****************************************************************************/
  52
  53
  54 /*
  55  * PES Packet management
  56  */
  57
  58 /*****************************************************************************
  59  * MoveChunk
  60  *****************************************************************************
  61  * Small utility function used to parse discontinuous headers safely. Copies
  62  * i_buf_len bytes of data to a buffer and returns the size copied.
  63  * This is a variation on the theme of input_ext-dec.h:GetChunk().
  64  *****************************************************************************/
  65 static __inline__ size_t MoveChunk( byte_t * p_dest,
  66                                     data_packet_t ** pp_data_src,
  67                                     byte_t ** pp_src,
  68                                     size_t i_buf_len )
  69 {
  70     ptrdiff_t           i_available;
  71
  72     if( (i_available = (*pp_data_src)->p_payload_end - *pp_src)
  73             >= i_buf_len )
  74     {
  75         if( p_dest != NULL )
  76             memcpy( p_dest, *pp_src, i_buf_len );
  77         *pp_src += i_buf_len;
  78         return( i_buf_len );
  79     }
  80     else
  81     {
  82         size_t          i_init_len = i_buf_len;
  83
  84         do
  85         {
  86             if( p_dest != NULL )
  87                 memcpy( p_dest, *pp_src, i_available );
  88             *pp_data_src = (*pp_data_src)->p_next;
  89             i_buf_len -= i_available;
  90             p_dest += i_available;
  91             if( *pp_data_src == NULL )
  92             {
  93                 *pp_src = NULL;
  94                 return( i_init_len - i_buf_len );
  95             }
  96             *pp_src = (*pp_data_src)->p_payload_start;
  97         }
  98         while( (i_available = (*pp_data_src)->p_payload_end - *pp_src)
  99                 <= i_buf_len );
 100
 101         if( i_buf_len )
 102         {
 103             if( p_dest != NULL )
 104                 memcpy( p_dest, *pp_src, i_buf_len );
 105             *pp_src += i_buf_len;
 106         }
 107         return( i_init_len );
 108     }
 109 }
 110
 111 /*****************************************************************************
 112  * input_ParsePES
 113  *****************************************************************************
 114  * Parse a finished PES packet and analyze its header.
 115  *****************************************************************************/
 116 #define PES_HEADER_SIZE     7
 117 void input_ParsePES( input_thread_t * p_input, es_descriptor_t * p_es )
 118 {
 119     data_packet_t * p_data;
 120     byte_t *        p_byte;
 121     byte_t          p_header[PES_HEADER_SIZE];
 122     int             i_done;
 123
 124 #define p_pes (p_es->p_pes)
 125
 126     //intf_DbgMsg("End of PES packet %p", 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_data = p_pes->p_first;
 132     p_byte = p_data->p_payload_start;
 133     i_done = 0;
 134
 135     if( MoveChunk( p_header, &p_data, &p_byte, PES_HEADER_SIZE )
 136             != PES_HEADER_SIZE )
 137     {
 138         intf_WarnMsg( 3, "PES packet too short to have a header" );
 139         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 140         p_pes = NULL;
 141         return;
 142     }
 143
 144     /* Get the PES size if defined */
 145     p_es->i_pes_real_size = U16_AT(p_header + 4) + 6;
 146
 147     /* First read the 6 header bytes common to all PES packets:
 148      * use them to test the PES validity */
 149     if( (p_header[0] || p_header[1] || (p_header[2] != 1)) )
 150     {
 151         /* packet_start_code_prefix != 0x000001 */
 152         intf_ErrMsg( "PES packet doesn't start with 0x000001 : data loss" );
 153         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 154         p_pes = NULL;
 155     }
 156     else
 157     {
 158         int i_pes_header_size, i_payload_size;
 159
 160         if ( p_es->i_pes_real_size &&
 161              (p_es->i_pes_real_size != p_pes->i_pes_size) )
 162         {
 163             /* PES_packet_length is set and != total received payload */
 164             /* Warn the decoder that the data may be corrupt. */
 165             intf_WarnMsg( 3, "PES sizes do not match : packet corrupted" );
 166             p_pes->b_messed_up = 1;
 167         }
 168
 169         switch( p_es->i_stream_id )
 170         {
 171         case 0xBC:  /* Program stream map */
 172         case 0xBE:  /* Padding */
 173         case 0xBF:  /* Private stream 2 */
 174         case 0xB0:  /* ECM */
 175         case 0xB1:  /* EMM */
 176         case 0xFF:  /* Program stream directory */
 177         case 0xF2:  /* DSMCC stream */
 178         case 0xF8:  /* ITU-T H.222.1 type E stream */
 179             /* The payload begins immediately after the 6 bytes header, so
 180              * we have finished with the parsing */
 181             i_pes_header_size = 6;
 182             break;
 183
 184         default:
 185             if( (p_header[6] & 0xC0) == 0x80 )
 186             {
 187                 /* MPEG-2 : the PES header contains at least 3 more bytes. */
 188                 size_t      i_max_len;
 189
 190                 p_pes->b_data_alignment = p_header[6] & 0x04;
 191
 192                 /* Re-use p_header buffer now that we don't need it. */
 193                 i_max_len = MoveChunk( p_header, &p_data, &p_byte, 7 );
 194                 if( i_max_len < 2 )
 195                 {
 196                     intf_WarnMsg( 3,
 197                             "PES packet too short to have a MPEG-2 header" );
 198                     p_input->p_plugin->pf_delete_pes( p_input->p_method_data,
 199                                                       p_pes );
 200                     p_pes = NULL;
 201                     return;
 202                 }
 203
 204                 p_pes->b_has_pts = p_header[0] & 0x80;
 205                 i_pes_header_size = p_header[1] + 9;
 206
 207                 /* Now parse the optional header extensions */
 208                 if( p_pes->b_has_pts )
 209                 {
 210                     if( i_max_len < 7 )
 211                     {
 212                         intf_WarnMsg( 3,
 213                             "PES packet too short to have a MPEG-2 header" );
 214                         p_input->p_plugin->pf_delete_pes(
 215                                                       p_input->p_method_data,
 216                                                       p_pes );
 217                         p_pes = NULL;
 218                         return;
 219                     }
 220                     p_pes->i_pts =
 221                       ( ((mtime_t)(p_header[2] & 0x0E) << 29) |
 222                         (((mtime_t)U16_AT(p_header + 3) << 14) - (1 << 14)) |
 223                         ((mtime_t)U16_AT(p_header + 5) >> 1) ) * 300;
 224                     p_pes->i_pts /= 27;
 225                 }
 226             }
 227             else
 228             {
 229                 /* Probably MPEG-1 */
 230                 i_pes_header_size = 6;
 231                 p_data = p_pes->p_first;
 232                 p_byte = p_data->p_payload_start;
 233                 /* Cannot fail because the previous one succeeded. */
 234                 MoveChunk( NULL, &p_data, &p_byte, 6 );
 235
 236                 while( *p_byte == 0xFF && i_pes_header_size < 22 )
 237                 {
 238                     i_pes_header_size++;
 239                     if( MoveChunk( NULL, &p_data, &p_byte, 1 ) != 1 )
 240                     {
 241                         intf_WarnMsg( 3,
 242                             "PES packet too short to have a MPEG-1 header" );
 243                         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 244                         p_pes = NULL;
 245                         return;
 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                     /* Erm... why ? --Sam */
 260                     /* Well... According to the recommendation, it is for
 261                      * STD_buffer_scale and STD_buffer_size. --Meuuh */
 262                     i_pes_header_size += 2;
 263                     if( MoveChunk( NULL, &p_data, &p_byte, 2 ) != 2 )
 264                     {
 265                         intf_WarnMsg( 3,
 266                             "PES packet too short to have a MPEG-1 header" );
 267                         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 268                         p_pes = NULL;
 269                         return;
 270                     }
 271                 }
 272
 273                 i_pes_header_size++;
 274
 275                 if( *p_byte & 0x10 )
 276                 {
 277                     /* DTS */
 278                     i_pes_header_size += 5;
 279                 }
 280                 if( (p_pes->b_has_pts = (*p_byte & 0x20)) )
 281                 {
 282                     /* PTS */
 283                     byte_t      p_pts[5];
 284
 285                     i_pes_header_size += 4;
 286                     if( MoveChunk( p_pts, &p_data, &p_byte, 5 ) != 5 )
 287                     {
 288                         intf_WarnMsg( 3,
 289                             "PES packet too short to have a MPEG-1 header" );
 290                         p_input->p_plugin->pf_delete_pes(
 291                                             p_input->p_method_data, p_pes );
 292                         p_pes = NULL;
 293                         return;
 294                     }
 295
 296                     p_pes->i_pts =
 297                       ( ((mtime_t)(p_pts[0] & 0x0E) << 29) |
 298                         (((mtime_t)U16_AT(p_pts + 1) << 14) - (1 << 14)) |
 299                         ((mtime_t)U16_AT(p_pts + 3) >> 1) ) * 300;
 300                     p_pes->i_pts /= 27;
 301                 }
 302             }
 303
 304             /* PTS management */
 305             if( p_pes->b_has_pts )
 306             {
 307                 //intf_Msg("%lld", p_pes->i_pts);
 308                 switch( p_es->p_pgrm->i_synchro_state )
 309                 {
 310                 case SYNCHRO_NOT_STARTED:
 311                 case SYNCHRO_START:
 312                     p_pes->b_has_pts = 0;
 313                     break;
 314
 315                 case SYNCHRO_REINIT: /* We skip a PES | Why ?? --Meuuh */
 316                     p_pes->b_has_pts = 0;
 317                     p_es->p_pgrm->i_synchro_state = SYNCHRO_START;
 318                     break;
 319
 320                 case SYNCHRO_OK:
 321                     p_pes->i_pts += p_es->p_pgrm->delta_cr
 322                                          + p_es->p_pgrm->delta_absolute
 323                                          + DEFAULT_PTS_DELAY;
 324                     break;
 325                 }
 326             }
 327             break;
 328         }
 329
 330         if( p_es->i_stream_id == 0xbd )
 331         {
 332             /* With private stream 1, the first byte of the payload
 333              * is a stream_private_id, so skip it. */
 334             i_pes_header_size++;
 335         }
 336
 337         /* Now we've parsed the header, we just have to indicate in some
 338          * specific data packets where the PES payload begins (renumber
 339          * p_payload_start), so that the decoders can find the beginning
 340          * of their data right out of the box. */
 341         p_data = p_pes->p_first;
 342         i_payload_size = p_data->p_payload_end
 343                                  - p_data->p_payload_start;
 344         while( i_pes_header_size > i_payload_size )
 345         {
 346             /* These packets are entirely filled by the PES header. */
 347             i_pes_header_size -= i_payload_size;
 348             p_data->p_payload_start = p_data->p_payload_end;
 349             /* Go to the next data packet. */
 350             if( (p_data = p_data->p_next) == NULL )
 351             {
 352                 intf_ErrMsg( "PES header bigger than payload" );
 353                 p_input->p_plugin->pf_delete_pes( p_input->p_method_data,
 354                                                   p_pes );
 355                 p_pes = NULL;
 356                 return;
 357             }
 358             i_payload_size = p_data->p_payload_end
 359                                  - p_data->p_payload_start;
 360         }
 361         /* This last packet is partly header, partly payload. */
 362         if( i_payload_size < i_pes_header_size )
 363         {
 364             intf_ErrMsg( "PES header bigger than payload" );
 365             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 366             p_pes = NULL;
 367             return;
 368         }
 369         p_data->p_payload_start += i_pes_header_size;
 370
 371         /* Now we can eventually put the PES packet in the decoder's
 372          * PES fifo */
 373         if( p_es->p_decoder_fifo != NULL )
 374         {
 375             input_DecodePES( p_es->p_decoder_fifo, p_pes );
 376         }
 377         else
 378         {
 379             intf_ErrMsg("No fifo to receive PES %p (who wrote this damn code ?)",
 380                         p_pes);
 381             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 382         }
 383         p_pes = NULL;
 384     }
 385 #undef p_pes
 386 }
 387
 388 /*****************************************************************************
 389  * input_GatherPES:
 390  *****************************************************************************
 391  * Gather a PES packet.
 392  *****************************************************************************/
 393 void input_GatherPES( input_thread_t * p_input, data_packet_t * p_data,
 394                       es_descriptor_t * p_es,
 395                       boolean_t b_unit_start, boolean_t b_packet_lost )
 396 {
 397 #define p_pes (p_es->p_pes)
 398
 399     //intf_DbgMsg("PES-demultiplexing %p (%p)", p_ts_packet, p_pes);
 400
 401     /* If we lost data, insert a NULL data packet (philosophy : 0 is quite
 402      * often an escape sequence in decoders, so that should make them wait
 403      * for the next start code). */
 404     if( b_packet_lost || p_es->b_discontinuity )
 405     {
 406         data_packet_t *             p_pad_data;
 407
 408         if( (p_pad_data = p_input->p_plugin->pf_new_packet(
 409                                             p_input->p_method_data,
 410                                             PADDING_PACKET_SIZE )) == NULL )
 411         {
 412             intf_ErrMsg("Out of memory");
 413             p_input->b_error = 1;
 414             return;
 415         }
 416         memset( p_data->p_buffer, 0, PADDING_PACKET_SIZE );
 417         p_pad_data->b_discard_payload = 1;
 418
 419         if( p_pes != NULL )
 420         {
 421             p_pes->b_messed_up = p_pes->b_discontinuity = 1;
 422             input_GatherPES( p_input, p_pad_data, p_es, 0, 0 );
 423         }
 424         else
 425         {
 426             if( (p_pes = p_input->p_plugin->pf_new_pes(
 427                                             p_input->p_method_data )) == NULL )
 428             {
 429                 intf_ErrMsg("Out of memory");
 430                 p_input->b_error = 1;
 431                 return;
 432             }
 433
 434             p_pes->p_first = p_pad_data;
 435             p_pes->b_messed_up = p_pes->b_discontinuity = 1;
 436             input_DecodePES( p_es->p_decoder_fifo, p_pes );
 437         }
 438
 439         p_es->b_discontinuity = 0;
 440     }
 441
 442     if( b_unit_start && p_pes != NULL )
 443     {
 444         /* If the TS packet contains the begining of a new PES packet, and
 445          * if we were reassembling a PES packet, then the PES should be
 446          * complete now, so parse its header and give it to the decoders. */
 447         input_ParsePES( p_input, p_es );
 448     }
 449
 450     if( !b_unit_start && p_pes == NULL )
 451     {
 452         /* Random access... */
 453         p_input->p_plugin->pf_delete_packet( p_input->p_method_data, p_data );
 454     }
 455     else
 456     {
 457         if( b_unit_start )
 458         {
 459             /* If we are at the beginning of a new PES packet, we must fetch
 460              * a new PES buffer to begin with the reassembly of this PES
 461              * packet. This is also here that we can synchronize with the
 462              * stream if we lost packets or if the decoder has just
 463              * started. */
 464             if( (p_pes = p_input->p_plugin->pf_new_pes( p_input->p_method_data ) ) == NULL )
 465             {
 466                 intf_ErrMsg("Out of memory");
 467                 p_input->b_error = 1;
 468                 return;
 469             }
 470             //intf_DbgMsg("New PES packet %p (first data: %p)", p_pes, p_data);
 471             p_pes->p_first = p_data;
 472
 473             /* If the PES header fits in the first data packet, we can
 474              * already set p_gather->i_pes_real_size. */
 475             if( p_data->p_payload_end - p_data->p_payload_start
 476                     >= PES_HEADER_SIZE )
 477             {
 478                 p_es->i_pes_real_size =
 479                                 U16_AT(p_data->p_payload_start + 4) + 6;
 480             }
 481             else
 482             {
 483                 p_es->i_pes_real_size = 0;
 484             }
 485         }
 486         else
 487         {
 488             /* Update the relations between the data packets */
 489             p_es->p_last->p_next = p_data;
 490         }
 491
 492         p_data->p_next = NULL;
 493         p_es->p_last = p_data;
 494
 495         /* Size of the payload carried in the data packet */
 496         p_pes->i_pes_size += (p_data->p_payload_end
 497                                  - p_data->p_payload_start);
 498
 499         /* We can check if the packet is finished */
 500         if( p_pes->i_pes_size == p_es->i_pes_real_size )
 501         {
 502             /* The packet is finished, parse it */
 503             input_ParsePES( p_input, p_es );
 504         }
 505     }
 506 #undef p_pes
 507 }
 508
 509
 510 /*
 511  * Pace control
 512  */
 513
 514 /*
 515  *   DISCUSSION : SYNCHRONIZATION METHOD
 516  *
 517  *   In some cases we can impose the pace of reading (when reading from a
 518  *   file or a pipe), and for the synchronization we simply sleep() until
 519  *   it is time to deliver the packet to the decoders. When reading from
 520  *   the network, we must be read at the same pace as the server writes,
 521  *   otherwise the kernel's buffer will trash packets. The risk is now to
 522  *   overflow the input buffers in case the server goes too fast, that is
 523  *   why we do these calculations :
 524  *
 525  *   We compute an average for the pcr because we want to eliminate the
 526  *   network jitter and keep the low frequency variations. The average is
 527  *   in fact a low pass filter and the jitter is a high frequency signal
 528  *   that is why it is eliminated by the filter/average.
 529  *
 530  *   The low frequency variations enable us to synchronize the client clock
 531  *   with the server clock because they represent the time variation between
 532  *   the 2 clocks. Those variations (ie the filtered pcr) are used to compute
 533  *   the presentation dates for the audio and video frames. With those dates
 534  *   we can decode (or trash) the MPEG2 stream at "exactly" the same rate
 535  *   as it is sent by the server and so we keep the synchronization between
 536  *   the server and the client.
 537  *
 538  *   It is a very important matter if you want to avoid underflow or overflow
 539  *   in all the FIFOs, but it may be not enough.
 540  */
 541
 542 /*****************************************************************************
 543  * Constants
 544  *****************************************************************************/
 545
 546 /* Maximum number of samples used to compute the dynamic average value,
 547  * it is also the maximum of c_average_count in pgrm_ts_data_t.
 548  * We use the following formula :
 549  * new_average = (old_average * c_average + new_sample_value) / (c_average +1) */
 550 #define CR_MAX_AVERAGE_COUNTER 40
 551
 552 /* Maximum gap allowed between two CRs. */
 553 #define CR_MAX_GAP 1000000
 554
 555 /*****************************************************************************
 556  * CRReInit : Reinitialize the clock reference
 557  *****************************************************************************/
 558 static void CRReInit( pgrm_descriptor_t * p_pgrm )
 559 {
 560     p_pgrm->delta_cr        = 0;
 561     p_pgrm->last_cr         = 0;
 562     p_pgrm->c_average_count = 0;
 563 }
 564
 565 /* FIXME: find a better name */
 566 /*****************************************************************************
 567  * CRDecode : Decode a clock reference
 568  *****************************************************************************/
 569 static void CRDecode( input_thread_t * p_input, pgrm_descriptor_t * p_pgrm,
 570                       mtime_t cr_time )
 571 {
 572     if( p_pgrm->i_synchro_state != SYNCHRO_OK )
 573     {
 574         switch( p_pgrm->i_synchro_state )
 575         {
 576         case SYNCHRO_START:
 577             p_pgrm->delta_absolute = mdate() - cr_time;
 578             p_pgrm->i_synchro_state = SYNCHRO_OK;
 579             break;
 580
 581         case SYNCHRO_NOT_STARTED:
 582             p_pgrm->i_synchro_state = SYNCHRO_START;
 583             break;
 584
 585         default:
 586             break;
 587         }
 588     }
 589     else
 590     {
 591         if( p_pgrm->b_discontinuity ||
 592             ( p_pgrm->last_cr != 0 &&
 593                   (    (p_pgrm->last_cr - cr_time) > CR_MAX_GAP
 594                     || (p_pgrm->last_cr - cr_time) < - CR_MAX_GAP ) ) )
 595         {
 596             int i_es;
 597
 598             /* Stream discontinuity. */
 599             intf_WarnMsg( 3, "CR re-initialiazed" );
 600             CRReInit( p_pgrm );
 601             p_pgrm->i_synchro_state = SYNCHRO_REINIT;
 602             p_pgrm->b_discontinuity = 0;
 603
 604             /* Warn all the elementary streams */
 605             for( i_es = 0; i_es < p_pgrm->i_es_number; i_es++ )
 606             {
 607                 p_pgrm->pp_es[i_es]->b_discontinuity = 1;
 608             }
 609         }
 610         p_pgrm->last_cr = cr_time;
 611
 612         if( p_input->stream.b_pace_control )
 613         {
 614             /* Wait a while before delivering the packets to the decoder. */
 615             mwait( cr_time + p_pgrm->delta_absolute );
 616         }
 617         else
 618         {
 619             mtime_t                 sys_time, delta_cr;
 620
 621             sys_time = mdate();
 622             delta_cr = sys_time - cr_time;
 623
 624             if( p_pgrm->c_average_count == CR_MAX_AVERAGE_COUNTER )
 625             {
 626                 p_pgrm->delta_cr = ( delta_cr + (p_pgrm->delta_cr
 627                                               * (CR_MAX_AVERAGE_COUNTER - 1)) )
 628                                      / CR_MAX_AVERAGE_COUNTER;
 629             }
 630             else
 631             {
 632                 p_pgrm->delta_cr = ( delta_cr + (p_pgrm->delta_cr
 633                                               * p_pgrm->c_average_count) )
 634                                      / ( p_pgrm->c_average_count + 1 );
 635                 p_pgrm->c_average_count++;
 636             }
 637         }
 638     }
 639 }
 640
 641
 642 /*
 643  * PS Demultiplexing
 644  */
 645
 646 /*****************************************************************************
 647  * GetID: Get the ID of a stream
 648  *****************************************************************************/
 649 static u16 GetID( data_packet_t * p_data )
 650 {
 651     u16         i_id;
 652
 653     i_id = p_data->p_buffer[3];                                 /* stream_id */
 654     if( i_id == 0xBD )
 655     {
 656         /* stream_private_id */
 657         i_id |= p_data->p_buffer[ 9 + p_data->p_buffer[8] ] << 8;
 658     }
 659     return( i_id );
 660 }
 661
 662 /*****************************************************************************
 663  * DecodePSM: Decode the Program Stream Map information
 664  *****************************************************************************/
 665 static void DecodePSM( input_thread_t * p_input, data_packet_t * p_data )
 666 {
 667     stream_ps_data_t *  p_demux =
 668                  (stream_ps_data_t *)p_input->stream.p_demux_data;
 669     byte_t *            p_byte;
 670     byte_t *            p_end;
 671     int                 i;
 672     int                 i_new_es_number = 0;
 673
 674     intf_Msg("input info: Your stream contains Program Stream Map information");
 675     intf_Msg("input info: Please send a mail to <massiot@via.ecp.fr>");
 676
 677     p_demux->b_has_PSM = 1;
 678
 679     if( p_data->p_payload_start + 10 > p_data->p_payload_end )
 680     {
 681         intf_ErrMsg( "PSM too short : packet corrupt" );
 682         return;
 683     }
 684
 685     if( p_demux->i_PSM_version == (p_data->p_buffer[6] & 0x1F) )
 686     {
 687         /* Already got that one. */
 688         return;
 689     }
 690
 691     intf_DbgMsg( "Building PSM" );
 692     p_demux->i_PSM_version = p_data->p_buffer[6] & 0x1F;
 693
 694     /* Go to elementary_stream_map_length, jumping over
 695      * program_stream_info. */
 696     p_byte = p_data->p_payload_start + 10
 697               + U16_AT(&p_data->p_payload_start[8]);
 698     if( p_byte > p_data->p_payload_end )
 699     {
 700         intf_ErrMsg( "PSM too short : packet corrupt" );
 701         return;
 702     }
 703     /* This is the full size of the elementary_stream_map.
 704      * 2 == elementary_stream_map_length
 705      * 4 == CRC_32 */
 706     p_end = p_byte + 2 + U16_AT(p_byte) - 4;
 707     p_byte += 2;
 708     if( p_end > p_data->p_payload_end )
 709     {
 710         intf_ErrMsg( "PSM too short : packet corrupt" );
 711         return;
 712     }
 713
 714     vlc_mutex_lock( &p_input->stream.stream_lock );
 715
 716     /* 4 == minimum useful size of a section */
 717     while( p_byte + 4 <= p_end )
 718     {
 719         es_descriptor_t *   p_es = NULL;
 720         u8                  i_stream_id = p_byte[1];
 721         /* FIXME: there will be a problem with private streams... (same
 722          * stream_id) */
 723
 724         /* Look for the ES in the ES table */
 725         for( i = i_new_es_number;
 726              i < p_input->stream.pp_programs[0]->i_es_number;
 727              i++ )
 728         {
 729             if( p_input->stream.pp_programs[0]->pp_es[i]->i_stream_id
 730                     == i_stream_id )
 731             {
 732                 p_es = p_input->stream.pp_programs[0]->pp_es[i];
 733                 if( p_es->i_type != p_byte[0] )
 734                 {
 735                     input_DelES( p_input, p_es );
 736                     p_es = NULL;
 737                 }
 738                 else
 739                 {
 740                     /* Move the ES to the beginning. */
 741                     i_new_es_number++;
 742                     p_input->stream.pp_programs[0]->pp_es[i]
 743                         = p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ];
 744                     p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ]
 745                         = p_es;
 746                 }
 747                 break;
 748             }
 749         }
 750
 751         /* The goal is to have all the ES we have just read in the
 752          * beginning of the pp_es table, and all the others at the end,
 753          * so that we can close them more easily at the end. */
 754         if( p_es == NULL )
 755         {
 756             p_es = input_AddES( p_input, p_input->stream.pp_programs[0],
 757                                 i_stream_id, 0 );
 758             p_es->i_type = p_byte[0];
 759             i_new_es_number++;
 760
 761             /* input_AddES has inserted the new element at the end. */
 762             p_input->stream.pp_programs[0]->pp_es[
 763                 p_input->stream.pp_programs[0]->i_es_number ]
 764                 = p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ];
 765             p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ] = p_es;
 766         }
 767         p_byte += 4 + U16_AT(&p_byte[2]);
 768     }
 769
 770     /* Un-select the streams that are no longer parts of the program. */
 771     for( i = i_new_es_number;
 772          i < p_input->stream.pp_programs[0]->i_es_number;
 773          i++ )
 774     {
 775         input_DelES( p_input,
 776                      p_input->stream.pp_programs[0]->pp_es[i_new_es_number] );
 777         /* Yes, I wrote *i_new_es_number* */
 778     }
 779     vlc_mutex_unlock( &p_input->stream.stream_lock );
 780 }
 781
 782 /*****************************************************************************
 783  * input_ParsePS: read the PS header
 784  *****************************************************************************/
 785 es_descriptor_t * input_ParsePS( input_thread_t * p_input,
 786                                  data_packet_t * p_data )
 787 {
 788     u32                 i_code;
 789     es_descriptor_t *   p_es = NULL;
 790
 791     i_code = U32_AT( p_data->p_buffer );
 792     if( i_code > 0x1BC ) /* ES start code */
 793     {
 794         u16                 i_id;
 795         int                 i_dummy;
 796
 797         /* This is a PES packet. Find out if we want it or not. */
 798         i_id = GetID( p_data );
 799
 800         vlc_mutex_lock( &p_input->stream.stream_lock );
 801         if( p_input->stream.pp_programs[0]->b_is_ok )
 802         {
 803             /* Look only at the selected ES. */
 804             for( i_dummy = 0; i_dummy < p_input->stream.i_selected_es_number;
 805                  i_dummy++ )
 806             {
 807                 if( p_input->stream.pp_selected_es[i_dummy] != NULL
 808                     && p_input->stream.pp_selected_es[i_dummy]->i_id == i_id )
 809                 {
 810                     p_es = p_input->stream.pp_selected_es[i_dummy];
 811                     break;
 812                 }
 813             }
 814         }
 815         else
 816         {
 817             stream_ps_data_t * p_demux =
 818               (stream_ps_data_t *)p_input->stream.pp_programs[0]->p_demux_data;
 819
 820             /* Search all ES ; if not found -> AddES */
 821             p_es = input_FindES( p_input, i_id );
 822
 823             if( p_es == NULL && !p_demux->b_has_PSM )
 824             {
 825                 p_es = input_AddES( p_input, p_input->stream.pp_programs[0],
 826                                     i_id, 0 );
 827                 if( p_es != NULL )
 828                 {
 829                     p_es->i_stream_id = p_data->p_buffer[3];
 830
 831                     /* Set stream type and auto-spawn. */
 832                     if( (i_id & 0xF0) == 0xE0 )
 833                     {
 834                         /* MPEG video */
 835                         p_es->i_type = MPEG2_VIDEO_ES;
 836 #ifdef AUTO_SPAWN
 837                         if( !p_input->stream.b_seekable )
 838                             input_SelectES( p_input, p_es );
 839 #endif
 840                     }
 841                     else if( (i_id & 0xE0) == 0xC0 )
 842                     {
 843                         /* MPEG audio */
 844                         p_es->i_type = MPEG2_AUDIO_ES;
 845 #ifdef AUTO_SPAWN
 846                         if( main_GetIntVariable( INPUT_DVD_AUDIO_VAR, 0 )
 847                                 == REQUESTED_MPEG
 848                           && main_GetIntVariable( INPUT_DVD_CHANNEL_VAR, 0 )
 849                                 == (p_es->i_id & 0x1F) )
 850                         {
 851                             if( !p_input->stream.b_seekable )
 852                                 input_SelectES( p_input, p_es );
 853                         }
 854 #endif
 855                     }
 856                     else if( (i_id & 0xF0FF) == 0x80BD )
 857                     {
 858                         /* AC3 audio (0x80->0x8F) */
 859                         p_es->i_type = AC3_AUDIO_ES;
 860 #ifdef AUTO_SPAWN
 861                         if( main_GetIntVariable( INPUT_DVD_AUDIO_VAR, 0 )
 862                                 == REQUESTED_AC3
 863                          && main_GetIntVariable( INPUT_DVD_CHANNEL_VAR, 0 )
 864                                 == ((p_es->i_id & 0xF00) >> 8) )
 865                         {
 866                             if( !p_input->stream.b_seekable )
 867                                 input_SelectES( p_input, p_es );
 868                         }
 869 #endif
 870                     }
 871                     else if( (i_id & 0xE0FF) == 0x20BD )
 872                     {
 873                         /* Subtitles video (0x20->0x3F) */
 874                         p_es->i_type = DVD_SPU_ES;
 875 #ifdef AUTO_SPAWN
 876                         if( main_GetIntVariable( INPUT_DVD_SUBTITLE_VAR, 0 )
 877                                 == ((p_es->i_id & 0x1F00) >> 8) )
 878                         {
 879                             if( !p_input->stream.b_seekable )
 880                                 input_SelectES( p_input, p_es );
 881                         }
 882 #endif
 883                     }
 884                     else if( (i_id & 0xF0FF) == 0xA0BD )
 885                     {
 886                         /* LPCM audio (0xA0->0xAF) */
 887                         p_es->i_type = LPCM_AUDIO_ES;
 888                         /* FIXME : write the decoder */
 889                     }
 890                     else
 891                     {
 892                         p_es->i_type = UNKNOWN_ES;
 893                     }
 894                 }
 895             }
 896         } /* stream.b_is_ok */
 897         vlc_mutex_unlock( &p_input->stream.stream_lock );
 898     } /* i_code > 0xBC */
 899
 900     return( p_es );
 901 }
 902
 903 /*****************************************************************************
 904  * input_DemuxPS: first step of demultiplexing: the PS header
 905  *****************************************************************************/
 906 void input_DemuxPS( input_thread_t * p_input, data_packet_t * p_data )
 907 {
 908     u32                 i_code;
 909     boolean_t           b_trash = 0;
 910     es_descriptor_t *   p_es = NULL;
 911
 912     i_code = U32_AT( p_data->p_buffer );
 913     if( i_code <= 0x1BC )
 914     {
 915         switch( i_code )
 916         {
 917         case 0x1BA: /* PACK_START_CODE */
 918             {
 919                 /* Convert the SCR in microseconds. */
 920                 mtime_t         scr_time;
 921
 922                 if( (p_data->p_buffer[4] & 0xC0) == 0x40 )
 923                 {
 924                     /* MPEG-2 */
 925                     scr_time =
 926                       (( ((mtime_t)(p_data->p_buffer[4] & 0x38) << 27) |
 927                          ((mtime_t)(U32_AT(p_data->p_buffer + 4) & 0x03FFF800)
 928                                         << 4) |
 929                          ((mtime_t)(U32_AT(p_data->p_buffer + 6) & 0x03FFF800)
 930                                         >> 11)
 931                       ) * 300) / 27;
 932                 }
 933                 else
 934                 {
 935                     /* MPEG-1 SCR is like PTS */
 936                     scr_time =
 937                       (( ((mtime_t)(p_data->p_buffer[4] & 0x0E) << 29) |
 938                          (((mtime_t)U16_AT(p_data->p_buffer + 5) << 14)
 939                            - (1 << 14)) |
 940                          ((mtime_t)U16_AT(p_data->p_buffer + 7) >> 1)
 941                       ) * 300) / 27;
 942                 }
 943                 /* Call the pace control. */
 944                 //intf_Msg("+%lld", scr_time);
 945                 CRDecode( p_input, p_input->stream.pp_programs[0],
 946                           scr_time );
 947                 b_trash = 1;
 948             }
 949             break;
 950
 951         case 0x1BB: /* SYSTEM_START_CODE */
 952             b_trash = 1;                              /* Nothing interesting */
 953             break;
 954
 955         case 0x1BC: /* PROGRAM_STREAM_MAP_CODE */
 956             DecodePSM( p_input, p_data );
 957             b_trash = 1;
 958             break;
 959
 960         case 0x1B9: /* PROGRAM_END_CODE */
 961             b_trash = 1;
 962             break;
 963
 964         default:
 965             /* This should not happen */
 966             b_trash = 1;
 967             intf_WarnMsg( 1, "Unwanted packet received with start code %x",
 968                           i_code );
 969         }
 970     }
 971     else
 972     {
 973         p_es = input_ParsePS( p_input, p_data );
 974
 975         if( p_es != NULL && p_es->p_decoder_fifo != NULL )
 976         {
 977 #ifdef STATS
 978             p_es->c_packets++;
 979 #endif
 980             input_GatherPES( p_input, p_data, p_es, 1, 0 );
 981         }
 982         else
 983         {
 984             b_trash = 1;
 985         }
 986     }
 987
 988     /* Trash the packet if it has no payload or if it isn't selected */
 989     if( b_trash )
 990     {
 991         p_input->p_plugin->pf_delete_packet( p_input, p_data );
 992 #ifdef STATS
 993         p_input->c_packets_trashed++;
 994 #endif
 995     }
 996 }
 997
 998
 999 /*
1000  * TS Demultiplexing
1001  */
1002
1003 /*****************************************************************************
1004  * input_DemuxTS: first step of demultiplexing: the TS header
1005  *****************************************************************************/
1006 void input_DemuxTS( input_thread_t * p_input, data_packet_t * p_data )
1007 {
1008     int                 i_pid, i_dummy;
1009     boolean_t           b_adaptation;         /* Adaptation field is present */
1010     boolean_t           b_payload;                 /* Packet carries payload */
1011     boolean_t           b_unit_start;  /* A PSI or a PES start in the packet */
1012     boolean_t           b_trash = 0;             /* Is the packet unuseful ? */
1013     boolean_t           b_lost = 0;             /* Was there a packet loss ? */
1014     es_descriptor_t *   p_es = NULL;
1015     es_ts_data_t *      p_es_demux = NULL;
1016     pgrm_ts_data_t *    p_pgrm_demux = NULL;
1017
1018 #define p (p_data->p_buffer)
1019
1020     //intf_DbgMsg("input debug: TS-demultiplexing packet %p, pid %d",
1021     //            p_ts_packet, U16_AT(&p[1]) & 0x1fff);
1022
1023     /* Extract flags values from TS common header. */
1024     i_pid = U16_AT(&p[1]) & 0x1fff;
1025     b_unit_start = (p[1] & 0x40);
1026     b_adaptation = (p[3] & 0x20);
1027     b_payload = (p[3] & 0x10);
1028
1029     /* Find out the elementary stream. */
1030     vlc_mutex_lock( &p_input->stream.stream_lock );
1031     p_es = input_FindES( p_input, i_pid );
1032     vlc_mutex_unlock( &p_input->stream.stream_lock );
1033
1034     if( p_es == NULL || p_es->p_decoder_fifo == NULL )
1035     {
1036         /* Not selected. Just read the adaptation field for a PCR. */
1037         b_trash = 1;
1038     }
1039
1040     if( (p_es->p_decoder_fifo != NULL) || (p_pgrm_demux->i_pcr_pid == i_pid) )
1041     {
1042 #ifdef STATS
1043         p_es->c_packets++;
1044 #endif
1045
1046         /* Extract adaptation field information if any */
1047         if( !b_adaptation )
1048         {
1049             /* We don't have any adaptation_field, so payload starts
1050              * immediately after the 4 byte TS header */
1051             p_data->p_payload_start += 4;
1052         }
1053         else
1054         {
1055             /* p[4] is adaptation_field_length minus one */
1056             p_data->p_payload_start += 5 + p[4];
1057
1058             /* The adaptation field can be limited to the
1059              * adaptation_field_length byte, so that there is nothing to do:
1060              * skip this possibility */
1061             if( p[4] )
1062             {
1063                 /* If the packet has both adaptation_field and payload,
1064                  * adaptation_field cannot be more than 182 bytes long; if
1065                  * there is only an adaptation_field, it must fill the next
1066                  * 183 bytes. */
1067                 if( b_payload ? (p[4] > 182) : (p[4] != 183) )
1068                 {
1069                     intf_WarnMsg( 2,
1070                         "invalid TS adaptation field (%p)",
1071                         p_data );
1072                     p_data->b_discard_payload = 1;
1073 #ifdef STATS
1074                     p_es->c_invalid_packets++;
1075 #endif
1076                 }
1077
1078                 /* Now we are sure that the byte containing flags is present:
1079                  * read it */
1080                 else
1081                 {
1082                     /* discontinuity_indicator */
1083                     if( p[5] & 0x80 )
1084                     {
1085                         intf_WarnMsg( 2,
1086                             "discontinuity_indicator"
1087                             " encountered by TS demux (position read: %d,"
1088                             " saved: %d)",
1089                             p[5] & 0x80, p_es_demux->i_continuity_counter );
1090
1091                         /* If the PID carries the PCR, there will be a system
1092                          * time-based discontinuity. We let the PCR decoder
1093                          * handle that. */
1094                         p_es->p_pgrm->b_discontinuity = 1;
1095
1096                         /* There also may be a continuity_counter
1097                          * discontinuity: resynchronise our counter with
1098                          * the one of the stream. */
1099                         p_es_demux->i_continuity_counter = (p[3] & 0x0f) - 1;
1100                     }
1101
1102                     /* If this is a PCR_PID, and this TS packet contains a
1103                      * PCR, we pass it along to the PCR decoder. */
1104                     if( (p_pgrm_demux->i_pcr_pid == i_pid) && (p[5] & 0x10) )
1105                     {
1106                         /* There should be a PCR field in the packet, check
1107                          * if the adaptation field is long enough to carry
1108                          * it. */
1109                         if( p[4] >= 7 )
1110                         {
1111                             /* Convert the PCR in microseconds.
1112                              * WARNING: do not remove the casts in the
1113                              * following calculation ! */
1114                             mtime_t     pcr_time;
1115                             pcr_time =
1116                                     ( (( (mtime_t)U32_AT((u32*)&p[6]) << 1 )
1117                                       | ( p[10] >> 7 )) * 300 ) / 27;
1118                             /* Call the pace control. */
1119                             CRDecode( p_input, p_es->p_pgrm, pcr_time );
1120                         }
1121                     } /* PCR ? */
1122                 } /* valid TS adaptation field ? */
1123             } /* length > 0 */
1124         } /* has adaptation field */
1125
1126         /* Check the continuity of the stream. */
1127         i_dummy = ((p[3] & 0x0f) - p_es_demux->i_continuity_counter) & 0x0f;
1128         if( i_dummy == 1 )
1129         {
1130             /* Everything is ok, just increase our counter */
1131             p_es_demux->i_continuity_counter++;
1132         }
1133         else
1134         {
1135             if( !b_payload && i_dummy == 0 )
1136             {
1137                 /* This is a packet without payload, this is allowed by the
1138                  * draft. As there is nothing interesting in this packet
1139                  * (except PCR that have already been handled), we can trash
1140                  * the packet. */
1141                 intf_WarnMsg( 1,
1142                               "Packet without payload received by TS demux" );
1143                 b_trash = 1;
1144             }
1145             else if( i_dummy <= 0 )
1146             {
1147                 /* FIXME: this can never happen, can it ? --Meuuh */
1148                 /* Duplicate packet: mark it as being to be trashed. */
1149                 intf_WarnMsg( 1, "Duplicate packet received by TS demux" );
1150                 b_trash = 1;
1151             }
1152             else if( p_es_demux->i_continuity_counter == 0xFF )
1153             {
1154                 /* This means that the packet is the first one we receive for
1155                  * this ES since the continuity counter ranges between 0 and
1156                  * 0x0F excepts when it has been initialized by the input:
1157                  * init the counter to the correct value. */
1158                 intf_DbgMsg( "First packet for PID %d received by TS demux",
1159                              p_es->i_id );
1160                 p_es_demux->i_continuity_counter = (p[3] & 0x0f);
1161             }
1162             else
1163             {
1164                 /* This can indicate that we missed a packet or that the
1165                  * continuity_counter wrapped and we received a dup packet:
1166                  * as we don't know, do as if we missed a packet to be sure
1167                  * to recover from this situation */
1168                 intf_WarnMsg( 2,
1169                            "Packet lost by TS demux: current %d, packet %d",
1170                            p_es_demux->i_continuity_counter & 0x0f,
1171                            p[3] & 0x0f );
1172                 b_lost = 1;
1173                 p_es_demux->i_continuity_counter = p[3] & 0x0f;
1174             } /* not continuous */
1175         } /* continuity */
1176     } /* if selected or PCR */
1177
1178     /* Trash the packet if it has no payload or if it isn't selected */
1179     if( b_trash )
1180     {
1181         p_input->p_plugin->pf_delete_packet( p_input, p_data );
1182 #ifdef STATS
1183         p_input->c_packets_trashed++;
1184 #endif
1185     }
1186     else
1187     {
1188         if( p_es_demux->b_psi )
1189         {
1190             /* The payload contains PSI tables */
1191 #if 0
1192             input_DemuxPSI( p_input, p_data, p_es,
1193                             b_unit_start, b_lost );
1194 #endif
1195         }
1196         else
1197         {
1198             /* The payload carries a PES stream */
1199             if( b_unit_start )
1200             input_GatherPES( p_input, p_data, p_es, b_unit_start, b_lost );
1201         }
1202     }
1203
1204 #undef p
1205 }