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 1.26 2001/01/10 19:22:11 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
  31 #include "config.h"
  32 #include "common.h"
  33 #include "threads.h"
  34 #include "mtime.h"
  35
  36 #include "intf_msg.h"
  37
  38 #include "stream_control.h"
  39 #include "input_ext-intf.h"
  40 #include "input_ext-dec.h"
  41
  42 #include "input.h"
  43 #include "mpeg_system.h"
  44
  45 #include "main.h"                           /* AC3/MPEG channel, SPU channel */
  46
  47 /*****************************************************************************
  48  * Local prototypes
  49  *****************************************************************************/
  50
  51
  52 /*
  53  * PES Packet management
  54  */
  55
  56 /*****************************************************************************
  57  * MoveChunk
  58  *****************************************************************************
  59  * Small utility function used to parse discontinuous headers safely. Copies
  60  * i_buf_len bytes of data to a buffer and returns the size copied.
  61  * This is a variation on the theme of input_ext-dec.h:GetChunk().
  62  *****************************************************************************/
  63 static __inline__ size_t MoveChunk( byte_t * p_dest,
  64                                     data_packet_t ** pp_data_src,
  65                                     byte_t ** pp_src,
  66                                     size_t i_buf_len )
  67 {
  68     ptrdiff_t           i_available;
  69
  70     if( (i_available = (*pp_data_src)->p_payload_end - *pp_src)
  71             >= i_buf_len )
  72     {
  73         if( p_dest != NULL )
  74             memcpy( p_dest, *pp_src, i_buf_len );
  75         *pp_src += i_buf_len;
  76         return( i_buf_len );
  77     }
  78     else
  79     {
  80         size_t          i_init_len = i_buf_len;
  81
  82         do
  83         {
  84             if( p_dest != NULL )
  85                 memcpy( p_dest, *pp_src, i_available );
  86             *pp_data_src = (*pp_data_src)->p_next;
  87             i_buf_len -= i_available;
  88             p_dest += i_available;
  89             if( *pp_data_src == NULL )
  90             {
  91                 *pp_src = NULL;
  92                 return( i_init_len - i_buf_len );
  93             }
  94             *pp_src = (*pp_data_src)->p_payload_start;
  95         }
  96         while( (i_available = (*pp_data_src)->p_payload_end - *pp_src)
  97                 <= i_buf_len );
  98
  99         if( i_buf_len )
 100         {
 101             if( p_dest != NULL )
 102                 memcpy( p_dest, *pp_src, i_buf_len );
 103             *pp_src += i_buf_len;
 104         }
 105         return( i_init_len );
 106     }
 107 }
 108
 109 /*****************************************************************************
 110  * input_ParsePES
 111  *****************************************************************************
 112  * Parse a finished PES packet and analyze its header.
 113  *****************************************************************************/
 114 #define PES_HEADER_SIZE     7
 115 void input_ParsePES( input_thread_t * p_input, es_descriptor_t * p_es )
 116 {
 117     data_packet_t * p_data;
 118     byte_t *        p_byte;
 119     byte_t          p_header[PES_HEADER_SIZE];
 120     int             i_done;
 121
 122 #define p_pes (p_es->p_pes)
 123
 124     //intf_DbgMsg("End of PES packet %p", p_pes);
 125
 126     /* Parse the header. The header has a variable length, but in order
 127      * to improve the algorithm, we will read the 14 bytes we may be
 128      * interested in */
 129     p_data = p_pes->p_first;
 130     p_byte = p_data->p_payload_start;
 131     i_done = 0;
 132
 133     if( MoveChunk( p_header, &p_data, &p_byte, PES_HEADER_SIZE )
 134             != PES_HEADER_SIZE )
 135     {
 136         intf_WarnMsg( 3, "PES packet too short to have a header" );
 137         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 138         p_pes = NULL;
 139         return;
 140     }
 141
 142     /* Get the PES size if defined */
 143     p_es->i_pes_real_size = U16_AT(p_header + 4) + 6;
 144
 145     /* First read the 6 header bytes common to all PES packets:
 146      * use them to test the PES validity */
 147     if( (p_header[0] || p_header[1] || (p_header[2] != 1)) )
 148     {
 149         /* packet_start_code_prefix != 0x000001 */
 150         intf_ErrMsg( "PES packet doesn't start with 0x000001 : data loss" );
 151         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 152         p_pes = NULL;
 153     }
 154     else
 155     {
 156         int i_pes_header_size, i_payload_size;
 157
 158         if ( p_es->i_pes_real_size &&
 159              (p_es->i_pes_real_size != p_pes->i_pes_size) )
 160         {
 161             /* PES_packet_length is set and != total received payload */
 162             /* Warn the decoder that the data may be corrupt. */
 163             intf_WarnMsg( 3, "PES sizes do not match : packet corrupted" );
 164             p_pes->b_messed_up = 1;
 165         }
 166
 167         switch( p_es->i_stream_id )
 168         {
 169         case 0xBC:  /* Program stream map */
 170         case 0xBE:  /* Padding */
 171         case 0xBF:  /* Private stream 2 */
 172         case 0xB0:  /* ECM */
 173         case 0xB1:  /* EMM */
 174         case 0xFF:  /* Program stream directory */
 175         case 0xF2:  /* DSMCC stream */
 176         case 0xF8:  /* ITU-T H.222.1 type E stream */
 177             /* The payload begins immediately after the 6 bytes header, so
 178              * we have finished with the parsing */
 179             i_pes_header_size = 6;
 180             break;
 181
 182         default:
 183             if( (p_header[6] & 0xC0) == 0x80 )
 184             {
 185                 /* MPEG-2 : the PES header contains at least 3 more bytes. */
 186                 size_t      i_max_len;
 187                 boolean_t   b_has_pts, b_has_dts;
 188                 byte_t      p_full_header[12];
 189
 190                 p_pes->b_data_alignment = p_header[6] & 0x04;
 191
 192                 i_max_len = MoveChunk( p_full_header, &p_data, &p_byte, 12 );
 193                 if( i_max_len < 2 )
 194                 {
 195                     intf_WarnMsg( 3,
 196                             "PES packet too short to have a MPEG-2 header" );
 197                     p_input->p_plugin->pf_delete_pes( p_input->p_method_data,
 198                                                       p_pes );
 199                     p_pes = NULL;
 200                     return;
 201                 }
 202
 203                 b_has_pts = p_full_header[0] & 0x80;
 204                 b_has_dts = p_full_header[0] & 0x40;
 205                 i_pes_header_size = p_full_header[1] + 9;
 206
 207                 /* Now parse the optional header extensions */
 208                 if( 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_full_header[2] & 0x0E) << 29) |
 222                       (((mtime_t)U16_AT(p_full_header + 3) << 14) - (1 << 14)) |
 223                       ((mtime_t)U16_AT(p_full_header + 5) >> 1) ) * 300;
 224                     p_pes->i_pts /= 27;
 225
 226                     if( b_has_dts )
 227                     {
 228                         if( i_max_len < 12 )
 229                         {
 230                             intf_WarnMsg( 3,
 231                               "PES packet too short to have a MPEG-2 header" );
 232                             p_input->p_plugin->pf_delete_pes(
 233                                     p_input->p_method_data,
 234                                     p_pes );
 235                             p_pes = NULL;
 236                             return;
 237                         }
 238                         p_pes->i_dts =
 239                         ( ((mtime_t)(p_full_header[7] & 0x0E) << 29) |
 240                           (((mtime_t)U16_AT(p_full_header + 8) << 14)
 241                                 - (1 << 14)) |
 242                           ((mtime_t)U16_AT(p_full_header + 10) >> 1) ) * 300;
 243                         p_pes->i_dts /= 27;
 244                     }
 245                 }
 246             }
 247             else
 248             {
 249                 /* Probably MPEG-1 */
 250                 boolean_t       b_has_pts, b_has_dts;
 251
 252                 i_pes_header_size = 6;
 253                 p_data = p_pes->p_first;
 254                 p_byte = p_data->p_payload_start;
 255                 /* Cannot fail because the previous one succeeded. */
 256                 MoveChunk( NULL, &p_data, &p_byte, 6 );
 257
 258                 while( *p_byte == 0xFF && i_pes_header_size < 22 )
 259                 {
 260                     i_pes_header_size++;
 261                     if( MoveChunk( NULL, &p_data, &p_byte, 1 ) != 1 )
 262                     {
 263                         intf_WarnMsg( 3,
 264                             "PES packet too short to have a MPEG-1 header" );
 265                         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 266                         p_pes = NULL;
 267                         return;
 268                     }
 269                 }
 270                 if( i_pes_header_size == 22 )
 271                 {
 272                     intf_ErrMsg( "Too much MPEG-1 stuffing" );
 273                     p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 274                     p_pes = NULL;
 275                     return;
 276                 }
 277
 278                 if( (*p_byte & 0xC0) == 0x40 )
 279                 {
 280                     /* Don't ask why... --Meuuh */
 281                     /* Erm... why ? --Sam */
 282                     /* Well... According to the recommendation, it is for
 283                      * STD_buffer_scale and STD_buffer_size. --Meuuh */
 284                     i_pes_header_size += 2;
 285                     if( MoveChunk( NULL, &p_data, &p_byte, 2 ) != 2 )
 286                     {
 287                         intf_WarnMsg( 3,
 288                             "PES packet too short to have a MPEG-1 header" );
 289                         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 290                         p_pes = NULL;
 291                         return;
 292                     }
 293                 }
 294
 295                 i_pes_header_size++;
 296
 297                 b_has_pts = *p_byte & 0x20;
 298                 b_has_dts = *p_byte & 0x10;
 299
 300                 if( b_has_pts )
 301                 {
 302                     byte_t      p_ts[5];
 303
 304                     i_pes_header_size += 4;
 305                     if( MoveChunk( p_ts, &p_data, &p_byte, 5 ) != 5 )
 306                     {
 307                         intf_WarnMsg( 3,
 308                             "PES packet too short to have a MPEG-1 header" );
 309                         p_input->p_plugin->pf_delete_pes(
 310                                             p_input->p_method_data, p_pes );
 311                         p_pes = NULL;
 312                         return;
 313                     }
 314
 315                     p_pes->i_pts =
 316                       ( ((mtime_t)(p_ts[0] & 0x0E) << 29) |
 317                         (((mtime_t)U16_AT(p_ts + 1) << 14) - (1 << 14)) |
 318                         ((mtime_t)U16_AT(p_ts + 3) >> 1) ) * 300;
 319                     p_pes->i_pts /= 27;
 320
 321                     if( b_has_dts )
 322                     {
 323                         i_pes_header_size += 5;
 324                         if( MoveChunk( p_ts, &p_data, &p_byte, 5 ) != 5 )
 325                         {
 326                             intf_WarnMsg( 3,
 327                               "PES packet too short to have a MPEG-1 header" );
 328                             p_input->p_plugin->pf_delete_pes(
 329                                     p_input->p_method_data, p_pes );
 330                             p_pes = NULL;
 331                             return;
 332                         }
 333
 334                         p_pes->i_dts =
 335                             ( ((mtime_t)(p_ts[0] & 0x0E) << 29) |
 336                               (((mtime_t)U16_AT(p_ts + 1) << 14) - (1 << 14)) |
 337                               ((mtime_t)U16_AT(p_ts + 3) >> 1) ) * 300;
 338                         p_pes->i_dts /= 27;
 339                     }
 340                 }
 341             }
 342
 343             /* PTS management */
 344             if( p_pes->i_pts )
 345             {
 346                 //intf_Msg("%lld", p_pes->i_pts);
 347                 switch( p_es->p_pgrm->i_synchro_state )
 348                 {
 349                 case SYNCHRO_NOT_STARTED:
 350                 case SYNCHRO_START:
 351                     p_pes->i_pts = p_pes->i_dts = 0;
 352                     break;
 353
 354                 case SYNCHRO_REINIT: /* We skip a PES | Why ?? --Meuuh */
 355                     p_pes->i_pts = p_pes->i_dts = 0;
 356                     p_es->p_pgrm->i_synchro_state = SYNCHRO_START;
 357                     break;
 358
 359                 case SYNCHRO_OK:
 360                     p_pes->i_pts += p_es->p_pgrm->delta_cr
 361                                          + p_es->p_pgrm->delta_absolute
 362                                          + DEFAULT_PTS_DELAY;
 363                     if( p_pes->i_dts )
 364                     {
 365                         p_pes->i_dts += p_es->p_pgrm->delta_cr
 366                                              + p_es->p_pgrm->delta_absolute
 367                                              + DEFAULT_PTS_DELAY;
 368                     }
 369                     break;
 370                 }
 371             }
 372             break;
 373         }
 374
 375         if( p_es->i_stream_id == 0xbd )
 376         {
 377             /* With private stream 1, the first byte of the payload
 378              * is a stream_private_id, so skip it. */
 379             i_pes_header_size++;
 380         }
 381
 382         /* Now we've parsed the header, we just have to indicate in some
 383          * specific data packets where the PES payload begins (renumber
 384          * p_payload_start), so that the decoders can find the beginning
 385          * of their data right out of the box. */
 386         p_data = p_pes->p_first;
 387         i_payload_size = p_data->p_payload_end
 388                                  - p_data->p_payload_start;
 389         while( i_pes_header_size > i_payload_size )
 390         {
 391             /* These packets are entirely filled by the PES header. */
 392             i_pes_header_size -= i_payload_size;
 393             p_data->p_payload_start = p_data->p_payload_end;
 394             /* Go to the next data packet. */
 395             if( (p_data = p_data->p_next) == NULL )
 396             {
 397                 intf_ErrMsg( "PES header bigger than payload" );
 398                 p_input->p_plugin->pf_delete_pes( p_input->p_method_data,
 399                                                   p_pes );
 400                 p_pes = NULL;
 401                 return;
 402             }
 403             i_payload_size = p_data->p_payload_end
 404                                  - p_data->p_payload_start;
 405         }
 406         /* This last packet is partly header, partly payload. */
 407         if( i_payload_size < i_pes_header_size )
 408         {
 409             intf_ErrMsg( "PES header bigger than payload" );
 410             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 411             p_pes = NULL;
 412             return;
 413         }
 414         p_data->p_payload_start += i_pes_header_size;
 415
 416         /* Now we can eventually put the PES packet in the decoder's
 417          * PES fifo */
 418         if( p_es->p_decoder_fifo != NULL )
 419         {
 420             input_DecodePES( p_es->p_decoder_fifo, p_pes );
 421         }
 422         else
 423         {
 424             intf_ErrMsg("No fifo to receive PES %p (who wrote this damn code ?)",
 425                         p_pes);
 426             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 427         }
 428         p_pes = NULL;
 429     }
 430 #undef p_pes
 431 }
 432
 433 /*****************************************************************************
 434  * input_GatherPES:
 435  *****************************************************************************
 436  * Gather a PES packet.
 437  *****************************************************************************/
 438 void input_GatherPES( input_thread_t * p_input, data_packet_t * p_data,
 439                       es_descriptor_t * p_es,
 440                       boolean_t b_unit_start, boolean_t b_packet_lost )
 441 {
 442 #define p_pes (p_es->p_pes)
 443
 444     //intf_DbgMsg("PES-demultiplexing %p (%p)", p_ts_packet, p_pes);
 445
 446     /* If we lost data, insert a NULL data packet (philosophy : 0 is quite
 447      * often an escape sequence in decoders, so that should make them wait
 448      * for the next start code). */
 449     if( b_packet_lost || p_es->b_discontinuity )
 450     {
 451         input_NullPacket( p_input, p_es );
 452     }
 453
 454     if( b_unit_start && p_pes != NULL )
 455     {
 456         /* If the data packet contains the begining of a new PES packet, and
 457          * if we were reassembling a PES packet, then the PES should be
 458          * complete now, so parse its header and give it to the decoders. */
 459         input_ParsePES( p_input, p_es );
 460     }
 461
 462     if( !b_unit_start && p_pes == NULL )
 463     {
 464         /* Random access... */
 465         p_input->p_plugin->pf_delete_packet( p_input->p_method_data, p_data );
 466     }
 467     else
 468     {
 469         if( b_unit_start )
 470         {
 471             /* If we are at the beginning of a new PES packet, we must fetch
 472              * a new PES buffer to begin with the reassembly of this PES
 473              * packet. This is also here that we can synchronize with the
 474              * stream if we lost packets or if the decoder has just
 475              * started. */
 476             if( (p_pes = p_input->p_plugin->pf_new_pes( p_input->p_method_data ) ) == NULL )
 477             {
 478                 intf_ErrMsg("Out of memory");
 479                 p_input->b_error = 1;
 480                 return;
 481             }
 482             //intf_DbgMsg("New PES packet %p (first data: %p)", p_pes, p_data);
 483             p_pes->p_first = p_data;
 484
 485             /* If the PES header fits in the first data packet, we can
 486              * already set p_gather->i_pes_real_size. */
 487             if( p_data->p_payload_end - p_data->p_payload_start
 488                     >= PES_HEADER_SIZE )
 489             {
 490                 p_es->i_pes_real_size =
 491                                 U16_AT(p_data->p_payload_start + 4) + 6;
 492             }
 493             else
 494             {
 495                 p_es->i_pes_real_size = 0;
 496             }
 497         }
 498         else
 499         {
 500             /* Update the relations between the data packets */
 501             p_es->p_last->p_next = p_data;
 502         }
 503
 504         p_es->p_last = p_data;
 505
 506         /* Size of the payload carried in the data packet */
 507         p_pes->i_pes_size += (p_data->p_payload_end
 508                                  - p_data->p_payload_start);
 509
 510         /* We can check if the packet is finished */
 511         if( p_pes->i_pes_size == p_es->i_pes_real_size )
 512         {
 513             /* The packet is finished, parse it */
 514             input_ParsePES( p_input, p_es );
 515         }
 516     }
 517 #undef p_pes
 518 }
 519
 520
 521 /*
 522  * Pace control
 523  */
 524
 525 /*
 526  *   DISCUSSION : SYNCHRONIZATION METHOD
 527  *
 528  *   In some cases we can impose the pace of reading (when reading from a
 529  *   file or a pipe), and for the synchronization we simply sleep() until
 530  *   it is time to deliver the packet to the decoders. When reading from
 531  *   the network, we must be read at the same pace as the server writes,
 532  *   otherwise the kernel's buffer will trash packets. The risk is now to
 533  *   overflow the input buffers in case the server goes too fast, that is
 534  *   why we do these calculations :
 535  *
 536  *   We compute an average for the pcr because we want to eliminate the
 537  *   network jitter and keep the low frequency variations. The average is
 538  *   in fact a low pass filter and the jitter is a high frequency signal
 539  *   that is why it is eliminated by the filter/average.
 540  *
 541  *   The low frequency variations enable us to synchronize the client clock
 542  *   with the server clock because they represent the time variation between
 543  *   the 2 clocks. Those variations (ie the filtered pcr) are used to compute
 544  *   the presentation dates for the audio and video frames. With those dates
 545  *   we can decode (or trash) the MPEG2 stream at "exactly" the same rate
 546  *   as it is sent by the server and so we keep the synchronization between
 547  *   the server and the client.
 548  *
 549  *   It is a very important matter if you want to avoid underflow or overflow
 550  *   in all the FIFOs, but it may be not enough.
 551  */
 552
 553 /*****************************************************************************
 554  * Constants
 555  *****************************************************************************/
 556
 557 /* Maximum number of samples used to compute the dynamic average value,
 558  * it is also the maximum of c_average_count in pgrm_ts_data_t.
 559  * We use the following formula :
 560  * new_average = (old_average * c_average + new_sample_value) / (c_average +1) */
 561 #define CR_MAX_AVERAGE_COUNTER 40
 562
 563 /* Maximum gap allowed between two CRs. */
 564 #define CR_MAX_GAP 1000000
 565
 566 /*****************************************************************************
 567  * CRReInit : Reinitialize the clock reference
 568  *****************************************************************************/
 569 static void CRReInit( pgrm_descriptor_t * p_pgrm )
 570 {
 571     p_pgrm->delta_cr        = 0;
 572     p_pgrm->last_cr         = 0;
 573     p_pgrm->c_average_count = 0;
 574 }
 575
 576 /* FIXME: find a better name */
 577 /*****************************************************************************
 578  * CRDecode : Decode a clock reference
 579  *****************************************************************************/
 580 static void CRDecode( input_thread_t * p_input, pgrm_descriptor_t * p_pgrm,
 581                       mtime_t cr_time )
 582 {
 583     if( p_pgrm->i_synchro_state != SYNCHRO_OK )
 584     {
 585         switch( p_pgrm->i_synchro_state )
 586         {
 587         case SYNCHRO_START:
 588             p_pgrm->delta_absolute = mdate() - cr_time;
 589             p_pgrm->i_synchro_state = SYNCHRO_OK;
 590             break;
 591
 592         case SYNCHRO_NOT_STARTED:
 593             p_pgrm->i_synchro_state = SYNCHRO_START;
 594             break;
 595
 596         default:
 597             break;
 598         }
 599     }
 600     else
 601     {
 602         if( p_pgrm->b_discontinuity ||
 603             ( p_pgrm->last_cr != 0 &&
 604                   (    (p_pgrm->last_cr - cr_time) > CR_MAX_GAP
 605                     || (p_pgrm->last_cr - cr_time) < - CR_MAX_GAP ) ) )
 606         {
 607             int i_es;
 608
 609             /* Stream discontinuity. */
 610             intf_WarnMsg( 3, "CR re-initialiazed" );
 611             CRReInit( p_pgrm );
 612             p_pgrm->i_synchro_state = SYNCHRO_REINIT;
 613             p_pgrm->b_discontinuity = 0;
 614
 615             /* Warn all the elementary streams */
 616             for( i_es = 0; i_es < p_pgrm->i_es_number; i_es++ )
 617             {
 618                 p_pgrm->pp_es[i_es]->b_discontinuity = 1;
 619             }
 620         }
 621         p_pgrm->last_cr = cr_time;
 622
 623         if( p_input->stream.b_pace_control )
 624         {
 625             /* Wait a while before delivering the packets to the decoder. */
 626             mwait( cr_time + p_pgrm->delta_absolute );
 627         }
 628         else
 629         {
 630             mtime_t                 sys_time, delta_cr;
 631
 632             sys_time = mdate();
 633             delta_cr = sys_time - cr_time;
 634
 635             if( p_pgrm->c_average_count == CR_MAX_AVERAGE_COUNTER )
 636             {
 637                 p_pgrm->delta_cr = ( delta_cr + (p_pgrm->delta_cr
 638                                               * (CR_MAX_AVERAGE_COUNTER - 1)) )
 639                                      / CR_MAX_AVERAGE_COUNTER;
 640             }
 641             else
 642             {
 643                 p_pgrm->delta_cr = ( delta_cr + (p_pgrm->delta_cr
 644                                               * p_pgrm->c_average_count) )
 645                                      / ( p_pgrm->c_average_count + 1 );
 646                 p_pgrm->c_average_count++;
 647             }
 648         }
 649     }
 650 }
 651
 652
 653 /*
 654  * PS Demultiplexing
 655  */
 656
 657 /*****************************************************************************
 658  * GetID: Get the ID of a stream
 659  *****************************************************************************/
 660 static u16 GetID( data_packet_t * p_data )
 661 {
 662     u16         i_id;
 663
 664     i_id = p_data->p_buffer[3];                                 /* stream_id */
 665     if( i_id == 0xBD )
 666     {
 667         /* stream_private_id */
 668         i_id |= p_data->p_buffer[ 9 + p_data->p_buffer[8] ] << 8;
 669     }
 670     return( i_id );
 671 }
 672
 673 /*****************************************************************************
 674  * DecodePSM: Decode the Program Stream Map information
 675  *****************************************************************************/
 676 static void DecodePSM( input_thread_t * p_input, data_packet_t * p_data )
 677 {
 678     stream_ps_data_t *  p_demux =
 679                  (stream_ps_data_t *)p_input->stream.p_demux_data;
 680     byte_t *            p_byte;
 681     byte_t *            p_end;
 682     int                 i;
 683     int                 i_new_es_number = 0;
 684
 685     intf_Msg("input info: Your stream contains Program Stream Map information");
 686     intf_Msg("input info: Please send a mail to <massiot@via.ecp.fr>");
 687
 688     if( p_data->p_payload_start + 10 > p_data->p_payload_end )
 689     {
 690         intf_ErrMsg( "PSM too short : packet corrupt" );
 691         return;
 692     }
 693
 694     if( p_demux->b_has_PSM
 695         && p_demux->i_PSM_version == (p_data->p_buffer[6] & 0x1F) )
 696     {
 697         /* Already got that one. */
 698         return;
 699     }
 700
 701     intf_DbgMsg( "Building PSM" );
 702     p_demux->b_has_PSM = 1;
 703     p_demux->i_PSM_version = p_data->p_buffer[6] & 0x1F;
 704
 705     /* Go to elementary_stream_map_length, jumping over
 706      * program_stream_info. */
 707     p_byte = p_data->p_payload_start + 10
 708               + U16_AT(&p_data->p_payload_start[8]);
 709     if( p_byte > p_data->p_payload_end )
 710     {
 711         intf_ErrMsg( "PSM too short : packet corrupt" );
 712         return;
 713     }
 714     /* This is the full size of the elementary_stream_map.
 715      * 2 == elementary_stream_map_length
 716      * Please note that CRC_32 is not included in the length. */
 717     p_end = p_byte + 2 + U16_AT(p_byte);
 718     p_byte += 2;
 719     if( p_end > p_data->p_payload_end )
 720     {
 721         intf_ErrMsg( "PSM too short : packet corrupt" );
 722         return;
 723     }
 724
 725     vlc_mutex_lock( &p_input->stream.stream_lock );
 726
 727     /* 4 == minimum useful size of a section */
 728     while( p_byte + 4 <= p_end )
 729     {
 730         es_descriptor_t *   p_es = NULL;
 731         u8                  i_stream_id = p_byte[1];
 732         /* FIXME: there will be a problem with private streams... (same
 733          * stream_id) */
 734
 735         /* Look for the ES in the ES table */
 736         for( i = i_new_es_number;
 737              i < p_input->stream.pp_programs[0]->i_es_number;
 738              i++ )
 739         {
 740             if( p_input->stream.pp_programs[0]->pp_es[i]->i_stream_id
 741                     == i_stream_id )
 742             {
 743                 p_es = p_input->stream.pp_programs[0]->pp_es[i];
 744                 if( p_es->i_type != p_byte[0] )
 745                 {
 746                     input_DelES( p_input, p_es );
 747                     p_es = NULL;
 748                 }
 749                 else
 750                 {
 751                     /* Move the ES to the beginning. */
 752                     p_input->stream.pp_programs[0]->pp_es[i]
 753                         = p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ];
 754                     p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ]
 755                         = p_es;
 756                     i_new_es_number++;
 757                 }
 758                 break;
 759             }
 760         }
 761
 762         /* The goal is to have all the ES we have just read in the
 763          * beginning of the pp_es table, and all the others at the end,
 764          * so that we can close them more easily at the end. */
 765         if( p_es == NULL )
 766         {
 767             p_es = input_AddES( p_input, p_input->stream.pp_programs[0],
 768                                 i_stream_id, 0 );
 769             p_es->i_type = p_byte[0];
 770
 771             /* input_AddES has inserted the new element at the end. */
 772             p_input->stream.pp_programs[0]->pp_es[
 773                 p_input->stream.pp_programs[0]->i_es_number ]
 774                 = p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ];
 775             p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ] = p_es;
 776             i_new_es_number++;
 777         }
 778         p_byte += 4 + U16_AT(&p_byte[2]);
 779     }
 780
 781     /* Un-select the streams that are no longer parts of the program. */
 782     for( i = i_new_es_number;
 783          i < p_input->stream.pp_programs[0]->i_es_number;
 784          i++ )
 785     {
 786         /* We remove pp_es[i_new_es_member] and not pp_es[i] because the
 787          * list will be emptied starting from the end */
 788         input_DelES( p_input,
 789                      p_input->stream.pp_programs[0]->pp_es[i_new_es_number] );
 790     }
 791
 792 #ifdef STATS
 793     intf_Msg( "input info: The stream map after the PSM is now :" );
 794     input_DumpStream( p_input );
 795 #endif
 796
 797     vlc_mutex_unlock( &p_input->stream.stream_lock );
 798 }
 799
 800 /*****************************************************************************
 801  * input_ParsePS: read the PS header
 802  *****************************************************************************/
 803 es_descriptor_t * input_ParsePS( input_thread_t * p_input,
 804                                  data_packet_t * p_data )
 805 {
 806     u32                 i_code;
 807     es_descriptor_t *   p_es = NULL;
 808
 809     i_code = U32_AT( p_data->p_buffer );
 810     if( i_code > 0x1BC ) /* ES start code */
 811     {
 812         u16                 i_id;
 813         int                 i_dummy;
 814
 815         /* This is a PES packet. Find out if we want it or not. */
 816         i_id = GetID( p_data );
 817
 818         vlc_mutex_lock( &p_input->stream.stream_lock );
 819         if( p_input->stream.pp_programs[0]->b_is_ok )
 820         {
 821             /* Look only at the selected ES. */
 822             for( i_dummy = 0; i_dummy < p_input->stream.i_selected_es_number;
 823                  i_dummy++ )
 824             {
 825                 if( p_input->stream.pp_selected_es[i_dummy] != NULL
 826                     && p_input->stream.pp_selected_es[i_dummy]->i_id == i_id )
 827                 {
 828                     p_es = p_input->stream.pp_selected_es[i_dummy];
 829                     break;
 830                 }
 831             }
 832         }
 833         else
 834         {
 835             stream_ps_data_t * p_demux =
 836               (stream_ps_data_t *)p_input->stream.pp_programs[0]->p_demux_data;
 837
 838             /* Search all ES ; if not found -> AddES */
 839             p_es = input_FindES( p_input, i_id );
 840
 841             if( p_es == NULL && !p_demux->b_has_PSM )
 842             {
 843                 p_es = input_AddES( p_input, p_input->stream.pp_programs[0],
 844                                     i_id, 0 );
 845                 if( p_es != NULL )
 846                 {
 847                     p_es->i_stream_id = p_data->p_buffer[3];
 848
 849                     /* Set stream type and auto-spawn. */
 850                     if( (i_id & 0xF0) == 0xE0 )
 851                     {
 852                         /* MPEG video */
 853                         p_es->i_type = MPEG2_VIDEO_ES;
 854 #ifdef AUTO_SPAWN
 855                         if( !p_input->stream.b_seekable )
 856                             input_SelectES( p_input, p_es );
 857 #endif
 858                     }
 859                     else if( (i_id & 0xE0) == 0xC0 )
 860                     {
 861                         /* MPEG audio */
 862                         p_es->i_type = MPEG2_AUDIO_ES;
 863 #ifdef AUTO_SPAWN
 864                         if( main_GetIntVariable( INPUT_DVD_AUDIO_VAR, 0 )
 865                                 == REQUESTED_MPEG
 866                           && main_GetIntVariable( INPUT_DVD_CHANNEL_VAR, 0 )
 867                                 == (p_es->i_id & 0x1F) )
 868                         {
 869                             if( !p_input->stream.b_seekable )
 870                                 input_SelectES( p_input, p_es );
 871                         }
 872 #endif
 873                     }
 874                     else if( (i_id & 0xF0FF) == 0x80BD )
 875                     {
 876                         /* AC3 audio (0x80->0x8F) */
 877                         p_es->i_type = AC3_AUDIO_ES;
 878 #ifdef AUTO_SPAWN
 879                         if( main_GetIntVariable( INPUT_DVD_AUDIO_VAR, 0 )
 880                                 == REQUESTED_AC3
 881                          && main_GetIntVariable( INPUT_DVD_CHANNEL_VAR, 0 )
 882                                 == ((p_es->i_id & 0xF00) >> 8) )
 883                         {
 884                             if( !p_input->stream.b_seekable )
 885                                 input_SelectES( p_input, p_es );
 886                         }
 887 #endif
 888                     }
 889                     else if( (i_id & 0xE0FF) == 0x20BD )
 890                     {
 891                         /* Subtitles video (0x20->0x3F) */
 892                         p_es->i_type = DVD_SPU_ES;
 893 #ifdef AUTO_SPAWN
 894                         if( main_GetIntVariable( INPUT_DVD_SUBTITLE_VAR, -1 )
 895                                 == ((p_es->i_id & 0x1F00) >> 8) )
 896                         {
 897                             if( !p_input->stream.b_seekable )
 898                                 input_SelectES( p_input, p_es );
 899                         }
 900 #endif
 901                     }
 902                     else if( (i_id & 0xF0FF) == 0xA0BD )
 903                     {
 904                         /* LPCM audio (0xA0->0xAF) */
 905                         p_es->i_type = LPCM_AUDIO_ES;
 906                         /* FIXME : write the decoder */
 907                     }
 908                     else
 909                     {
 910                         p_es->i_type = UNKNOWN_ES;
 911                     }
 912                 }
 913             }
 914         } /* stream.b_is_ok */
 915         vlc_mutex_unlock( &p_input->stream.stream_lock );
 916     } /* i_code > 0xBC */
 917
 918     return( p_es );
 919 }
 920
 921 /*****************************************************************************
 922  * input_DemuxPS: first step of demultiplexing: the PS header
 923  *****************************************************************************/
 924 void input_DemuxPS( input_thread_t * p_input, data_packet_t * p_data )
 925 {
 926     u32                 i_code;
 927     boolean_t           b_trash = 0;
 928     es_descriptor_t *   p_es = NULL;
 929
 930     i_code = U32_AT( p_data->p_buffer );
 931     if( i_code <= 0x1BC )
 932     {
 933         switch( i_code )
 934         {
 935         case 0x1BA: /* PACK_START_CODE */
 936             {
 937                 /* Convert the SCR in microseconds. */
 938                 mtime_t         scr_time;
 939
 940                 if( (p_data->p_buffer[4] & 0xC0) == 0x40 )
 941                 {
 942                     /* MPEG-2 */
 943                     scr_time =
 944                       (( ((mtime_t)(p_data->p_buffer[4] & 0x38) << 27) |
 945                          ((mtime_t)(U32_AT(p_data->p_buffer + 4) & 0x03FFF800)
 946                                         << 4) |
 947                          ((mtime_t)(U32_AT(p_data->p_buffer + 6) & 0x03FFF800)
 948                                         >> 11)
 949                       ) * 300) / 27;
 950                 }
 951                 else
 952                 {
 953                     /* MPEG-1 SCR is like PTS */
 954                     scr_time =
 955                       (( ((mtime_t)(p_data->p_buffer[4] & 0x0E) << 29) |
 956                          (((mtime_t)U16_AT(p_data->p_buffer + 5) << 14)
 957                            - (1 << 14)) |
 958                          ((mtime_t)U16_AT(p_data->p_buffer + 7) >> 1)
 959                       ) * 300) / 27;
 960                 }
 961                 /* Call the pace control. */
 962                 //intf_Msg("+%lld", scr_time);
 963                 CRDecode( p_input, p_input->stream.pp_programs[0],
 964                           scr_time );
 965                 b_trash = 1;
 966             }
 967             break;
 968
 969         case 0x1BB: /* SYSTEM_START_CODE */
 970             b_trash = 1;                              /* Nothing interesting */
 971             break;
 972
 973         case 0x1BC: /* PROGRAM_STREAM_MAP_CODE */
 974             DecodePSM( p_input, p_data );
 975             b_trash = 1;
 976             break;
 977
 978         case 0x1B9: /* PROGRAM_END_CODE */
 979             b_trash = 1;
 980             break;
 981
 982         default:
 983             /* This should not happen */
 984             b_trash = 1;
 985             intf_WarnMsg( 1, "Unwanted packet received with start code %x",
 986                           i_code );
 987         }
 988     }
 989     else
 990     {
 991         p_es = input_ParsePS( p_input, p_data );
 992
 993         if( p_es != NULL && p_es->p_decoder_fifo != NULL )
 994         {
 995 #ifdef STATS
 996             p_es->c_packets++;
 997 #endif
 998             input_GatherPES( p_input, p_data, p_es, 1, 0 );
 999         }
1000         else
1001         {
1002             b_trash = 1;
1003         }
1004     }
1005
1006     /* Trash the packet if it has no payload or if it isn't selected */
1007     if( b_trash )
1008     {
1009         p_input->p_plugin->pf_delete_packet( p_input, p_data );
1010 #ifdef STATS
1011         p_input->c_packets_trashed++;
1012 #endif
1013     }
1014 }
1015
1016
1017 /*
1018  * TS Demultiplexing
1019  */
1020
1021 /*****************************************************************************
1022  * input_DemuxTS: first step of demultiplexing: the TS header
1023  *****************************************************************************/
1024 void input_DemuxTS( input_thread_t * p_input, data_packet_t * p_data )
1025 {
1026     int                 i_pid, i_dummy;
1027     boolean_t           b_adaptation;         /* Adaptation field is present */
1028     boolean_t           b_payload;                 /* Packet carries payload */
1029     boolean_t           b_unit_start;  /* A PSI or a PES start in the packet */
1030     boolean_t           b_trash = 0;             /* Is the packet unuseful ? */
1031     boolean_t           b_lost = 0;             /* Was there a packet loss ? */
1032     es_descriptor_t *   p_es = NULL;
1033     es_ts_data_t *      p_es_demux = NULL;
1034     pgrm_ts_data_t *    p_pgrm_demux = NULL;
1035
1036 #define p (p_data->p_buffer)
1037
1038     //intf_DbgMsg("input debug: TS-demultiplexing packet %p, pid %d",
1039     //            p_ts_packet, U16_AT(&p[1]) & 0x1fff);
1040
1041     /* Extract flags values from TS common header. */
1042     i_pid = U16_AT(&p[1]) & 0x1fff;
1043     b_unit_start = (p[1] & 0x40);
1044     b_adaptation = (p[3] & 0x20);
1045     b_payload = (p[3] & 0x10);
1046
1047     /* Find out the elementary stream. */
1048     vlc_mutex_lock( &p_input->stream.stream_lock );
1049     p_es = input_FindES( p_input, i_pid );
1050     vlc_mutex_unlock( &p_input->stream.stream_lock );
1051
1052     if( p_es == NULL || p_es->p_decoder_fifo == NULL )
1053     {
1054         /* Not selected. Just read the adaptation field for a PCR. */
1055         b_trash = 1;
1056     }
1057
1058     if( (p_es->p_decoder_fifo != NULL) || (p_pgrm_demux->i_pcr_pid == i_pid) )
1059     {
1060 #ifdef STATS
1061         p_es->c_packets++;
1062 #endif
1063
1064         /* Extract adaptation field information if any */
1065         if( !b_adaptation )
1066         {
1067             /* We don't have any adaptation_field, so payload starts
1068              * immediately after the 4 byte TS header */
1069             p_data->p_payload_start += 4;
1070         }
1071         else
1072         {
1073             /* p[4] is adaptation_field_length minus one */
1074             p_data->p_payload_start += 5 + p[4];
1075
1076             /* The adaptation field can be limited to the
1077              * adaptation_field_length byte, so that there is nothing to do:
1078              * skip this possibility */
1079             if( p[4] )
1080             {
1081                 /* If the packet has both adaptation_field and payload,
1082                  * adaptation_field cannot be more than 182 bytes long; if
1083                  * there is only an adaptation_field, it must fill the next
1084                  * 183 bytes. */
1085                 if( b_payload ? (p[4] > 182) : (p[4] != 183) )
1086                 {
1087                     intf_WarnMsg( 2,
1088                         "invalid TS adaptation field (%p)",
1089                         p_data );
1090                     p_data->b_discard_payload = 1;
1091 #ifdef STATS
1092                     p_es->c_invalid_packets++;
1093 #endif
1094                 }
1095
1096                 /* Now we are sure that the byte containing flags is present:
1097                  * read it */
1098                 else
1099                 {
1100                     /* discontinuity_indicator */
1101                     if( p[5] & 0x80 )
1102                     {
1103                         intf_WarnMsg( 2,
1104                             "discontinuity_indicator"
1105                             " encountered by TS demux (position read: %d,"
1106                             " saved: %d)",
1107                             p[5] & 0x80, p_es_demux->i_continuity_counter );
1108
1109                         /* If the PID carries the PCR, there will be a system
1110                          * time-based discontinuity. We let the PCR decoder
1111                          * handle that. */
1112                         p_es->p_pgrm->b_discontinuity = 1;
1113
1114                         /* There also may be a continuity_counter
1115                          * discontinuity: resynchronise our counter with
1116                          * the one of the stream. */
1117                         p_es_demux->i_continuity_counter = (p[3] & 0x0f) - 1;
1118                     }
1119
1120                     /* If this is a PCR_PID, and this TS packet contains a
1121                      * PCR, we pass it along to the PCR decoder. */
1122                     if( (p_pgrm_demux->i_pcr_pid == i_pid) && (p[5] & 0x10) )
1123                     {
1124                         /* There should be a PCR field in the packet, check
1125                          * if the adaptation field is long enough to carry
1126                          * it. */
1127                         if( p[4] >= 7 )
1128                         {
1129                             /* Convert the PCR in microseconds.
1130                              * WARNING: do not remove the casts in the
1131                              * following calculation ! */
1132                             mtime_t     pcr_time;
1133                             pcr_time =
1134                                     ( (( (mtime_t)U32_AT((u32*)&p[6]) << 1 )
1135                                       | ( p[10] >> 7 )) * 300 ) / 27;
1136                             /* Call the pace control. */
1137                             CRDecode( p_input, p_es->p_pgrm, pcr_time );
1138                         }
1139                     } /* PCR ? */
1140                 } /* valid TS adaptation field ? */
1141             } /* length > 0 */
1142         } /* has adaptation field */
1143
1144         /* Check the continuity of the stream. */
1145         i_dummy = ((p[3] & 0x0f) - p_es_demux->i_continuity_counter) & 0x0f;
1146         if( i_dummy == 1 )
1147         {
1148             /* Everything is ok, just increase our counter */
1149             p_es_demux->i_continuity_counter++;
1150         }
1151         else
1152         {
1153             if( !b_payload && i_dummy == 0 )
1154             {
1155                 /* This is a packet without payload, this is allowed by the
1156                  * draft. As there is nothing interesting in this packet
1157                  * (except PCR that have already been handled), we can trash
1158                  * the packet. */
1159                 intf_WarnMsg( 1,
1160                               "Packet without payload received by TS demux" );
1161                 b_trash = 1;
1162             }
1163             else if( i_dummy <= 0 )
1164             {
1165                 /* FIXME: this can never happen, can it ? --Meuuh */
1166                 /* Duplicate packet: mark it as being to be trashed. */
1167                 intf_WarnMsg( 1, "Duplicate packet received by TS demux" );
1168                 b_trash = 1;
1169             }
1170             else if( p_es_demux->i_continuity_counter == 0xFF )
1171             {
1172                 /* This means that the packet is the first one we receive for
1173                  * this ES since the continuity counter ranges between 0 and
1174                  * 0x0F excepts when it has been initialized by the input:
1175                  * init the counter to the correct value. */
1176                 intf_DbgMsg( "First packet for PID %d received by TS demux",
1177                              p_es->i_id );
1178                 p_es_demux->i_continuity_counter = (p[3] & 0x0f);
1179             }
1180             else
1181             {
1182                 /* This can indicate that we missed a packet or that the
1183                  * continuity_counter wrapped and we received a dup packet:
1184                  * as we don't know, do as if we missed a packet to be sure
1185                  * to recover from this situation */
1186                 intf_WarnMsg( 2,
1187                            "Packet lost by TS demux: current %d, packet %d",
1188                            p_es_demux->i_continuity_counter & 0x0f,
1189                            p[3] & 0x0f );
1190                 b_lost = 1;
1191                 p_es_demux->i_continuity_counter = p[3] & 0x0f;
1192             } /* not continuous */
1193         } /* continuity */
1194     } /* if selected or PCR */
1195
1196     /* Trash the packet if it has no payload or if it isn't selected */
1197     if( b_trash )
1198     {
1199         p_input->p_plugin->pf_delete_packet( p_input, p_data );
1200 #ifdef STATS
1201         p_input->c_packets_trashed++;
1202 #endif
1203     }
1204     else
1205     {
1206         if( p_es_demux->b_psi )
1207         {
1208             /* The payload contains PSI tables */
1209 #if 0
1210             input_DemuxPSI( p_input, p_data, p_es,
1211                             b_unit_start, b_lost );
1212 #endif
1213         }
1214         else
1215         {
1216             /* The payload carries a PES stream */
1217             if( b_unit_start )
1218             input_GatherPES( p_input, p_data, p_es, b_unit_start, b_lost );
1219         }
1220     }
1221
1222 #undef p
1223 }