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 1.24 2001/01/05 18:46:44 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 #include "input_dec.h"
  45
  46 #include "main.h"                           /* AC3/MPEG channel, SPU channel */
  47
  48 /*****************************************************************************
  49  * Local prototypes
  50  *****************************************************************************/
  51
  52
  53 /*
  54  * PES Packet management
  55  */
  56
  57 /*****************************************************************************
  58  * MoveChunk
  59  *****************************************************************************
  60  * Small utility function used to parse discontinuous headers safely. Copies
  61  * i_buf_len bytes of data to a buffer and returns the size copied.
  62  * This is a variation on the theme of input_ext-dec.h:GetChunk().
  63  *****************************************************************************/
  64 static __inline__ size_t MoveChunk( byte_t * p_dest,
  65                                     data_packet_t ** pp_data_src,
  66                                     byte_t ** pp_src,
  67                                     size_t i_buf_len )
  68 {
  69     ptrdiff_t           i_available;
  70
  71     if( (i_available = (*pp_data_src)->p_payload_end - *pp_src)
  72             >= i_buf_len )
  73     {
  74         if( p_dest != NULL )
  75             memcpy( p_dest, *pp_src, i_buf_len );
  76         *pp_src += i_buf_len;
  77         return( i_buf_len );
  78     }
  79     else
  80     {
  81         size_t          i_init_len = i_buf_len;
  82
  83         do
  84         {
  85             if( p_dest != NULL )
  86                 memcpy( p_dest, *pp_src, i_available );
  87             *pp_data_src = (*pp_data_src)->p_next;
  88             i_buf_len -= i_available;
  89             p_dest += i_available;
  90             if( *pp_data_src == NULL )
  91             {
  92                 *pp_src = NULL;
  93                 return( i_init_len - i_buf_len );
  94             }
  95             *pp_src = (*pp_data_src)->p_payload_start;
  96         }
  97         while( (i_available = (*pp_data_src)->p_payload_end - *pp_src)
  98                 <= i_buf_len );
  99
 100         if( i_buf_len )
 101         {
 102             if( p_dest != NULL )
 103                 memcpy( p_dest, *pp_src, i_buf_len );
 104             *pp_src += i_buf_len;
 105         }
 106         return( i_init_len );
 107     }
 108 }
 109
 110 /*****************************************************************************
 111  * input_ParsePES
 112  *****************************************************************************
 113  * Parse a finished PES packet and analyze its header.
 114  *****************************************************************************/
 115 #define PES_HEADER_SIZE     7
 116 void input_ParsePES( input_thread_t * p_input, es_descriptor_t * p_es )
 117 {
 118     data_packet_t * p_data;
 119     byte_t *        p_byte;
 120     byte_t          p_header[PES_HEADER_SIZE];
 121     int             i_done;
 122
 123 #define p_pes (p_es->p_pes)
 124
 125     //intf_DbgMsg("End of PES packet %p", p_pes);
 126
 127     /* Parse the header. The header has a variable length, but in order
 128      * to improve the algorithm, we will read the 14 bytes we may be
 129      * interested in */
 130     p_data = p_pes->p_first;
 131     p_byte = p_data->p_payload_start;
 132     i_done = 0;
 133
 134     if( MoveChunk( p_header, &p_data, &p_byte, PES_HEADER_SIZE )
 135             != PES_HEADER_SIZE )
 136     {
 137         intf_WarnMsg( 3, "PES packet too short to have a header" );
 138         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 139         p_pes = NULL;
 140         return;
 141     }
 142
 143     /* Get the PES size if defined */
 144     p_es->i_pes_real_size = U16_AT(p_header + 4) + 6;
 145
 146     /* First read the 6 header bytes common to all PES packets:
 147      * use them to test the PES validity */
 148     if( (p_header[0] || p_header[1] || (p_header[2] != 1)) )
 149     {
 150         /* packet_start_code_prefix != 0x000001 */
 151         intf_ErrMsg( "PES packet doesn't start with 0x000001 : data loss" );
 152         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 153         p_pes = NULL;
 154     }
 155     else
 156     {
 157         int i_pes_header_size, i_payload_size;
 158
 159         if ( p_es->i_pes_real_size &&
 160              (p_es->i_pes_real_size != p_pes->i_pes_size) )
 161         {
 162             /* PES_packet_length is set and != total received payload */
 163             /* Warn the decoder that the data may be corrupt. */
 164             intf_WarnMsg( 3, "PES sizes do not match : packet corrupted" );
 165             p_pes->b_messed_up = 1;
 166         }
 167
 168         switch( p_es->i_stream_id )
 169         {
 170         case 0xBC:  /* Program stream map */
 171         case 0xBE:  /* Padding */
 172         case 0xBF:  /* Private stream 2 */
 173         case 0xB0:  /* ECM */
 174         case 0xB1:  /* EMM */
 175         case 0xFF:  /* Program stream directory */
 176         case 0xF2:  /* DSMCC stream */
 177         case 0xF8:  /* ITU-T H.222.1 type E stream */
 178             /* The payload begins immediately after the 6 bytes header, so
 179              * we have finished with the parsing */
 180             i_pes_header_size = 6;
 181             break;
 182
 183         default:
 184             if( (p_header[6] & 0xC0) == 0x80 )
 185             {
 186                 /* MPEG-2 : the PES header contains at least 3 more bytes. */
 187                 size_t      i_max_len;
 188                 boolean_t   b_has_pts, b_has_dts;
 189                 byte_t      p_full_header[12];
 190
 191                 p_pes->b_data_alignment = p_header[6] & 0x04;
 192
 193                 i_max_len = MoveChunk( p_full_header, &p_data, &p_byte, 12 );
 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                 b_has_pts = p_full_header[0] & 0x80;
 205                 b_has_dts = p_full_header[0] & 0x40;
 206                 i_pes_header_size = p_full_header[1] + 9;
 207
 208                 /* Now parse the optional header extensions */
 209                 if( b_has_pts )
 210                 {
 211                     if( i_max_len < 7 )
 212                     {
 213                         intf_WarnMsg( 3,
 214                             "PES packet too short to have a MPEG-2 header" );
 215                         p_input->p_plugin->pf_delete_pes(
 216                                                       p_input->p_method_data,
 217                                                       p_pes );
 218                         p_pes = NULL;
 219                         return;
 220                     }
 221                     p_pes->i_pts =
 222                     ( ((mtime_t)(p_full_header[2] & 0x0E) << 29) |
 223                       (((mtime_t)U16_AT(p_full_header + 3) << 14) - (1 << 14)) |
 224                       ((mtime_t)U16_AT(p_full_header + 5) >> 1) ) * 300;
 225                     p_pes->i_pts /= 27;
 226
 227                     if( b_has_dts )
 228                     {
 229                         if( i_max_len < 12 )
 230                         {
 231                             intf_WarnMsg( 3,
 232                               "PES packet too short to have a MPEG-2 header" );
 233                             p_input->p_plugin->pf_delete_pes(
 234                                     p_input->p_method_data,
 235                                     p_pes );
 236                             p_pes = NULL;
 237                             return;
 238                         }
 239                         p_pes->i_dts =
 240                         ( ((mtime_t)(p_full_header[7] & 0x0E) << 29) |
 241                           (((mtime_t)U16_AT(p_full_header + 8) << 14)
 242                                 - (1 << 14)) |
 243                           ((mtime_t)U16_AT(p_full_header + 10) >> 1) ) * 300;
 244                         p_pes->i_dts /= 27;
 245                     }
 246                 }
 247             }
 248             else
 249             {
 250                 /* Probably MPEG-1 */
 251                 boolean_t       b_has_pts, b_has_dts;
 252
 253                 i_pes_header_size = 6;
 254                 p_data = p_pes->p_first;
 255                 p_byte = p_data->p_payload_start;
 256                 /* Cannot fail because the previous one succeeded. */
 257                 MoveChunk( NULL, &p_data, &p_byte, 6 );
 258
 259                 while( *p_byte == 0xFF && i_pes_header_size < 22 )
 260                 {
 261                     i_pes_header_size++;
 262                     if( MoveChunk( NULL, &p_data, &p_byte, 1 ) != 1 )
 263                     {
 264                         intf_WarnMsg( 3,
 265                             "PES packet too short to have a MPEG-1 header" );
 266                         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 267                         p_pes = NULL;
 268                         return;
 269                     }
 270                 }
 271                 if( i_pes_header_size == 22 )
 272                 {
 273                     intf_ErrMsg( "Too much MPEG-1 stuffing" );
 274                     p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 275                     p_pes = NULL;
 276                     return;
 277                 }
 278
 279                 if( (*p_byte & 0xC0) == 0x40 )
 280                 {
 281                     /* Don't ask why... --Meuuh */
 282                     /* Erm... why ? --Sam */
 283                     /* Well... According to the recommendation, it is for
 284                      * STD_buffer_scale and STD_buffer_size. --Meuuh */
 285                     i_pes_header_size += 2;
 286                     if( MoveChunk( NULL, &p_data, &p_byte, 2 ) != 2 )
 287                     {
 288                         intf_WarnMsg( 3,
 289                             "PES packet too short to have a MPEG-1 header" );
 290                         p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 291                         p_pes = NULL;
 292                         return;
 293                     }
 294                 }
 295
 296                 i_pes_header_size++;
 297
 298                 b_has_pts = *p_byte & 0x20;
 299                 b_has_dts = *p_byte & 0x10;
 300
 301                 if( b_has_pts )
 302                 {
 303                     byte_t      p_ts[5];
 304
 305                     i_pes_header_size += 4;
 306                     if( MoveChunk( p_ts, &p_data, &p_byte, 5 ) != 5 )
 307                     {
 308                         intf_WarnMsg( 3,
 309                             "PES packet too short to have a MPEG-1 header" );
 310                         p_input->p_plugin->pf_delete_pes(
 311                                             p_input->p_method_data, p_pes );
 312                         p_pes = NULL;
 313                         return;
 314                     }
 315
 316                     p_pes->i_pts =
 317                       ( ((mtime_t)(p_ts[0] & 0x0E) << 29) |
 318                         (((mtime_t)U16_AT(p_ts + 1) << 14) - (1 << 14)) |
 319                         ((mtime_t)U16_AT(p_ts + 3) >> 1) ) * 300;
 320                     p_pes->i_pts /= 27;
 321
 322                     if( b_has_dts )
 323                     {
 324                         i_pes_header_size += 5;
 325                         if( MoveChunk( p_ts, &p_data, &p_byte, 5 ) != 5 )
 326                         {
 327                             intf_WarnMsg( 3,
 328                               "PES packet too short to have a MPEG-1 header" );
 329                             p_input->p_plugin->pf_delete_pes(
 330                                     p_input->p_method_data, p_pes );
 331                             p_pes = NULL;
 332                             return;
 333                         }
 334
 335                         p_pes->i_dts =
 336                             ( ((mtime_t)(p_ts[0] & 0x0E) << 29) |
 337                               (((mtime_t)U16_AT(p_ts + 1) << 14) - (1 << 14)) |
 338                               ((mtime_t)U16_AT(p_ts + 3) >> 1) ) * 300;
 339                         p_pes->i_dts /= 27;
 340                     }
 341                 }
 342             }
 343
 344             /* PTS management */
 345             if( p_pes->i_pts )
 346             {
 347                 //intf_Msg("%lld", p_pes->i_pts);
 348                 switch( p_es->p_pgrm->i_synchro_state )
 349                 {
 350                 case SYNCHRO_NOT_STARTED:
 351                 case SYNCHRO_START:
 352                     p_pes->i_pts = p_pes->i_dts = 0;
 353                     break;
 354
 355                 case SYNCHRO_REINIT: /* We skip a PES | Why ?? --Meuuh */
 356                     p_pes->i_pts = p_pes->i_dts = 0;
 357                     p_es->p_pgrm->i_synchro_state = SYNCHRO_START;
 358                     break;
 359
 360                 case SYNCHRO_OK:
 361                     p_pes->i_pts += p_es->p_pgrm->delta_cr
 362                                          + p_es->p_pgrm->delta_absolute
 363                                          + DEFAULT_PTS_DELAY;
 364                     if( p_pes->i_dts )
 365                     {
 366                         p_pes->i_dts += p_es->p_pgrm->delta_cr
 367                                              + p_es->p_pgrm->delta_absolute
 368                                              + DEFAULT_PTS_DELAY;
 369                     }
 370                     break;
 371                 }
 372             }
 373             break;
 374         }
 375
 376         if( p_es->i_stream_id == 0xbd )
 377         {
 378             /* With private stream 1, the first byte of the payload
 379              * is a stream_private_id, so skip it. */
 380             i_pes_header_size++;
 381         }
 382
 383         /* Now we've parsed the header, we just have to indicate in some
 384          * specific data packets where the PES payload begins (renumber
 385          * p_payload_start), so that the decoders can find the beginning
 386          * of their data right out of the box. */
 387         p_data = p_pes->p_first;
 388         i_payload_size = p_data->p_payload_end
 389                                  - p_data->p_payload_start;
 390         while( i_pes_header_size > i_payload_size )
 391         {
 392             /* These packets are entirely filled by the PES header. */
 393             i_pes_header_size -= i_payload_size;
 394             p_data->p_payload_start = p_data->p_payload_end;
 395             /* Go to the next data packet. */
 396             if( (p_data = p_data->p_next) == NULL )
 397             {
 398                 intf_ErrMsg( "PES header bigger than payload" );
 399                 p_input->p_plugin->pf_delete_pes( p_input->p_method_data,
 400                                                   p_pes );
 401                 p_pes = NULL;
 402                 return;
 403             }
 404             i_payload_size = p_data->p_payload_end
 405                                  - p_data->p_payload_start;
 406         }
 407         /* This last packet is partly header, partly payload. */
 408         if( i_payload_size < i_pes_header_size )
 409         {
 410             intf_ErrMsg( "PES header bigger than payload" );
 411             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 412             p_pes = NULL;
 413             return;
 414         }
 415         p_data->p_payload_start += i_pes_header_size;
 416
 417         /* Now we can eventually put the PES packet in the decoder's
 418          * PES fifo */
 419         if( p_es->p_decoder_fifo != NULL )
 420         {
 421             input_DecodePES( p_es->p_decoder_fifo, p_pes );
 422         }
 423         else
 424         {
 425             intf_ErrMsg("No fifo to receive PES %p (who wrote this damn code ?)",
 426                         p_pes);
 427             p_input->p_plugin->pf_delete_pes( p_input->p_method_data, p_pes );
 428         }
 429         p_pes = NULL;
 430     }
 431 #undef p_pes
 432 }
 433
 434 /*****************************************************************************
 435  * input_GatherPES:
 436  *****************************************************************************
 437  * Gather a PES packet.
 438  *****************************************************************************/
 439 void input_GatherPES( input_thread_t * p_input, data_packet_t * p_data,
 440                       es_descriptor_t * p_es,
 441                       boolean_t b_unit_start, boolean_t b_packet_lost )
 442 {
 443 #define p_pes (p_es->p_pes)
 444
 445     //intf_DbgMsg("PES-demultiplexing %p (%p)", p_ts_packet, p_pes);
 446
 447     /* If we lost data, insert a NULL data packet (philosophy : 0 is quite
 448      * often an escape sequence in decoders, so that should make them wait
 449      * for the next start code). */
 450     if( b_packet_lost || p_es->b_discontinuity )
 451     {
 452         data_packet_t *             p_pad_data;
 453
 454         if( (p_pad_data = p_input->p_plugin->pf_new_packet(
 455                                             p_input->p_method_data,
 456                                             PADDING_PACKET_SIZE )) == NULL )
 457         {
 458             intf_ErrMsg("Out of memory");
 459             p_input->b_error = 1;
 460             return;
 461         }
 462         memset( p_data->p_buffer, 0, PADDING_PACKET_SIZE );
 463         p_pad_data->b_discard_payload = 1;
 464
 465         if( p_pes != NULL )
 466         {
 467             p_pes->b_messed_up = p_pes->b_discontinuity = 1;
 468             input_GatherPES( p_input, p_pad_data, p_es, 0, 0 );
 469         }
 470         else
 471         {
 472             if( (p_pes = p_input->p_plugin->pf_new_pes(
 473                                             p_input->p_method_data )) == NULL )
 474             {
 475                 intf_ErrMsg("Out of memory");
 476                 p_input->b_error = 1;
 477                 return;
 478             }
 479
 480             p_pes->p_first = p_pad_data;
 481             p_pes->b_messed_up = p_pes->b_discontinuity = 1;
 482             input_DecodePES( p_es->p_decoder_fifo, p_pes );
 483         }
 484
 485         p_es->b_discontinuity = 0;
 486     }
 487
 488     if( b_unit_start && p_pes != NULL )
 489     {
 490         /* If the TS packet contains the begining of a new PES packet, and
 491          * if we were reassembling a PES packet, then the PES should be
 492          * complete now, so parse its header and give it to the decoders. */
 493         input_ParsePES( p_input, p_es );
 494     }
 495
 496     if( !b_unit_start && p_pes == NULL )
 497     {
 498         /* Random access... */
 499         p_input->p_plugin->pf_delete_packet( p_input->p_method_data, p_data );
 500     }
 501     else
 502     {
 503         if( b_unit_start )
 504         {
 505             /* If we are at the beginning of a new PES packet, we must fetch
 506              * a new PES buffer to begin with the reassembly of this PES
 507              * packet. This is also here that we can synchronize with the
 508              * stream if we lost packets or if the decoder has just
 509              * started. */
 510             if( (p_pes = p_input->p_plugin->pf_new_pes( p_input->p_method_data ) ) == NULL )
 511             {
 512                 intf_ErrMsg("Out of memory");
 513                 p_input->b_error = 1;
 514                 return;
 515             }
 516             //intf_DbgMsg("New PES packet %p (first data: %p)", p_pes, p_data);
 517             p_pes->p_first = p_data;
 518
 519             /* If the PES header fits in the first data packet, we can
 520              * already set p_gather->i_pes_real_size. */
 521             if( p_data->p_payload_end - p_data->p_payload_start
 522                     >= PES_HEADER_SIZE )
 523             {
 524                 p_es->i_pes_real_size =
 525                                 U16_AT(p_data->p_payload_start + 4) + 6;
 526             }
 527             else
 528             {
 529                 p_es->i_pes_real_size = 0;
 530             }
 531         }
 532         else
 533         {
 534             /* Update the relations between the data packets */
 535             p_es->p_last->p_next = p_data;
 536         }
 537
 538         p_data->p_next = NULL;
 539         p_es->p_last = p_data;
 540
 541         /* Size of the payload carried in the data packet */
 542         p_pes->i_pes_size += (p_data->p_payload_end
 543                                  - p_data->p_payload_start);
 544
 545         /* We can check if the packet is finished */
 546         if( p_pes->i_pes_size == p_es->i_pes_real_size )
 547         {
 548             /* The packet is finished, parse it */
 549             input_ParsePES( p_input, p_es );
 550         }
 551     }
 552 #undef p_pes
 553 }
 554
 555
 556 /*
 557  * Pace control
 558  */
 559
 560 /*
 561  *   DISCUSSION : SYNCHRONIZATION METHOD
 562  *
 563  *   In some cases we can impose the pace of reading (when reading from a
 564  *   file or a pipe), and for the synchronization we simply sleep() until
 565  *   it is time to deliver the packet to the decoders. When reading from
 566  *   the network, we must be read at the same pace as the server writes,
 567  *   otherwise the kernel's buffer will trash packets. The risk is now to
 568  *   overflow the input buffers in case the server goes too fast, that is
 569  *   why we do these calculations :
 570  *
 571  *   We compute an average for the pcr because we want to eliminate the
 572  *   network jitter and keep the low frequency variations. The average is
 573  *   in fact a low pass filter and the jitter is a high frequency signal
 574  *   that is why it is eliminated by the filter/average.
 575  *
 576  *   The low frequency variations enable us to synchronize the client clock
 577  *   with the server clock because they represent the time variation between
 578  *   the 2 clocks. Those variations (ie the filtered pcr) are used to compute
 579  *   the presentation dates for the audio and video frames. With those dates
 580  *   we can decode (or trash) the MPEG2 stream at "exactly" the same rate
 581  *   as it is sent by the server and so we keep the synchronization between
 582  *   the server and the client.
 583  *
 584  *   It is a very important matter if you want to avoid underflow or overflow
 585  *   in all the FIFOs, but it may be not enough.
 586  */
 587
 588 /*****************************************************************************
 589  * Constants
 590  *****************************************************************************/
 591
 592 /* Maximum number of samples used to compute the dynamic average value,
 593  * it is also the maximum of c_average_count in pgrm_ts_data_t.
 594  * We use the following formula :
 595  * new_average = (old_average * c_average + new_sample_value) / (c_average +1) */
 596 #define CR_MAX_AVERAGE_COUNTER 40
 597
 598 /* Maximum gap allowed between two CRs. */
 599 #define CR_MAX_GAP 1000000
 600
 601 /*****************************************************************************
 602  * CRReInit : Reinitialize the clock reference
 603  *****************************************************************************/
 604 static void CRReInit( pgrm_descriptor_t * p_pgrm )
 605 {
 606     p_pgrm->delta_cr        = 0;
 607     p_pgrm->last_cr         = 0;
 608     p_pgrm->c_average_count = 0;
 609 }
 610
 611 /* FIXME: find a better name */
 612 /*****************************************************************************
 613  * CRDecode : Decode a clock reference
 614  *****************************************************************************/
 615 static void CRDecode( input_thread_t * p_input, pgrm_descriptor_t * p_pgrm,
 616                       mtime_t cr_time )
 617 {
 618     if( p_pgrm->i_synchro_state != SYNCHRO_OK )
 619     {
 620         switch( p_pgrm->i_synchro_state )
 621         {
 622         case SYNCHRO_START:
 623             p_pgrm->delta_absolute = mdate() - cr_time;
 624             p_pgrm->i_synchro_state = SYNCHRO_OK;
 625             break;
 626
 627         case SYNCHRO_NOT_STARTED:
 628             p_pgrm->i_synchro_state = SYNCHRO_START;
 629             break;
 630
 631         default:
 632             break;
 633         }
 634     }
 635     else
 636     {
 637         if( p_pgrm->b_discontinuity ||
 638             ( p_pgrm->last_cr != 0 &&
 639                   (    (p_pgrm->last_cr - cr_time) > CR_MAX_GAP
 640                     || (p_pgrm->last_cr - cr_time) < - CR_MAX_GAP ) ) )
 641         {
 642             int i_es;
 643
 644             /* Stream discontinuity. */
 645             intf_WarnMsg( 3, "CR re-initialiazed" );
 646             CRReInit( p_pgrm );
 647             p_pgrm->i_synchro_state = SYNCHRO_REINIT;
 648             p_pgrm->b_discontinuity = 0;
 649
 650             /* Warn all the elementary streams */
 651             for( i_es = 0; i_es < p_pgrm->i_es_number; i_es++ )
 652             {
 653                 p_pgrm->pp_es[i_es]->b_discontinuity = 1;
 654             }
 655         }
 656         p_pgrm->last_cr = cr_time;
 657
 658         if( p_input->stream.b_pace_control )
 659         {
 660             /* Wait a while before delivering the packets to the decoder. */
 661             mwait( cr_time + p_pgrm->delta_absolute );
 662         }
 663         else
 664         {
 665             mtime_t                 sys_time, delta_cr;
 666
 667             sys_time = mdate();
 668             delta_cr = sys_time - cr_time;
 669
 670             if( p_pgrm->c_average_count == CR_MAX_AVERAGE_COUNTER )
 671             {
 672                 p_pgrm->delta_cr = ( delta_cr + (p_pgrm->delta_cr
 673                                               * (CR_MAX_AVERAGE_COUNTER - 1)) )
 674                                      / CR_MAX_AVERAGE_COUNTER;
 675             }
 676             else
 677             {
 678                 p_pgrm->delta_cr = ( delta_cr + (p_pgrm->delta_cr
 679                                               * p_pgrm->c_average_count) )
 680                                      / ( p_pgrm->c_average_count + 1 );
 681                 p_pgrm->c_average_count++;
 682             }
 683         }
 684     }
 685 }
 686
 687
 688 /*
 689  * PS Demultiplexing
 690  */
 691
 692 /*****************************************************************************
 693  * GetID: Get the ID of a stream
 694  *****************************************************************************/
 695 static u16 GetID( data_packet_t * p_data )
 696 {
 697     u16         i_id;
 698
 699     i_id = p_data->p_buffer[3];                                 /* stream_id */
 700     if( i_id == 0xBD )
 701     {
 702         /* stream_private_id */
 703         i_id |= p_data->p_buffer[ 9 + p_data->p_buffer[8] ] << 8;
 704     }
 705     return( i_id );
 706 }
 707
 708 /*****************************************************************************
 709  * DecodePSM: Decode the Program Stream Map information
 710  *****************************************************************************/
 711 static void DecodePSM( input_thread_t * p_input, data_packet_t * p_data )
 712 {
 713     stream_ps_data_t *  p_demux =
 714                  (stream_ps_data_t *)p_input->stream.p_demux_data;
 715     byte_t *            p_byte;
 716     byte_t *            p_end;
 717     int                 i;
 718     int                 i_new_es_number = 0;
 719
 720     intf_Msg("input info: Your stream contains Program Stream Map information");
 721     intf_Msg("input info: Please send a mail to <massiot@via.ecp.fr>");
 722
 723     if( p_data->p_payload_start + 10 > p_data->p_payload_end )
 724     {
 725         intf_ErrMsg( "PSM too short : packet corrupt" );
 726         return;
 727     }
 728
 729     if( p_demux->b_has_PSM
 730         && p_demux->i_PSM_version == (p_data->p_buffer[6] & 0x1F) )
 731     {
 732         /* Already got that one. */
 733         return;
 734     }
 735
 736     intf_DbgMsg( "Building PSM" );
 737     p_demux->b_has_PSM = 1;
 738     p_demux->i_PSM_version = p_data->p_buffer[6] & 0x1F;
 739
 740     /* Go to elementary_stream_map_length, jumping over
 741      * program_stream_info. */
 742     p_byte = p_data->p_payload_start + 10
 743               + U16_AT(&p_data->p_payload_start[8]);
 744     if( p_byte > p_data->p_payload_end )
 745     {
 746         intf_ErrMsg( "PSM too short : packet corrupt" );
 747         return;
 748     }
 749     /* This is the full size of the elementary_stream_map.
 750      * 2 == elementary_stream_map_length
 751      * Please note that CRC_32 is not included in the length. */
 752     p_end = p_byte + 2 + U16_AT(p_byte);
 753     p_byte += 2;
 754     if( p_end > p_data->p_payload_end )
 755     {
 756         intf_ErrMsg( "PSM too short : packet corrupt" );
 757         return;
 758     }
 759
 760     vlc_mutex_lock( &p_input->stream.stream_lock );
 761
 762     /* 4 == minimum useful size of a section */
 763     while( p_byte + 4 <= p_end )
 764     {
 765         es_descriptor_t *   p_es = NULL;
 766         u8                  i_stream_id = p_byte[1];
 767         /* FIXME: there will be a problem with private streams... (same
 768          * stream_id) */
 769
 770         /* Look for the ES in the ES table */
 771         for( i = i_new_es_number;
 772              i < p_input->stream.pp_programs[0]->i_es_number;
 773              i++ )
 774         {
 775             if( p_input->stream.pp_programs[0]->pp_es[i]->i_stream_id
 776                     == i_stream_id )
 777             {
 778                 p_es = p_input->stream.pp_programs[0]->pp_es[i];
 779                 if( p_es->i_type != p_byte[0] )
 780                 {
 781                     input_DelES( p_input, p_es );
 782                     p_es = NULL;
 783                 }
 784                 else
 785                 {
 786                     /* Move the ES to the beginning. */
 787                     p_input->stream.pp_programs[0]->pp_es[i]
 788                         = p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ];
 789                     p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ]
 790                         = p_es;
 791                     i_new_es_number++;
 792                 }
 793                 break;
 794             }
 795         }
 796
 797         /* The goal is to have all the ES we have just read in the
 798          * beginning of the pp_es table, and all the others at the end,
 799          * so that we can close them more easily at the end. */
 800         if( p_es == NULL )
 801         {
 802             p_es = input_AddES( p_input, p_input->stream.pp_programs[0],
 803                                 i_stream_id, 0 );
 804             p_es->i_type = p_byte[0];
 805
 806             /* input_AddES has inserted the new element at the end. */
 807             p_input->stream.pp_programs[0]->pp_es[
 808                 p_input->stream.pp_programs[0]->i_es_number ]
 809                 = p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ];
 810             p_input->stream.pp_programs[0]->pp_es[ i_new_es_number ] = p_es;
 811             i_new_es_number++;
 812         }
 813         p_byte += 4 + U16_AT(&p_byte[2]);
 814     }
 815
 816     /* Un-select the streams that are no longer parts of the program. */
 817     for( i = i_new_es_number;
 818          i < p_input->stream.pp_programs[0]->i_es_number;
 819          i++ )
 820     {
 821         input_DelES( p_input,
 822                      p_input->stream.pp_programs[0]->pp_es[i_new_es_number] );
 823         /* Yes, I wrote *i_new_es_number* */
 824     }
 825
 826 #ifdef STATS
 827     intf_Msg( "input info: The stream map after the PSM is now :" );
 828     input_DumpStream( p_input );
 829 #endif
 830
 831     vlc_mutex_unlock( &p_input->stream.stream_lock );
 832 }
 833
 834 /*****************************************************************************
 835  * input_ParsePS: read the PS header
 836  *****************************************************************************/
 837 es_descriptor_t * input_ParsePS( input_thread_t * p_input,
 838                                  data_packet_t * p_data )
 839 {
 840     u32                 i_code;
 841     es_descriptor_t *   p_es = NULL;
 842
 843     i_code = U32_AT( p_data->p_buffer );
 844     if( i_code > 0x1BC ) /* ES start code */
 845     {
 846         u16                 i_id;
 847         int                 i_dummy;
 848
 849         /* This is a PES packet. Find out if we want it or not. */
 850         i_id = GetID( p_data );
 851
 852         vlc_mutex_lock( &p_input->stream.stream_lock );
 853         if( p_input->stream.pp_programs[0]->b_is_ok )
 854         {
 855             /* Look only at the selected ES. */
 856             for( i_dummy = 0; i_dummy < p_input->stream.i_selected_es_number;
 857                  i_dummy++ )
 858             {
 859                 if( p_input->stream.pp_selected_es[i_dummy] != NULL
 860                     && p_input->stream.pp_selected_es[i_dummy]->i_id == i_id )
 861                 {
 862                     p_es = p_input->stream.pp_selected_es[i_dummy];
 863                     break;
 864                 }
 865             }
 866         }
 867         else
 868         {
 869             stream_ps_data_t * p_demux =
 870               (stream_ps_data_t *)p_input->stream.pp_programs[0]->p_demux_data;
 871
 872             /* Search all ES ; if not found -> AddES */
 873             p_es = input_FindES( p_input, i_id );
 874
 875             if( p_es == NULL && !p_demux->b_has_PSM )
 876             {
 877                 p_es = input_AddES( p_input, p_input->stream.pp_programs[0],
 878                                     i_id, 0 );
 879                 if( p_es != NULL )
 880                 {
 881                     p_es->i_stream_id = p_data->p_buffer[3];
 882
 883                     /* Set stream type and auto-spawn. */
 884                     if( (i_id & 0xF0) == 0xE0 )
 885                     {
 886                         /* MPEG video */
 887                         p_es->i_type = MPEG2_VIDEO_ES;
 888 #ifdef AUTO_SPAWN
 889                         if( !p_input->stream.b_seekable )
 890                             input_SelectES( p_input, p_es );
 891 #endif
 892                     }
 893                     else if( (i_id & 0xE0) == 0xC0 )
 894                     {
 895                         /* MPEG audio */
 896                         p_es->i_type = MPEG2_AUDIO_ES;
 897 #ifdef AUTO_SPAWN
 898                         if( main_GetIntVariable( INPUT_DVD_AUDIO_VAR, 0 )
 899                                 == REQUESTED_MPEG
 900                           && main_GetIntVariable( INPUT_DVD_CHANNEL_VAR, 0 )
 901                                 == (p_es->i_id & 0x1F) )
 902                         {
 903                             if( !p_input->stream.b_seekable )
 904                                 input_SelectES( p_input, p_es );
 905                         }
 906 #endif
 907                     }
 908                     else if( (i_id & 0xF0FF) == 0x80BD )
 909                     {
 910                         /* AC3 audio (0x80->0x8F) */
 911                         p_es->i_type = AC3_AUDIO_ES;
 912 #ifdef AUTO_SPAWN
 913                         if( main_GetIntVariable( INPUT_DVD_AUDIO_VAR, 0 )
 914                                 == REQUESTED_AC3
 915                          && main_GetIntVariable( INPUT_DVD_CHANNEL_VAR, 0 )
 916                                 == ((p_es->i_id & 0xF00) >> 8) )
 917                         {
 918                             if( !p_input->stream.b_seekable )
 919                                 input_SelectES( p_input, p_es );
 920                         }
 921 #endif
 922                     }
 923                     else if( (i_id & 0xE0FF) == 0x20BD )
 924                     {
 925                         /* Subtitles video (0x20->0x3F) */
 926                         p_es->i_type = DVD_SPU_ES;
 927 #ifdef AUTO_SPAWN
 928                         if( main_GetIntVariable( INPUT_DVD_SUBTITLE_VAR, -1 )
 929                                 == ((p_es->i_id & 0x1F00) >> 8) )
 930                         {
 931                             if( !p_input->stream.b_seekable )
 932                                 input_SelectES( p_input, p_es );
 933                         }
 934 #endif
 935                     }
 936                     else if( (i_id & 0xF0FF) == 0xA0BD )
 937                     {
 938                         /* LPCM audio (0xA0->0xAF) */
 939                         p_es->i_type = LPCM_AUDIO_ES;
 940                         /* FIXME : write the decoder */
 941                     }
 942                     else
 943                     {
 944                         p_es->i_type = UNKNOWN_ES;
 945                     }
 946                 }
 947             }
 948         } /* stream.b_is_ok */
 949         vlc_mutex_unlock( &p_input->stream.stream_lock );
 950     } /* i_code > 0xBC */
 951
 952     return( p_es );
 953 }
 954
 955 /*****************************************************************************
 956  * input_DemuxPS: first step of demultiplexing: the PS header
 957  *****************************************************************************/
 958 void input_DemuxPS( input_thread_t * p_input, data_packet_t * p_data )
 959 {
 960     u32                 i_code;
 961     boolean_t           b_trash = 0;
 962     es_descriptor_t *   p_es = NULL;
 963
 964     i_code = U32_AT( p_data->p_buffer );
 965     if( i_code <= 0x1BC )
 966     {
 967         switch( i_code )
 968         {
 969         case 0x1BA: /* PACK_START_CODE */
 970             {
 971                 /* Convert the SCR in microseconds. */
 972                 mtime_t         scr_time;
 973
 974                 if( (p_data->p_buffer[4] & 0xC0) == 0x40 )
 975                 {
 976                     /* MPEG-2 */
 977                     scr_time =
 978                       (( ((mtime_t)(p_data->p_buffer[4] & 0x38) << 27) |
 979                          ((mtime_t)(U32_AT(p_data->p_buffer + 4) & 0x03FFF800)
 980                                         << 4) |
 981                          ((mtime_t)(U32_AT(p_data->p_buffer + 6) & 0x03FFF800)
 982                                         >> 11)
 983                       ) * 300) / 27;
 984                 }
 985                 else
 986                 {
 987                     /* MPEG-1 SCR is like PTS */
 988                     scr_time =
 989                       (( ((mtime_t)(p_data->p_buffer[4] & 0x0E) << 29) |
 990                          (((mtime_t)U16_AT(p_data->p_buffer + 5) << 14)
 991                            - (1 << 14)) |
 992                          ((mtime_t)U16_AT(p_data->p_buffer + 7) >> 1)
 993                       ) * 300) / 27;
 994                 }
 995                 /* Call the pace control. */
 996                 //intf_Msg("+%lld", scr_time);
 997                 CRDecode( p_input, p_input->stream.pp_programs[0],
 998                           scr_time );
 999                 b_trash = 1;
1000             }
1001             break;
1002
1003         case 0x1BB: /* SYSTEM_START_CODE */
1004             b_trash = 1;                              /* Nothing interesting */
1005             break;
1006
1007         case 0x1BC: /* PROGRAM_STREAM_MAP_CODE */
1008             DecodePSM( p_input, p_data );
1009             b_trash = 1;
1010             break;
1011
1012         case 0x1B9: /* PROGRAM_END_CODE */
1013             b_trash = 1;
1014             break;
1015
1016         default:
1017             /* This should not happen */
1018             b_trash = 1;
1019             intf_WarnMsg( 1, "Unwanted packet received with start code %x",
1020                           i_code );
1021         }
1022     }
1023     else
1024     {
1025         p_es = input_ParsePS( p_input, p_data );
1026
1027         if( p_es != NULL && p_es->p_decoder_fifo != NULL )
1028         {
1029 #ifdef STATS
1030             p_es->c_packets++;
1031 #endif
1032             input_GatherPES( p_input, p_data, p_es, 1, 0 );
1033         }
1034         else
1035         {
1036             b_trash = 1;
1037         }
1038     }
1039
1040     /* Trash the packet if it has no payload or if it isn't selected */
1041     if( b_trash )
1042     {
1043         p_input->p_plugin->pf_delete_packet( p_input, p_data );
1044 #ifdef STATS
1045         p_input->c_packets_trashed++;
1046 #endif
1047     }
1048 }
1049
1050
1051 /*
1052  * TS Demultiplexing
1053  */
1054
1055 /*****************************************************************************
1056  * input_DemuxTS: first step of demultiplexing: the TS header
1057  *****************************************************************************/
1058 void input_DemuxTS( input_thread_t * p_input, data_packet_t * p_data )
1059 {
1060     int                 i_pid, i_dummy;
1061     boolean_t           b_adaptation;         /* Adaptation field is present */
1062     boolean_t           b_payload;                 /* Packet carries payload */
1063     boolean_t           b_unit_start;  /* A PSI or a PES start in the packet */
1064     boolean_t           b_trash = 0;             /* Is the packet unuseful ? */
1065     boolean_t           b_lost = 0;             /* Was there a packet loss ? */
1066     es_descriptor_t *   p_es = NULL;
1067     es_ts_data_t *      p_es_demux = NULL;
1068     pgrm_ts_data_t *    p_pgrm_demux = NULL;
1069
1070 #define p (p_data->p_buffer)
1071
1072     //intf_DbgMsg("input debug: TS-demultiplexing packet %p, pid %d",
1073     //            p_ts_packet, U16_AT(&p[1]) & 0x1fff);
1074
1075     /* Extract flags values from TS common header. */
1076     i_pid = U16_AT(&p[1]) & 0x1fff;
1077     b_unit_start = (p[1] & 0x40);
1078     b_adaptation = (p[3] & 0x20);
1079     b_payload = (p[3] & 0x10);
1080
1081     /* Find out the elementary stream. */
1082     vlc_mutex_lock( &p_input->stream.stream_lock );
1083     p_es = input_FindES( p_input, i_pid );
1084     vlc_mutex_unlock( &p_input->stream.stream_lock );
1085
1086     if( p_es == NULL || p_es->p_decoder_fifo == NULL )
1087     {
1088         /* Not selected. Just read the adaptation field for a PCR. */
1089         b_trash = 1;
1090     }
1091
1092     if( (p_es->p_decoder_fifo != NULL) || (p_pgrm_demux->i_pcr_pid == i_pid) )
1093     {
1094 #ifdef STATS
1095         p_es->c_packets++;
1096 #endif
1097
1098         /* Extract adaptation field information if any */
1099         if( !b_adaptation )
1100         {
1101             /* We don't have any adaptation_field, so payload starts
1102              * immediately after the 4 byte TS header */
1103             p_data->p_payload_start += 4;
1104         }
1105         else
1106         {
1107             /* p[4] is adaptation_field_length minus one */
1108             p_data->p_payload_start += 5 + p[4];
1109
1110             /* The adaptation field can be limited to the
1111              * adaptation_field_length byte, so that there is nothing to do:
1112              * skip this possibility */
1113             if( p[4] )
1114             {
1115                 /* If the packet has both adaptation_field and payload,
1116                  * adaptation_field cannot be more than 182 bytes long; if
1117                  * there is only an adaptation_field, it must fill the next
1118                  * 183 bytes. */
1119                 if( b_payload ? (p[4] > 182) : (p[4] != 183) )
1120                 {
1121                     intf_WarnMsg( 2,
1122                         "invalid TS adaptation field (%p)",
1123                         p_data );
1124                     p_data->b_discard_payload = 1;
1125 #ifdef STATS
1126                     p_es->c_invalid_packets++;
1127 #endif
1128                 }
1129
1130                 /* Now we are sure that the byte containing flags is present:
1131                  * read it */
1132                 else
1133                 {
1134                     /* discontinuity_indicator */
1135                     if( p[5] & 0x80 )
1136                     {
1137                         intf_WarnMsg( 2,
1138                             "discontinuity_indicator"
1139                             " encountered by TS demux (position read: %d,"
1140                             " saved: %d)",
1141                             p[5] & 0x80, p_es_demux->i_continuity_counter );
1142
1143                         /* If the PID carries the PCR, there will be a system
1144                          * time-based discontinuity. We let the PCR decoder
1145                          * handle that. */
1146                         p_es->p_pgrm->b_discontinuity = 1;
1147
1148                         /* There also may be a continuity_counter
1149                          * discontinuity: resynchronise our counter with
1150                          * the one of the stream. */
1151                         p_es_demux->i_continuity_counter = (p[3] & 0x0f) - 1;
1152                     }
1153
1154                     /* If this is a PCR_PID, and this TS packet contains a
1155                      * PCR, we pass it along to the PCR decoder. */
1156                     if( (p_pgrm_demux->i_pcr_pid == i_pid) && (p[5] & 0x10) )
1157                     {
1158                         /* There should be a PCR field in the packet, check
1159                          * if the adaptation field is long enough to carry
1160                          * it. */
1161                         if( p[4] >= 7 )
1162                         {
1163                             /* Convert the PCR in microseconds.
1164                              * WARNING: do not remove the casts in the
1165                              * following calculation ! */
1166                             mtime_t     pcr_time;
1167                             pcr_time =
1168                                     ( (( (mtime_t)U32_AT((u32*)&p[6]) << 1 )
1169                                       | ( p[10] >> 7 )) * 300 ) / 27;
1170                             /* Call the pace control. */
1171                             CRDecode( p_input, p_es->p_pgrm, pcr_time );
1172                         }
1173                     } /* PCR ? */
1174                 } /* valid TS adaptation field ? */
1175             } /* length > 0 */
1176         } /* has adaptation field */
1177
1178         /* Check the continuity of the stream. */
1179         i_dummy = ((p[3] & 0x0f) - p_es_demux->i_continuity_counter) & 0x0f;
1180         if( i_dummy == 1 )
1181         {
1182             /* Everything is ok, just increase our counter */
1183             p_es_demux->i_continuity_counter++;
1184         }
1185         else
1186         {
1187             if( !b_payload && i_dummy == 0 )
1188             {
1189                 /* This is a packet without payload, this is allowed by the
1190                  * draft. As there is nothing interesting in this packet
1191                  * (except PCR that have already been handled), we can trash
1192                  * the packet. */
1193                 intf_WarnMsg( 1,
1194                               "Packet without payload received by TS demux" );
1195                 b_trash = 1;
1196             }
1197             else if( i_dummy <= 0 )
1198             {
1199                 /* FIXME: this can never happen, can it ? --Meuuh */
1200                 /* Duplicate packet: mark it as being to be trashed. */
1201                 intf_WarnMsg( 1, "Duplicate packet received by TS demux" );
1202                 b_trash = 1;
1203             }
1204             else if( p_es_demux->i_continuity_counter == 0xFF )
1205             {
1206                 /* This means that the packet is the first one we receive for
1207                  * this ES since the continuity counter ranges between 0 and
1208                  * 0x0F excepts when it has been initialized by the input:
1209                  * init the counter to the correct value. */
1210                 intf_DbgMsg( "First packet for PID %d received by TS demux",
1211                              p_es->i_id );
1212                 p_es_demux->i_continuity_counter = (p[3] & 0x0f);
1213             }
1214             else
1215             {
1216                 /* This can indicate that we missed a packet or that the
1217                  * continuity_counter wrapped and we received a dup packet:
1218                  * as we don't know, do as if we missed a packet to be sure
1219                  * to recover from this situation */
1220                 intf_WarnMsg( 2,
1221                            "Packet lost by TS demux: current %d, packet %d",
1222                            p_es_demux->i_continuity_counter & 0x0f,
1223                            p[3] & 0x0f );
1224                 b_lost = 1;
1225                 p_es_demux->i_continuity_counter = p[3] & 0x0f;
1226             } /* not continuous */
1227         } /* continuity */
1228     } /* if selected or PCR */
1229
1230     /* Trash the packet if it has no payload or if it isn't selected */
1231     if( b_trash )
1232     {
1233         p_input->p_plugin->pf_delete_packet( p_input, p_data );
1234 #ifdef STATS
1235         p_input->c_packets_trashed++;
1236 #endif
1237     }
1238     else
1239     {
1240         if( p_es_demux->b_psi )
1241         {
1242             /* The payload contains PSI tables */
1243 #if 0
1244             input_DemuxPSI( p_input, p_data, p_es,
1245                             b_unit_start, b_lost );
1246 #endif
1247         }
1248         else
1249         {
1250             /* The payload carries a PES stream */
1251             if( b_unit_start )
1252             input_GatherPES( p_input, p_data, p_es, b_unit_start, b_lost );
1253         }
1254     }
1255
1256 #undef p
1257 }