modules/demux/smf.c

   1 /*****************************************************************************
   2  * smf.c : Standard MIDI File (.mid) demux module for vlc
   3  *****************************************************************************
   4  * Copyright © 2007 Rémi Denis-Courmont
   5  * $Id$
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU Lesser General Public License as published by
   9  * the Free Software Foundation; either version 2.1 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this program; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  20  *****************************************************************************/
  21
  22 #ifdef HAVE_CONFIG_H
  23 # include "config.h"
  24 #endif
  25
  26 #include <vlc_common.h>
  27 #include <vlc_plugin.h>
  28 #include <vlc_demux.h>
  29 #include <vlc_charset.h>
  30 #include <limits.h>
  31
  32 #include <assert.h>
  33
  34 #define TEMPO_MIN  20
  35 #define TEMPO_MAX 250 /* Beats per minute */
  36
  37 /**
  38  * Reads MIDI variable length (7, 14, 21 or 28 bits) integer.
  39  * @return read value, or -1 on EOF/error.
  40  */
  41 static int32_t ReadVarInt (stream_t *s)
  42 {
  43     uint32_t val = 0;
  44     uint8_t byte;
  45
  46     for (unsigned i = 0; i < 4; i++)
  47     {
  48         if (vlc_stream_Read (s, &byte, 1) < 1)
  49             return -1;
  50
  51         val = (val << 7) | (byte & 0x7f);
  52         if ((byte & 0x80) == 0)
  53             return val;
  54     }
  55
  56     return -1;
  57 }
  58
  59 typedef struct smf_track_t
  60 {
  61     uint64_t next;   /*< Time of next message (in term of pulses) */
  62     uint64_t start;  /*< Start offset in the file */
  63     uint32_t length; /*< Bytes length */
  64     uint32_t offset; /*< Read offset relative to the start offset */
  65     uint8_t  running_event; /*< Running (previous) event */
  66 } mtrk_t;
  67
  68 /**
  69  * Reads (delta) time from the next event of a given track.
  70  * @param s stream to read data from (must be positioned at the right offset)
  71  */
  72 static int ReadDeltaTime (stream_t *s, mtrk_t *track)
  73 {
  74     int32_t delta_time;
  75
  76     assert (vlc_stream_Tell (s) == track->start + track->offset);
  77
  78     if (track->offset >= track->length)
  79     {
  80         /* This track is done */
  81         track->next = UINT64_MAX;
  82         return 0;
  83     }
  84
  85     delta_time = ReadVarInt (s);
  86     if (delta_time < 0)
  87         return -1;
  88
  89     track->next += delta_time;
  90     track->offset = vlc_stream_Tell (s) - track->start;
  91     return 0;
  92 }
  93
  94 struct demux_sys_t
  95 {
  96     es_out_id_t *es;
  97     date_t       pts; /*< Play timestamp */
  98     uint64_t     pulse; /*< Pulses counter */
  99     mtime_t      tick; /*< Last tick timestamp */
 100
 101     mtime_t      duration; /*< Total duration */
 102     unsigned     ppqn;   /*< Pulses Per Quarter Note */
 103     /* by the way, "quarter note" is "noire" in French */
 104
 105     unsigned     trackc; /*< Number of tracks */
 106     mtrk_t       trackv[]; /*< Track states */
 107 };
 108
 109 /**
 110  * Non-MIDI Meta events handler
 111  */
 112 static
 113 int HandleMeta (demux_t *p_demux, mtrk_t *tr)
 114 {
 115     stream_t *s = p_demux->s;
 116     demux_sys_t *p_sys = p_demux->p_sys;
 117     uint8_t *payload;
 118     uint8_t type;
 119     int32_t length;
 120     int ret = 0;
 121
 122     if (vlc_stream_Read (s, &type, 1) != 1)
 123         return -1;
 124
 125     length = ReadVarInt (s);
 126     if (length < 0)
 127         return -1;
 128
 129     payload = malloc (length + 1);
 130     if ((payload == NULL)
 131      || (vlc_stream_Read (s, payload, length) != length))
 132     {
 133         free (payload);
 134         return -1;
 135     }
 136
 137     payload[length] = '\0';
 138
 139     switch (type)
 140     {
 141         case 0x00: /* Sequence Number */
 142             break;
 143
 144         case 0x01: /* Text (comment) */
 145             EnsureUTF8 ((char *)payload);
 146             msg_Info (p_demux, "Text      : %s", (char *)payload);
 147             break;
 148
 149         case 0x02: /* Copyright */
 150             EnsureUTF8 ((char *)payload);
 151             msg_Info (p_demux, "Copyright : %s", (char *)payload);
 152             break;
 153
 154         case 0x03: /* Track name */
 155             EnsureUTF8 ((char *)payload);
 156             msg_Info (p_demux, "Track name: %s", (char *)payload);
 157             break;
 158
 159         case 0x04: /* Instrument name */
 160             EnsureUTF8 ((char *)payload);
 161             msg_Info (p_demux, "Instrument: %s", (char *)payload);
 162             break;
 163
 164         case 0x05: /* Lyric (one syllable) */
 165             /*EnsureUTF8 ((char *)payload);*/
 166             break;
 167
 168         case 0x06: /* Marker text */
 169             EnsureUTF8 ((char *)payload);
 170             msg_Info (p_demux, "Marker    : %s", (char *)payload);
 171             break;
 172
 173         case 0x07: /* Cue point (WAVE filename) */
 174             EnsureUTF8 ((char *)payload);
 175             msg_Info (p_demux, "Cue point : %s", (char *)payload);
 176             break;
 177
 178         case 0x08: /* Program/Patch name */
 179             EnsureUTF8 ((char *)payload);
 180             msg_Info (p_demux, "Patch name: %s", (char *)payload);
 181             break;
 182
 183         case 0x09: /* MIDI port name */
 184             EnsureUTF8 ((char *)payload);
 185             msg_Dbg (p_demux, "MIDI port : %s", (char *)payload);
 186             break;
 187
 188         case 0x2F: /* End of track */
 189             if (tr->start + tr->length != vlc_stream_Tell (s))
 190             {
 191                 msg_Err (p_demux, "misplaced end of track");
 192                 ret = -1;
 193             }
 194             break;
 195
 196         case 0x51: /* Tempo */
 197             if (length == 3)
 198             {
 199                 uint32_t uspqn = (payload[0] << 16)
 200                                | (payload[1] << 8) | payload[2];
 201                 unsigned tempo = 60 * 1000000 / (uspqn ? uspqn : 1);
 202                 msg_Dbg (p_demux, "tempo: %uus/qn -> %u BPM",
 203                          (unsigned)uspqn, tempo);
 204
 205                 if (tempo < TEMPO_MIN)
 206                 {
 207                     msg_Warn (p_demux, "tempo too slow -> %u BPM", TEMPO_MIN);
 208                     tempo = TEMPO_MIN;
 209                 }
 210                 else
 211                 if (tempo > TEMPO_MAX)
 212                 {
 213                     msg_Warn (p_demux, "tempo too fast -> %u BPM", TEMPO_MAX);
 214                     tempo = TEMPO_MAX;
 215                 }
 216                 date_Change (&p_sys->pts, p_sys->ppqn * tempo, 60);
 217             }
 218             else
 219                 ret = -1;
 220             break;
 221
 222         case 0x54: /* SMPTE offset */
 223             if (length == 5)
 224                 msg_Warn (p_demux, "SMPTE offset not implemented");
 225             else
 226                 ret = -1;
 227             break;
 228
 229         case 0x58: /* Time signature */
 230             if (length == 4)
 231                 ;
 232             else
 233                 ret = -1;
 234             break;
 235
 236         case 0x59: /* Key signature */
 237             if (length == 2)
 238                 ;
 239             else
 240                 ret = -1;
 241             break;
 242
 243         case 0x7f: /* Proprietary event */
 244             msg_Dbg (p_demux, "ignored proprietary SMF Meta Event (%d bytes)",
 245                      length);
 246             break;
 247
 248         default:
 249             msg_Warn (p_demux, "unknown SMF Meta Event type 0x%02X (%d bytes)",
 250                       type, length);
 251     }
 252
 253     free (payload);
 254     return ret;
 255 }
 256
 257 static
 258 int HandleMessage (demux_t *p_demux, mtrk_t *tr, es_out_t *out)
 259 {
 260     stream_t *s = p_demux->s;
 261     block_t *block;
 262     uint8_t first, event;
 263     unsigned datalen;
 264
 265     if (vlc_stream_Seek (s, tr->start + tr->offset)
 266      || (vlc_stream_Read (s, &first, 1) != 1))
 267         return -1;
 268
 269     event = (first & 0x80) ? first : tr->running_event;
 270
 271     switch (event & 0xf0)
 272     {
 273         case 0xF0: /* System Exclusive */
 274             switch (event)
 275             {
 276                 case 0xF0: /* System Specific start */
 277                 case 0xF7: /* System Specific continuation */
 278                 {
 279                     /* Variable length followed by SysEx event data */
 280                     int32_t len = ReadVarInt (s);
 281                     if (len == -1)
 282                         return -1;
 283
 284                     block = vlc_stream_Block (s, len);
 285                     if (block == NULL)
 286                         return -1;
 287                     block = block_Realloc (block, 1, len);
 288                     if (block == NULL)
 289                         return -1;
 290                     block->p_buffer[0] = event;
 291                     goto send;
 292                 }
 293                 case 0xFF: /* SMF Meta Event */
 294                     if (HandleMeta (p_demux, tr))
 295                         return -1;
 296                     /* We MUST NOT pass this event forward. It would be
 297                      * confused as a MIDI Reset real-time event. */
 298                     goto skip;
 299                 case 0xF1:
 300                 case 0xF3:
 301                     datalen = 1;
 302                     break;
 303                 case 0xF2:
 304                     datalen = 2;
 305                     break;
 306                 case 0xF4:
 307                 case 0xF5:
 308                     /* We cannot handle undefined "common" (non-real-time)
 309                      * events inside SMF, as we cannot differentiate a
 310                      * one byte delta-time (< 0x80) from event data. */
 311                 default:
 312                     datalen = 0;
 313                     break;
 314             }
 315             break;
 316         case 0xC0:
 317         case 0xD0:
 318             datalen = 1;
 319             break;
 320         default:
 321             datalen = 2;
 322             break;
 323     }
 324
 325     /* FIXME: one message per block is very inefficient */
 326     block = block_Alloc (1 + datalen);
 327     if (block == NULL)
 328         goto skip;
 329
 330     block->p_buffer[0] = event;
 331     if (first & 0x80)
 332     {
 333         if (vlc_stream_Read(s, block->p_buffer + 1, datalen) < datalen)
 334             goto error;
 335     }
 336     else
 337     {
 338         if (datalen == 0)
 339         {   /* implicit running status requires non-empty payload */
 340             msg_Err (p_demux, "malformatted MIDI event");
 341             goto error;
 342         }
 343
 344         block->p_buffer[1] = first;
 345         if (datalen > 1
 346          && vlc_stream_Read(s, block->p_buffer + 2, datalen - 1) < datalen - 1)
 347             goto error;
 348     }
 349
 350 send:
 351     block->i_dts = block->i_pts = date_Get (&p_demux->p_sys->pts);
 352     if (out != NULL)
 353         es_out_Send (out, p_demux->p_sys->es, block);
 354     else
 355         block_Release (block);
 356
 357 skip:
 358     if (event < 0xF8)
 359         /* If event is not real-time, update running status */
 360         tr->running_event = event;
 361
 362     tr->offset = vlc_stream_Tell (s) - tr->start;
 363     return 0;
 364
 365 error:
 366     block_Release(block);
 367     return -1;
 368 }
 369
 370 static int SeekSet0 (demux_t *demux)
 371 {
 372     stream_t *stream = demux->s;
 373     demux_sys_t *sys = demux->p_sys;
 374
 375     /* Default SMF tempo is 120BPM, i.e. half a second per quarter note */
 376     date_Init (&sys->pts, sys->ppqn * 2, 1);
 377     date_Set (&sys->pts, VLC_TS_0);
 378     sys->pulse = 0;
 379     sys->tick = VLC_TS_0;
 380
 381     for (unsigned i = 0; i < sys->trackc; i++)
 382     {
 383         mtrk_t *tr = sys->trackv + i;
 384
 385         tr->offset = 0;
 386         tr->next = 0;
 387         /* Why 0xF6 (Tuning Calibration)?
 388          * Because it has zero bytes of data, so the parser will detect the
 389          * error if the first event uses running status. */
 390         tr->running_event = 0xF6;
 391
 392         if (vlc_stream_Seek (stream, tr->start)
 393          || ReadDeltaTime (stream, tr))
 394         {
 395             msg_Err (demux, "fatal parsing error");
 396             return -1;
 397         }
 398     }
 399
 400     return 0;
 401 }
 402
 403 static int ReadEvents (demux_t *demux, uint64_t *restrict pulse,
 404                        es_out_t *out)
 405 {
 406     uint64_t cur_pulse = *pulse, next_pulse = UINT64_MAX;
 407     demux_sys_t *sys = demux->p_sys;
 408
 409     for (unsigned i = 0; i < sys->trackc; i++)
 410     {
 411         mtrk_t *track = sys->trackv + i;
 412
 413         while (track->next <= cur_pulse)
 414         {
 415             if (HandleMessage (demux, track, out)
 416              || ReadDeltaTime (demux->s, track))
 417             {
 418                 msg_Err (demux, "fatal parsing error");
 419                 return -1;
 420             }
 421         }
 422
 423         if (next_pulse > track->next)
 424             next_pulse = track->next;
 425     }
 426
 427     if (next_pulse != UINT64_MAX)
 428         date_Increment (&sys->pts, next_pulse - cur_pulse);
 429     *pulse = next_pulse;
 430     return 0;
 431 }
 432
 433 #define TICK (CLOCK_FREQ / 100)
 434
 435 /*****************************************************************************
 436  * Demux: read chunks and send them to the synthesizer
 437  *****************************************************************************
 438  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 439  *****************************************************************************/
 440 static int Demux (demux_t *demux)
 441 {
 442     demux_sys_t *sys = demux->p_sys;
 443
 444     /* MIDI Tick emulation (ping the decoder every 10ms) */
 445     if (sys->tick <= date_Get (&sys->pts))
 446     {
 447         block_t *tick = block_Alloc (1);
 448         if (unlikely(tick == NULL))
 449             return VLC_ENOMEM;
 450
 451         tick->p_buffer[0] = 0xF9;
 452         tick->i_dts = tick->i_pts = sys->tick;
 453
 454         es_out_Send (demux->out, sys->es, tick);
 455         es_out_SetPCR (demux->out, sys->tick);
 456
 457         sys->tick += TICK;
 458         return 1;
 459     }
 460
 461     /* MIDI events in chronological order across all tracks */
 462     uint64_t pulse = sys->pulse;
 463
 464     if (ReadEvents (demux, &pulse, demux->out))
 465         return VLC_EGENERIC;
 466
 467     if (pulse == UINT64_MAX)
 468         return 0; /* all tracks are done */
 469
 470     sys->pulse = pulse;
 471     return 1;
 472 }
 473
 474 static int Seek (demux_t *demux, mtime_t pts)
 475 {
 476     demux_sys_t *sys = demux->p_sys;
 477
 478     /* Rewind if needed */
 479     if (pts < date_Get (&sys->pts) && SeekSet0 (demux))
 480         return VLC_EGENERIC;
 481
 482     /* Fast forward */
 483     uint64_t pulse = sys->pulse;
 484
 485     while (pts > date_Get (&sys->pts))
 486     {
 487         if (pulse == UINT64_MAX)
 488             return VLC_SUCCESS; /* premature end */
 489         if (ReadEvents (demux, &pulse, NULL))
 490             return VLC_EGENERIC;
 491     }
 492
 493     sys->pulse = pulse;
 494     sys->tick = ((date_Get (&sys->pts) - VLC_TS_0) / TICK) * TICK + VLC_TS_0;
 495     return VLC_SUCCESS;
 496 }
 497
 498 /*****************************************************************************
 499  * Control:
 500  *****************************************************************************/
 501 static int Control (demux_t *demux, int i_query, va_list args)
 502 {
 503     demux_sys_t *sys = demux->p_sys;
 504
 505     switch (i_query)
 506     {
 507         case DEMUX_CAN_SEEK:
 508             *va_arg (args, bool *) = true;
 509             break;
 510         case DEMUX_GET_POSITION:
 511             if (!sys->duration)
 512                 return VLC_EGENERIC;
 513             *va_arg (args, double *) = (sys->tick - (double)VLC_TS_0)
 514                                      / sys->duration;
 515             break;
 516         case DEMUX_SET_POSITION:
 517             return Seek (demux, va_arg (args, double) * sys->duration);
 518         case DEMUX_GET_LENGTH:
 519             *va_arg (args, int64_t *) = sys->duration;
 520             break;
 521         case DEMUX_GET_TIME:
 522             *va_arg (args, int64_t *) = sys->tick - VLC_TS_0;
 523             break;
 524         case DEMUX_SET_TIME:
 525             return Seek (demux, va_arg (args, int64_t));
 526         default:
 527             return VLC_EGENERIC;
 528     }
 529     return VLC_SUCCESS;
 530 }
 531
 532 /**
 533  * Probes file format and starts demuxing.
 534  */
 535 static int Open (vlc_object_t *obj)
 536 {
 537     demux_t *demux = (demux_t *)obj;
 538     stream_t *stream = demux->s;
 539     const uint8_t *peek;
 540     bool multitrack;
 541
 542     /* (Try to) parse the SMF header */
 543     /* Header chunk always has 6 bytes payload */
 544     if (vlc_stream_Peek (stream, &peek, 14) < 14)
 545         return VLC_EGENERIC;
 546
 547     /* Skip RIFF MIDI header if present */
 548     if (!memcmp (peek, "RIFF", 4) && !memcmp (peek + 8, "RMID", 4))
 549     {
 550         uint32_t riff_len = GetDWLE (peek + 4);
 551
 552         msg_Dbg (demux, "detected RIFF MIDI file (%"PRIu32" bytes)", riff_len);
 553         if ((vlc_stream_Read (stream, NULL, 12) < 12))
 554             return VLC_EGENERIC;
 555
 556         /* Look for the RIFF data chunk */
 557         for (;;)
 558         {
 559             char chnk_hdr[8];
 560             uint32_t chnk_len;
 561
 562             if ((riff_len < 8)
 563              || (vlc_stream_Read (stream, chnk_hdr, 8) < 8))
 564                 return VLC_EGENERIC;
 565
 566             riff_len -= 8;
 567             chnk_len = GetDWLE (chnk_hdr + 4);
 568             if (riff_len < chnk_len)
 569                 return VLC_EGENERIC;
 570             riff_len -= chnk_len;
 571
 572             if (!memcmp (chnk_hdr, "data", 4))
 573                 break; /* found! */
 574
 575             if (vlc_stream_Read (stream, NULL, chnk_len) < (ssize_t)chnk_len)
 576                 return VLC_EGENERIC;
 577         }
 578
 579         /* Read real SMF header. Assume RIFF data chunk length is proper. */
 580         if (vlc_stream_Peek (stream, &peek, 14) < 14)
 581             return VLC_EGENERIC;
 582     }
 583
 584     if (memcmp (peek, "MThd\x00\x00\x00\x06", 8))
 585         return VLC_EGENERIC;
 586     peek += 8;
 587
 588     /* First word: SMF type */
 589     switch (GetWBE (peek))
 590     {
 591         case 0:
 592             multitrack = false;
 593             break;
 594         case 1:
 595             multitrack = true;
 596             break;
 597         default:
 598             /* We don't implement SMF2 (as do many) */
 599             msg_Err (demux, "unsupported SMF file type %u", GetWBE (peek));
 600             return VLC_EGENERIC;
 601     }
 602     peek += 2;
 603
 604     /* Second word: number of tracks */
 605     unsigned tracks = GetWBE (peek);
 606     peek += 2;
 607     if (!multitrack && (tracks != 1))
 608     {
 609         msg_Err (demux, "invalid SMF type 0 file");
 610         return VLC_EGENERIC;
 611     }
 612
 613     msg_Dbg (demux, "detected Standard MIDI File (type %u) with %u track(s)",
 614              multitrack, tracks);
 615
 616     /* Third/last word: timing */
 617     unsigned ppqn = GetWBE (peek);
 618     if (ppqn & 0x8000)
 619     {   /* FIXME */
 620         msg_Err (demux, "SMPTE timestamps not implemented");
 621         return VLC_EGENERIC;
 622     }
 623     else
 624     {
 625         if (ppqn == 0)
 626         {
 627             msg_Err(demux, "invalid SMF file PPQN: %u", ppqn);
 628             return VLC_EGENERIC;
 629         }
 630         msg_Dbg (demux, " %u pulses per quarter note", ppqn);
 631     }
 632
 633     demux_sys_t *sys = malloc (sizeof (*sys) + (sizeof (mtrk_t) * tracks));
 634     if (unlikely(sys == NULL))
 635         return VLC_ENOMEM;
 636
 637     /* We've had a valid SMF header - now skip it*/
 638     if (vlc_stream_Read (stream, NULL, 14) < 14)
 639         goto error;
 640
 641     demux->p_sys = sys;
 642     sys->duration = 0;
 643     sys->ppqn = ppqn;
 644     sys->trackc = tracks;
 645
 646     /* Prefetch track offsets */
 647     for (unsigned i = 0; i < tracks; i++)
 648     {
 649         mtrk_t *tr = sys->trackv + i;
 650         uint8_t head[8];
 651
 652         /* Seeking screws streaming up, but there is no way around this, as
 653          * SMF1 tracks are performed simultaneously.
 654          * Not a big deal as SMF1 are usually only a few kbytes anyway. */
 655         if (i > 0 && vlc_stream_Seek (stream, tr[-1].start + tr[-1].length))
 656         {
 657             msg_Err (demux, "cannot build SMF index (corrupted file?)");
 658             goto error;
 659         }
 660
 661         for (;;)
 662         {
 663             if (vlc_stream_Read (stream, head, 8) < 8)
 664             {
 665                 /* FIXME: don't give up if we have at least one valid track */
 666                 msg_Err (demux, "incomplete SMF chunk, file is corrupted");
 667                 goto error;
 668             }
 669
 670             if (memcmp (head, "MTrk", 4) == 0)
 671                 break;
 672
 673             uint_fast32_t chunk_len = GetDWBE(head + 4);
 674             msg_Dbg(demux, "skipping unknown SMF chunk (%"PRIuFAST32" bytes)",
 675                     chunk_len);
 676             if (vlc_stream_Seek(stream, vlc_stream_Tell(stream) + chunk_len))
 677                 goto error;
 678         }
 679
 680         tr->start = vlc_stream_Tell (stream);
 681         tr->length = GetDWBE (head + 4);
 682     }
 683
 684     bool b;
 685     if (vlc_stream_Control (stream, STREAM_CAN_FASTSEEK, &b) == 0 && b)
 686     {
 687         if (SeekSet0 (demux))
 688             goto error;
 689
 690         for (uint64_t pulse = 0; pulse != UINT64_MAX;)
 691              if (ReadEvents (demux, &pulse, NULL))
 692                  break;
 693
 694         sys->duration = date_Get (&sys->pts);
 695     }
 696
 697     if (SeekSet0 (demux))
 698         goto error;
 699
 700     es_format_t  fmt;
 701     es_format_Init (&fmt, AUDIO_ES, VLC_CODEC_MIDI);
 702     fmt.audio.i_channels = 2;
 703     fmt.audio.i_rate = 44100; /* dummy value */
 704     sys->es = es_out_Add (demux->out, &fmt);
 705
 706     demux->pf_demux = Demux;
 707     demux->pf_control = Control;
 708     return VLC_SUCCESS;
 709
 710 error:
 711     free (sys);
 712     return VLC_EGENERIC;
 713 }
 714
 715 /**
 716  * Releases allocate resources.
 717  */
 718 static void Close (vlc_object_t * p_this)
 719 {
 720     demux_t *p_demux = (demux_t *)p_this;
 721     demux_sys_t *p_sys = p_demux->p_sys;
 722
 723     free (p_sys);
 724 }
 725
 726 vlc_module_begin ()
 727     set_description (N_("SMF demuxer"))
 728     set_category (CAT_INPUT)
 729     set_subcategory (SUBCAT_INPUT_DEMUX)
 730     set_capability ("demux", 20)
 731     set_callbacks (Open, Close)
 732 vlc_module_end ()