1 /*****************************************************************************
2 * smf.c : Standard MIDI File (.mid) demux module for vlc
3 *****************************************************************************
4 * Copyright © 2007 Rémi Denis-Courmont
5 * $Id: ab03097a80101cacf645f5d1c7d89765b25a1ec0 $
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 */
ReadVarInt(stream_t * s)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 */
ReadDeltaTime(stream_t * s,mtrk_t * track)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
HandleMeta(demux_t * p_demux,mtrk_t * tr)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 msg_Warn(p_demux, "invalid key signature");
239 break;
240
241 case 0x7f: /* Proprietary event */
242 msg_Dbg (p_demux, "ignored proprietary SMF Meta Event (%d bytes)",
243 length);
244 break;
245
246 default:
247 msg_Warn (p_demux, "unknown SMF Meta Event type 0x%02X (%d bytes)",
248 type, length);
249 }
250
251 free (payload);
252 return ret;
253 }
254
255 static
HandleMessage(demux_t * p_demux,mtrk_t * tr,es_out_t * out)256 int HandleMessage (demux_t *p_demux, mtrk_t *tr, es_out_t *out)
257 {
258 stream_t *s = p_demux->s;
259 block_t *block;
260 uint8_t first, event;
261 unsigned datalen;
262
263 if (vlc_stream_Seek (s, tr->start + tr->offset)
264 || (vlc_stream_Read (s, &first, 1) != 1))
265 return -1;
266
267 event = (first & 0x80) ? first : tr->running_event;
268
269 switch (event & 0xf0)
270 {
271 case 0xF0: /* System Exclusive */
272 switch (event)
273 {
274 case 0xF0: /* System Specific start */
275 case 0xF7: /* System Specific continuation */
276 {
277 /* Variable length followed by SysEx event data */
278 int32_t len = ReadVarInt (s);
279 if (len == -1)
280 return -1;
281
282 block = vlc_stream_Block (s, len);
283 if (block == NULL)
284 return -1;
285 block = block_Realloc (block, 1, len);
286 if (block == NULL)
287 return -1;
288 block->p_buffer[0] = event;
289 goto send;
290 }
291 case 0xFF: /* SMF Meta Event */
292 if (HandleMeta (p_demux, tr))
293 return -1;
294 /* We MUST NOT pass this event forward. It would be
295 * confused as a MIDI Reset real-time event. */
296 goto skip;
297 case 0xF1:
298 case 0xF3:
299 datalen = 1;
300 break;
301 case 0xF2:
302 datalen = 2;
303 break;
304 case 0xF4:
305 case 0xF5:
306 /* We cannot handle undefined "common" (non-real-time)
307 * events inside SMF, as we cannot differentiate a
308 * one byte delta-time (< 0x80) from event data. */
309 default:
310 datalen = 0;
311 break;
312 }
313 break;
314 case 0xC0:
315 case 0xD0:
316 datalen = 1;
317 break;
318 default:
319 datalen = 2;
320 break;
321 }
322
323 /* FIXME: one message per block is very inefficient */
324 block = block_Alloc (1 + datalen);
325 if (block == NULL)
326 goto skip;
327
328 block->p_buffer[0] = event;
329 if (first & 0x80)
330 {
331 if (vlc_stream_Read(s, block->p_buffer + 1, datalen) < datalen)
332 goto error;
333 }
334 else
335 {
336 if (datalen == 0)
337 { /* implicit running status requires non-empty payload */
338 msg_Err (p_demux, "malformatted MIDI event");
339 goto error;
340 }
341
342 block->p_buffer[1] = first;
343 if (datalen > 1
344 && vlc_stream_Read(s, block->p_buffer + 2, datalen - 1) < datalen - 1)
345 goto error;
346 }
347
348 send:
349 block->i_dts = block->i_pts = date_Get (&p_demux->p_sys->pts);
350 if (out != NULL)
351 es_out_Send (out, p_demux->p_sys->es, block);
352 else
353 block_Release (block);
354
355 skip:
356 if (event < 0xF8)
357 /* If event is not real-time, update running status */
358 tr->running_event = event;
359
360 tr->offset = vlc_stream_Tell (s) - tr->start;
361 return 0;
362
363 error:
364 block_Release(block);
365 return -1;
366 }
367
SeekSet0(demux_t * demux)368 static int SeekSet0 (demux_t *demux)
369 {
370 stream_t *stream = demux->s;
371 demux_sys_t *sys = demux->p_sys;
372
373 /* Default SMF tempo is 120BPM, i.e. half a second per quarter note */
374 date_Init (&sys->pts, sys->ppqn * 2, 1);
375 date_Set (&sys->pts, VLC_TS_0);
376 sys->pulse = 0;
377 sys->tick = VLC_TS_0;
378
379 for (unsigned i = 0; i < sys->trackc; i++)
380 {
381 mtrk_t *tr = sys->trackv + i;
382
383 tr->offset = 0;
384 tr->next = 0;
385 /* Why 0xF6 (Tuning Calibration)?
386 * Because it has zero bytes of data, so the parser will detect the
387 * error if the first event uses running status. */
388 tr->running_event = 0xF6;
389
390 if (vlc_stream_Seek (stream, tr->start)
391 || ReadDeltaTime (stream, tr))
392 {
393 msg_Err (demux, "fatal parsing error");
394 return -1;
395 }
396 }
397
398 return 0;
399 }
400
ReadEvents(demux_t * demux,uint64_t * restrict pulse,es_out_t * out)401 static int ReadEvents (demux_t *demux, uint64_t *restrict pulse,
402 es_out_t *out)
403 {
404 uint64_t cur_pulse = *pulse, next_pulse = UINT64_MAX;
405 demux_sys_t *sys = demux->p_sys;
406
407 for (unsigned i = 0; i < sys->trackc; i++)
408 {
409 mtrk_t *track = sys->trackv + i;
410
411 while (track->next <= cur_pulse)
412 {
413 if (HandleMessage (demux, track, out)
414 || ReadDeltaTime (demux->s, track))
415 {
416 msg_Err (demux, "fatal parsing error");
417 return -1;
418 }
419 }
420
421 if (next_pulse > track->next)
422 next_pulse = track->next;
423 }
424
425 if (next_pulse != UINT64_MAX)
426 date_Increment (&sys->pts, next_pulse - cur_pulse);
427 *pulse = next_pulse;
428 return 0;
429 }
430
431 #define TICK (CLOCK_FREQ / 100)
432
433 /*****************************************************************************
434 * Demux: read chunks and send them to the synthesizer
435 *****************************************************************************
436 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
437 *****************************************************************************/
Demux(demux_t * demux)438 static int Demux (demux_t *demux)
439 {
440 demux_sys_t *sys = demux->p_sys;
441
442 /* MIDI Tick emulation (ping the decoder every 10ms) */
443 if (sys->tick <= date_Get (&sys->pts))
444 {
445 block_t *tick = block_Alloc (1);
446 if (unlikely(tick == NULL))
447 return VLC_ENOMEM;
448
449 tick->p_buffer[0] = 0xF9;
450 tick->i_dts = tick->i_pts = sys->tick;
451
452 es_out_Send (demux->out, sys->es, tick);
453 es_out_SetPCR (demux->out, sys->tick);
454
455 sys->tick += TICK;
456 return 1;
457 }
458
459 /* MIDI events in chronological order across all tracks */
460 uint64_t pulse = sys->pulse;
461
462 if (ReadEvents (demux, &pulse, demux->out))
463 return VLC_EGENERIC;
464
465 if (pulse == UINT64_MAX)
466 return 0; /* all tracks are done */
467
468 sys->pulse = pulse;
469 return 1;
470 }
471
Seek(demux_t * demux,mtime_t pts)472 static int Seek (demux_t *demux, mtime_t pts)
473 {
474 demux_sys_t *sys = demux->p_sys;
475
476 /* Rewind if needed */
477 if (pts < date_Get (&sys->pts) && SeekSet0 (demux))
478 return VLC_EGENERIC;
479
480 /* Fast forward */
481 uint64_t pulse = sys->pulse;
482
483 while (pts > date_Get (&sys->pts))
484 {
485 if (pulse == UINT64_MAX)
486 return VLC_SUCCESS; /* premature end */
487 if (ReadEvents (demux, &pulse, NULL))
488 return VLC_EGENERIC;
489 }
490
491 sys->pulse = pulse;
492 sys->tick = ((date_Get (&sys->pts) - VLC_TS_0) / TICK) * TICK + VLC_TS_0;
493 return VLC_SUCCESS;
494 }
495
496 /*****************************************************************************
497 * Control:
498 *****************************************************************************/
Control(demux_t * demux,int i_query,va_list args)499 static int Control (demux_t *demux, int i_query, va_list args)
500 {
501 demux_sys_t *sys = demux->p_sys;
502
503 switch (i_query)
504 {
505 case DEMUX_CAN_SEEK:
506 *va_arg (args, bool *) = true;
507 break;
508 case DEMUX_GET_POSITION:
509 if (!sys->duration)
510 return VLC_EGENERIC;
511 *va_arg (args, double *) = (sys->tick - (double)VLC_TS_0)
512 / sys->duration;
513 break;
514 case DEMUX_SET_POSITION:
515 return Seek (demux, va_arg (args, double) * sys->duration);
516 case DEMUX_GET_LENGTH:
517 *va_arg (args, int64_t *) = sys->duration;
518 break;
519 case DEMUX_GET_TIME:
520 *va_arg (args, int64_t *) = sys->tick - VLC_TS_0;
521 break;
522 case DEMUX_SET_TIME:
523 return Seek (demux, va_arg (args, int64_t));
524 default:
525 return VLC_EGENERIC;
526 }
527 return VLC_SUCCESS;
528 }
529
530 /**
531 * Probes file format and starts demuxing.
532 */
Open(vlc_object_t * obj)533 static int Open (vlc_object_t *obj)
534 {
535 demux_t *demux = (demux_t *)obj;
536 stream_t *stream = demux->s;
537 const uint8_t *peek;
538 bool multitrack;
539
540 /* (Try to) parse the SMF header */
541 /* Header chunk always has 6 bytes payload */
542 if (vlc_stream_Peek (stream, &peek, 14) < 14)
543 return VLC_EGENERIC;
544
545 /* Skip RIFF MIDI header if present */
546 if (!memcmp (peek, "RIFF", 4) && !memcmp (peek + 8, "RMID", 4))
547 {
548 uint32_t riff_len = GetDWLE (peek + 4);
549
550 msg_Dbg (demux, "detected RIFF MIDI file (%"PRIu32" bytes)", riff_len);
551 if ((vlc_stream_Read (stream, NULL, 12) < 12))
552 return VLC_EGENERIC;
553
554 /* Look for the RIFF data chunk */
555 for (;;)
556 {
557 char chnk_hdr[8];
558 uint32_t chnk_len;
559
560 if ((riff_len < 8)
561 || (vlc_stream_Read (stream, chnk_hdr, 8) < 8))
562 return VLC_EGENERIC;
563
564 riff_len -= 8;
565 chnk_len = GetDWLE (chnk_hdr + 4);
566 if (riff_len < chnk_len)
567 return VLC_EGENERIC;
568 riff_len -= chnk_len;
569
570 if (!memcmp (chnk_hdr, "data", 4))
571 break; /* found! */
572
573 if (vlc_stream_Read (stream, NULL, chnk_len) < (ssize_t)chnk_len)
574 return VLC_EGENERIC;
575 }
576
577 /* Read real SMF header. Assume RIFF data chunk length is proper. */
578 if (vlc_stream_Peek (stream, &peek, 14) < 14)
579 return VLC_EGENERIC;
580 }
581
582 if (memcmp (peek, "MThd\x00\x00\x00\x06", 8))
583 return VLC_EGENERIC;
584 peek += 8;
585
586 /* First word: SMF type */
587 switch (GetWBE (peek))
588 {
589 case 0:
590 multitrack = false;
591 break;
592 case 1:
593 multitrack = true;
594 break;
595 default:
596 /* We don't implement SMF2 (as do many) */
597 msg_Err (demux, "unsupported SMF file type %u", GetWBE (peek));
598 return VLC_EGENERIC;
599 }
600 peek += 2;
601
602 /* Second word: number of tracks */
603 unsigned tracks = GetWBE (peek);
604 peek += 2;
605 if (!multitrack && (tracks != 1))
606 {
607 msg_Err (demux, "invalid SMF type 0 file");
608 return VLC_EGENERIC;
609 }
610
611 msg_Dbg (demux, "detected Standard MIDI File (type %u) with %u track(s)",
612 multitrack, tracks);
613
614 /* Third/last word: timing */
615 unsigned ppqn = GetWBE (peek);
616 if (ppqn & 0x8000)
617 { /* FIXME */
618 msg_Err (demux, "SMPTE timestamps not implemented");
619 return VLC_EGENERIC;
620 }
621 else
622 {
623 if (ppqn == 0)
624 {
625 msg_Err(demux, "invalid SMF file PPQN: %u", ppqn);
626 return VLC_EGENERIC;
627 }
628 msg_Dbg (demux, " %u pulses per quarter note", ppqn);
629 }
630
631 demux_sys_t *sys = malloc (sizeof (*sys) + (sizeof (mtrk_t) * tracks));
632 if (unlikely(sys == NULL))
633 return VLC_ENOMEM;
634
635 /* We've had a valid SMF header - now skip it*/
636 if (vlc_stream_Read (stream, NULL, 14) < 14)
637 goto error;
638
639 demux->p_sys = sys;
640 sys->duration = 0;
641 sys->ppqn = ppqn;
642 sys->trackc = tracks;
643
644 /* Prefetch track offsets */
645 for (unsigned i = 0; i < tracks; i++)
646 {
647 mtrk_t *tr = sys->trackv + i;
648 uint8_t head[8];
649
650 /* Seeking screws streaming up, but there is no way around this, as
651 * SMF1 tracks are performed simultaneously.
652 * Not a big deal as SMF1 are usually only a few kbytes anyway. */
653 if (i > 0 && vlc_stream_Seek (stream, tr[-1].start + tr[-1].length))
654 {
655 msg_Err (demux, "cannot build SMF index (corrupted file?)");
656 goto error;
657 }
658
659 for (;;)
660 {
661 if (vlc_stream_Read (stream, head, 8) < 8)
662 {
663 /* FIXME: don't give up if we have at least one valid track */
664 msg_Err (demux, "incomplete SMF chunk, file is corrupted");
665 goto error;
666 }
667
668 if (memcmp (head, "MTrk", 4) == 0)
669 break;
670
671 uint_fast32_t chunk_len = GetDWBE(head + 4);
672 msg_Dbg(demux, "skipping unknown SMF chunk (%"PRIuFAST32" bytes)",
673 chunk_len);
674 if (vlc_stream_Seek(stream, vlc_stream_Tell(stream) + chunk_len))
675 goto error;
676 }
677
678 tr->start = vlc_stream_Tell (stream);
679 tr->length = GetDWBE (head + 4);
680 }
681
682 bool b;
683 if (vlc_stream_Control (stream, STREAM_CAN_FASTSEEK, &b) == 0 && b)
684 {
685 if (SeekSet0 (demux))
686 goto error;
687
688 for (uint64_t pulse = 0; pulse != UINT64_MAX;)
689 if (ReadEvents (demux, &pulse, NULL))
690 break;
691
692 sys->duration = date_Get (&sys->pts);
693 }
694
695 if (SeekSet0 (demux))
696 goto error;
697
698 es_format_t fmt;
699 es_format_Init (&fmt, AUDIO_ES, VLC_CODEC_MIDI);
700 fmt.audio.i_channels = 2;
701 fmt.audio.i_rate = 44100; /* dummy value */
702 sys->es = es_out_Add (demux->out, &fmt);
703
704 demux->pf_demux = Demux;
705 demux->pf_control = Control;
706 return VLC_SUCCESS;
707
708 error:
709 free (sys);
710 return VLC_EGENERIC;
711 }
712
713 /**
714 * Releases allocate resources.
715 */
Close(vlc_object_t * p_this)716 static void Close (vlc_object_t * p_this)
717 {
718 demux_t *p_demux = (demux_t *)p_this;
719 demux_sys_t *p_sys = p_demux->p_sys;
720
721 free (p_sys);
722 }
723
724 vlc_module_begin ()
725 set_description (N_("SMF demuxer"))
726 set_category (CAT_INPUT)
727 set_subcategory (SUBCAT_INPUT_DEMUX)
728 set_capability ("demux", 20)
729 set_callbacks (Open, Close)
730 vlc_module_end ()
731