xref: /netbsd-src/usr.bin/midiplay/midiplay.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: midiplay.c,v 1.25 2006/07/01 11:05:42 he Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 2002 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Lennart Augustsson (augustss@NetBSD.org).
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 #include <sys/cdefs.h>
39 
40 #ifndef lint
41 __RCSID("$NetBSD: midiplay.c,v 1.25 2006/07/01 11:05:42 he Exp $");
42 #endif
43 
44 
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <fcntl.h>
48 #include <err.h>
49 #include <unistd.h>
50 #include <string.h>
51 #include <sys/types.h>
52 #include <sys/stat.h>
53 #include <sys/ioctl.h>
54 #include <sys/midiio.h>
55 
56 #define DEVMUSIC "/dev/music"
57 
58 struct track {
59 	struct track *indirect; /* for fast swaps in heap code */
60 	u_char *start, *end;
61 	u_long delta;
62 	u_char status;
63 };
64 
65 #define MIDI_META 0xff
66 
67 #define META_SEQNO	0x00
68 #define META_TEXT	0x01
69 #define META_COPYRIGHT	0x02
70 #define META_TRACK	0x03
71 #define META_INSTRUMENT	0x04
72 #define META_LYRIC	0x05
73 #define META_MARKER	0x06
74 #define META_CUE	0x07
75 #define META_CHPREFIX	0x20
76 #define META_EOT	0x2f
77 #define META_SET_TEMPO	0x51
78 #define META_KEY	0x59
79 #define META_SMPTE	0x54
80 #define META_TIMESIGN	0x58
81 
82 char *metanames[] = {
83 	"", "Text", "Copyright", "Track", "Instrument",
84 	"Lyric", "Marker", "Cue",
85 };
86 
87 static int midi_lengths[] = { 2,2,2,2,1,1,2,0 };
88 /* Number of bytes in a MIDI command */
89 #define MIDI_LENGTH(d) (midi_lengths[((d) >> 4) & 7])
90 
91 void usage(void);
92 void send_event(seq_event_t *);
93 void dometa(u_int, u_char *, u_int);
94 void midireset(void);
95 void send_sysex(u_char *, u_int);
96 u_long getvar(struct track *);
97 u_long getlen(struct track *);
98 void playfile(FILE *, char *);
99 void playdata(u_char *, u_int, char *);
100 int main(int argc, char **argv);
101 
102 void Heapify(struct track *, int, int);
103 void BuildHeap(struct track *, int);
104 int ShrinkHeap(struct track *, int);
105 
106 /*
107  * This sample plays at an apparent tempo of 120 bpm when the BASETEMPO is 150
108  * bpm, because the quavers are 5 divisions (4 on 1 off) rather than 4 total.
109  */
110 #define P(c) 1,0x90,c,0x7f,4,0x80,c,0
111 #define PL(c) 1,0x90,c,0x7f,8,0x80,c,0
112 #define C 0x3c
113 #define D 0x3e
114 #define E 0x40
115 #define F 0x41
116 
117 u_char sample[] = {
118 	'M','T','h','d',  0,0,0,6,  0,1,  0,1,  0,8,
119 	'M','T','r','k',  0,0,0,4+13*8,
120 	P(C), P(C), P(C), P(E), P(D), P(D), P(D),
121 	P(F), P(E), P(E), P(D), P(D), PL(C),
122 	0, 0xff, 0x2f, 0
123 };
124 #undef P
125 #undef PL
126 #undef C
127 #undef D
128 #undef E
129 #undef F
130 
131 #define MARK_HEADER "MThd"
132 #define MARK_TRACK "MTrk"
133 #define MARK_LEN 4
134 
135 #define	RMID_SIG "RIFF"
136 #define	RMID_MIDI_ID "RMID"
137 #define	RMID_DATA_ID "data"
138 
139 #define SIZE_LEN 4
140 #define HEADER_LEN 6
141 
142 #define GET8(p) ((p)[0])
143 #define GET16(p) (((p)[0] << 8) | (p)[1])
144 #define GET24(p) (((p)[0] << 16) | ((p)[1] << 8) | (p)[2])
145 #define GET32(p) (((p)[0] << 24) | ((p)[1] << 16) | ((p)[2] << 8) | (p)[3])
146 #define GET32_LE(p) (((p)[3] << 24) | ((p)[2] << 16) | ((p)[1] << 8) | (p)[0])
147 
148 void
149 usage(void)
150 {
151 	printf("usage: %s [-d unit] [-f file] [-l] [-m] [-p pgm] [-q] "
152 	       "[-t %%tempo] [-v] [-x] [file ...]\n",
153 		getprogname());
154 	exit(1);
155 }
156 
157 int showmeta = 0;
158 int verbose = 0;
159 #define BASETEMPO 400000		/* us/beat(=24 clks or qn) (150 bpm) */
160 u_int tempo_set = 0;
161 u_int tempo_abs = 0;
162 u_int ttempo = 100;
163 int unit = 0;
164 int play = 1;
165 int fd = -1;
166 int sameprogram = 0;
167 int insysex = 0;
168 int svsysex = 0; /* number of sysex bytes saved internally */
169 
170 void
171 send_event(seq_event_t *ev)
172 {
173 	/*
174 	printf("%02x %02x %02x %02x %02x %02x %02x %02x\n",
175 	       ev->arr[0], ev->arr[1], ev->arr[2], ev->arr[3],
176 	       ev->arr[4], ev->arr[5], ev->arr[6], ev->arr[7]);
177 	*/
178 	if (play)
179 		write(fd, ev, sizeof *ev);
180 }
181 
182 u_long
183 getvar(struct track *tp)
184 {
185 	u_long r, c;
186 
187 	r = 0;
188 	do {
189 		c = *tp->start++;
190 		r = (r << 7) | (c & 0x7f);
191 	} while ((c & 0x80) && tp->start < tp->end);
192 	return r;
193 }
194 
195 u_long
196 getlen(struct track *tp)
197 {
198 	u_long len;
199 	len = getvar(tp);
200 	if (tp->start + len > tp->end)
201 		errx(1, "bogus item length exceeds remaining track size");
202 	return len;
203 }
204 
205 void
206 dometa(u_int meta, u_char *p, u_int len)
207 {
208 	static char const * const keys[] = {
209 	        "Cb", "Gb", "Db", "Ab", "Eb", "Bb", "F",
210 		"C",
211 		"G", "D", "A", "E", "B", "F#", "C#",
212 		"G#", "D#", "A#" /* for minors */
213 	};
214 	seq_event_t ev;
215 	uint32_t usperbeat;
216 
217 	switch (meta) {
218 	case META_TEXT:
219 	case META_COPYRIGHT:
220 	case META_TRACK:
221 	case META_INSTRUMENT:
222 	case META_LYRIC:
223 	case META_MARKER:
224 	case META_CUE:
225 		if (showmeta) {
226 			printf("%s: ", metanames[meta]);
227 			fwrite(p, len, 1, stdout);
228 			printf("\n");
229 		}
230 		break;
231 	case META_SET_TEMPO:
232 		usperbeat = GET24(p);
233 		ev = SEQ_MK_TIMING(TEMPO,
234 		    .bpm=(60000000. / usperbeat) * (ttempo / 100.) + 0.5);
235 		if (showmeta)
236 			printf("Tempo: %u us/'beat'(24 midiclks)"
237 			       " at %u%%; adjusted bpm = %u\n",
238 			       usperbeat, ttempo, ev.t_TEMPO.bpm);
239 		if (tempo_abs)
240 			warnx("tempo event ignored"
241 			      " in absolute-timed MIDI file");
242 		else {
243 			send_event(&ev);
244 			if (!tempo_set) {
245 				tempo_set = 1;
246 				send_event(&SEQ_MK_TIMING(START));
247 			}
248 		}
249 		break;
250 	case META_TIMESIGN:
251 		ev = SEQ_MK_TIMING(TIMESIG,
252 		    .numerator=p[0],      .lg2denom=p[1],
253 		    .clks_per_click=p[2], .dsq_per_24clks=p[3]);
254 		if (showmeta) {
255 			printf("Time signature: %d/%d."
256 			       " Click every %d midiclk%s"
257 			       " (24 midiclks = %d 32nd note%s)\n",
258 			       ev.t_TIMESIG.numerator,
259 			       1 << ev.t_TIMESIG.lg2denom,
260 			       ev.t_TIMESIG.clks_per_click,
261 			       1 == ev.t_TIMESIG.clks_per_click ? "" : "s",
262 			       ev.t_TIMESIG.dsq_per_24clks,
263 			       1 == ev.t_TIMESIG.dsq_per_24clks ? "" : "s");
264 		}
265 		/* send_event(&ev); not implemented in sequencer */
266 		break;
267 	case META_KEY:
268 		if (showmeta)
269 			printf("Key: %s %s\n",
270 			       keys[((char)p[0]) + p[1] ? 10 : 7],
271 			       p[1] ? "minor" : "major");
272 		break;
273 	default:
274 		break;
275 	}
276 }
277 
278 void
279 midireset(void)
280 {
281 	/* General MIDI reset sequence */
282 	send_event(&SEQ_MK_SYSEX(unit,[0]=0x7e, 0x7f, 0x09, 0x01, 0xf7));
283 }
284 
285 #define SYSEX_CHUNK 6
286 void
287 send_sysex(u_char *p, u_int l)
288 {
289 	seq_event_t event;
290 	static u_char bf[6];
291 
292 	if ( 0 == l ) {
293 		warnx("zero-length system-exclusive event");
294 		return;
295 	}
296 
297 	/*
298 	 * This block is needed only to handle the possibility that a sysex
299 	 * message is broken into multiple events in a MIDI file that do not
300 	 * have length six; the /dev/music sequencer assumes a sysex message is
301 	 * finished with the first SYSEX event carrying fewer than six bytes,
302 	 * even if the last is not MIDI_SYSEX_END. So, we need to be careful
303 	 * not to send a short sysex event until we have seen the end byte.
304 	 * Instead, save some straggling bytes in bf, and send when we have a
305 	 * full six (or an end byte). Note bf/saved/insysex should be per-
306 	 * device, if we supported output to more than one device at a time.
307 	 */
308 	if ( svsysex > 0 ) {
309 		if ( l > sizeof bf - svsysex ) {
310 			memcpy(bf + svsysex, p, sizeof bf - svsysex);
311 			l -= sizeof bf - svsysex;
312 			p += sizeof bf - svsysex;
313 			send_event(&SEQ_MK_SYSEX(unit,[0]=
314 			    bf[0],bf[1],bf[2],bf[3],bf[4],bf[5]));
315 			svsysex = 0;
316 		} else {
317 			memcpy(bf + svsysex, p, l);
318 			svsysex += l;
319 			p += l;
320 			if ( MIDI_SYSEX_END == bf[svsysex-1] ) {
321 				event = SEQ_MK_SYSEX(unit);
322 				memcpy(event.sysex.buffer, bf, svsysex);
323 				send_event(&event);
324 				svsysex = insysex = 0;
325 			} else
326 				insysex = 1;
327 			return;
328 		}
329 	}
330 
331 	/*
332 	 * l > 0. May as well test now whether we will be left 'insysex'
333 	 * after processing this event.
334 	 */
335 	insysex = ( MIDI_SYSEX_END != p[l-1] );
336 
337 	/*
338 	 * If not for multi-event sysexes and chunk-size weirdness, this
339 	 * function could pretty much start here. :)
340 	 */
341 	while ( l >= SYSEX_CHUNK ) {
342 		send_event(&SEQ_MK_SYSEX(unit,[0]=
343 		    p[0],p[1],p[2],p[3],p[4],p[5]));
344 		p += SYSEX_CHUNK;
345 		l -= SYSEX_CHUNK;
346 	}
347 	if ( l > 0 ) {
348 		if ( insysex ) {
349 			memcpy(bf, p, l);
350 			svsysex = l;
351 		} else { /* a <6 byte chunk is ok if it's REALLY the end */
352 			event = SEQ_MK_SYSEX(unit);
353 			memcpy(event.sysex.buffer, p, l);
354 			send_event(&event);
355 		}
356 	}
357 }
358 
359 void
360 playfile(FILE *f, char *name)
361 {
362 	u_char *buf, *nbuf;
363 	u_int tot, n, size, nread;
364 
365 	/*
366 	 * We need to read the whole file into memory for easy processing.
367 	 * Using mmap() would be nice, but some file systems do not support
368 	 * it, nor does reading from e.g. a pipe.  The latter also precludes
369 	 * finding out the file size without reading it.
370 	 */
371 	size = 1000;
372 	buf = malloc(size);
373 	if (buf == 0)
374 		errx(1, "malloc() failed");
375 	nread = size;
376 	tot = 0;
377 	for (;;) {
378 		n = fread(buf + tot, 1, nread, f);
379 		tot += n;
380 		if (n < nread)
381 			break;
382 		/* There must be more to read. */
383 		nread = size;
384 		nbuf = realloc(buf, size * 2);
385 		if (nbuf == NULL)
386 			errx(1, "realloc() failed");
387 		buf = nbuf;
388 		size *= 2;
389 	}
390 	playdata(buf, tot, name);
391 	free(buf);
392 }
393 
394 void
395 playdata(u_char *buf, u_int tot, char *name)
396 {
397 	int format, ntrks, divfmt, ticks, t;
398 	u_int len, mlen, status, chan;
399 	u_char *p, *end, byte, meta, *msg;
400 	struct track *tracks;
401 	struct track *tp;
402 
403 	end = buf + tot;
404 	if (verbose)
405 		printf("Playing %s (%d bytes) ... \n", name, tot);
406 
407 	if (tot < MARK_LEN + 4) {
408 		warnx("Not a MIDI file, too short");
409 		return;
410 	}
411 
412 	if (memcmp(buf, RMID_SIG, MARK_LEN) == 0) {
413 		u_char *eod;
414 		/* Detected a RMID file, let's just check if it's
415 		 * a MIDI file */
416 		if (GET32_LE(buf + MARK_LEN) != tot - 8) {
417 			warnx("Not a RMID file, bad header");
418 			return;
419 		}
420 
421 		buf += MARK_LEN + 4;
422 		if (memcmp(buf, RMID_MIDI_ID, MARK_LEN) != 0) {
423 			warnx("Not a RMID file, bad ID");
424 			return;
425 		}
426 
427 		/* Now look for the 'data' chunk, which contains
428 		 * MIDI data */
429 		buf += MARK_LEN;
430 
431 		/* Test against end-8 since we must have at least 8 bytes
432 		 * left to read */
433 		while(buf < end-8 && memcmp(buf, RMID_DATA_ID, MARK_LEN))
434 			buf += GET32_LE(buf+4) + 8; /* MARK_LEN + 4 */
435 
436 		if (buf >= end-8) {
437 			warnx("Not a valid RMID file, no data chunk");
438 			return;
439 		}
440 
441 		buf += MARK_LEN; /* "data" */
442 		eod = buf + 4 + GET32_LE(buf);
443 		if (eod >= end) {
444 			warnx("Not a valid RMID file, bad data chunk size");
445 			return;
446 		}
447 
448 		end = eod;
449 		buf += 4;
450 	}
451 
452 	if (memcmp(buf, MARK_HEADER, MARK_LEN) != 0) {
453 		warnx("Not a MIDI file, missing header");
454 		return;
455 	}
456 
457 	if (GET32(buf + MARK_LEN) != HEADER_LEN) {
458 		warnx("Not a MIDI file, bad header");
459 		return;
460 	}
461 	format = GET16(buf + MARK_LEN + SIZE_LEN);
462 	ntrks = GET16(buf + MARK_LEN + SIZE_LEN + 2);
463 	divfmt = GET8(buf + MARK_LEN + SIZE_LEN + 4);
464 	ticks = GET8(buf + MARK_LEN + SIZE_LEN + 5);
465 	p = buf + MARK_LEN + SIZE_LEN + HEADER_LEN;
466 	/*
467 	 * Set the timebase (or timebase and tempo, for absolute-timed files).
468 	 * PORTABILITY: some sequencers actually check the timebase against
469 	 * available timing sources and may adjust it accordingly (storing a
470 	 * new value in the ioctl arg) which would require us to compensate
471 	 * somehow. That possibility is ignored for now, as NetBSD's sequencer
472 	 * currently synthesizes all timebases, for better or worse, from the
473 	 * system clock.
474 	 *
475 	 * For a non-absolute file, if timebase is set to the file's divisions
476 	 * value, and tempo set in the obvious way, then the timing deltas in
477 	 * the MTrks require no scaling. A downside to this approach is that
478 	 * the sequencer API wants tempo in (integer) beats per minute, which
479 	 * limits how finely tempo can be specified. That might be got around
480 	 * in some cases by frobbing tempo and timebase more obscurely, but this
481 	 * player is meant to be simple and clear.
482 	 */
483 	if ((divfmt & 0x80) == 0) {
484 		ticks |= divfmt << 8;
485 		if (ioctl(fd, SEQUENCER_TMR_TIMEBASE, &(int){ticks}) < 0)
486 			err(1, "SEQUENCER_TMR_TIMEBASE");
487 	} else {
488 		tempo_abs = tempo_set = 1;
489 		divfmt = -(int8_t)divfmt;
490 		/*
491 		 * divfmt is frames per second; multiplying by 60 to set tempo
492 		 * in frames per minute could exceed sequencer's (arbitrary)
493 		 * tempo limits, so factor 60 as 12*5, set tempo in frames per
494 		 * 12 seconds, and account for the 5 in timebase.
495 		 */
496 		send_event(&SEQ_MK_TIMING(TEMPO,
497 		    .bpm=(12*divfmt) * (ttempo/100.) + 0.5));
498 		if (ioctl(fd, SEQUENCER_TMR_TIMEBASE, &(int){5*ticks}) < 0)
499 			err(1, "SEQUENCER_TMR_TIMEBASE");
500 	}
501 	if (verbose > 1)
502 		printf(tempo_abs ?
503 		       "format=%d ntrks=%d abs fps=%u subdivs=%u\n" :
504 		       "format=%d ntrks=%d divisions=%u\n",
505 		       format, ntrks, tempo_abs ? divfmt : ticks, ticks);
506 	if (format != 0 && format != 1) {
507 		warnx("Cannot play MIDI file of type %d", format);
508 		return;
509 	}
510 	if (ntrks == 0)
511 		return;
512 	tracks = malloc(ntrks * sizeof(struct track));
513 	if (tracks == NULL)
514 		errx(1, "malloc() tracks failed");
515 	for (t = 0; t < ntrks; ) {
516 		if (p >= end - MARK_LEN - SIZE_LEN) {
517 			warnx("Cannot find track %d", t);
518 			goto ret;
519 		}
520 		len = GET32(p + MARK_LEN);
521 		if (len > 1000000) { /* a safe guard */
522 			warnx("Crazy track length");
523 			goto ret;
524 		}
525 		if (memcmp(p, MARK_TRACK, MARK_LEN) == 0) {
526 			tracks[t].start = p + MARK_LEN + SIZE_LEN;
527 			tracks[t].end = tracks[t].start + len;
528 			tracks[t].delta = getvar(&tracks[t]);
529 			tracks[t].indirect = &tracks[t]; /* -> self for now */
530 			t++;
531 		}
532 		p += MARK_LEN + SIZE_LEN + len;
533 	}
534 
535 	/*
536 	 * Force every channel to the same patch if requested by the user.
537 	 */
538 	if (sameprogram) {
539 		for(t = 0; t < 16; t++) {
540 			send_event(&SEQ_MK_CHN(PGM_CHANGE, .device=unit,
541 			    .channel=t, .program=sameprogram-1));
542 		}
543 	}
544 	/*
545 	 * Play MIDI events by selecting the track with the lowest
546 	 * delta.  Execute the event, update the delta and repeat.
547 	 *
548 	 * The ticks variable is the number of ticks that make up a beat
549 	 * (beat: 24 MIDI clocks always, a quarter note by usual convention)
550 	 * and is used as a reference value for the delays between
551 	 * the MIDI events.
552 	 */
553 	BuildHeap(tracks, ntrks); /* tracks[0].indirect is always next */
554 	for (;;) {
555 		tp = tracks[0].indirect;
556 		if ((verbose > 2 && tp->delta > 0)  ||  verbose > 3) {
557 			printf("DELAY %4ld TRACK %2td%s",
558 			       tp->delta, tp - tracks, verbose>3?" ":"\n");
559 			fflush(stdout);
560 		}
561 		if (tp->delta > 0) {
562 			if (!tempo_set) {
563 				if (verbose || showmeta)
564 					printf("No initial tempo;"
565 					       " defaulting:\n");
566 				dometa(META_SET_TEMPO, (u_char[]){
567 				    BASETEMPO >> 16,
568 				    (BASETEMPO >> 8) & 0xff,
569 				    BASETEMPO & 0xff},
570 				    3);
571 			}
572 			send_event(&SEQ_MK_TIMING(WAIT_REL,
573 			    .divisions=tp->delta));
574 		}
575 		byte = *tp->start++;
576 		if (byte == MIDI_META) {
577 			meta = *tp->start++;
578 			mlen = getlen(tp);
579 			if (verbose > 3)
580 				printf("META %02x (%d)\n", meta, mlen);
581 			dometa(meta, tp->start, mlen);
582 			tp->start += mlen;
583 		} else {
584 			if (MIDI_IS_STATUS(byte))
585 				tp->status = byte;
586 			else
587 				tp->start--;
588 			mlen = MIDI_LENGTH(tp->status);
589 			msg = tp->start;
590 			if (verbose > 3) {
591 			    if (mlen == 1)
592 				printf("MIDI %02x (%d) %02x\n",
593 				       tp->status, mlen, msg[0]);
594 			    else
595 				printf("MIDI %02x (%d) %02x %02x\n",
596 				       tp->status, mlen, msg[0], msg[1]);
597 			}
598 			if (insysex && tp->status != MIDI_SYSEX_END) {
599 				warnx("incomplete system exclusive message"
600 				      " aborted");
601 				svsysex = insysex = 0;
602 			}
603 			status = MIDI_GET_STATUS(tp->status);
604 			chan = MIDI_GET_CHAN(tp->status);
605 			switch (status) {
606 			case MIDI_NOTEOFF:
607 				send_event(&SEQ_MK_CHN(NOTEOFF, .device=unit,
608 				.channel=chan, .key=msg[0], .velocity=msg[1]));
609 				break;
610 			case MIDI_NOTEON:
611 				send_event(&SEQ_MK_CHN(NOTEON, .device=unit,
612 				.channel=chan, .key=msg[0], .velocity=msg[1]));
613 				break;
614 			case MIDI_KEY_PRESSURE:
615 				send_event(&SEQ_MK_CHN(KEY_PRESSURE,
616 				.device=unit, .channel=chan,
617 				.key=msg[0], .pressure=msg[1]));
618 				break;
619 			case MIDI_CTL_CHANGE:
620 				send_event(&SEQ_MK_CHN(CTL_CHANGE,
621 				.device=unit, .channel=chan,
622 				.controller=msg[0], .value=msg[1]));
623 				break;
624 			case MIDI_PGM_CHANGE:
625 				if (!sameprogram)
626 					send_event(&SEQ_MK_CHN(PGM_CHANGE,
627 					.device=unit, .channel=chan,
628 					.program=msg[0]));
629 				break;
630 			case MIDI_CHN_PRESSURE:
631 				send_event(&SEQ_MK_CHN(CHN_PRESSURE,
632 				.device=unit, .channel=chan, .pressure=msg[0]));
633 				break;
634 			case MIDI_PITCH_BEND:
635 				send_event(&SEQ_MK_CHN(PITCH_BEND,
636 				.device=unit, .channel=chan,
637 				.value=(msg[0] & 0x7f) | ((msg[1] & 0x7f)<<7)));
638 				break;
639 			case MIDI_SYSTEM_PREFIX:
640 				mlen = getlen(tp);
641 				if (tp->status == MIDI_SYSEX_START) {
642 					send_sysex(tp->start, mlen);
643 					break;
644 				} else if (tp->status == MIDI_SYSEX_END) {
645 				/* SMF uses SYSEX_END as CONTINUATION/ESCAPE */
646 					if (insysex) { /* CONTINUATION */
647 						send_sysex(tp->start, mlen);
648 					} else { /* ESCAPE */
649 						for ( ; mlen > 0 ; -- mlen ) {
650 							send_event(
651 							    &SEQ_MK_EVENT(putc,
652 							    SEQOLD_MIDIPUTC,
653 							    .device=unit,
654 							    .byte=*(tp->start++)
655 							    ));
656 						}
657 					}
658 					break;
659 				}
660 				/* Sorry, can't do this yet; FALLTHROUGH */
661 			default:
662 				if (verbose)
663 					printf("MIDI event 0x%02x ignored\n",
664 					       tp->status);
665 			}
666 			tp->start += mlen;
667 		}
668 		if (tp->start >= tp->end) {
669 			ntrks = ShrinkHeap(tracks, ntrks); /* track gone */
670 			if (0 == ntrks)
671 				break;
672 		} else
673 			tp->delta = getvar(tp);
674 		Heapify(tracks, ntrks, 0);
675 	}
676 	if (ioctl(fd, SEQUENCER_SYNC, 0) < 0)
677 		err(1, "SEQUENCER_SYNC");
678 
679  ret:
680 	free(tracks);
681 }
682 
683 int
684 main(int argc, char **argv)
685 {
686 	int ch;
687 	int listdevs = 0;
688 	int example = 0;
689 	int nmidi;
690 	const char *file = DEVMUSIC;
691 	const char *sunit;
692 	struct synth_info info;
693 	FILE *f;
694 
695 	if ((sunit = getenv("MIDIUNIT")))
696 		unit = atoi(sunit);
697 
698 	while ((ch = getopt(argc, argv, "?d:f:lmp:qt:vx")) != -1) {
699 		switch(ch) {
700 		case 'd':
701 			unit = atoi(optarg);
702 			break;
703 		case 'f':
704 			file = optarg;
705 			break;
706 		case 'l':
707 			listdevs++;
708 			break;
709 		case 'm':
710 			showmeta++;
711 			break;
712 		case 'p':
713 			sameprogram = atoi(optarg);
714 			break;
715 		case 'q':
716 			play = 0;
717 			break;
718 		case 't':
719 			ttempo = atoi(optarg);
720 			break;
721 		case 'v':
722 			verbose++;
723 			break;
724 		case 'x':
725 			example++;
726 			break;
727 		case '?':
728 		default:
729 			usage();
730 		}
731 	}
732 	argc -= optind;
733 	argv += optind;
734 
735 	if (!play)
736 		goto output;
737 
738 	fd = open(file, O_WRONLY);
739 	if (fd < 0)
740 		err(1, "%s", file);
741 	if (ioctl(fd, SEQUENCER_NRMIDIS, &nmidi) < 0)
742 		err(1, "ioctl(SEQUENCER_NRMIDIS) failed, ");
743 	if (nmidi == 0)
744 		errx(1, "Sorry, no MIDI devices available");
745 	if (listdevs) {
746 		for (info.device = 0; info.device < nmidi; info.device++) {
747 			if (ioctl(fd, SEQUENCER_INFO, &info) < 0)
748 				err(1, "ioctl(SEQUENCER_INFO) failed, ");
749 			printf("%d: %s\n", info.device, info.name);
750 		}
751 		exit(0);
752 	}
753 
754  output:
755 	if (example)
756 		while (example--)
757 			playdata(sample, sizeof sample, "<Gubben Noa>");
758 	else if (argc == 0)
759 		playfile(stdin, "<stdin>");
760 	else
761 		while (argc--) {
762 			f = fopen(*argv, "r");
763 			if (f == NULL)
764 				err(1, "%s", *argv);
765 			else {
766 				playfile(f, *argv);
767 				fclose(f);
768 			}
769 			argv++;
770 		}
771 
772 	exit(0);
773 }
774 
775 /*
776  * relative-time priority queue (min-heap). Properties:
777  * 1. The delta time at a node is relative to the node's parent's time.
778  * 2. When an event is dequeued from a track, the delta time of the new head
779  *    event is relative to the time of the event just dequeued.
780  * Therefore:
781  * 3. After dequeueing the head event from the track at heap root, the next
782  *    event's time is directly comparable to the root's children.
783  * These properties allow the heap to be maintained with delta times throughout.
784  * Insert is also implementable, but not needed: all the tracks are present
785  * at first; they just go away as they end.
786  */
787 
788 #define PARENT(i) ((i-1)>>1)
789 #define LEFT(i)   ((i<<1)+1)
790 #define RIGHT(i)  ((i+1)<<1)
791 #define DTIME(i)  (t[i].indirect->delta)
792 #define SWAP(i,j) do { \
793     struct track *_t = t[i].indirect; \
794     t[i].indirect = t[j].indirect; \
795     t[j].indirect = _t; \
796     } while ( /*CONSTCOND*/ 0 )
797 
798 void
799 Heapify(struct track *t, int ntrks, int node)
800 {
801 	int lc, rc, mn;
802 
803 	lc = LEFT(node);
804 	rc = RIGHT(node);
805 
806 	if (rc >= ntrks) {			/* no right child */
807 		if (lc >= ntrks)		/* node is a leaf */
808 			return;
809 		if (DTIME(node) > DTIME(lc))
810 			SWAP(node,lc);
811 		DTIME(lc) -= DTIME(node);
812 		return;				/* no rc ==> lc is a leaf */
813 	}
814 
815 	mn = lc;
816 	if (DTIME(lc) > DTIME(rc))
817 		mn = rc;
818 	if (DTIME(node) <= DTIME(mn)) {
819 		DTIME(rc) -= DTIME(node);
820 		DTIME(lc) -= DTIME(node);
821 		return;
822 	}
823 
824 	SWAP(node,mn);
825 	DTIME(rc) -= DTIME(node);
826 	DTIME(lc) -= DTIME(node);
827 	Heapify(t, ntrks, mn); /* gcc groks tail recursion */
828 }
829 
830 void
831 BuildHeap(struct track *t, int ntrks)
832 {
833 	int node;
834 
835 	for ( node = PARENT(ntrks-1); node --> 0; )
836 		Heapify(t, ntrks, node);
837 }
838 
839 /*
840  * Make the heap 1 item smaller by discarding the track at the root. Move the
841  * rightmost bottom-level leaf to the root and decrement ntrks. It remains to
842  * run Heapify, which the caller is expected to do. Returns the new ntrks.
843  */
844 int
845 ShrinkHeap(struct track *t, int ntrks)
846 {
847 	int ancest;
848 
849 	-- ntrks;
850 	for ( ancest = PARENT(ntrks); ancest > 0; ancest = PARENT(ancest) )
851 		DTIME(ntrks) += DTIME(ancest);
852 	t[0].indirect = t[ntrks].indirect;
853 	return ntrks;
854 }
855