midirecord.c revision 1.9 1 /* $NetBSD: midirecord.c,v 1.9 2015/06/21 06:04:45 mrg Exp $ */
2
3 /*
4 * Copyright (c) 2014 Matthew R. Green
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 /*
30 * midirecord(1), similar to audiorecord(1).
31 */
32
33 #include <sys/cdefs.h>
34
35 #ifndef lint
36 __RCSID("$NetBSD: midirecord.c,v 1.9 2015/06/21 06:04:45 mrg Exp $");
37 #endif
38
39 #include <sys/param.h>
40 #include <sys/midiio.h>
41 #include <sys/ioctl.h>
42 #include <sys/time.h>
43 #include <sys/uio.h>
44
45 #include <err.h>
46 #include <errno.h>
47 #include <ctype.h>
48 #include <fcntl.h>
49 #include <paths.h>
50 #include <signal.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55 #include <util.h>
56 #include <assert.h>
57 #include <stdbool.h>
58
59 #include "libaudio.h"
60
61 static const char *midi_device;
62 static unsigned *filt_devnos = NULL;
63 static unsigned *filt_chans = NULL;
64 static unsigned num_filt_devnos, num_filt_chans;
65 static char *raw_output;
66 static int midifd;
67 static int aflag, qflag, oflag;
68 static bool debug = false;
69 int verbose;
70 static int outfd, rawfd = -1;
71 static ssize_t data_size;
72 static struct timeval record_time;
73 static struct timeval start_time;
74 static int tempo = 120;
75 static unsigned notes_per_beat = 24;
76 static bool ignore_timer_fail = false;
77 static bool stdout_mode = false;
78
79 static void debug_log(const char *, size_t, const char *, ...)
80 __printflike(3, 4);
81 static size_t midi_event_local_to_output(seq_event_t, u_char *, size_t);
82 static size_t midi_event_timer_wait_abs_to_output(seq_event_t, u_char *,
83 size_t);
84 static size_t midi_event_timer_to_output(seq_event_t, u_char *, size_t);
85 static size_t midi_event_chn_common_to_output(seq_event_t, u_char *, size_t);
86 static size_t midi_event_chn_voice_to_output(seq_event_t, u_char *, size_t);
87 static size_t midi_event_sysex_to_output(seq_event_t, u_char *, size_t);
88 static size_t midi_event_fullsize_to_output(seq_event_t, u_char *, size_t);
89 static size_t midi_event_to_output(seq_event_t, u_char *, size_t);
90 static int timeleft(struct timeval *, struct timeval *);
91 static bool filter_array(unsigned, unsigned *, size_t);
92 static bool filter_dev(unsigned);
93 static bool filter_chan(unsigned);
94 static bool filter_devchan(unsigned, unsigned);
95 static void parse_ints(const char *, unsigned **, unsigned *, const char *);
96 static void cleanup(int) __dead;
97 static void rewrite_header(void);
98 static void write_midi_header(void);
99 static void write_midi_trailer(void);
100 static void usage(void) __dead;
101
102 #define PATH_DEV_MUSIC "/dev/music"
103
104 int
105 main(int argc, char *argv[])
106 {
107 u_char *buffer;
108 size_t bufsize = 0;
109 int ch, no_time_limit = 1;
110
111 while ((ch = getopt(argc, argv, "aB:c:Dd:f:hn:oqr:t:T:V")) != -1) {
112 switch (ch) {
113 case 'a':
114 aflag++;
115 break;
116 case 'B':
117 bufsize = strsuftoll("read buffer size", optarg,
118 1, UINT_MAX);
119 break;
120 case 'c':
121 parse_ints(optarg, &filt_chans, &num_filt_chans,
122 "channels");
123 break;
124 case 'D':
125 debug = true;
126 break;
127 case 'd':
128 parse_ints(optarg, &filt_devnos, &num_filt_devnos,
129 "devices");
130 break;
131 case 'f':
132 midi_device = optarg;
133 ignore_timer_fail = true;
134 break;
135 case 'n':
136 decode_uint(optarg, ¬es_per_beat);
137 break;
138 case 'o':
139 oflag++; /* time stamp starts at proc start */
140 break;
141 case 'q':
142 qflag++;
143 break;
144 case 'r':
145 raw_output = optarg;
146 break;
147 case 't':
148 no_time_limit = 0;
149 decode_time(optarg, &record_time);
150 break;
151 case 'T':
152 decode_int(optarg, &tempo);
153 break;
154 case 'V':
155 verbose++;
156 break;
157 /* case 'h': */
158 default:
159 usage();
160 /* NOTREACHED */
161 }
162 }
163 argc -= optind;
164 argv += optind;
165
166 if (argc != 1)
167 usage();
168
169 /*
170 * work out the buffer size to use, and allocate it. don't allow it
171 * to be too small.
172 */
173 if (bufsize < 32)
174 bufsize = 32 * 1024;
175 buffer = malloc(bufsize);
176 if (buffer == NULL)
177 err(1, "couldn't malloc buffer of %d size", (int)bufsize);
178
179 /*
180 * open the music device
181 */
182 if (midi_device == NULL && (midi_device = getenv("MIDIDEVICE")) == NULL)
183 midi_device = PATH_DEV_MUSIC;
184 midifd = open(midi_device, O_RDONLY);
185 if (midifd < 0)
186 err(1, "failed to open %s", midi_device);
187
188 /* open the output file */
189 if (argv[0][0] != '-' || argv[0][1] != '\0') {
190 int mode = O_CREAT|(aflag ? O_APPEND : O_TRUNC)|O_WRONLY;
191
192 outfd = open(*argv, mode, 0666);
193 if (outfd < 0)
194 err(1, "could not open %s", *argv);
195 } else {
196 stdout_mode = true;
197 outfd = STDOUT_FILENO;
198 }
199
200 /* open the raw output file */
201 if (raw_output) {
202 int mode = O_CREAT|(aflag ? O_APPEND : O_TRUNC)|O_WRONLY;
203
204 rawfd = open(raw_output, mode, 0666);
205 if (rawfd < 0)
206 err(1, "could not open %s", raw_output);
207 }
208
209 /* start the midi timer */
210 if (ioctl(midifd, SEQUENCER_TMR_START, NULL) < 0) {
211 if (ignore_timer_fail)
212 warn("failed to start midi timer");
213 else
214 err(1, "failed to start midi timer");
215 }
216
217 /* set the timebase */
218 if (ioctl(midifd, SEQUENCER_TMR_TIMEBASE, ¬es_per_beat) < 0) {
219 if (ignore_timer_fail)
220 warn("SEQUENCER_TMR_TIMEBASE: notes_per_beat %d",
221 notes_per_beat);
222 else
223 err(1, "SEQUENCER_TMR_TIMEBASE: notes_per_beat %d",
224 notes_per_beat);
225 }
226
227 /* set the tempo */
228 if (ioctl(midifd, SEQUENCER_TMR_TEMPO, &tempo) < 0) {
229 if (ignore_timer_fail)
230 warn("SEQUENCER_TMR_TIMEBASE: tempo %d", tempo);
231 else
232 err(1, "SEQUENCER_TMR_TIMEBASE: tempo %d", tempo);
233 }
234
235 signal(SIGINT, cleanup);
236
237 data_size = 0;
238
239 if (verbose)
240 fprintf(stderr, "tempo=%d notes_per_beat=%u\n",
241 tempo, notes_per_beat);
242
243 if (!no_time_limit && verbose)
244 fprintf(stderr, "recording for %lu seconds, %lu microseconds\n",
245 (u_long)record_time.tv_sec, (u_long)record_time.tv_usec);
246
247 /* Create a midi header. */
248 write_midi_header();
249
250 (void)gettimeofday(&start_time, NULL);
251 while (no_time_limit || timeleft(&start_time, &record_time)) {
252 seq_event_t e;
253 size_t wrsize;
254 size_t rdsize;
255
256 rdsize = (size_t)read(midifd, &e, sizeof e);
257 if (rdsize == 0)
258 break;
259
260 if (rdsize != sizeof e)
261 err(1, "read failed");
262
263 if (rawfd != -1 && write(rawfd, &e, sizeof e) != sizeof e)
264 err(1, "write to raw file failed");
265
266 /* convert 'e' into something useful for output */
267 wrsize = midi_event_to_output(e, buffer, bufsize);
268
269 if (wrsize) {
270 if ((size_t)write(outfd, buffer, wrsize) != wrsize)
271 err(1, "write failed");
272 data_size += wrsize;
273 }
274 }
275 cleanup(0);
276 }
277
278 static void
279 debug_log(const char *file, size_t line, const char *fmt, ...)
280 {
281 va_list ap;
282
283 if (!debug)
284 return;
285 fprintf(stderr, "%s:%zu: ", file, line);
286 va_start(ap, fmt);
287 vfprintf(stderr, fmt, ap);
288 va_end(ap);
289 fprintf(stderr, "\n");
290 }
291
292 #define LOG(fmt...) \
293 debug_log(__func__, __LINE__, fmt)
294
295
296 /*
297 * handle a SEQ_LOCAL event. NetBSD /dev/music doesn't generate these.
298 */
299 static size_t
300 midi_event_local_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
301 {
302 size_t size = 0;
303
304 LOG("UNHANDLED SEQ_LOCAL");
305
306 return size;
307 }
308
309 /*
310 * convert a midi absolute time event to a variable length delay
311 */
312 static size_t
313 midi_event_timer_wait_abs_to_output(
314 seq_event_t e,
315 u_char *buffer,
316 size_t bufsize)
317 {
318 static unsigned prev_div;
319 unsigned cur_div;
320 unsigned val = 0, xdiv;
321 int vallen = 0, i;
322
323 if (prev_div == 0 && !oflag)
324 prev_div = e.t_WAIT_ABS.divisions;
325 cur_div = e.t_WAIT_ABS.divisions;
326
327 xdiv = cur_div - prev_div;
328 if (xdiv) {
329 while (xdiv) {
330 uint32_t extra = val ? 0x80 : 0;
331
332 val <<= 8;
333 val |= (xdiv & 0x7f) | extra;
334 xdiv >>= 7;
335 vallen++;
336 }
337 } else
338 vallen = 1;
339
340 for (i = 0; i < vallen; i++) {
341 buffer[i] = val & 0xff;
342 val >>= 8;
343 }
344 for (; i < 4; i++)
345 buffer[i] = 0;
346 LOG("TMR_WAIT_ABS: new div %x (cur %x prev %x): bufval (len=%u): "
347 "%02x:%02x:%02x:%02x",
348 cur_div - prev_div, cur_div, prev_div,
349 vallen, buffer[0], buffer[1], buffer[2], buffer[3]);
350
351 prev_div = cur_div;
352
353 return vallen;
354 }
355
356 /*
357 * handle a SEQ_TIMING event.
358 */
359 static size_t
360 midi_event_timer_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
361 {
362 size_t size = 0;
363
364 LOG("SEQ_TIMING");
365 switch (e.timing.op) {
366 case TMR_WAIT_REL:
367 /* NetBSD /dev/music doesn't generate these. */
368 LOG("UNHANDLED TMR_WAIT_REL: divisions: %x", e.t_WAIT_REL.divisions);
369 break;
370
371 case TMR_WAIT_ABS:
372 size = midi_event_timer_wait_abs_to_output(e, buffer, bufsize);
373 break;
374
375 case TMR_STOP:
376 case TMR_START:
377 case TMR_CONTINUE:
378 case TMR_TEMPO:
379 case TMR_ECHO:
380 case TMR_CLOCK:
381 case TMR_SPP:
382 case TMR_TIMESIG:
383 /* NetBSD /dev/music doesn't generate these. */
384 LOG("UNHANDLED timer op: %x", e.timing.op);
385 break;
386
387 default:
388 LOG("unknown timer op: %x", e.timing.op);
389 break;
390 }
391
392 return size;
393 }
394
395 /*
396 * handle a SEQ_CHN_COMMON event.
397 */
398 static size_t
399 midi_event_chn_common_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
400 {
401 size_t size = 0;
402
403 assert(e.common.channel < 16);
404 LOG("SEQ_CHN_COMMON");
405
406 if (filter_devchan(e.common.device, e.common.channel))
407 return 0;
408
409 switch (e.common.op) {
410 case MIDI_CTL_CHANGE:
411 buffer[0] = MIDI_CTL_CHANGE | e.c_CTL_CHANGE.channel;
412 buffer[1] = e.c_CTL_CHANGE.controller;
413 buffer[2] = e.c_CTL_CHANGE.value;
414 LOG("MIDI_CTL_CHANGE: channel %x ctrl %x val %x",
415 e.c_CTL_CHANGE.channel, e.c_CTL_CHANGE.controller,
416 e.c_CTL_CHANGE.value);
417 size = 3;
418 break;
419
420 case MIDI_PGM_CHANGE:
421 buffer[0] = MIDI_PGM_CHANGE | e.c_PGM_CHANGE.channel;
422 buffer[1] = e.c_PGM_CHANGE.program;
423 LOG("MIDI_PGM_CHANGE: channel %x program %x",
424 e.c_PGM_CHANGE.channel, e.c_PGM_CHANGE.program);
425 size = 2;
426 break;
427
428 case MIDI_CHN_PRESSURE:
429 buffer[0] = MIDI_CHN_PRESSURE | e.c_CHN_PRESSURE.channel;
430 buffer[1] = e.c_CHN_PRESSURE.pressure;
431 LOG("MIDI_CHN_PRESSURE: channel %x pressure %x",
432 e.c_CHN_PRESSURE.channel, e.c_CHN_PRESSURE.pressure);
433 size = 2;
434 break;
435
436 case MIDI_PITCH_BEND:
437 buffer[0] = MIDI_PITCH_BEND | e.c_PITCH_BEND.channel;
438 /* 14 bits split over 2 data bytes, lsb first */
439 buffer[1] = e.c_PITCH_BEND.value & 0x7f;
440 buffer[2] = (e.c_PITCH_BEND.value >> 7) & 0x7f;
441 LOG("MIDI_PITCH_BEND: channel %x val %x",
442 e.c_PITCH_BEND.channel, e.c_PITCH_BEND.value);
443 size = 3;
444 break;
445
446 default:
447 LOG("unknown common op: %x", e.voice.op);
448 break;
449 }
450
451 return size;
452 }
453
454 /*
455 * handle a SEQ_CHN_VOICE event.
456 */
457 static size_t
458 midi_event_chn_voice_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
459 {
460 size_t size = 0;
461
462 assert(e.common.channel < 16);
463 LOG("SEQ_CHN_VOICE");
464
465 if (filter_devchan(e.voice.device, e.voice.channel))
466 return 0;
467
468 switch (e.voice.op) {
469 case MIDI_NOTEOFF:
470 buffer[0] = MIDI_NOTEOFF | e.c_NOTEOFF.channel;
471 buffer[1] = e.c_NOTEOFF.key;
472 buffer[2] = e.c_NOTEOFF.velocity;
473
474 LOG("MIDI_NOTEOFF: channel %x key %x velocity %x",
475 e.c_NOTEOFF.channel, e.c_NOTEOFF.key, e.c_NOTEOFF.velocity);
476 size = 3;
477 break;
478
479 case MIDI_NOTEON:
480 buffer[0] = MIDI_NOTEON | e.c_NOTEON.channel;
481 buffer[1] = e.c_NOTEON.key;
482 buffer[2] = e.c_NOTEON.velocity;
483
484 LOG("MIDI_NOTEON: channel %x key %x velocity %x",
485 e.c_NOTEON.channel, e.c_NOTEON.key, e.c_NOTEON.velocity);
486 size = 3;
487 break;
488
489 case MIDI_KEY_PRESSURE:
490 buffer[0] = MIDI_KEY_PRESSURE | e.c_KEY_PRESSURE.channel;
491 buffer[1] = e.c_KEY_PRESSURE.key;
492 buffer[2] = e.c_KEY_PRESSURE.pressure;
493
494 LOG("MIDI_KEY_PRESSURE: channel %x key %x pressure %x",
495 e.c_KEY_PRESSURE.channel, e.c_KEY_PRESSURE.key,
496 e.c_KEY_PRESSURE.pressure);
497 size = 3;
498 break;
499
500 default:
501 LOG("unknown voice op: %x", e.voice.op);
502 break;
503 }
504
505 return size;
506 }
507
508 /*
509 * handle a SEQ_SYSEX event. NetBSD /dev/music doesn't generate these.
510 */
511 static size_t
512 midi_event_sysex_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
513 {
514 size_t size = 0;
515
516 LOG("UNHANDLED SEQ_SYSEX");
517
518 return size;
519 }
520
521 /*
522 * handle a SEQ_FULLSIZE event. NetBSD /dev/music doesn't generate these.
523 */
524 static size_t
525 midi_event_fullsize_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
526 {
527 size_t size = 0;
528
529 LOG("UNHANDLED SEQ_FULLSIZE");
530
531 return size;
532 }
533
534 /*
535 * main handler for MIDI events.
536 */
537 static size_t
538 midi_event_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
539 {
540 size_t size = 0;
541
542 /* XXX so far we only process 4 byte returns */
543 assert(bufsize >= 4);
544
545 LOG("event: %02x:%02x:%02x:%02x %02x:%02x:%02x:%02x", e.tag,
546 e.unknown.byte[0], e.unknown.byte[1],
547 e.unknown.byte[2], e.unknown.byte[3],
548 e.unknown.byte[4], e.unknown.byte[5],
549 e.unknown.byte[6]);
550
551 switch (e.tag) {
552 case SEQ_LOCAL:
553 size = midi_event_local_to_output(e, buffer, bufsize);
554 break;
555
556 case SEQ_TIMING:
557 size = midi_event_timer_to_output(e, buffer, bufsize);
558 break;
559
560 case SEQ_CHN_COMMON:
561 size = midi_event_chn_common_to_output(e, buffer, bufsize);
562 break;
563
564 case SEQ_CHN_VOICE:
565 size = midi_event_chn_voice_to_output(e, buffer, bufsize);
566 break;
567
568 case SEQ_SYSEX:
569 size = midi_event_sysex_to_output(e, buffer, bufsize);
570 break;
571
572 case SEQ_FULLSIZE:
573 size = midi_event_fullsize_to_output(e, buffer, bufsize);
574 break;
575
576 default:
577 errx(1, "don't understand midi tag %x", e.tag);
578 }
579
580 return size;
581 }
582
583 static bool
584 filter_array(unsigned val, unsigned *array, size_t arraylen)
585 {
586
587 if (array == NULL)
588 return false;
589
590 for (; arraylen; arraylen--)
591 if (array[arraylen - 1] == val)
592 return false;
593
594 return true;
595 }
596
597 static bool
598 filter_dev(unsigned device)
599 {
600
601 if (filter_array(device, filt_devnos, num_filt_devnos))
602 return true;
603
604 return false;
605 }
606
607 static bool
608 filter_chan(unsigned channel)
609 {
610
611 if (filter_array(channel, filt_chans, num_filt_chans))
612 return true;
613
614 return false;
615 }
616
617 static bool
618 filter_devchan(unsigned device, unsigned channel)
619 {
620
621 if (filter_dev(device) || filter_chan(channel))
622 return true;
623
624 return false;
625 }
626
627 static int
628 timeleft(struct timeval *start_tvp, struct timeval *record_tvp)
629 {
630 struct timeval now, diff;
631
632 (void)gettimeofday(&now, NULL);
633 timersub(&now, start_tvp, &diff);
634 timersub(record_tvp, &diff, &now);
635
636 return (now.tv_sec > 0 || (now.tv_sec == 0 && now.tv_usec > 0));
637 }
638
639 static void
640 parse_ints(const char *str, unsigned **arrayp, unsigned *sizep, const char *msg)
641 {
642 unsigned count = 1, u, longest = 0, c = 0;
643 unsigned *ip;
644 const char *s, *os;
645 char *num_buf;
646
647 /*
648 * count all the comma separated values, and figre out
649 * the longest one.
650 */
651 for (s = str; *s; s++) {
652 c++;
653 if (*s == ',') {
654 count++;
655 if (c > longest)
656 longest = c;
657 c = 0;
658 }
659 }
660 *sizep = count;
661
662 num_buf = malloc(longest + 1);
663 ip = malloc(sizeof(*ip) * count);
664 if (!ip || !num_buf)
665 errx(1, "malloc failed");
666
667 for (count = 0, s = os = str, u = 0; *s; s++) {
668 if (*s == ',') {
669 num_buf[u] = '\0';
670 decode_uint(num_buf, &ip[count++]);
671 os = s + 1;
672 u = 0;
673 } else
674 num_buf[u++] = *s;
675 }
676 num_buf[u] = '\0';
677 decode_uint(num_buf, &ip[count++]);
678 *arrayp = ip;
679
680 if (verbose) {
681 fprintf(stderr, "Filtering %s in:", msg);
682 for (size_t i = 0; i < *sizep; i++)
683 fprintf(stderr, " %u", ip[i]);
684 fprintf(stderr, "\n");
685 }
686
687 free(num_buf);
688 }
689
690 static void
691 cleanup(int signo)
692 {
693
694 write_midi_trailer();
695 rewrite_header();
696
697 if (ioctl(midifd, SEQUENCER_TMR_STOP, NULL) < 0) {
698 if (ignore_timer_fail)
699 warn("failed to stop midi timer");
700 else
701 err(1, "failed to stop midi timer");
702 }
703
704 close(outfd);
705 close(midifd);
706 if (signo != 0)
707 (void)raise_default_signal(signo);
708
709 exit(0);
710 }
711
712 static void
713 rewrite_header(void)
714 {
715
716 /* can't do this here! */
717 if (stdout_mode)
718 return;
719
720 if (lseek(outfd, (off_t)0, SEEK_SET) == (off_t)-1)
721 err(1, "could not seek to start of file for header rewrite");
722 write_midi_header();
723 }
724
725 #define BYTE1(x) ((x) & 0xff)
726 #define BYTE2(x) (((x) >> 8) & 0xff)
727 #define BYTE3(x) (((x) >> 16) & 0xff)
728 #define BYTE4(x) (((x) >> 24) & 0xff)
729
730 static void
731 write_midi_header(void)
732 {
733 unsigned char header[] = {
734 'M', 'T', 'h', 'd',
735 0, 0, 0, 6,
736 0, 1,
737 0, 0, /* ntracks */
738 0, 0, /* notes per beat */
739 };
740 /* XXX only support one track so far */
741 unsigned ntracks = 1;
742 unsigned char track[] = {
743 'M', 'T', 'r', 'k',
744 0, 0, 0, 0,
745 };
746 unsigned char bpm[] = {
747 0, 0xff, 0x51, 0x3,
748 0, 0, 0, /* inverse tempo */
749 };
750 unsigned total_size = data_size + sizeof header + sizeof track + sizeof bpm;
751
752 header[10] = BYTE2(ntracks);
753 header[11] = BYTE1(ntracks);
754 header[12] = BYTE2(notes_per_beat);
755 header[13] = BYTE1(notes_per_beat);
756
757 track[4] = BYTE4(total_size);
758 track[5] = BYTE3(total_size);
759 track[6] = BYTE2(total_size);
760 track[7] = BYTE1(total_size);
761
762 #define TEMPO_INV(x) (60000000UL / (x))
763 bpm[4] = BYTE3(TEMPO_INV(tempo));
764 bpm[5] = BYTE2(TEMPO_INV(tempo));
765 bpm[6] = BYTE1(TEMPO_INV(tempo));
766
767 if (write(outfd, header, sizeof header) != sizeof header)
768 err(1, "write of header failed");
769 if (write(outfd, track, sizeof track) != sizeof track)
770 err(1, "write of track header failed");
771 if (write(outfd, bpm, sizeof bpm) != sizeof bpm)
772 err(1, "write of bpm header failed");
773
774 LOG("wrote header: ntracks=%u notes_per_beat=%u tempo=%d total_size=%u",
775 ntracks, notes_per_beat, tempo, total_size);
776 }
777
778 static void
779 write_midi_trailer(void)
780 {
781 unsigned char trailer[] = {
782 0, 0xff, 0x2f, 0,
783 };
784
785 if (write(outfd, trailer, sizeof trailer) != sizeof trailer)
786 err(1, "write of trailer failed");
787 }
788
789 static void
790 usage(void)
791 {
792
793 fprintf(stderr, "Usage: %s [-aDfhqV] [options] {outfile|-}\n",
794 getprogname());
795 fprintf(stderr, "Options:\n"
796 "\t-B buffer size\n"
797 "\t-c channels\n"
798 "\t-d devices\n"
799 "\t-f sequencerdev\n"
800 "\t-n notesperbeat\n"
801 "\t-r raw_output\n"
802 "\t-T tempo\n"
803 "\t-t recording time\n");
804 exit(EXIT_FAILURE);
805 }
806