midirecord.c revision 1.5 1 /* $NetBSD: midirecord.c,v 1.5 2015/01/01 04:57:01 christos 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 1.5 2015/01/01 04:57:01 christos 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
78 static void debug_log(const char *, size_t, const char *, ...);
79 static size_t midi_event_local_to_output(seq_event_t, u_char *, size_t);
80 static size_t midi_event_timer_wait_abs_to_output(seq_event_t, u_char *,
81 size_t);
82 static size_t midi_event_timer_to_output(seq_event_t, u_char *, size_t);
83 static size_t midi_event_chn_common_to_output(seq_event_t, u_char *, size_t);
84 static size_t midi_event_chn_voice_to_output(seq_event_t, u_char *, size_t);
85 static size_t midi_event_sysex_to_output(seq_event_t, u_char *, size_t);
86 static size_t midi_event_fullsize_to_output(seq_event_t, u_char *, size_t);
87 static size_t midi_event_to_output(seq_event_t, u_char *, size_t);
88 static int timeleft(struct timeval *, struct timeval *);
89 static bool filter_array(unsigned, unsigned *, size_t);
90 static bool filter_dev(unsigned);
91 static bool filter_chan(unsigned);
92 static bool filter_devchan(unsigned, unsigned);
93 static void parse_ints(const char *, unsigned **, unsigned *, const char *);
94 static void cleanup(int) __dead;
95 static void rewrite_header(void);
96 static void write_midi_header(void);
97 static void write_midi_trailer(void);
98 static void usage(void) __dead;
99
100 #define PATH_DEV_MUSIC "/dev/music"
101
102 int
103 main(int argc, char *argv[])
104 {
105 u_char *buffer;
106 size_t bufsize = 0;
107 int ch, no_time_limit = 1;
108
109 while ((ch = getopt(argc, argv, "aB:c:Dd:f:hn:oqr:t:T:V")) != -1) {
110 switch (ch) {
111 case 'a':
112 aflag++;
113 break;
114 case 'B':
115 bufsize = strsuftoll("read buffer size", optarg,
116 1, UINT_MAX);
117 break;
118 case 'c':
119 parse_ints(optarg, &filt_chans, &num_filt_chans,
120 "channels");
121 break;
122 case 'D':
123 debug++;
124 break;
125 case 'd':
126 parse_ints(optarg, &filt_devnos, &num_filt_devnos,
127 "devices");
128 break;
129 case 'f':
130 midi_device = optarg;
131 ignore_timer_fail = true;
132 break;
133 case 'n':
134 decode_uint(optarg, ¬es_per_beat);
135 break;
136 case 'o':
137 oflag++; /* time stamp starts at proc start */
138 break;
139 case 'q':
140 qflag++;
141 break;
142 case 'r':
143 raw_output = optarg;
144 break;
145 case 't':
146 no_time_limit = 0;
147 decode_time(optarg, &record_time);
148 break;
149 case 'T':
150 decode_int(optarg, &tempo);
151 break;
152 case 'V':
153 verbose++;
154 break;
155 /* case 'h': */
156 default:
157 usage();
158 /* NOTREACHED */
159 }
160 }
161 argc -= optind;
162 argv += optind;
163
164 if (argc != 1)
165 usage();
166
167 /*
168 * work out the buffer size to use, and allocate it. don't allow it
169 * to be too small.
170 */
171 if (bufsize < 32)
172 bufsize = 32 * 1024;
173 buffer = malloc(bufsize);
174 if (buffer == NULL)
175 err(1, "couldn't malloc buffer of %d size", (int)bufsize);
176
177 /*
178 * open the music device
179 */
180 if (midi_device == NULL && (midi_device = getenv("MIDIDEVICE")) == NULL)
181 midi_device = PATH_DEV_MUSIC;
182 midifd = open(midi_device, O_RDONLY);
183 if (midifd < 0)
184 err(1, "failed to open %s", midi_device);
185
186 /* open the output file */
187 if (argv[0][0] != '-' || argv[0][1] != '\0') {
188 int mode = O_CREAT|(aflag ? O_APPEND : O_TRUNC)|O_WRONLY;
189
190 outfd = open(*argv, mode, 0666);
191 if (outfd < 0)
192 err(1, "could not open %s", *argv);
193 } else
194 outfd = STDOUT_FILENO;
195
196 /* open the raw output file */
197 if (raw_output) {
198 int mode = O_CREAT|(aflag ? O_APPEND : O_TRUNC)|O_WRONLY;
199
200 rawfd = open(raw_output, mode, 0666);
201 if (rawfd < 0)
202 err(1, "could not open %s", raw_output);
203 }
204
205 /* start the midi timer */
206 if (ioctl(midifd, SEQUENCER_TMR_START, NULL) < 0) {
207 if (ignore_timer_fail)
208 warn("failed to start midi timer");
209 else
210 err(1, "failed to start midi timer");
211 }
212
213 /* set the timebase */
214 if (ioctl(midifd, SEQUENCER_TMR_TIMEBASE, ¬es_per_beat) < 0) {
215 if (ignore_timer_fail)
216 warn("SEQUENCER_TMR_TIMEBASE: notes_per_beat %d",
217 notes_per_beat);
218 else
219 err(1, "SEQUENCER_TMR_TIMEBASE: notes_per_beat %d",
220 notes_per_beat);
221 }
222
223 /* set the tempo */
224 if (ioctl(midifd, SEQUENCER_TMR_TEMPO, &tempo) < 0) {
225 if (ignore_timer_fail)
226 warn("SEQUENCER_TMR_TIMEBASE: tempo %d", tempo);
227 else
228 err(1, "SEQUENCER_TMR_TIMEBASE: tempo %d", tempo);
229 }
230
231 signal(SIGINT, cleanup);
232
233 data_size = 0;
234
235 if (verbose)
236 fprintf(stderr, "tempo=%d notes_per_beat=%d\n",
237 tempo, notes_per_beat);
238
239 if (!no_time_limit && verbose)
240 fprintf(stderr, "recording for %lu seconds, %lu microseconds\n",
241 (u_long)record_time.tv_sec, (u_long)record_time.tv_usec);
242
243 /* Create a midi header. */
244 write_midi_header();
245
246 (void)gettimeofday(&start_time, NULL);
247 while (no_time_limit || timeleft(&start_time, &record_time)) {
248 seq_event_t e;
249 size_t wrsize;
250 size_t rdsize;
251
252 rdsize = (size_t)read(midifd, &e, sizeof e);
253 if (rdsize == 0)
254 break;
255
256 if (rdsize != sizeof e)
257 err(1, "read failed");
258
259 if (rawfd != -1 && write(rawfd, &e, sizeof e) != sizeof e)
260 err(1, "write to raw file failed");
261
262 /* convert 'e' into something useful for output */
263 wrsize = midi_event_to_output(e, buffer, bufsize);
264
265 if (wrsize) {
266 if ((size_t)write(outfd, buffer, wrsize) != wrsize)
267 err(1, "write failed");
268 data_size += wrsize;
269 }
270 }
271 cleanup(0);
272 }
273
274 static void
275 debug_log(const char *file, size_t line, const char *fmt, ...)
276 {
277 va_list ap;
278
279 if (!debug)
280 return;
281 fprintf(stderr, "%s:%zd: ", file, line);
282 va_start(ap, fmt);
283 vfprintf(stderr, fmt, ap);
284 va_end(ap);
285 fprintf(stderr, "\n");
286 }
287
288 #define LOG(fmt...) \
289 debug_log(__func__, __LINE__, fmt)
290
291
292 /*
293 * handle a SEQ_LOCAL event. NetBSD /dev/music doesn't generate these.
294 */
295 static size_t
296 midi_event_local_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
297 {
298 size_t size = 0;
299
300 LOG("UNHANDLED SEQ_COCAL");
301
302 return size;
303 }
304
305 /*
306 * convert a midi absolute time event to a variable length delay
307 */
308 static size_t
309 midi_event_timer_wait_abs_to_output(
310 seq_event_t e,
311 u_char *buffer,
312 size_t bufsize)
313 {
314 static unsigned prev_div;
315 unsigned cur_div;
316 unsigned val = 0, xdiv;
317 int vallen = 0, i;
318
319 if (prev_div == 0 && !oflag)
320 prev_div = e.t_WAIT_ABS.divisions;
321 cur_div = e.t_WAIT_ABS.divisions;
322
323 xdiv = cur_div - prev_div;
324 if (xdiv) {
325 while (xdiv) {
326 uint32_t extra = val ? 0x80 : 0;
327
328 val <<= 8;
329 val |= (xdiv & 0x7f) | extra;
330 xdiv >>= 7;
331 vallen++;
332 }
333 } else
334 vallen = 1;
335
336 for (i = 0; i < vallen; i++) {
337 buffer[i] = val & 0xff;
338 val >>= 8;
339 }
340 for (; i < 4; i++)
341 buffer[i] = 0;
342 LOG("TMR_WAIT_ABS: new div %x (cur %x prev %x): bufval (len=%u): "
343 "%02x:%02x:%02x:%02x",
344 cur_div - prev_div, cur_div, prev_div,
345 vallen, buffer[0], buffer[1], buffer[2], buffer[3]);
346
347 prev_div = cur_div;
348
349 return vallen;
350 }
351
352 /*
353 * handle a SEQ_TIMING event.
354 */
355 static size_t
356 midi_event_timer_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
357 {
358 size_t size = 0;
359
360 LOG("SEQ_TIMING");
361 switch (e.timing.op) {
362 case TMR_WAIT_REL:
363 /* NetBSD /dev/music doesn't generate these. */
364 LOG("UNHANDLED TMR_WAIT_REL: divisions: %x", e.t_WAIT_REL.divisions);
365 break;
366
367 case TMR_WAIT_ABS:
368 size = midi_event_timer_wait_abs_to_output(e, buffer, bufsize);
369 break;
370
371 case TMR_STOP:
372 case TMR_START:
373 case TMR_CONTINUE:
374 case TMR_TEMPO:
375 case TMR_ECHO:
376 case TMR_CLOCK:
377 case TMR_SPP:
378 case TMR_TIMESIG:
379 /* NetBSD /dev/music doesn't generate these. */
380 LOG("UNHANDLED timer op: %x", e.timing.op);
381 break;
382
383 default:
384 LOG("unknown timer op: %x", e.timing.op);
385 break;
386 }
387
388 return size;
389 }
390
391 /*
392 * handle a SEQ_CHN_COMMON event.
393 */
394 static size_t
395 midi_event_chn_common_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
396 {
397 size_t size = 0;
398
399 assert(e.common.channel < 16);
400 LOG("SEQ_CHN_COMMON");
401
402 if (filter_devchan(e.common.device, e.common.channel))
403 return 0;
404
405 switch (e.common.op) {
406 case MIDI_CTL_CHANGE:
407 buffer[0] = MIDI_CTL_CHANGE | e.c_CTL_CHANGE.channel;
408 buffer[1] = e.c_CTL_CHANGE.controller;
409 buffer[2] = e.c_CTL_CHANGE.value;
410 LOG("MIDI_CTL_CHANGE: channel %x ctrl %x val %x",
411 e.c_CTL_CHANGE.channel, e.c_CTL_CHANGE.controller,
412 e.c_CTL_CHANGE.value);
413 size = 3;
414 break;
415
416 case MIDI_PGM_CHANGE:
417 buffer[0] = MIDI_PGM_CHANGE | e.c_PGM_CHANGE.channel;
418 buffer[1] = e.c_PGM_CHANGE.program;
419 LOG("MIDI_PGM_CHANGE: channel %x program %x",
420 e.c_PGM_CHANGE.channel, e.c_PGM_CHANGE.program);
421 size = 2;
422 break;
423
424 case MIDI_CHN_PRESSURE:
425 buffer[0] = MIDI_CHN_PRESSURE | e.c_CHN_PRESSURE.channel;
426 buffer[1] = e.c_CHN_PRESSURE.pressure;
427 LOG("MIDI_CHN_PRESSURE: channel %x pressure %x",
428 e.c_CHN_PRESSURE.channel, e.c_CHN_PRESSURE.pressure);
429 size = 2;
430 break;
431
432 case MIDI_PITCH_BEND:
433 buffer[0] = MIDI_PITCH_BEND | e.c_PITCH_BEND.channel;
434 /* 14 bits split over 2 data bytes, lsb first */
435 buffer[1] = e.c_PITCH_BEND.value & 0x7f;
436 buffer[2] = (e.c_PITCH_BEND.value >> 7) & 0x7f;
437 LOG("MIDI_PITCH_BEND: channel %x val %x",
438 e.c_PITCH_BEND.channel, e.c_PITCH_BEND.value);
439 size = 3;
440 break;
441
442 default:
443 LOG("unknown common op: %x", e.voice.op);
444 break;
445 }
446
447 return size;
448 }
449
450 /*
451 * handle a SEQ_CHN_VOICE event.
452 */
453 static size_t
454 midi_event_chn_voice_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
455 {
456 size_t size = 0;
457
458 assert(e.common.channel < 16);
459 LOG("SEQ_CHN_VOICE");
460
461 if (filter_devchan(e.voice.device, e.voice.channel))
462 return 0;
463
464 switch (e.voice.op) {
465 case MIDI_NOTEOFF:
466 buffer[0] = MIDI_NOTEOFF | e.c_NOTEOFF.channel;
467 buffer[1] = e.c_NOTEOFF.key;
468 buffer[2] = e.c_NOTEOFF.velocity;
469
470 LOG("MIDI_NOTEOFF: channel %x key %x velocity %x",
471 e.c_NOTEOFF.channel, e.c_NOTEOFF.key, e.c_NOTEOFF.velocity);
472 size = 3;
473 break;
474
475 case MIDI_NOTEON:
476 buffer[0] = MIDI_NOTEON | e.c_NOTEON.channel;
477 buffer[1] = e.c_NOTEON.key;
478 buffer[2] = e.c_NOTEON.velocity;
479
480 LOG("MIDI_NOTEON: channel %x key %x velocity %x",
481 e.c_NOTEON.channel, e.c_NOTEON.key, e.c_NOTEON.velocity);
482 size = 3;
483 break;
484
485 case MIDI_KEY_PRESSURE:
486 buffer[0] = MIDI_KEY_PRESSURE | e.c_KEY_PRESSURE.channel;
487 buffer[1] = e.c_KEY_PRESSURE.key;
488 buffer[2] = e.c_KEY_PRESSURE.pressure;
489
490 LOG("MIDI_KEY_PRESSURE: channel %x key %x pressure %x",
491 e.c_KEY_PRESSURE.channel, e.c_KEY_PRESSURE.key,
492 e.c_KEY_PRESSURE.pressure);
493 size = 3;
494 break;
495
496 default:
497 LOG("unknown voice op: %x", e.voice.op);
498 break;
499 }
500
501 return size;
502 }
503
504 /*
505 * handle a SEQ_SYSEX event. NetBSD /dev/music doesn't generate these.
506 */
507 static size_t
508 midi_event_sysex_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
509 {
510 size_t size = 0;
511
512 LOG("UNHANDLED SEQ_SYSEX");
513
514 return size;
515 }
516
517 /*
518 * handle a SEQ_FULLSIZE event. NetBSD /dev/music doesn't generate these.
519 */
520 static size_t
521 midi_event_fullsize_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
522 {
523 size_t size = 0;
524
525 LOG("UNHANDLED SEQ_FULLSIZE");
526
527 return size;
528 }
529
530 /*
531 * main handler for MIDI events.
532 */
533 static size_t
534 midi_event_to_output(seq_event_t e, u_char *buffer, size_t bufsize)
535 {
536 size_t size = 0;
537
538 /* XXX so far we only process 4 byte returns */
539 assert(bufsize >= 4);
540
541 LOG("event: %02x:%02x:%02x:%02x %02x:%02x:%02x:%02x", e.tag,
542 e.unknown.byte[0], e.unknown.byte[1],
543 e.unknown.byte[2], e.unknown.byte[3],
544 e.unknown.byte[4], e.unknown.byte[5],
545 e.unknown.byte[6]);
546
547 switch (e.tag) {
548 case SEQ_LOCAL:
549 size = midi_event_local_to_output(e, buffer, bufsize);
550 break;
551
552 case SEQ_TIMING:
553 size = midi_event_timer_to_output(e, buffer, bufsize);
554 break;
555
556 case SEQ_CHN_COMMON:
557 size = midi_event_chn_common_to_output(e, buffer, bufsize);
558 break;
559
560 case SEQ_CHN_VOICE:
561 size = midi_event_chn_voice_to_output(e, buffer, bufsize);
562 break;
563
564 case SEQ_SYSEX:
565 size = midi_event_sysex_to_output(e, buffer, bufsize);
566 break;
567
568 case SEQ_FULLSIZE:
569 size = midi_event_fullsize_to_output(e, buffer, bufsize);
570 break;
571
572 default:
573 errx(1, "don't understand midi tag %x", e.tag);
574 }
575
576 return size;
577 }
578
579 static bool
580 filter_array(unsigned val, unsigned *array, size_t arraylen)
581 {
582
583 if (array == NULL)
584 return false;
585
586 for (; arraylen; arraylen--)
587 if (array[arraylen - 1] == val)
588 return false;
589
590 return true;
591 }
592
593 static bool
594 filter_dev(unsigned device)
595 {
596
597 if (filter_array(device, filt_devnos, num_filt_devnos))
598 return true;
599
600 return false;
601 }
602
603 static bool
604 filter_chan(unsigned channel)
605 {
606
607 if (filter_array(channel, filt_chans, num_filt_chans))
608 return true;
609
610 return false;
611 }
612
613 static bool
614 filter_devchan(unsigned device, unsigned channel)
615 {
616
617 if (filter_dev(device) || filter_chan(channel))
618 return true;
619
620 return false;
621 }
622
623 static int
624 timeleft(struct timeval *start_tvp, struct timeval *record_tvp)
625 {
626 struct timeval now, diff;
627
628 (void)gettimeofday(&now, NULL);
629 timersub(&now, start_tvp, &diff);
630 timersub(record_tvp, &diff, &now);
631
632 return (now.tv_sec > 0 || (now.tv_sec == 0 && now.tv_usec > 0));
633 }
634
635 static void
636 parse_ints(const char *str, unsigned **arrayp, unsigned *sizep, const char *msg)
637 {
638 unsigned count = 1, u, longest = 0, c = 0;
639 unsigned *ip;
640 const char *s, *os;
641 char *num_buf;
642
643 /*
644 * count all the comma separated values, and figre out
645 * the longest one.
646 */
647 for (s = str; *s; s++) {
648 c++;
649 if (*s == ',') {
650 count++;
651 if (c > longest)
652 longest = c;
653 c = 0;
654 }
655 }
656 *sizep = count;
657
658 num_buf = malloc(longest + 1);
659 ip = malloc(sizeof(*ip) * count);
660 if (!ip || !num_buf)
661 errx(1, "malloc failed");
662
663 for (count = 0, s = os = str, u = 0; *s; s++) {
664 if (*s == ',') {
665 num_buf[u] = '\0';
666 decode_uint(num_buf, &ip[count++]);
667 os = s + 1;
668 u = 0;
669 } else
670 num_buf[u++] = *s;
671 }
672 num_buf[u] = '\0';
673 decode_uint(num_buf, &ip[count++]);
674 *arrayp = ip;
675
676 if (verbose) {
677 fprintf(stderr, "Filtering %s in:", msg);
678 for (size_t i = 0; i < *sizep; i++)
679 fprintf(stderr, " %u", ip[i]);
680 fprintf(stderr, "\n");
681 }
682
683 free(num_buf);
684 }
685
686 static void
687 cleanup(int signo)
688 {
689
690 write_midi_trailer();
691 rewrite_header();
692
693 if (ioctl(midifd, SEQUENCER_TMR_STOP, NULL) < 0) {
694 if (ignore_timer_fail)
695 warn("failed to stop midi timer");
696 else
697 err(1, "failed to stop midi timer");
698 }
699
700 close(outfd);
701 close(midifd);
702 if (signo != 0)
703 (void)raise_default_signal(signo);
704
705 exit(0);
706 }
707
708 static void
709 rewrite_header(void)
710 {
711
712 /* can't do this here! */
713 if (outfd == STDOUT_FILENO)
714 return;
715
716 if (lseek(outfd, (off_t)0, SEEK_SET) == (off_t)-1)
717 err(1, "could not seek to start of file for header rewrite");
718 write_midi_header();
719 }
720
721 #define BYTE1(x) ((x) & 0xff)
722 #define BYTE2(x) (((x) >> 8) & 0xff)
723 #define BYTE3(x) (((x) >> 16) & 0xff)
724 #define BYTE4(x) (((x) >> 24) & 0xff)
725
726 static void
727 write_midi_header(void)
728 {
729 unsigned char header[] = {
730 'M', 'T', 'h', 'd',
731 0, 0, 0, 6,
732 0, 1,
733 0, 0, /* ntracks */
734 0, 0, /* notes per beat */
735 };
736 /* XXX only spport one track so far */
737 unsigned ntracks = 1;
738 unsigned char track[] = {
739 'M', 'T', 'r', 'k',
740 0, 0, 0, 0,
741 };
742 unsigned char bpm[] = {
743 0, 0xff, 0x51, 0x3,
744 0, 0, 0, /* inverse tempo */
745 };
746 unsigned total_size = data_size + sizeof header + sizeof track + sizeof bpm;
747
748 header[10] = BYTE2(ntracks);
749 header[11] = BYTE1(ntracks);
750 header[12] = BYTE2(notes_per_beat);
751 header[13] = BYTE1(notes_per_beat);
752
753 track[4] = BYTE4(total_size);
754 track[5] = BYTE3(total_size);
755 track[6] = BYTE2(total_size);
756 track[7] = BYTE1(total_size);
757
758 #define TEMPO_INV(x) (60000000UL / (x))
759 bpm[4] = BYTE3(TEMPO_INV(tempo));
760 bpm[5] = BYTE2(TEMPO_INV(tempo));
761 bpm[6] = BYTE1(TEMPO_INV(tempo));
762
763 if (write(outfd, header, sizeof header) != sizeof header)
764 err(1, "write of header failed");
765 if (write(outfd, track, sizeof track) != sizeof track)
766 err(1, "write of track header failed");
767 if (write(outfd, bpm, sizeof bpm) != sizeof bpm)
768 err(1, "write of bpm header failed");
769
770 LOG("wrote header: ntracks=%u notes_per_beat=%u tempo=%d total_size=%u",
771 ntracks, notes_per_beat, tempo, total_size);
772 }
773
774 static void
775 write_midi_trailer(void)
776 {
777 unsigned char trailer[] = {
778 0, 0xff, 0x2f, 0,
779 };
780
781 if (write(outfd, trailer, sizeof trailer) != sizeof trailer)
782 err(1, "write of trailer failed");
783 }
784
785 static void
786 usage(void)
787 {
788
789 fprintf(stderr, "Usage: %s [-aDfhqV] [options] {outfile|-}\n",
790 getprogname());
791 fprintf(stderr, "Options:\n"
792 "\t-B buffer size\n"
793 "\t-c channels\n"
794 "\t-d devices\n"
795 "\t-f sequencerdev\n"
796 "\t-n notesperbeat\n"
797 "\t-r raw_output\n"
798 "\t-T tempo\n"
799 "\t-t recording time\n");
800 exit(EXIT_FAILURE);
801 }
802