libsmf

- Main Page
- Data Structures
- Files

- File List
- Globals

smf_load.c
Go to the documentation of this file.
1 /*-
2 * Copyright (c) 2007, 2008 Edward Tomasz Napierała <trasz@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * ALTHOUGH THIS SOFTWARE IS MADE OF WIN AND SCIENCE, IT IS PROVIDED BY THE
15 * AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18 * THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
19 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
20 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
21 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
23 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
24 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 */
27
35 /* Reference: http://www.borg.com/~jglatt/tech/midifile.htm */
36
37 #include <stdlib.h>
38 #include <string.h>
39 #include <assert.h>
40 #include <math.h>
41 #include <errno.h>
42 #include <ctype.h>
43 #ifdef __MINGW32__
44 #include <windows.h>
45 #else /* ! __MINGW32__ */
46 #include <arpa/inet.h>
47 #endif /* ! __MINGW32__ */
48 #include "smf.h"
49 #include "smf_private.h"
50
55 static struct chunk_header_struct *
56 next_chunk(smf_t *smf)
57 {
58 struct chunk_header_struct *chunk;
59 void *next_chunk_ptr;
60
61 assert(smf->file_buffer != NULL);
62 assert(smf->file_buffer_length > 0);
63 assert(smf->next_chunk_offset >= 0);
64
65 if (smf->next_chunk_offset + sizeof(struct chunk_header_struct) >= smf->file_buffer_length) {
66 g_critical("SMF warning: no more chunks left.");
67 return (NULL);
68 }
69
70 next_chunk_ptr = (unsigned char *)smf->file_buffer + smf->next_chunk_offset;
71
72 chunk = (struct chunk_header_struct *)next_chunk_ptr;
73
74 if (!isalpha(chunk->id[0]) || !isalpha(chunk->id[1]) || !isalpha(chunk->id[2]) || !isalpha(chunk->id[3])) {
75 g_critical("SMF error: chunk signature contains at least one non-alphanumeric byte.");
76 return (NULL);
77 }
78
79 /*
80 * XXX: On SPARC, after compiling with "-fast" option there will be SIGBUS here.
81 * Please compile with -xmemalign=8i".
82 */
83 smf->next_chunk_offset += sizeof(struct chunk_header_struct) + ntohl(chunk->length);
84
85 if (smf->next_chunk_offset > smf->file_buffer_length) {
86 g_critical("SMF warning: malformed chunk; truncated file?");
87 smf->next_chunk_offset = smf->file_buffer_length;
88 }
89
90 return (chunk);
91 }
92
96 static int
97 chunk_signature_matches(const struct chunk_header_struct *chunk, const char *signature)
98 {
99 if (!memcmp(chunk->id, signature, 4))
100 return (1);
101
102 return (0);
103 }
104
108 static int
109 parse_mthd_header(smf_t *smf)
110 {
111 int len;
112 struct chunk_header_struct *mthd, *tmp_mthd;
113
114 /* Make sure compiler didn't do anything stupid. */
115 assert(sizeof(struct chunk_header_struct) == 8);
116
117 /*
118 * We could just do "mthd = smf->file_buffer;" here, but this way we wouldn't
119 * get useful error messages.
120 */
121 if (smf->file_buffer_length < 6) {
122 g_critical("SMF error: file is too short, it cannot be a MIDI file.");
123
124 return (-1);
125 }
126
127 tmp_mthd = smf->file_buffer;
128
129 if (!chunk_signature_matches(tmp_mthd, "MThd")) {
130 g_critical("SMF error: MThd signature not found, is that a MIDI file?");
131
132 return (-2);
133 }
134
135 /* Ok, now use next_chunk(). */
136 mthd = next_chunk(smf);
137 if (mthd == NULL)
138 return (-3);
139
140 assert(mthd == tmp_mthd);
141
142 len = ntohl(mthd->length);
143 if (len != 6) {
144 g_critical("SMF error: MThd chunk length %d, must be 6.", len);
145
146 return (-4);
147 }
148
149 return (0);
150 }
151
155 static int
156 parse_mthd_chunk(smf_t *smf)
157 {
158 signed char first_byte_of_division, second_byte_of_division;
159
160 struct mthd_chunk_struct *mthd;
161
162 assert(sizeof(struct mthd_chunk_struct) == 14);
163
164 if (parse_mthd_header(smf))
165 return (1);
166
167 mthd = (struct mthd_chunk_struct *)smf->file_buffer;
168
169 smf->format = ntohs(mthd->format);
170 if (smf->format < 0 || smf->format > 2) {
171 g_critical("SMF error: bad MThd format field value: %d, valid values are 0-2, inclusive.", smf->format);
172 return (-1);
173 }
174
175 if (smf->format == 2) {
176 g_critical("SMF file uses format #2, no support for that yet.");
177 return (-2);
178 }
179
180 smf->expected_number_of_tracks = ntohs(mthd->number_of_tracks);
181 if (smf->expected_number_of_tracks <= 0) {
182 g_critical("SMF error: bad number of tracks: %d, must be greater than zero.", smf->expected_number_of_tracks);
183 return (-3);
184 }
185
186 /* XXX: endianess? */
187 first_byte_of_division = *((signed char *)&(mthd->division));
188 second_byte_of_division = *((signed char *)&(mthd->division) + 1);
189
190 if (first_byte_of_division >= 0) {
191 smf->ppqn = ntohs(mthd->division);
192 smf->frames_per_second = 0;
193 smf->resolution = 0;
194 } else {
195 smf->ppqn = 0;
196 smf->frames_per_second = - first_byte_of_division;
197 smf->resolution = second_byte_of_division;
198 }
199
200 if (smf->ppqn == 0) {
201 g_critical("SMF file uses FPS timing instead of PPQN, no support for that yet.");
202 return (-4);
203 }
204
205 return (0);
206 }
207
214 static int
215 extract_vlq(const unsigned char *buf, const int buffer_length, int *value, int *len)
216 {
217 int val = 0;
218 const unsigned char *c = buf;
219
220 assert(buffer_length > 0);
221
222 for (;;) {
223 if (c >= buf + buffer_length) {
224 g_critical("End of buffer in extract_vlq().");
225 return (-1);
226 }
227
228 val = (val << 7) + (*c & 0x7F);
229
230 if (*c & 0x80)
231 c++;
232 else
233 break;
234 };
235
236 *value = val;
237 *len = c - buf + 1;
238
239 if (*len > 4) {
240 g_critical("SMF error: Variable Length Quantities longer than four bytes are not supported yet.");
241 return (-2);
242 }
243
244 return (0);
245 }
246
250 int
251 is_status_byte(const unsigned char status)
252 {
253 return (status & 0x80);
254 }
255
256 static int
257 is_sysex_byte(const unsigned char status)
258 {
259 if (status == 0xF0)
260 return (1);
261
262 return (0);
263 }
264
265 static int
266 is_escape_byte(const unsigned char status)
267 {
268 if (status == 0xF7)
269 return (1);
270
271 return (0);
272 }
273
281 static int
282 expected_sysex_length(const unsigned char status, const unsigned char *second_byte, const int buffer_length, int *consumed_bytes)
283 {
284 int sysex_length, len;
285
286 assert(status == 0xF0);
287
288 if (buffer_length < 3) {
289 g_critical("SMF error: end of buffer in expected_sysex_length().");
290 return (-1);
291 }
292
293 if (extract_vlq(second_byte, buffer_length, &sysex_length, &len))
294 return (-1);
295
296 if (consumed_bytes != NULL)
297 *consumed_bytes = len;
298
299 /* +1, because the length does not include status byte. */
300 return (sysex_length + 1);
301 }
302
303 static int
304 expected_escaped_length(const unsigned char status, const unsigned char *second_byte, const int buffer_length, int *consumed_bytes)
305 {
306 /* -1, because we do not want to account for 0x7F status. */
307 return (expected_sysex_length(status, second_byte, buffer_length, consumed_bytes) - 1);
308 }
309
315 static int
316 expected_message_length(unsigned char status, const unsigned char *second_byte, const int buffer_length)
317 {
318 /* Make sure this really is a valid status byte. */
319 assert(is_status_byte(status));
320
321 /* We cannot use this routine for sysexes. */
322 assert(!is_sysex_byte(status));
323
324 /* We cannot use this routine for escaped events. */
325 assert(!is_escape_byte(status));
326
327 /* Buffer length may be zero, for e.g. realtime messages. */
328 assert(buffer_length >= 0);
329
330 /* Is this a metamessage? */
331 if (status == 0xFF) {
332 if (buffer_length < 2) {
333 g_critical("SMF error: end of buffer in expected_message_length().");
334 return (-1);
335 }
336
337 /*
338 * Format of this kind of messages is like this: 0xFF 0xwhatever 0xlength and then "length" bytes.
339 * Second byte points to this: ^^^^^^^^^^
340 */
341 return (*(second_byte + 1) + 3);
342 }
343
344 if ((status & 0xF0) == 0xF0) {
345 switch (status) {
346 case 0xF2: /* Song Position Pointer. */
347 return (3);
348
349 case 0xF1: /* MTC Quarter Frame. */
350 case 0xF3: /* Song Select. */
351 return (2);
352
353 case 0xF6: /* Tune Request. */
354 case 0xF8: /* MIDI Clock. */
355 case 0xF9: /* Tick. */
356 case 0xFA: /* MIDI Start. */
357 case 0xFB: /* MIDI Continue. */
358 case 0xFC: /* MIDI Stop. */
359 case 0xFE: /* Active Sense. */
360 return (1);
361
362 default:
363 g_critical("SMF error: unknown 0xFx-type status byte '0x%x'.", status);
364 return (-2);
365 }
366 }
367
368 /* Filter out the channel. */
369 status &= 0xF0;
370
371 switch (status) {
372 case 0x80: /* Note Off. */
373 case 0x90: /* Note On. */
374 case 0xA0: /* AfterTouch. */
375 case 0xB0: /* Control Change. */
376 case 0xE0: /* Pitch Wheel. */
377 return (3);
378
379 case 0xC0: /* Program Change. */
380 case 0xD0: /* Channel Pressure. */
381 return (2);
382
383 default:
384 g_critical("SMF error: unknown status byte '0x%x'.", status);
385 return (-3);
386 }
387 }
388
389 static int
390 extract_sysex_event(const unsigned char *buf, const int buffer_length, smf_event_t *event, int *len, int last_status)
391 {
392 int status, message_length, vlq_length;
393 const unsigned char *c = buf;
394
395 status = *buf;
396
397 assert(is_sysex_byte(status));
398
399 c++;
400
401 message_length = expected_sysex_length(status, c, buffer_length - 1, &vlq_length);
402
403 if (message_length < 0)
404 return (-3);
405
406 c += vlq_length;
407
408 if (vlq_length + message_length >= buffer_length) {
409 g_critical("End of buffer in extract_sysex_event().");
410 return (-5);
411 }
412
413 event->midi_buffer_length = message_length;
414 event->midi_buffer = malloc(event->midi_buffer_length);
415 if (event->midi_buffer == NULL) {
416 g_critical("Cannot allocate memory in extract_sysex_event(): %s", strerror(errno));
417 return (-4);
418 }
419
420 event->midi_buffer[0] = status;
421 memcpy(event->midi_buffer + 1, c, message_length - 1);
422
423 *len = vlq_length + message_length;
424
425 return (0);
426 }
427
428 static int
429 extract_escaped_event(const unsigned char *buf, const int buffer_length, smf_event_t *event, int *len, int last_status)
430 {
431 int status, message_length, vlq_length;
432 const unsigned char *c = buf;
433
434 status = *buf;
435
436 assert(is_escape_byte(status));
437
438 c++;
439
440 message_length = expected_escaped_length(status, c, buffer_length - 1, &vlq_length);
441
442 if (message_length < 0)
443 return (-3);
444
445 c += vlq_length;
446
447 if (vlq_length + message_length >= buffer_length) {
448 g_critical("End of buffer in extract_escaped_event().");
449 return (-5);
450 }
451
452 event->midi_buffer_length = message_length;
453 event->midi_buffer = malloc(event->midi_buffer_length);
454 if (event->midi_buffer == NULL) {
455 g_critical("Cannot allocate memory in extract_escaped_event(): %s", strerror(errno));
456 return (-4);
457 }
458
459 memcpy(event->midi_buffer, c, message_length);
460
461 if (smf_event_is_valid(event)) {
462 g_critical("Escaped event is invalid.");
463 return (-1);
464 }
465
466 if (smf_event_is_system_realtime(event) || smf_event_is_system_common(event)) {
467 g_warning("Escaped event is not System Realtime nor System Common.");
468 }
469
470 *len = vlq_length + message_length;
471
472 return (0);
473 }
474
475
481 static int
482 extract_midi_event(const unsigned char *buf, const int buffer_length, smf_event_t *event, int *len, int last_status)
483 {
484 int status, message_length;
485 const unsigned char *c = buf;
486
487 assert(buffer_length > 0);
488
489 /* Is the first byte the status byte? */
490 if (is_status_byte(*c)) {
491 status = *c;
492 c++;
493
494 } else {
495 /* No, we use running status then. */
496 status = last_status;
497 }
498
499 if (!is_status_byte(status)) {
500 g_critical("SMF error: bad status byte (MSB is zero).");
501 return (-1);
502 }
503
504 if (is_sysex_byte(status))
505 return (extract_sysex_event(buf, buffer_length, event, len, last_status));
506
507 if (is_escape_byte(status))
508 return (extract_escaped_event(buf, buffer_length, event, len, last_status));
509
510 /* At this point, "c" points to first byte following the status byte. */
511 message_length = expected_message_length(status, c, buffer_length - (c - buf));
512
513 if (message_length < 0)
514 return (-3);
515
516 if (message_length - 1 > buffer_length - (c - buf)) {
517 g_critical("End of buffer in extract_midi_event().");
518 return (-5);
519 }
520
521 event->midi_buffer_length = message_length;
522 event->midi_buffer = malloc(event->midi_buffer_length);
523 if (event->midi_buffer == NULL) {
524 g_critical("Cannot allocate memory in extract_midi_event(): %s", strerror(errno));
525 return (-4);
526 }
527
528 event->midi_buffer[0] = status;
529 memcpy(event->midi_buffer + 1, c, message_length - 1);
530
531 *len = c + message_length - 1 - buf;
532
533 return (0);
534 }
535
542 static smf_event_t *
543 parse_next_event(smf_track_t *track)
544 {
545 int time = 0, len, buffer_length;
546 unsigned char *c, *start;
547
548 smf_event_t *event = smf_event_new();
549 if (event == NULL)
550 goto error;
551
552 c = start = (unsigned char *)track->file_buffer + track->next_event_offset;
553
554 assert(track->file_buffer != NULL);
555 assert(track->file_buffer_length > 0);
556 assert(track->next_event_offset > 0);
557
558 buffer_length = track->file_buffer_length - track->next_event_offset;
559 assert(buffer_length > 0);
560
561 /* First, extract time offset from previous event. */
562 if (extract_vlq(c, buffer_length, &time, &len))
563 goto error;
564
565 c += len;
566 buffer_length -= len;
567
568 if (buffer_length <= 0)
569 goto error;
570
571 /* Now, extract the actual event. */
572 if (extract_midi_event(c, buffer_length, event, &len, track->last_status))
573 goto error;
574
575 c += len;
576 buffer_length -= len;
577 track->last_status = event->midi_buffer[0];
578 track->next_event_offset += c - start;
579
580 smf_track_add_event_delta_pulses(track, event, time);
581
582 return (event);
583
584 error:
585 if (event != NULL)
586 smf_event_delete(event);
587
588 return (NULL);
589 }
590
595 static char *
596 make_string(const unsigned char *buf, const int buffer_length, int len)
597 {
598 char *str;
599
600 assert(buffer_length > 0);
601 assert(len > 0);
602
603 if (len > buffer_length) {
604 g_critical("End of buffer in make_string().");
605
606 len = buffer_length;
607 }
608
609 str = malloc(len + 1);
610 if (str == NULL) {
611 g_critical("Cannot allocate memory in make_string().");
612 return (NULL);
613 }
614
615 memcpy(str, buf, len);
616 str[len] = '\0';
617
618 return (str);
619 }
620
626 int
627 smf_event_is_textual(const smf_event_t *event)
628 {
629 if (!smf_event_is_metadata(event))
630 return (0);
631
632 if (event->midi_buffer_length < 4)
633 return (0);
634
635 if (event->midi_buffer[3] < 1 && event->midi_buffer[3] > 9)
636 return (0);
637
638 return (1);
639 }
640
646 char *
647 smf_event_extract_text(const smf_event_t *event)
648 {
649 int string_length = -1, length_length = -1;
650
651 if (!smf_event_is_textual(event))
652 return (NULL);
653
654 if (event->midi_buffer_length < 3) {
655 g_critical("smf_event_extract_text: truncated MIDI message.");
656 return (NULL);
657 }
658
659 extract_vlq((void *)&(event->midi_buffer[2]), event->midi_buffer_length - 2, &string_length, &length_length);
660
661 if (string_length <= 0) {
662 g_critical("smf_event_extract_text: truncated MIDI message.");
663 return (NULL);
664 }
665
666 return (make_string((void *)(&event->midi_buffer[2] + length_length), event->midi_buffer_length - 2 - length_length, string_length));
667 }
668
673 static int
674 parse_mtrk_header(smf_track_t *track)
675 {
676 struct chunk_header_struct *mtrk;
677
678 /* Make sure compiler didn't do anything stupid. */
679 assert(sizeof(struct chunk_header_struct) == 8);
680 assert(track->smf != NULL);
681
682 mtrk = next_chunk(track->smf);
683
684 if (mtrk == NULL)
685 return (-1);
686
687 if (!chunk_signature_matches(mtrk, "MTrk")) {
688 g_warning("SMF warning: Expected MTrk signature, got %c%c%c%c instead; ignoring this chunk.",
689 mtrk->id[0], mtrk->id[1], mtrk->id[2], mtrk->id[3]);
690
691 return (-2);
692 }
693
694 track->file_buffer = mtrk;
695 track->file_buffer_length = sizeof(struct chunk_header_struct) + ntohl(mtrk->length);
696 track->next_event_offset = sizeof(struct chunk_header_struct);
697
698 return (0);
699 }
700
704 static int
705 event_is_end_of_track(const smf_event_t *event)
706 {
707 if (event->midi_buffer[0] == 0xFF && event->midi_buffer[1] == 0x2F)
708 return (1);
709
710 return (0);
711 }
712
717 int
718 smf_event_length_is_valid(const smf_event_t *event)
719 {
720 assert(event);
721 assert(event->midi_buffer);
722
723 if (event->midi_buffer_length < 1)
724 return (0);
725
726 /* We cannot use expected_message_length on sysexes. */
727 if (smf_event_is_sysex(event))
728 return (1);
729
730 if (event->midi_buffer_length != expected_message_length(event->midi_buffer[0],
731 &(event->midi_buffer[1]), event->midi_buffer_length - 1)) {
732
733 return (0);
734 }
735
736 return (1);
737 }
738
743 /* XXX: this routine requires some more work to detect more errors. */
744 int
745 smf_event_is_valid(const smf_event_t *event)
746 {
747 assert(event);
748 assert(event->midi_buffer);
749 assert(event->midi_buffer_length >= 1);
750
751 if (!is_status_byte(event->midi_buffer[0])) {
752 g_critical("First byte of MIDI message is not a valid status byte.");
753
754 return (0);
755 }
756
757 if (!smf_event_length_is_valid(event))
758 return (0);
759
760 return (1);
761 }
762
766 static int
767 parse_mtrk_chunk(smf_track_t *track)
768 {
769 smf_event_t *event;
770
771 if (parse_mtrk_header(track))
772 return (-1);
773
774 for (;;) {
775 event = parse_next_event(track);
776
777 /* Couldn't parse an event? */
778 if (event == NULL) {
779 g_critical("Unable to parse MIDI event; truncating track.");
780 if (smf_track_add_eot_delta_pulses(track, 0) != 0) {
781 g_critical("smf_track_add_eot_delta_pulses failed.");
782 return (-2);
783 }
784 break;
785 }
786
787 assert(smf_event_is_valid(event));
788
789 if (event_is_end_of_track(event))
790 break;
791 }
792
793 track->file_buffer = NULL;
794 track->file_buffer_length = 0;
795 track->next_event_offset = -1;
796
797 return (0);
798 }
799
803 static int
804 load_file_into_buffer(void **file_buffer, int *file_buffer_length, const char *file_name)
805 {
806 FILE *stream = fopen(file_name, "rb");
807
808 if (stream == NULL) {
809 g_critical("Cannot open input file: %s", strerror(errno));
810
811 return (-1);
812 }
813
814 if (fseek(stream, 0, SEEK_END)) {
815 g_critical("fseek(3) failed: %s", strerror(errno));
816
817 return (-2);
818 }
819
820 *file_buffer_length = ftell(stream);
821 if (*file_buffer_length == -1) {
822 g_critical("ftell(3) failed: %s", strerror(errno));
823
824 return (-3);
825 }
826
827 if (fseek(stream, 0, SEEK_SET)) {
828 g_critical("fseek(3) failed: %s", strerror(errno));
829
830 return (-4);
831 }
832
833 *file_buffer = malloc(*file_buffer_length);
834 if (*file_buffer == NULL) {
835 g_critical("malloc(3) failed: %s", strerror(errno));
836
837 return (-5);
838 }
839
840 if (fread(*file_buffer, 1, *file_buffer_length, stream) != *file_buffer_length) {
841 g_critical("fread(3) failed: %s", strerror(errno));
842
843 return (-6);
844 }
845
846 if (fclose(stream)) {
847 g_critical("fclose(3) failed: %s", strerror(errno));
848
849 return (-7);
850 }
851
852 return (0);
853 }
854
859 smf_t *
860 smf_load_from_memory(const void *buffer, const int buffer_length)
861 {
862 int i;
863
864 smf_t *smf = smf_new();
865
866 smf->file_buffer = (void *)buffer;
867 smf->file_buffer_length = buffer_length;
868 smf->next_chunk_offset = 0;
869
870 if (parse_mthd_chunk(smf))
871 return (NULL);
872
873 for (i = 1; i <= smf->expected_number_of_tracks; i++) {
874 smf_track_t *track = smf_track_new();
875 if (track == NULL)
876 return (NULL);
877
878 smf_add_track(smf, track);
879
880 /* Skip unparseable chunks. */
881 if (parse_mtrk_chunk(track)) {
882 g_warning("SMF warning: Cannot load track.");
883 smf_track_delete(track);
884 }
885
886 track->file_buffer = NULL;
887 track->file_buffer_length = 0;
888 track->next_event_offset = -1;
889 }
890
891 if (smf->expected_number_of_tracks != smf->number_of_tracks) {
892 g_warning("SMF warning: MThd header declared %d tracks, but only %d found; continuing anyway.",
893 smf->expected_number_of_tracks, smf->number_of_tracks);
894
895 smf->expected_number_of_tracks = smf->number_of_tracks;
896 }
897
898 smf->file_buffer = NULL;
899 smf->file_buffer_length = 0;
900 smf->next_chunk_offset = -1;
901
902 return (smf);
903 }
904
911 smf_t *
912 smf_load(const char *file_name)
913 {
914 int file_buffer_length;
915 void *file_buffer;
916 smf_t *smf;
917
918 if (load_file_into_buffer(&file_buffer, &file_buffer_length, file_name))
919 return (NULL);
920
921 smf = smf_load_from_memory(file_buffer, file_buffer_length);
922
923 memset(file_buffer, 0, file_buffer_length);
924 free(file_buffer);
925
926 if (smf == NULL)
927 return (NULL);
928
929 smf_rewind(smf);
930
931 return (smf);
932 }
933
smf_rewind
void smf_rewind(smf_t *smf)
Rewinds the SMF.
Definition: smf.c:899
mthd_chunk_struct
SMF chunk, used only by smf_load.c and smf_save.c.
Definition: smf_private.h:59
smf_struct::next_chunk_offset
int next_chunk_offset
Definition: smf.h:243
smf_track_struct::last_status
int last_status
Definition: smf.h:280
smf_struct::format
int format
Definition: smf.h:231
smf_struct::file_buffer
void * file_buffer
Definition: smf.h:241
smf_track_add_event_delta_pulses
void smf_track_add_event_delta_pulses(smf_track_t *track, smf_event_t *event, int pulses)
Adds event to the track at the time "pulses" clocks from the previous event in this track...
Definition: smf_tempo.c:403
chunk_header_struct
SMF chunk header, used only by smf_load.c and smf_save.c.
Definition: smf_private.h:53
smf_event_struct::midi_buffer
unsigned char * midi_buffer
Pointer to the buffer containing MIDI message.
Definition: smf.h:322
smf_track_add_eot_delta_pulses
int smf_track_add_eot_delta_pulses(smf_track_t *track, int delta)
Add End Of Track metaevent.
Definition: smf.c:524
smf_struct
Represents a "song", that is, collection of one or more tracks.
Definition: smf.h:230
chunk_header_struct::length
uint32_t length
Definition: smf_private.h:55
smf_track_struct
Represents a single track.
Definition: smf.h:271
smf_add_track
void smf_add_track(smf_t *smf, smf_track_t *track)
Appends smf_track_t to smf.
Definition: smf.c:156
smf_struct::ppqn
int ppqn
These fields are extracted from "division" field of MThd header.
Definition: smf.h:234
smf_event_is_metadata
int smf_event_is_metadata(const smf_event_t *event) WARN_UNUSED_RESULT
Definition: smf_decode.c:57
smf_event_delete
void smf_event_delete(smf_event_t *event)
Detaches event from its track and frees it.
Definition: smf.c:363
smf_load
smf_t * smf_load(const char *file_name)
Loads SMF file.
Definition: smf_load.c:912
smf_event_is_system_common
int smf_event_is_system_common(const smf_event_t *event) WARN_UNUSED_RESULT
Definition: smf_decode.c:90
smf_track_struct::smf
smf_t * smf
Definition: smf.h:272
smf_struct::expected_number_of_tracks
int expected_number_of_tracks
Definition: smf.h:244
smf_event_length_is_valid
int smf_event_length_is_valid(const smf_event_t *event)
Definition: smf_load.c:718
smf_event_is_sysex
int smf_event_is_sysex(const smf_event_t *event) WARN_UNUSED_RESULT
Definition: smf_decode.c:104
smf_track_new
smf_track_t * smf_track_new(void)
Allocates new smf_track_t structure.
Definition: smf.c:110
smf_event_struct::midi_buffer_length
int midi_buffer_length
Length of the MIDI message in the buffer, in bytes.
Definition: smf.h:325
smf_struct::frames_per_second
int frames_per_second
Definition: smf.h:235
smf_struct::number_of_tracks
int number_of_tracks
Definition: smf.h:237
smf_track_struct::next_event_offset
int next_event_offset
Private, used by smf.c.
Definition: smf.h:284
smf_event_new
smf_event_t * smf_event_new(void)
Allocates new smf_event_t structure.
Definition: smf.c:217
smf_event_is_system_realtime
int smf_event_is_system_realtime(const smf_event_t *event) WARN_UNUSED_RESULT
Definition: smf_decode.c:72
mthd_chunk_struct::number_of_tracks
uint16_t number_of_tracks
Definition: smf_private.h:62
smf.h
Public interface declaration for libsmf, Standard MIDI File format library.
smf_struct::resolution
int resolution
Definition: smf.h:236
smf_event_is_textual
int smf_event_is_textual(const smf_event_t *event)
Definition: smf_load.c:627
is_status_byte
int is_status_byte(const unsigned char status)
Returns 1 if the given byte is a valid status byte, 0 otherwise.
Definition: smf_load.c:251
smf_struct::file_buffer_length
int file_buffer_length
Definition: smf.h:242
mthd_chunk_struct::format
uint16_t format
Definition: smf_private.h:61
smf_track_struct::file_buffer_length
int file_buffer_length
Definition: smf.h:279
smf_event_struct
Represents a single MIDI event or metaevent.
Definition: smf.h:301
smf_private.h
Private header.
smf_track_struct::file_buffer
void * file_buffer
These are private fields using only by loading and saving routines.
Definition: smf.h:278
mthd_chunk_struct::division
uint16_t division
Definition: smf_private.h:63
smf_track_delete
void smf_track_delete(smf_track_t *track)
Detaches track from its smf and frees it.
Definition: smf.c:131
chunk_header_struct::id
char id[4]
Definition: smf_private.h:54
smf_event_extract_text
char * smf_event_extract_text(const smf_event_t *event)
Extracts text from "textual metaevents", such as Text or Lyric.
Definition: smf_load.c:647
smf_load_from_memory
smf_t * smf_load_from_memory(const void *buffer, const int buffer_length)
Creates new SMF and fills it with data loaded from the given buffer.
Definition: smf_load.c:860
smf_new
smf_t * smf_new(void)
Allocates new smf_t structure.
Definition: smf.c:55
smf_event_is_valid
int smf_event_is_valid(const smf_event_t *event)
Definition: smf_load.c:745
smf
smf_t * smf
Definition: smfsh.c:56