2 * Copyright (c) 2007, 2008 Edward Tomasz NapieraĆa <trasz@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
31 * Standard MIDI File format loader.
35 /* Reference: http://www.borg.com/~jglatt/tech/midifile.htm */
43 #ifdef PLATFORM_WINDOWS
46 #include <arpa/inet.h>
49 #include "smf_private.h"
52 * Returns pointer to the next SMF chunk in smf->buffer, based on length of the previous one.
53 * Returns NULL in case of error.
55 static struct chunk_header_struct *
56 next_chunk(smf_t *smf)
58 struct chunk_header_struct *chunk;
61 assert(smf->file_buffer != NULL);
62 assert(smf->file_buffer_length > 0);
64 if (smf->next_chunk_offset + sizeof(struct chunk_header_struct) >= smf->file_buffer_length) {
65 g_critical("SMF warning: no more chunks left.");
69 next_chunk_ptr = (unsigned char *)smf->file_buffer + smf->next_chunk_offset;
71 chunk = (struct chunk_header_struct *)next_chunk_ptr;
73 if (!isalpha(chunk->id[0]) || !isalpha(chunk->id[1]) || !isalpha(chunk->id[2]) || !isalpha(chunk->id[3])) {
74 g_critical("SMF error: chunk signature contains at least one non-alphanumeric byte.");
79 * XXX: On SPARC, after compiling with "-fast" option there will be SIGBUS here.
80 * Please compile with -xmemalign=8i".
82 smf->next_chunk_offset += sizeof(struct chunk_header_struct) + ntohl(chunk->length);
84 if (smf->next_chunk_offset > smf->file_buffer_length) {
85 g_critical("SMF error: malformed chunk; truncated file?");
92 * Returns 1, iff signature of the "chunk" is the same as string passed as "signature".
95 chunk_signature_matches(const struct chunk_header_struct *chunk, const char *signature)
97 if (!memcmp(chunk->id, signature, 4))
104 * Verifies if MThd header looks OK. Returns 0 iff it does.
107 parse_mthd_header(smf_t *smf)
110 struct chunk_header_struct *mthd, *tmp_mthd;
112 /* Make sure compiler didn't do anything stupid. */
113 assert(sizeof(struct chunk_header_struct) == 8);
116 * We could just do "mthd = smf->file_buffer;" here, but this way we wouldn't
117 * get useful error messages.
119 if (smf->file_buffer_length < 6) {
120 g_critical("SMF error: file is too short, it cannot be a MIDI file.");
125 tmp_mthd = (struct chunk_header_struct*)smf->file_buffer;
127 if (!chunk_signature_matches(tmp_mthd, "MThd")) {
128 g_critical("SMF error: MThd signature not found, is that a MIDI file?");
133 /* Ok, now use next_chunk(). */
134 mthd = next_chunk(smf);
138 assert(mthd == tmp_mthd);
140 len = ntohl(mthd->length);
142 g_critical("SMF error: MThd chunk length %d, must be 6.", len);
151 * Parses MThd chunk, filling "smf" structure with values extracted from it. Returns 0 iff everything went OK.
154 parse_mthd_chunk(smf_t *smf)
156 signed char first_byte_of_division, second_byte_of_division;
158 struct mthd_chunk_struct *mthd;
160 assert(sizeof(struct mthd_chunk_struct) == 14);
162 if (parse_mthd_header(smf))
165 mthd = (struct mthd_chunk_struct *)smf->file_buffer;
167 smf->format = ntohs(mthd->format);
168 if (smf->format < 0 || smf->format > 2) {
169 g_critical("SMF error: bad MThd format field value: %d, valid values are 0-2, inclusive.", smf->format);
173 if (smf->format == 2) {
174 g_critical("SMF file uses format #2, no support for that yet.");
178 smf->expected_number_of_tracks = ntohs(mthd->number_of_tracks);
179 if (smf->expected_number_of_tracks <= 0) {
180 g_critical("SMF error: bad number of tracks: %d, must be greater than zero.", smf->expected_number_of_tracks);
184 /* XXX: endianess? */
185 first_byte_of_division = *((signed char *)&(mthd->division));
186 second_byte_of_division = *((signed char *)&(mthd->division) + 1);
188 if (first_byte_of_division >= 0) {
189 smf->ppqn = ntohs(mthd->division);
190 smf->frames_per_second = 0;
194 smf->frames_per_second = - first_byte_of_division;
195 smf->resolution = second_byte_of_division;
198 if (smf->ppqn == 0) {
199 g_critical("SMF file uses FPS timing instead of PPQN, no support for that yet.");
207 * Interprets Variable Length Quantity pointed at by "buf" and puts its value into "value" and number
208 * of bytes consumed into "len", making sure it does not read past "buf" + "buffer_length".
209 * Explanation of Variable Length Quantities is here: http://www.borg.com/~jglatt/tech/midifile/vari.htm
210 * Returns 0 iff everything went OK, different value in case of error.
213 smf_extract_vlq(const unsigned char *buf, const size_t buffer_length, uint32_t *value, uint32_t *len)
216 const unsigned char *c = buf;
219 if (c >= buf + buffer_length) {
220 g_critical("End of buffer in extract_vlq().");
224 val = (val << 7) + (*c & 0x7F);
237 g_critical("SMF error: Variable Length Quantities longer than four bytes are not supported yet.");
245 * Returns 1 if the given byte is a valid status byte, 0 otherwise.
248 is_status_byte(const unsigned char status)
250 return (status & 0x80);
254 is_sysex_byte(const unsigned char status)
263 is_escape_byte(const unsigned char status)
272 * Just like expected_message_length(), but only for System Exclusive messages.
273 * Note that value returned by this thing here is the length of SysEx "on the wire",
274 * not the number of bytes that this sysex takes in the file - in SMF format sysex
275 * contains VLQ telling how many bytes it takes, "on the wire" format does not have
279 expected_sysex_length(const unsigned char status, const unsigned char *second_byte, const size_t buffer_length, int32_t *consumed_bytes)
281 uint32_t sysex_length = 0;
287 assert(status == 0xF0);
290 if (buffer_length < 3) {
291 g_critical("SMF error: end of buffer in expected_sysex_length().");
295 smf_extract_vlq(second_byte, buffer_length, &sysex_length, &len);
297 if (consumed_bytes != NULL)
298 *consumed_bytes = len;
300 /* +1, because the length does not include status byte. */
301 return (sysex_length + 1);
305 expected_escaped_length(const unsigned char status, const unsigned char *second_byte, const size_t buffer_length, int32_t *consumed_bytes)
307 /* -1, because we do not want to account for 0x7F status. */
308 return (expected_sysex_length(status, second_byte, buffer_length, consumed_bytes) - 1);
312 * Returns expected length of the midi message (including the status byte), in bytes, for the given status byte.
313 * The "second_byte" points to the expected second byte of the MIDI message. "buffer_length" is the buffer
314 * length limit, counting from "second_byte". Returns value < 0 iff there was an error.
317 expected_message_length(unsigned char status, const unsigned char *second_byte, const size_t buffer_length)
319 /* Make sure this really is a valid status byte. */
320 assert(is_status_byte(status));
322 /* We cannot use this routine for sysexes. */
323 assert(!is_sysex_byte(status));
325 /* We cannot use this routine for escaped events. */
326 assert(!is_escape_byte(status));
328 /* Is this a metamessage? */
329 if (status == 0xFF) {
330 if (buffer_length < 2) {
331 g_critical("SMF error: end of buffer in expected_message_length().");
336 * Format of this kind of messages is like this: 0xFF 0xwhatever 0xlength and then "length" bytes.
337 * Second byte points to this: ^^^^^^^^^^
339 return (*(second_byte + 1) + 3);
342 if ((status & 0xF0) == 0xF0) {
344 case 0xF2: /* Song Position Pointer. */
347 case 0xF1: /* MTC Quarter Frame. */
348 case 0xF3: /* Song Select. */
351 case 0xF6: /* Tune Request. */
352 case 0xF8: /* MIDI Clock. */
353 case 0xF9: /* Tick. */
354 case 0xFA: /* MIDI Start. */
355 case 0xFB: /* MIDI Continue. */
356 case 0xFC: /* MIDI Stop. */
357 case 0xFE: /* Active Sense. */
361 g_critical("SMF error: unknown 0xFx-type status byte '0x%x'.", status);
366 /* Filter out the channel. */
370 case 0x80: /* Note Off. */
371 case 0x90: /* Note On. */
372 case 0xA0: /* AfterTouch. */
373 case 0xB0: /* Control Change. */
374 case 0xE0: /* Pitch Wheel. */
377 case 0xC0: /* Program Change. */
378 case 0xD0: /* Channel Pressure. */
382 g_critical("SMF error: unknown status byte '0x%x'.", status);
388 extract_sysex_event(const unsigned char *buf, const size_t buffer_length, smf_event_t *event, uint32_t *len, int last_status)
393 int32_t vlq_length, message_length;
394 const unsigned char *c = buf;
398 if (!(is_sysex_byte(status))) {
399 g_critical("Corrupt sysex status byte in extract_sysex_event().");
405 message_length = expected_sysex_length(status, c, buffer_length - 1, &vlq_length);
407 if (message_length < 0)
412 if (vlq_length + (size_t)message_length >= buffer_length) {
413 g_critical("End of buffer in extract_sysex_event().");
417 event->midi_buffer_length = message_length;
418 event->midi_buffer = (uint8_t*)malloc(event->midi_buffer_length);
419 if (event->midi_buffer == NULL) {
420 g_critical("Cannot allocate memory in extract_sysex_event(): %s", strerror(errno));
424 event->midi_buffer[0] = status;
425 memcpy(event->midi_buffer + 1, c, message_length - 1);
427 *len = vlq_length + message_length;
433 extract_escaped_event(const unsigned char *buf, const size_t buffer_length, smf_event_t *event, uint32_t *len, int last_status)
438 int32_t message_length = 0;
439 int32_t vlq_length = 0;
440 const unsigned char *c = buf;
444 if (!(is_escape_byte(status))) {
445 g_critical("Corrupt escape status byte in extract_escaped_event().");
451 message_length = expected_escaped_length(status, c, buffer_length - 1, &vlq_length);
453 if (message_length < 0)
458 if (vlq_length + (size_t)message_length >= buffer_length) {
459 g_critical("End of buffer in extract_escaped_event().");
463 event->midi_buffer_length = message_length;
464 event->midi_buffer = (uint8_t*)malloc(event->midi_buffer_length);
465 if (event->midi_buffer == NULL) {
466 g_critical("Cannot allocate memory in extract_escaped_event(): %s", strerror(errno));
470 memcpy(event->midi_buffer, c, message_length);
472 if (smf_event_is_valid(event)) {
473 g_critical("Escaped event is invalid.");
477 if (smf_event_is_system_realtime(event) || smf_event_is_system_common(event)) {
478 g_warning("Escaped event is not System Realtime nor System Common.");
481 *len = vlq_length + message_length;
488 * Puts MIDI data extracted from from "buf" into "event" and number of consumed bytes into "len".
489 * In case valid status is not found, it uses "last_status" (so called "running status").
490 * Returns 0 iff everything went OK, value < 0 in case of error.
493 extract_midi_event(const unsigned char *buf, const size_t buffer_length, smf_event_t *event, uint32_t *len, int last_status)
496 int32_t message_length;
497 const unsigned char *c = buf;
499 assert(buffer_length > 0);
501 /* Is the first byte the status byte? */
502 if (is_status_byte(*c)) {
507 /* No, we use running status then. */
508 status = last_status;
511 if (!is_status_byte(status)) {
512 g_critical("SMF error: bad status byte (MSB is zero).");
516 if (is_sysex_byte(status))
517 return (extract_sysex_event(buf, buffer_length, event, len, last_status));
519 if (is_escape_byte(status))
520 return (extract_escaped_event(buf, buffer_length, event, len, last_status));
522 /* At this point, "c" points to first byte following the status byte. */
523 message_length = expected_message_length(status, c, buffer_length - (c - buf));
525 if (message_length < 0)
528 if ((size_t)message_length > buffer_length - (c - buf) + 1) {
529 g_critical("End of buffer in extract_midi_event().");
533 event->midi_buffer_length = message_length;
534 event->midi_buffer = (uint8_t*)malloc(event->midi_buffer_length);
535 if (event->midi_buffer == NULL) {
536 g_critical("Cannot allocate memory in extract_midi_event(): %s", strerror(errno));
540 event->midi_buffer[0] = status;
541 memcpy(event->midi_buffer + 1, c, message_length - 1);
543 *len = c + message_length - 1 - buf;
549 * Locates, basing on track->next_event_offset, the next event data in track->buffer,
550 * interprets it, allocates smf_event_t and fills it properly. Returns smf_event_t
551 * or NULL, if there was an error. Allocating event means adding it to the track;
552 * see smf_event_new().
555 parse_next_event(smf_track_t *track)
559 size_t buffer_length;
560 unsigned char *c, *start;
562 smf_event_t *event = smf_event_new();
566 c = start = (unsigned char *)track->file_buffer + track->next_event_offset;
568 assert(track->file_buffer != NULL);
569 assert(track->file_buffer_length > 0);
570 assert(track->next_event_offset > 0);
572 buffer_length = track->file_buffer_length - track->next_event_offset;
573 /* if there was no meta-EOT event, buffer_length can be zero. This is
574 an error in the SMF file, but it shouldn't be treated as fatal.
576 if (buffer_length == 0) {
577 g_warning ("SMF warning: expected EOT at end of track, but none found");
580 /* First, extract time offset from previous event. */
581 if (smf_extract_vlq(c, buffer_length, &etime, &len)) {
586 buffer_length -= len;
588 if (buffer_length <= 0)
591 /* Now, extract the actual event. */
592 if (extract_midi_event(c, buffer_length, event, &len, track->last_status)) {
597 buffer_length -= len;
598 track->last_status = event->midi_buffer[0];
599 track->next_event_offset += c - start;
601 smf_track_add_event_delta_pulses(track, event, etime);
607 smf_event_delete(event);
613 * Takes "len" characters starting in "buf", making sure it does not access past the length of the buffer,
614 * and makes ordinary, zero-terminated string from it. May return NULL if there was any problem.
617 make_string(const unsigned char *buf, const size_t buffer_length, uint32_t len)
621 assert(buffer_length > 0);
624 if (len > buffer_length) {
625 g_critical("End of buffer in make_string().");
630 str = (char*)malloc(len + 1);
632 g_critical("Cannot allocate memory in make_string().");
636 memcpy(str, buf, len);
643 * \return 1, if passed a metaevent containing text, that is, Text, Copyright,
644 * Sequence/Track Name, Instrument, Lyric, Marker, Cue Point, Program Name,
645 * or Device Name; 0 otherwise.
648 smf_event_is_textual(const smf_event_t *event)
650 if (!smf_event_is_metadata(event))
653 if (event->midi_buffer_length < 4)
656 if (event->midi_buffer[3] < 1 || event->midi_buffer[3] > 9)
663 * Extracts text from "textual metaevents", such as Text or Lyric.
665 * \return Zero-terminated string extracted from "text events" or NULL, if there was any problem.
668 smf_event_extract_text(const smf_event_t *event)
670 uint32_t string_length = 0;
671 uint32_t length_length = 0;
673 if (!smf_event_is_textual(event))
676 if (event->midi_buffer_length < 3) {
677 g_critical("smf_event_extract_text: truncated MIDI message.");
681 smf_extract_vlq((const unsigned char*)(void *)&(event->midi_buffer[2]), event->midi_buffer_length - 2, &string_length, &length_length);
683 if (string_length <= 0) {
684 g_critical("smf_event_extract_text: truncated MIDI message.");
688 return (make_string((const unsigned char*)(void *)(&event->midi_buffer[2] + length_length), event->midi_buffer_length - 2 - length_length, string_length));
692 * Verify if the next chunk really is MTrk chunk, and if so, initialize some track variables and return 0.
693 * Return different value otherwise.
696 parse_mtrk_header(smf_track_t *track)
698 struct chunk_header_struct *mtrk;
700 /* Make sure compiler didn't do anything stupid. */
701 assert(sizeof(struct chunk_header_struct) == 8);
702 assert(track->smf != NULL);
704 mtrk = next_chunk(track->smf);
709 if (!chunk_signature_matches(mtrk, "MTrk")) {
710 g_warning("SMF warning: Expected MTrk signature, got %c%c%c%c instead; ignoring this chunk.",
711 mtrk->id[0], mtrk->id[1], mtrk->id[2], mtrk->id[3]);
716 track->file_buffer = mtrk;
717 track->file_buffer_length = sizeof(struct chunk_header_struct) + ntohl(mtrk->length);
718 track->next_event_offset = sizeof(struct chunk_header_struct);
724 * Return 1 if event is end-of-the-track, 0 otherwise.
727 event_is_end_of_track(const smf_event_t *event)
729 if (event->midi_buffer[0] == 0xFF && event->midi_buffer[1] == 0x2F)
736 * \return Nonzero, if event is as long as it should be, from the MIDI specification point of view.
737 * Does not work for SysExes - it doesn't recognize internal structure of SysEx.
740 smf_event_length_is_valid(const smf_event_t *event)
743 assert(event->midi_buffer);
747 if (event->midi_buffer_length < 1)
750 /* We cannot use expected_message_length on sysexes. */
751 if (smf_event_is_sysex(event))
755 expected = expected_message_length(event->midi_buffer[0],
756 &(event->midi_buffer[1]), event->midi_buffer_length - 1);
757 if (expected < 0 || event->midi_buffer_length != (size_t)expected) {
765 * \return Nonzero, if MIDI data in the event is valid, 0 otherwise. For example,
766 * it checks if event length is correct.
768 /* XXX: this routine requires some more work to detect more errors. */
770 smf_event_is_valid(const smf_event_t *event)
773 assert(event->midi_buffer);
774 assert(event->midi_buffer_length >= 1);
776 if (!is_status_byte(event->midi_buffer[0])) {
777 g_critical("First byte of MIDI message is not a valid status byte.");
782 if (!smf_event_length_is_valid(event))
789 * Parse events and put it on the track.
792 parse_mtrk_chunk(smf_track_t *track)
797 if (parse_mtrk_header(track))
801 event = parse_next_event(track);
803 /* Couldn't parse an event? */
804 if (event == NULL || !smf_event_is_valid(event)) {
809 if (event_is_end_of_track(event))
813 track->file_buffer = NULL;
814 track->file_buffer_length = 0;
815 track->next_event_offset = -1;
821 * Allocate buffer of proper size and read file contents into it.
824 load_file_into_buffer(void **file_buffer, size_t *file_buffer_length, FILE* stream)
828 if (stream == NULL) {
829 g_critical("Cannot open input file: %s", strerror(errno));
834 if (fseek(stream, 0, SEEK_END)) {
835 g_critical("fseek(3) failed: %s", strerror(errno));
840 offset = ftell(stream);
842 g_critical("ftell(3) failed: %s", strerror(errno));
846 *file_buffer_length = (size_t)offset;
848 if (fseek(stream, 0, SEEK_SET)) {
849 g_critical("fseek(3) failed: %s", strerror(errno));
854 *file_buffer = malloc(*file_buffer_length);
855 if (*file_buffer == NULL) {
856 g_critical("malloc(3) failed: %s", strerror(errno));
861 if (fread(*file_buffer, 1, *file_buffer_length, stream) != *file_buffer_length) {
862 g_critical("fread(3) failed: %s", strerror(errno));
872 * Creates new SMF and fills it with data loaded from the given buffer.
873 * \return SMF or NULL, if loading failed.
876 smf_load_from_memory(void *buffer, const size_t buffer_length)
881 smf_t *smf = smf_new();
883 smf->file_buffer = (void *) buffer;
884 smf->file_buffer_length = buffer_length;
885 smf->next_chunk_offset = 0;
887 if (parse_mthd_chunk(smf))
890 for (i = 1; i <= smf->expected_number_of_tracks; i++) {
891 smf_track_t *track = smf_track_new();
895 smf_add_track(smf, track);
897 ret = parse_mtrk_chunk(track);
899 track->file_buffer = NULL;
900 track->file_buffer_length = 0;
901 track->next_event_offset = -1;
904 g_warning("SMF warning: Error parsing track, continuing with data loaded so far.");
909 if (smf->expected_number_of_tracks != smf->number_of_tracks) {
910 g_warning("SMF warning: MThd header declared %d tracks, but only %d found; continuing anyway.",
911 smf->expected_number_of_tracks, smf->number_of_tracks);
913 smf->expected_number_of_tracks = smf->number_of_tracks;
916 smf->file_buffer = NULL;
917 smf->file_buffer_length = 0;
918 smf->next_chunk_offset = 0;
926 * \param file Open file.
927 * \return SMF or NULL, if loading failed.
932 size_t file_buffer_length;
936 if (load_file_into_buffer(&file_buffer, &file_buffer_length, file))
939 smf = smf_load_from_memory(file_buffer, file_buffer_length);
941 memset(file_buffer, 0, file_buffer_length);