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annotate src/smf_load.c @ 0:4264abea8b06

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smf-lite initial commit
author John Tsiombikas <nuclear@member.fsf.org>
date Thu, 26 Jan 2012 11:25:11 +0200
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nuclear@0 1 /*-
nuclear@0 2 * Copyright (c) 2007, 2008 Edward Tomasz Napierała <trasz@FreeBSD.org>
nuclear@0 3 * All rights reserved.
nuclear@0 4 *
nuclear@0 5 * Redistribution and use in source and binary forms, with or without
nuclear@0 6 * modification, are permitted provided that the following conditions
nuclear@0 7 * are met:
nuclear@0 8 * 1. Redistributions of source code must retain the above copyright
nuclear@0 9 * notice, this list of conditions and the following disclaimer.
nuclear@0 10 * 2. Redistributions in binary form must reproduce the above copyright
nuclear@0 11 * notice, this list of conditions and the following disclaimer in the
nuclear@0 12 * documentation and/or other materials provided with the distribution.
nuclear@0 13 *
nuclear@0 14 * ALTHOUGH THIS SOFTWARE IS MADE OF WIN AND SCIENCE, IT IS PROVIDED BY THE
nuclear@0 15 * AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
nuclear@0 16 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
nuclear@0 17 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
nuclear@0 18 * THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
nuclear@0 19 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
nuclear@0 20 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
nuclear@0 21 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
nuclear@0 22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
nuclear@0 23 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
nuclear@0 24 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
nuclear@0 25 *
nuclear@0 26 */
nuclear@0 27
nuclear@0 28 /**
nuclear@0 29 * \file
nuclear@0 30 *
nuclear@0 31 * Standard MIDI File format loader.
nuclear@0 32 *
nuclear@0 33 */
nuclear@0 34
nuclear@0 35 /* Reference: http://www.borg.com/~jglatt/tech/midifile.htm */
nuclear@0 36
nuclear@0 37 #include <stdlib.h>
nuclear@0 38 #include <string.h>
nuclear@0 39 #include <assert.h>
nuclear@0 40 #include <math.h>
nuclear@0 41 #include <errno.h>
nuclear@0 42 #include <ctype.h>
nuclear@0 43 #ifdef __MINGW32__
nuclear@0 44 #include <windows.h>
nuclear@0 45 #else /* ! __MINGW32__ */
nuclear@0 46 #include <arpa/inet.h>
nuclear@0 47 #endif /* ! __MINGW32__ */
nuclear@0 48 #include "smf.h"
nuclear@0 49 #include "smf_private.h"
nuclear@0 50
nuclear@0 51 /**
nuclear@0 52 * Returns pointer to the next SMF chunk in smf->buffer, based on length of the previous one.
nuclear@0 53 * Returns NULL in case of error.
nuclear@0 54 */
nuclear@0 55 static struct chunk_header_struct *
nuclear@0 56 next_chunk(smf_t *smf)
nuclear@0 57 {
nuclear@0 58 struct chunk_header_struct *chunk;
nuclear@0 59 void *next_chunk_ptr;
nuclear@0 60
nuclear@0 61 assert(smf->file_buffer != NULL);
nuclear@0 62 assert(smf->file_buffer_length > 0);
nuclear@0 63 assert(smf->next_chunk_offset >= 0);
nuclear@0 64
nuclear@0 65 if (smf->next_chunk_offset + sizeof(struct chunk_header_struct) >= smf->file_buffer_length) {
nuclear@0 66 fg_critical("SMF warning: no more chunks left.");
nuclear@0 67 return (NULL);
nuclear@0 68 }
nuclear@0 69
nuclear@0 70 next_chunk_ptr = (unsigned char *)smf->file_buffer + smf->next_chunk_offset;
nuclear@0 71
nuclear@0 72 chunk = (struct chunk_header_struct *)next_chunk_ptr;
nuclear@0 73
nuclear@0 74 if (!isalpha(chunk->id[0]) || !isalpha(chunk->id[1]) || !isalpha(chunk->id[2]) || !isalpha(chunk->id[3])) {
nuclear@0 75 fg_critical("SMF error: chunk signature contains at least one non-alphanumeric byte.");
nuclear@0 76 return (NULL);
nuclear@0 77 }
nuclear@0 78
nuclear@0 79 /*
nuclear@0 80 * XXX: On SPARC, after compiling with "-fast" option there will be SIGBUS here.
nuclear@0 81 * Please compile with -xmemalign=8i".
nuclear@0 82 */
nuclear@0 83 smf->next_chunk_offset += sizeof(struct chunk_header_struct) + ntohl(chunk->length);
nuclear@0 84
nuclear@0 85 if (smf->next_chunk_offset > smf->file_buffer_length) {
nuclear@0 86 fg_critical("SMF warning: malformed chunk; truncated file?");
nuclear@0 87 smf->next_chunk_offset = smf->file_buffer_length;
nuclear@0 88 }
nuclear@0 89
nuclear@0 90 return (chunk);
nuclear@0 91 }
nuclear@0 92
nuclear@0 93 /**
nuclear@0 94 * Returns 1, iff signature of the "chunk" is the same as string passed as "signature".
nuclear@0 95 */
nuclear@0 96 static int
nuclear@0 97 chunk_signature_matches(const struct chunk_header_struct *chunk, const char *signature)
nuclear@0 98 {
nuclear@0 99 if (!memcmp(chunk->id, signature, 4))
nuclear@0 100 return (1);
nuclear@0 101
nuclear@0 102 return (0);
nuclear@0 103 }
nuclear@0 104
nuclear@0 105 /**
nuclear@0 106 * Verifies if MThd header looks OK. Returns 0 iff it does.
nuclear@0 107 */
nuclear@0 108 static int
nuclear@0 109 parse_mthd_header(smf_t *smf)
nuclear@0 110 {
nuclear@0 111 int len;
nuclear@0 112 struct chunk_header_struct *mthd, *tmp_mthd;
nuclear@0 113
nuclear@0 114 /* Make sure compiler didn't do anything stupid. */
nuclear@0 115 assert(sizeof(struct chunk_header_struct) == 8);
nuclear@0 116
nuclear@0 117 /*
nuclear@0 118 * We could just do "mthd = smf->file_buffer;" here, but this way we wouldn't
nuclear@0 119 * get useful error messages.
nuclear@0 120 */
nuclear@0 121 if (smf->file_buffer_length < 6) {
nuclear@0 122 fg_critical("SMF error: file is too short, it cannot be a MIDI file.");
nuclear@0 123
nuclear@0 124 return (-1);
nuclear@0 125 }
nuclear@0 126
nuclear@0 127 tmp_mthd = smf->file_buffer;
nuclear@0 128
nuclear@0 129 if (!chunk_signature_matches(tmp_mthd, "MThd")) {
nuclear@0 130 fg_critical("SMF error: MThd signature not found, is that a MIDI file?");
nuclear@0 131
nuclear@0 132 return (-2);
nuclear@0 133 }
nuclear@0 134
nuclear@0 135 /* Ok, now use next_chunk(). */
nuclear@0 136 mthd = next_chunk(smf);
nuclear@0 137 if (mthd == NULL)
nuclear@0 138 return (-3);
nuclear@0 139
nuclear@0 140 assert(mthd == tmp_mthd);
nuclear@0 141
nuclear@0 142 len = ntohl(mthd->length);
nuclear@0 143 if (len != 6) {
nuclear@0 144 fg_critical("SMF error: MThd chunk length %d, must be 6.", len);
nuclear@0 145
nuclear@0 146 return (-4);
nuclear@0 147 }
nuclear@0 148
nuclear@0 149 return (0);
nuclear@0 150 }
nuclear@0 151
nuclear@0 152 /**
nuclear@0 153 * Parses MThd chunk, filling "smf" structure with values extracted from it. Returns 0 iff everything went OK.
nuclear@0 154 */
nuclear@0 155 static int
nuclear@0 156 parse_mthd_chunk(smf_t *smf)
nuclear@0 157 {
nuclear@0 158 signed char first_byte_of_division, second_byte_of_division;
nuclear@0 159
nuclear@0 160 struct mthd_chunk_struct *mthd;
nuclear@0 161
nuclear@0 162 assert(sizeof(struct mthd_chunk_struct) == 14);
nuclear@0 163
nuclear@0 164 if (parse_mthd_header(smf))
nuclear@0 165 return (1);
nuclear@0 166
nuclear@0 167 mthd = (struct mthd_chunk_struct *)smf->file_buffer;
nuclear@0 168
nuclear@0 169 smf->format = ntohs(mthd->format);
nuclear@0 170 if (smf->format < 0 || smf->format > 2) {
nuclear@0 171 fg_critical("SMF error: bad MThd format field value: %d, valid values are 0-2, inclusive.", smf->format);
nuclear@0 172 return (-1);
nuclear@0 173 }
nuclear@0 174
nuclear@0 175 if (smf->format == 2) {
nuclear@0 176 fg_critical("SMF file uses format #2, no support for that yet.");
nuclear@0 177 return (-2);
nuclear@0 178 }
nuclear@0 179
nuclear@0 180 smf->expected_number_of_tracks = ntohs(mthd->number_of_tracks);
nuclear@0 181 if (smf->expected_number_of_tracks <= 0) {
nuclear@0 182 fg_critical("SMF error: bad number of tracks: %d, must be greater than zero.", smf->expected_number_of_tracks);
nuclear@0 183 return (-3);
nuclear@0 184 }
nuclear@0 185
nuclear@0 186 /* XXX: endianess? */
nuclear@0 187 first_byte_of_division = *((signed char *)&(mthd->division));
nuclear@0 188 second_byte_of_division = *((signed char *)&(mthd->division) + 1);
nuclear@0 189
nuclear@0 190 if (first_byte_of_division >= 0) {
nuclear@0 191 smf->ppqn = ntohs(mthd->division);
nuclear@0 192 smf->frames_per_second = 0;
nuclear@0 193 smf->resolution = 0;
nuclear@0 194 } else {
nuclear@0 195 smf->ppqn = 0;
nuclear@0 196 smf->frames_per_second = - first_byte_of_division;
nuclear@0 197 smf->resolution = second_byte_of_division;
nuclear@0 198 }
nuclear@0 199
nuclear@0 200 if (smf->ppqn == 0) {
nuclear@0 201 fg_critical("SMF file uses FPS timing instead of PPQN, no support for that yet.");
nuclear@0 202 return (-4);
nuclear@0 203 }
nuclear@0 204
nuclear@0 205 return (0);
nuclear@0 206 }
nuclear@0 207
nuclear@0 208 /**
nuclear@0 209 * Interprets Variable Length Quantity pointed at by "buf" and puts its value into "value" and number
nuclear@0 210 * of bytes consumed into "len", making sure it does not read past "buf" + "buffer_length".
nuclear@0 211 * Explanation of Variable Length Quantities is here: http://www.borg.com/~jglatt/tech/midifile/vari.htm
nuclear@0 212 * Returns 0 iff everything went OK, different value in case of error.
nuclear@0 213 */
nuclear@0 214 static int
nuclear@0 215 extract_vlq(const unsigned char *buf, const int buffer_length, int *value, int *len)
nuclear@0 216 {
nuclear@0 217 int val = 0;
nuclear@0 218 const unsigned char *c = buf;
nuclear@0 219
nuclear@0 220 assert(buffer_length > 0);
nuclear@0 221
nuclear@0 222 for (;;) {
nuclear@0 223 if (c >= buf + buffer_length) {
nuclear@0 224 fg_critical("End of buffer in extract_vlq().");
nuclear@0 225 return (-1);
nuclear@0 226 }
nuclear@0 227
nuclear@0 228 val = (val << 7) + (*c & 0x7F);
nuclear@0 229
nuclear@0 230 if (*c & 0x80)
nuclear@0 231 c++;
nuclear@0 232 else
nuclear@0 233 break;
nuclear@0 234 };
nuclear@0 235
nuclear@0 236 *value = val;
nuclear@0 237 *len = c - buf + 1;
nuclear@0 238
nuclear@0 239 if (*len > 4) {
nuclear@0 240 fg_critical("SMF error: Variable Length Quantities longer than four bytes are not supported yet.");
nuclear@0 241 return (-2);
nuclear@0 242 }
nuclear@0 243
nuclear@0 244 return (0);
nuclear@0 245 }
nuclear@0 246
nuclear@0 247 /**
nuclear@0 248 * Returns 1 if the given byte is a valid status byte, 0 otherwise.
nuclear@0 249 */
nuclear@0 250 int
nuclear@0 251 is_status_byte(const unsigned char status)
nuclear@0 252 {
nuclear@0 253 return (status & 0x80);
nuclear@0 254 }
nuclear@0 255
nuclear@0 256 static int
nuclear@0 257 is_sysex_byte(const unsigned char status)
nuclear@0 258 {
nuclear@0 259 if (status == 0xF0)
nuclear@0 260 return (1);
nuclear@0 261
nuclear@0 262 return (0);
nuclear@0 263 }
nuclear@0 264
nuclear@0 265 static int
nuclear@0 266 is_escape_byte(const unsigned char status)
nuclear@0 267 {
nuclear@0 268 if (status == 0xF7)
nuclear@0 269 return (1);
nuclear@0 270
nuclear@0 271 return (0);
nuclear@0 272 }
nuclear@0 273
nuclear@0 274 /**
nuclear@0 275 * Just like expected_message_length(), but only for System Exclusive messages.
nuclear@0 276 * Note that value returned by this thing here is the length of SysEx "on the wire",
nuclear@0 277 * not the number of bytes that this sysex takes in the file - in SMF format sysex
nuclear@0 278 * contains VLQ telling how many bytes it takes, "on the wire" format does not have
nuclear@0 279 * this.
nuclear@0 280 */
nuclear@0 281 static int
nuclear@0 282 expected_sysex_length(const unsigned char status, const unsigned char *second_byte, const int buffer_length, int *consumed_bytes)
nuclear@0 283 {
nuclear@0 284 int sysex_length, len;
nuclear@0 285
nuclear@0 286 assert(status == 0xF0);
nuclear@0 287
nuclear@0 288 if (buffer_length < 3) {
nuclear@0 289 fg_critical("SMF error: end of buffer in expected_sysex_length().");
nuclear@0 290 return (-1);
nuclear@0 291 }
nuclear@0 292
nuclear@0 293 if (extract_vlq(second_byte, buffer_length, &sysex_length, &len))
nuclear@0 294 return (-1);
nuclear@0 295
nuclear@0 296 if (consumed_bytes != NULL)
nuclear@0 297 *consumed_bytes = len;
nuclear@0 298
nuclear@0 299 /* +1, because the length does not include status byte. */
nuclear@0 300 return (sysex_length + 1);
nuclear@0 301 }
nuclear@0 302
nuclear@0 303 static int
nuclear@0 304 expected_escaped_length(const unsigned char status, const unsigned char *second_byte, const int buffer_length, int *consumed_bytes)
nuclear@0 305 {
nuclear@0 306 /* -1, because we do not want to account for 0x7F status. */
nuclear@0 307 return (expected_sysex_length(status, second_byte, buffer_length, consumed_bytes) - 1);
nuclear@0 308 }
nuclear@0 309
nuclear@0 310 /**
nuclear@0 311 * Returns expected length of the midi message (including the status byte), in bytes, for the given status byte.
nuclear@0 312 * The "second_byte" points to the expected second byte of the MIDI message. "buffer_length" is the buffer
nuclear@0 313 * length limit, counting from "second_byte". Returns value < 0 iff there was an error.
nuclear@0 314 */
nuclear@0 315 static int
nuclear@0 316 expected_message_length(unsigned char status, const unsigned char *second_byte, const int buffer_length)
nuclear@0 317 {
nuclear@0 318 /* Make sure this really is a valid status byte. */
nuclear@0 319 assert(is_status_byte(status));
nuclear@0 320
nuclear@0 321 /* We cannot use this routine for sysexes. */
nuclear@0 322 assert(!is_sysex_byte(status));
nuclear@0 323
nuclear@0 324 /* We cannot use this routine for escaped events. */
nuclear@0 325 assert(!is_escape_byte(status));
nuclear@0 326
nuclear@0 327 /* Buffer length may be zero, for e.g. realtime messages. */
nuclear@0 328 assert(buffer_length >= 0);
nuclear@0 329
nuclear@0 330 /* Is this a metamessage? */
nuclear@0 331 if (status == 0xFF) {
nuclear@0 332 if (buffer_length < 2) {
nuclear@0 333 fg_critical("SMF error: end of buffer in expected_message_length().");
nuclear@0 334 return (-1);
nuclear@0 335 }
nuclear@0 336
nuclear@0 337 /*
nuclear@0 338 * Format of this kind of messages is like this: 0xFF 0xwhatever 0xlength and then "length" bytes.
nuclear@0 339 * Second byte points to this: ^^^^^^^^^^
nuclear@0 340 */
nuclear@0 341 return (*(second_byte + 1) + 3);
nuclear@0 342 }
nuclear@0 343
nuclear@0 344 if ((status & 0xF0) == 0xF0) {
nuclear@0 345 switch (status) {
nuclear@0 346 case 0xF2: /* Song Position Pointer. */
nuclear@0 347 return (3);
nuclear@0 348
nuclear@0 349 case 0xF1: /* MTC Quarter Frame. */
nuclear@0 350 case 0xF3: /* Song Select. */
nuclear@0 351 return (2);
nuclear@0 352
nuclear@0 353 case 0xF6: /* Tune Request. */
nuclear@0 354 case 0xF8: /* MIDI Clock. */
nuclear@0 355 case 0xF9: /* Tick. */
nuclear@0 356 case 0xFA: /* MIDI Start. */
nuclear@0 357 case 0xFB: /* MIDI Continue. */
nuclear@0 358 case 0xFC: /* MIDI Stop. */
nuclear@0 359 case 0xFE: /* Active Sense. */
nuclear@0 360 return (1);
nuclear@0 361
nuclear@0 362 default:
nuclear@0 363 fg_critical("SMF error: unknown 0xFx-type status byte '0x%x'.", status);
nuclear@0 364 return (-2);
nuclear@0 365 }
nuclear@0 366 }
nuclear@0 367
nuclear@0 368 /* Filter out the channel. */
nuclear@0 369 status &= 0xF0;
nuclear@0 370
nuclear@0 371 switch (status) {
nuclear@0 372 case 0x80: /* Note Off. */
nuclear@0 373 case 0x90: /* Note On. */
nuclear@0 374 case 0xA0: /* AfterTouch. */
nuclear@0 375 case 0xB0: /* Control Change. */
nuclear@0 376 case 0xE0: /* Pitch Wheel. */
nuclear@0 377 return (3);
nuclear@0 378
nuclear@0 379 case 0xC0: /* Program Change. */
nuclear@0 380 case 0xD0: /* Channel Pressure. */
nuclear@0 381 return (2);
nuclear@0 382
nuclear@0 383 default:
nuclear@0 384 fg_critical("SMF error: unknown status byte '0x%x'.", status);
nuclear@0 385 return (-3);
nuclear@0 386 }
nuclear@0 387 }
nuclear@0 388
nuclear@0 389 static int
nuclear@0 390 extract_sysex_event(const unsigned char *buf, const int buffer_length, smf_event_t *event, int *len, int last_status)
nuclear@0 391 {
nuclear@0 392 int status, message_length, vlq_length;
nuclear@0 393 const unsigned char *c = buf;
nuclear@0 394
nuclear@0 395 status = *buf;
nuclear@0 396
nuclear@0 397 assert(is_sysex_byte(status));
nuclear@0 398
nuclear@0 399 c++;
nuclear@0 400
nuclear@0 401 message_length = expected_sysex_length(status, c, buffer_length - 1, &vlq_length);
nuclear@0 402
nuclear@0 403 if (message_length < 0)
nuclear@0 404 return (-3);
nuclear@0 405
nuclear@0 406 c += vlq_length;
nuclear@0 407
nuclear@0 408 if (vlq_length + message_length >= buffer_length) {
nuclear@0 409 fg_critical("End of buffer in extract_sysex_event().");
nuclear@0 410 return (-5);
nuclear@0 411 }
nuclear@0 412
nuclear@0 413 event->midi_buffer_length = message_length;
nuclear@0 414 event->midi_buffer = malloc(event->midi_buffer_length);
nuclear@0 415 if (event->midi_buffer == NULL) {
nuclear@0 416 fg_critical("Cannot allocate memory in extract_sysex_event(): %s", strerror(errno));
nuclear@0 417 return (-4);
nuclear@0 418 }
nuclear@0 419
nuclear@0 420 event->midi_buffer[0] = status;
nuclear@0 421 memcpy(event->midi_buffer + 1, c, message_length - 1);
nuclear@0 422
nuclear@0 423 *len = vlq_length + message_length;
nuclear@0 424
nuclear@0 425 return (0);
nuclear@0 426 }
nuclear@0 427
nuclear@0 428 static int
nuclear@0 429 extract_escaped_event(const unsigned char *buf, const int buffer_length, smf_event_t *event, int *len, int last_status)
nuclear@0 430 {
nuclear@0 431 int status, message_length, vlq_length;
nuclear@0 432 const unsigned char *c = buf;
nuclear@0 433
nuclear@0 434 status = *buf;
nuclear@0 435
nuclear@0 436 assert(is_escape_byte(status));
nuclear@0 437
nuclear@0 438 c++;
nuclear@0 439
nuclear@0 440 message_length = expected_escaped_length(status, c, buffer_length - 1, &vlq_length);
nuclear@0 441
nuclear@0 442 if (message_length < 0)
nuclear@0 443 return (-3);
nuclear@0 444
nuclear@0 445 c += vlq_length;
nuclear@0 446
nuclear@0 447 if (vlq_length + message_length >= buffer_length) {
nuclear@0 448 fg_critical("End of buffer in extract_escaped_event().");
nuclear@0 449 return (-5);
nuclear@0 450 }
nuclear@0 451
nuclear@0 452 event->midi_buffer_length = message_length;
nuclear@0 453 event->midi_buffer = malloc(event->midi_buffer_length);
nuclear@0 454 if (event->midi_buffer == NULL) {
nuclear@0 455 fg_critical("Cannot allocate memory in extract_escaped_event(): %s", strerror(errno));
nuclear@0 456 return (-4);
nuclear@0 457 }
nuclear@0 458
nuclear@0 459 memcpy(event->midi_buffer, c, message_length);
nuclear@0 460
nuclear@0 461 if (smf_event_is_valid(event)) {
nuclear@0 462 fg_critical("Escaped event is invalid.");
nuclear@0 463 return (-1);
nuclear@0 464 }
nuclear@0 465
nuclear@0 466 if (smf_event_is_system_realtime(event) || smf_event_is_system_common(event)) {
nuclear@0 467 fg_warning("Escaped event is not System Realtime nor System Common.");
nuclear@0 468 }
nuclear@0 469
nuclear@0 470 *len = vlq_length + message_length;
nuclear@0 471
nuclear@0 472 return (0);
nuclear@0 473 }
nuclear@0 474
nuclear@0 475
nuclear@0 476 /**
nuclear@0 477 * Puts MIDI data extracted from from "buf" into "event" and number of consumed bytes into "len".
nuclear@0 478 * In case valid status is not found, it uses "last_status" (so called "running status").
nuclear@0 479 * Returns 0 iff everything went OK, value < 0 in case of error.
nuclear@0 480 */
nuclear@0 481 static int
nuclear@0 482 extract_midi_event(const unsigned char *buf, const int buffer_length, smf_event_t *event, int *len, int last_status)
nuclear@0 483 {
nuclear@0 484 int status, message_length;
nuclear@0 485 const unsigned char *c = buf;
nuclear@0 486
nuclear@0 487 assert(buffer_length > 0);
nuclear@0 488
nuclear@0 489 /* Is the first byte the status byte? */
nuclear@0 490 if (is_status_byte(*c)) {
nuclear@0 491 status = *c;
nuclear@0 492 c++;
nuclear@0 493
nuclear@0 494 } else {
nuclear@0 495 /* No, we use running status then. */
nuclear@0 496 status = last_status;
nuclear@0 497 }
nuclear@0 498
nuclear@0 499 if (!is_status_byte(status)) {
nuclear@0 500 fg_critical("SMF error: bad status byte (MSB is zero).");
nuclear@0 501 return (-1);
nuclear@0 502 }
nuclear@0 503
nuclear@0 504 if (is_sysex_byte(status))
nuclear@0 505 return (extract_sysex_event(buf, buffer_length, event, len, last_status));
nuclear@0 506
nuclear@0 507 if (is_escape_byte(status))
nuclear@0 508 return (extract_escaped_event(buf, buffer_length, event, len, last_status));
nuclear@0 509
nuclear@0 510 /* At this point, "c" points to first byte following the status byte. */
nuclear@0 511 message_length = expected_message_length(status, c, buffer_length - (c - buf));
nuclear@0 512
nuclear@0 513 if (message_length < 0)
nuclear@0 514 return (-3);
nuclear@0 515
nuclear@0 516 if (message_length - 1 > buffer_length - (c - buf)) {
nuclear@0 517 fg_critical("End of buffer in extract_midi_event().");
nuclear@0 518 return (-5);
nuclear@0 519 }
nuclear@0 520
nuclear@0 521 event->midi_buffer_length = message_length;
nuclear@0 522 event->midi_buffer = malloc(event->midi_buffer_length);
nuclear@0 523 if (event->midi_buffer == NULL) {
nuclear@0 524 fg_critical("Cannot allocate memory in extract_midi_event(): %s", strerror(errno));
nuclear@0 525 return (-4);
nuclear@0 526 }
nuclear@0 527
nuclear@0 528 event->midi_buffer[0] = status;
nuclear@0 529 memcpy(event->midi_buffer + 1, c, message_length - 1);
nuclear@0 530
nuclear@0 531 *len = c + message_length - 1 - buf;
nuclear@0 532
nuclear@0 533 return (0);
nuclear@0 534 }
nuclear@0 535
nuclear@0 536 /**
nuclear@0 537 * Locates, basing on track->next_event_offset, the next event data in track->buffer,
nuclear@0 538 * interprets it, allocates smf_event_t and fills it properly. Returns smf_event_t
nuclear@0 539 * or NULL, if there was an error. Allocating event means adding it to the track;
nuclear@0 540 * see smf_event_new().
nuclear@0 541 */
nuclear@0 542 static smf_event_t *
nuclear@0 543 parse_next_event(smf_track_t *track)
nuclear@0 544 {
nuclear@0 545 int time = 0, len, buffer_length;
nuclear@0 546 unsigned char *c, *start;
nuclear@0 547
nuclear@0 548 smf_event_t *event = smf_event_new();
nuclear@0 549 if (event == NULL)
nuclear@0 550 goto error;
nuclear@0 551
nuclear@0 552 c = start = (unsigned char *)track->file_buffer + track->next_event_offset;
nuclear@0 553
nuclear@0 554 assert(track->file_buffer != NULL);
nuclear@0 555 assert(track->file_buffer_length > 0);
nuclear@0 556 assert(track->next_event_offset > 0);
nuclear@0 557
nuclear@0 558 buffer_length = track->file_buffer_length - track->next_event_offset;
nuclear@0 559 assert(buffer_length > 0);
nuclear@0 560
nuclear@0 561 /* First, extract time offset from previous event. */
nuclear@0 562 if (extract_vlq(c, buffer_length, &time, &len))
nuclear@0 563 goto error;
nuclear@0 564
nuclear@0 565 c += len;
nuclear@0 566 buffer_length -= len;
nuclear@0 567
nuclear@0 568 if (buffer_length <= 0)
nuclear@0 569 goto error;
nuclear@0 570
nuclear@0 571 /* Now, extract the actual event. */
nuclear@0 572 if (extract_midi_event(c, buffer_length, event, &len, track->last_status))
nuclear@0 573 goto error;
nuclear@0 574
nuclear@0 575 c += len;
nuclear@0 576 buffer_length -= len;
nuclear@0 577 track->last_status = event->midi_buffer[0];
nuclear@0 578 track->next_event_offset += c - start;
nuclear@0 579
nuclear@0 580 smf_track_add_event_delta_pulses(track, event, time);
nuclear@0 581
nuclear@0 582 return (event);
nuclear@0 583
nuclear@0 584 error:
nuclear@0 585 if (event != NULL)
nuclear@0 586 smf_event_delete(event);
nuclear@0 587
nuclear@0 588 return (NULL);
nuclear@0 589 }
nuclear@0 590
nuclear@0 591 /**
nuclear@0 592 * Takes "len" characters starting in "buf", making sure it does not access past the length of the buffer,
nuclear@0 593 * and makes ordinary, zero-terminated string from it. May return NULL if there was any problem.
nuclear@0 594 */
nuclear@0 595 static char *
nuclear@0 596 make_string(const unsigned char *buf, const int buffer_length, int len)
nuclear@0 597 {
nuclear@0 598 char *str;
nuclear@0 599
nuclear@0 600 assert(buffer_length > 0);
nuclear@0 601 assert(len > 0);
nuclear@0 602
nuclear@0 603 if (len > buffer_length) {
nuclear@0 604 fg_critical("End of buffer in make_string().");
nuclear@0 605
nuclear@0 606 len = buffer_length;
nuclear@0 607 }
nuclear@0 608
nuclear@0 609 str = malloc(len + 1);
nuclear@0 610 if (str == NULL) {
nuclear@0 611 fg_critical("Cannot allocate memory in make_string().");
nuclear@0 612 return (NULL);
nuclear@0 613 }
nuclear@0 614
nuclear@0 615 memcpy(str, buf, len);
nuclear@0 616 str[len] = '\0';
nuclear@0 617
nuclear@0 618 return (str);
nuclear@0 619 }
nuclear@0 620
nuclear@0 621 /**
nuclear@0 622 * \return 1, if passed a metaevent containing text, that is, Text, Copyright,
nuclear@0 623 * Sequence/Track Name, Instrument, Lyric, Marker, Cue Point, Program Name,
nuclear@0 624 * or Device Name; 0 otherwise.
nuclear@0 625 */
nuclear@0 626 int
nuclear@0 627 smf_event_is_textual(const smf_event_t *event)
nuclear@0 628 {
nuclear@0 629 if (!smf_event_is_metadata(event))
nuclear@0 630 return (0);
nuclear@0 631
nuclear@0 632 if (event->midi_buffer_length < 4)
nuclear@0 633 return (0);
nuclear@0 634
nuclear@0 635 if (event->midi_buffer[3] < 1 && event->midi_buffer[3] > 9)
nuclear@0 636 return (0);
nuclear@0 637
nuclear@0 638 return (1);
nuclear@0 639 }
nuclear@0 640
nuclear@0 641 /**
nuclear@0 642 * Extracts text from "textual metaevents", such as Text or Lyric.
nuclear@0 643 *
nuclear@0 644 * \return Zero-terminated string extracted from "text events" or NULL, if there was any problem.
nuclear@0 645 */
nuclear@0 646 char *
nuclear@0 647 smf_event_extract_text(const smf_event_t *event)
nuclear@0 648 {
nuclear@0 649 int string_length = -1, length_length = -1;
nuclear@0 650
nuclear@0 651 if (!smf_event_is_textual(event))
nuclear@0 652 return (NULL);
nuclear@0 653
nuclear@0 654 if (event->midi_buffer_length < 3) {
nuclear@0 655 fg_critical("smf_event_extract_text: truncated MIDI message.");
nuclear@0 656 return (NULL);
nuclear@0 657 }
nuclear@0 658
nuclear@0 659 extract_vlq((void *)&(event->midi_buffer[2]), event->midi_buffer_length - 2, &string_length, &length_length);
nuclear@0 660
nuclear@0 661 if (string_length <= 0) {
nuclear@0 662 fg_critical("smf_event_extract_text: truncated MIDI message.");
nuclear@0 663 return (NULL);
nuclear@0 664 }
nuclear@0 665
nuclear@0 666 return (make_string((void *)(&event->midi_buffer[2] + length_length), event->midi_buffer_length - 2 - length_length, string_length));
nuclear@0 667 }
nuclear@0 668
nuclear@0 669 /**
nuclear@0 670 * Verify if the next chunk really is MTrk chunk, and if so, initialize some track variables and return 0.
nuclear@0 671 * Return different value otherwise.
nuclear@0 672 */
nuclear@0 673 static int
nuclear@0 674 parse_mtrk_header(smf_track_t *track)
nuclear@0 675 {
nuclear@0 676 struct chunk_header_struct *mtrk;
nuclear@0 677
nuclear@0 678 /* Make sure compiler didn't do anything stupid. */
nuclear@0 679 assert(sizeof(struct chunk_header_struct) == 8);
nuclear@0 680 assert(track->smf != NULL);
nuclear@0 681
nuclear@0 682 mtrk = next_chunk(track->smf);
nuclear@0 683
nuclear@0 684 if (mtrk == NULL)
nuclear@0 685 return (-1);
nuclear@0 686
nuclear@0 687 if (!chunk_signature_matches(mtrk, "MTrk")) {
nuclear@0 688 fg_warning("SMF warning: Expected MTrk signature, got %c%c%c%c instead; ignoring this chunk.",
nuclear@0 689 mtrk->id[0], mtrk->id[1], mtrk->id[2], mtrk->id[3]);
nuclear@0 690
nuclear@0 691 return (-2);
nuclear@0 692 }
nuclear@0 693
nuclear@0 694 track->file_buffer = mtrk;
nuclear@0 695 track->file_buffer_length = sizeof(struct chunk_header_struct) + ntohl(mtrk->length);
nuclear@0 696 track->next_event_offset = sizeof(struct chunk_header_struct);
nuclear@0 697
nuclear@0 698 return (0);
nuclear@0 699 }
nuclear@0 700
nuclear@0 701 /**
nuclear@0 702 * Return 1 if event is end-of-the-track, 0 otherwise.
nuclear@0 703 */
nuclear@0 704 static int
nuclear@0 705 event_is_end_of_track(const smf_event_t *event)
nuclear@0 706 {
nuclear@0 707 if (event->midi_buffer[0] == 0xFF && event->midi_buffer[1] == 0x2F)
nuclear@0 708 return (1);
nuclear@0 709
nuclear@0 710 return (0);
nuclear@0 711 }
nuclear@0 712
nuclear@0 713 /**
nuclear@0 714 * \return Nonzero, if event is as long as it should be, from the MIDI specification point of view.
nuclear@0 715 * Does not work for SysExes - it doesn't recognize internal structure of SysEx.
nuclear@0 716 */
nuclear@0 717 int
nuclear@0 718 smf_event_length_is_valid(const smf_event_t *event)
nuclear@0 719 {
nuclear@0 720 assert(event);
nuclear@0 721 assert(event->midi_buffer);
nuclear@0 722
nuclear@0 723 if (event->midi_buffer_length < 1)
nuclear@0 724 return (0);
nuclear@0 725
nuclear@0 726 /* We cannot use expected_message_length on sysexes. */
nuclear@0 727 if (smf_event_is_sysex(event))
nuclear@0 728 return (1);
nuclear@0 729
nuclear@0 730 if (event->midi_buffer_length != expected_message_length(event->midi_buffer[0],
nuclear@0 731 &(event->midi_buffer[1]), event->midi_buffer_length - 1)) {
nuclear@0 732
nuclear@0 733 return (0);
nuclear@0 734 }
nuclear@0 735
nuclear@0 736 return (1);
nuclear@0 737 }
nuclear@0 738
nuclear@0 739 /**
nuclear@0 740 * \return Nonzero, if MIDI data in the event is valid, 0 otherwise. For example,
nuclear@0 741 * it checks if event length is correct.
nuclear@0 742 */
nuclear@0 743 /* XXX: this routine requires some more work to detect more errors. */
nuclear@0 744 int
nuclear@0 745 smf_event_is_valid(const smf_event_t *event)
nuclear@0 746 {
nuclear@0 747 assert(event);
nuclear@0 748 assert(event->midi_buffer);
nuclear@0 749 assert(event->midi_buffer_length >= 1);
nuclear@0 750
nuclear@0 751 if (!is_status_byte(event->midi_buffer[0])) {
nuclear@0 752 fg_critical("First byte of MIDI message is not a valid status byte.");
nuclear@0 753
nuclear@0 754 return (0);
nuclear@0 755 }
nuclear@0 756
nuclear@0 757 if (!smf_event_length_is_valid(event))
nuclear@0 758 return (0);
nuclear@0 759
nuclear@0 760 return (1);
nuclear@0 761 }
nuclear@0 762
nuclear@0 763 /**
nuclear@0 764 * Parse events and put it on the track.
nuclear@0 765 */
nuclear@0 766 static int
nuclear@0 767 parse_mtrk_chunk(smf_track_t *track)
nuclear@0 768 {
nuclear@0 769 smf_event_t *event;
nuclear@0 770
nuclear@0 771 if (parse_mtrk_header(track))
nuclear@0 772 return (-1);
nuclear@0 773
nuclear@0 774 for (;;) {
nuclear@0 775 event = parse_next_event(track);
nuclear@0 776
nuclear@0 777 /* Couldn't parse an event? */
nuclear@0 778 if (event == NULL) {
nuclear@0 779 fg_critical("Unable to parse MIDI event; truncating track.");
nuclear@0 780 if (smf_track_add_eot_delta_pulses(track, 0) != 0) {
nuclear@0 781 fg_critical("smf_track_add_eot_delta_pulses failed.");
nuclear@0 782 return (-2);
nuclear@0 783 }
nuclear@0 784 break;
nuclear@0 785 }
nuclear@0 786
nuclear@0 787 assert(smf_event_is_valid(event));
nuclear@0 788
nuclear@0 789 if (event_is_end_of_track(event))
nuclear@0 790 break;
nuclear@0 791 }
nuclear@0 792
nuclear@0 793 track->file_buffer = NULL;
nuclear@0 794 track->file_buffer_length = 0;
nuclear@0 795 track->next_event_offset = -1;
nuclear@0 796
nuclear@0 797 return (0);
nuclear@0 798 }
nuclear@0 799
nuclear@0 800 /**
nuclear@0 801 * Allocate buffer of proper size and read file contents into it. Close file afterwards.
nuclear@0 802 */
nuclear@0 803 static int
nuclear@0 804 load_file_into_buffer(void **file_buffer, int *file_buffer_length, const char *file_name)
nuclear@0 805 {
nuclear@0 806 FILE *stream = fopen(file_name, "rb");
nuclear@0 807
nuclear@0 808 if (stream == NULL) {
nuclear@0 809 fg_critical("Cannot open input file: %s", strerror(errno));
nuclear@0 810
nuclear@0 811 return (-1);
nuclear@0 812 }
nuclear@0 813
nuclear@0 814 if (fseek(stream, 0, SEEK_END)) {
nuclear@0 815 fg_critical("fseek(3) failed: %s", strerror(errno));
nuclear@0 816
nuclear@0 817 return (-2);
nuclear@0 818 }
nuclear@0 819
nuclear@0 820 *file_buffer_length = ftell(stream);
nuclear@0 821 if (*file_buffer_length == -1) {
nuclear@0 822 fg_critical("ftell(3) failed: %s", strerror(errno));
nuclear@0 823
nuclear@0 824 return (-3);
nuclear@0 825 }
nuclear@0 826
nuclear@0 827 if (fseek(stream, 0, SEEK_SET)) {
nuclear@0 828 fg_critical("fseek(3) failed: %s", strerror(errno));
nuclear@0 829
nuclear@0 830 return (-4);
nuclear@0 831 }
nuclear@0 832
nuclear@0 833 *file_buffer = malloc(*file_buffer_length);
nuclear@0 834 if (*file_buffer == NULL) {
nuclear@0 835 fg_critical("malloc(3) failed: %s", strerror(errno));
nuclear@0 836
nuclear@0 837 return (-5);
nuclear@0 838 }
nuclear@0 839
nuclear@0 840 if (fread(*file_buffer, 1, *file_buffer_length, stream) != *file_buffer_length) {
nuclear@0 841 fg_critical("fread(3) failed: %s", strerror(errno));
nuclear@0 842
nuclear@0 843 return (-6);
nuclear@0 844 }
nuclear@0 845
nuclear@0 846 if (fclose(stream)) {
nuclear@0 847 fg_critical("fclose(3) failed: %s", strerror(errno));
nuclear@0 848
nuclear@0 849 return (-7);
nuclear@0 850 }
nuclear@0 851
nuclear@0 852 return (0);
nuclear@0 853 }
nuclear@0 854
nuclear@0 855 /**
nuclear@0 856 * Creates new SMF and fills it with data loaded from the given buffer.
nuclear@0 857 * \return SMF or NULL, if loading failed.
nuclear@0 858 */
nuclear@0 859 smf_t *
nuclear@0 860 smf_load_from_memory(const void *buffer, const int buffer_length)
nuclear@0 861 {
nuclear@0 862 int i;
nuclear@0 863
nuclear@0 864 smf_t *smf = smf_new();
nuclear@0 865
nuclear@0 866 smf->file_buffer = (void *)buffer;
nuclear@0 867 smf->file_buffer_length = buffer_length;
nuclear@0 868 smf->next_chunk_offset = 0;
nuclear@0 869
nuclear@0 870 if (parse_mthd_chunk(smf))
nuclear@0 871 return (NULL);
nuclear@0 872
nuclear@0 873 for (i = 1; i <= smf->expected_number_of_tracks; i++) {
nuclear@0 874 smf_track_t *track = smf_track_new();
nuclear@0 875 if (track == NULL)
nuclear@0 876 return (NULL);
nuclear@0 877
nuclear@0 878 smf_add_track(smf, track);
nuclear@0 879
nuclear@0 880 /* Skip unparseable chunks. */
nuclear@0 881 if (parse_mtrk_chunk(track)) {
nuclear@0 882 fg_warning("SMF warning: Cannot load track.");
nuclear@0 883 smf_track_delete(track);
nuclear@0 884 }
nuclear@0 885
nuclear@0 886 track->file_buffer = NULL;
nuclear@0 887 track->file_buffer_length = 0;
nuclear@0 888 track->next_event_offset = -1;
nuclear@0 889 }
nuclear@0 890
nuclear@0 891 if (smf->expected_number_of_tracks != smf->number_of_tracks) {
nuclear@0 892 fg_warning("SMF warning: MThd header declared %d tracks, but only %d found; continuing anyway.",
nuclear@0 893 smf->expected_number_of_tracks, smf->number_of_tracks);
nuclear@0 894
nuclear@0 895 smf->expected_number_of_tracks = smf->number_of_tracks;
nuclear@0 896 }
nuclear@0 897
nuclear@0 898 smf->file_buffer = NULL;
nuclear@0 899 smf->file_buffer_length = 0;
nuclear@0 900 smf->next_chunk_offset = -1;
nuclear@0 901
nuclear@0 902 return (smf);
nuclear@0 903 }
nuclear@0 904
nuclear@0 905 /**
nuclear@0 906 * Loads SMF file.
nuclear@0 907 *
nuclear@0 908 * \param file_name Path to the file.
nuclear@0 909 * \return SMF or NULL, if loading failed.
nuclear@0 910 */
nuclear@0 911 smf_t *
nuclear@0 912 smf_load(const char *file_name)
nuclear@0 913 {
nuclear@0 914 int file_buffer_length;
nuclear@0 915 void *file_buffer;
nuclear@0 916 smf_t *smf;
nuclear@0 917
nuclear@0 918 if (load_file_into_buffer(&file_buffer, &file_buffer_length, file_name))
nuclear@0 919 return (NULL);
nuclear@0 920
nuclear@0 921 smf = smf_load_from_memory(file_buffer, file_buffer_length);
nuclear@0 922
nuclear@0 923 memset(file_buffer, 0, file_buffer_length);
nuclear@0 924 free(file_buffer);
nuclear@0 925
nuclear@0 926 if (smf == NULL)
nuclear@0 927 return (NULL);
nuclear@0 928
nuclear@0 929 smf_rewind(smf);
nuclear@0 930
nuclear@0 931 return (smf);
nuclear@0 932 }
nuclear@0 933