midi_song.c

   1 /*
   2
   3     Ann Hell Ex Machina - Music Software
   4     Copyright (C) 2003/2006 Angel Ortega <angel@triptico.com>
   5
   6     midi_song.c - MIDI song event stream management
   7
   8     This program is free software; you can redistribute it and/or
   9     modify it under the terms of the GNU General Public License
  10     as published by the Free Software Foundation; either version 2
  11     of the License, or (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21
  22     http://www.triptico.com
  23
  24 */
  25
  26 #include "config.h"
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <math.h>
  32 #include <time.h>
  33 #include <unistd.h>
  34 #include <sys/types.h>
  35 #include <sys/stat.h>
  36 #include <fcntl.h>
  37
  38 #include "ahxm.h"
  39
  40 /*******************
  41         Data
  42 ********************/
  43
  44 struct midi_ev_generic
  45 {
  46         song_ev_type type;      /* event type */
  47         int msecs;              /* time in milliseconds */
  48         int trk_id;             /* track id */
  49         int channel;            /* MIDI channel */
  50 };
  51
  52 struct midi_ev_program
  53 {
  54         song_ev_type type;      /* SONG_EV_MIDI_PROGRAM */
  55         int msecs;
  56         int trk_id;
  57         int channel;
  58         int program;            /* MIDI program number */
  59 };
  60
  61 struct midi_ev_note_off
  62 {
  63         song_ev_type type;      /* SONG_EV_NOTE_OFF */
  64         int msecs;
  65         int trk_id;
  66         int channel;
  67         int note;               /* MIDI note */
  68 };
  69
  70 struct midi_ev_note_on
  71 {
  72         song_ev_type type;      /* SONG_EV_NOTE_ON */
  73         int msecs;
  74         int trk_id;
  75         int channel;
  76         int note;               /* MIDI note */
  77         int vel;                /* velocity (volume) */
  78 };
  79
  80 union midi_ev
  81 {
  82         struct midi_ev_generic generic;
  83         struct midi_ev_program midi_program;
  84         struct midi_ev_note_on note_on;
  85         struct midi_ev_note_off note_off;
  86 };
  87
  88
  89 /* the MIDI song stream */
  90
  91 static union midi_ev * midi_song = NULL;
  92 static int n_midi_ev = 0;
  93
  94 /* the MIDI tracks: just a track/channel table */
  95
  96 #define MIDI_TRACK_NUM 256
  97 static int track_channel[MIDI_TRACK_NUM];
  98
  99 /* MIDI message types */
 100
 101 #define MIDI_MSG_NOTE_ON    0x90
 102 #define MIDI_MSG_NOTE_OFF   0x80
 103 #define MIDI_MSG_CONTROLLER 0xB0
 104 #define MIDI_MSG_PROGRAM    0xC0
 105
 106 /* MIDI device fd */
 107 int midi_fd = -1;
 108
 109
 110 /*******************
 111         Code
 112 ********************/
 113
 114 static void add_midi_ev(union midi_ev * e)
 115 /* adds a MIDI song event */
 116 {
 117         if(e->generic.channel < 0)
 118                 return;
 119
 120         GROW(midi_song, n_midi_ev, union midi_ev);
 121
 122         /* store */
 123         memcpy(&midi_song[n_midi_ev], e, sizeof(union midi_ev));
 124
 125         n_midi_ev++;
 126 }
 127
 128
 129 static int midi_ev_cmp_by_time(const void * v1, const void * v2)
 130 /* MIDI song event compare function for qsort(), by time (for playing) */
 131 {
 132         struct midi_ev_generic * e1;
 133         struct midi_ev_generic * e2;
 134
 135         e1 = (struct midi_ev_generic *)v1; e2=(struct midi_ev_generic *)v2;
 136
 137         if(e1->msecs == e2->msecs)
 138                 return(e1->type - e2->type);
 139
 140         return(e1->msecs - e2->msecs);
 141 }
 142
 143
 144 static int midi_song_convert_events(void)
 145 /* converts generic song_ev events to MIDI events */
 146 {
 147         union song_ev * e;
 148         union midi_ev me;
 149         int msecs, msecs_ac, f_msecs;
 150         double time_ac, time_ac_m;
 151         int num, den;
 152         double mspw;
 153         int n;
 154         int b_track = -1;
 155
 156         /* resets the MIDI stream */
 157         if(midi_song != NULL)
 158         {
 159                 free(midi_song);
 160                 midi_song = NULL;
 161         }
 162
 163         n_midi_ev = 0;
 164
 165         /* sorts the song */
 166         song_sort();
 167
 168         mspw = 0;
 169         msecs = msecs_ac = f_msecs = 0;
 170         time_ac = time_ac_m = 0;
 171         num = den = 4;
 172
 173         /* by default, all channels are 'mute' until
 174            a channel is explicitly set */
 175         for(n = 0;n < MIDI_TRACK_NUM;n++)
 176                 track_channel[n] = -1;
 177
 178         /* travels the song events generating MIDI song events */
 179         for(n = 0;n < n_song_ev;n++)
 180         {
 181                 /* gets the song event */
 182                 e = &song[n];
 183
 184                 /* calculates the msecs */
 185                 msecs = ((e->generic.time - time_ac) * mspw) + msecs_ac;
 186
 187                 /* generic event data */
 188                 me.generic.type = e->generic.type;
 189                 me.generic.msecs = msecs;
 190                 me.generic.trk_id = e->generic.trk_id;
 191
 192                 /* if it's not a generic message, set MIDI channel */
 193                 if(e->generic.trk_id >= 0)
 194                         me.generic.channel = track_channel[e->generic.trk_id];
 195
 196                 /* account the biggest track number seen */
 197                 if(b_track < e->generic.trk_id) b_track = e->generic.trk_id;
 198
 199                 switch(e->generic.type)
 200                 {
 201                 case SONG_EV_TEMPO:
 202
 203                         /* updates accumulations */
 204                         msecs_ac = msecs;
 205                         time_ac = e->generic.time;
 206
 207                         /* calculates milliseconds-per-whole based on new tempo */
 208                         mspw = 1000.0 * 60.0;
 209                         mspw /= (e->tempo.tempo / 4.0);
 210
 211                         break;
 212
 213                 case SONG_EV_METER:
 214
 215                         /* just store the values */
 216                         num = e->meter.num;
 217                         den = e->meter.den;
 218                         time_ac_m = e->meter.time;
 219
 220                         break;
 221
 222                 case SONG_EV_MEASURE:
 223
 224                         song_test_measure_boundary(e->measure.time - time_ac_m,
 225                                 num, den, e->measure.line);
 226                         break;
 227
 228                 case SONG_EV_MIDI_CHANNEL:
 229
 230                         /* stores the channel for this track */
 231                         track_channel[e->midi_channel.trk_id] =
 232                                 e->midi_channel.channel;
 233                         break;
 234
 235                 case SONG_EV_NOTE:
 236
 237                         /* convert to note on / off pairs */
 238
 239                         me.note_on.type = SONG_EV_NOTE_ON;
 240                         me.note_on.note = e->note.note;
 241                         me.note_on.vel = (int)(e->note.vol * 127.0);
 242
 243                         add_midi_ev(&me);
 244
 245                         msecs += (int)(e->note.len * mspw);
 246
 247                         me.note_off.type = SONG_EV_NOTE_OFF;
 248                         me.note_off.msecs = msecs;
 249
 250                         add_midi_ev(&me);
 251                         break;
 252
 253                 case SONG_EV_BACK:
 254
 255                         /* move the cursor back */
 256                         msecs_ac -= (int)(e->back.len * mspw);
 257                         break;
 258
 259                 case SONG_EV_MIDI_PROGRAM:
 260
 261                         /* set MIDI program (instrument) */
 262                         me.midi_program.program = e->midi_program.program;
 263
 264                         add_midi_ev(&me);
 265                         break;
 266
 267                 case SONG_EV_SS_PITCH_STRETCH:
 268                 case SONG_EV_SS_PRINT_WAVE_TEMPO:
 269                 case SONG_EV_SS_WAV:
 270                 case SONG_EV_SS_PAT:
 271                 case SONG_EV_SS_SUSTAIN:
 272                 case SONG_EV_SS_VIBRATO:
 273                 case SONG_EV_SS_PORTAMENTO:
 274                 case SONG_EV_SS_CHANNEL:
 275                 case SONG_EV_SS_EFF_DELAY:
 276                 case SONG_EV_SS_EFF_ECHO:
 277                 case SONG_EV_SS_EFF_COMB:
 278                 case SONG_EV_SS_EFF_ALLPASS:
 279                 case SONG_EV_SS_EFF_FLANGER:
 280                 case SONG_EV_SS_EFF_WOBBLE:
 281                 case SONG_EV_SS_EFF_SQWOBBLE:
 282                 case SONG_EV_SS_EFF_HFWOBBLE:
 283                 case SONG_EV_SS_EFF_FADER:
 284                 case SONG_EV_SS_EFF_REVERB:
 285                 case SONG_EV_SS_EFF_FOLDBACK:
 286                 case SONG_EV_SS_EFF_OFF:
 287
 288                         /* softsynth events are ignored */
 289                         break;
 290
 291                 case SONG_EV_SONG_INFO:
 292
 293                         /* song info should be used */
 294                         break;
 295
 296                 case SONG_EV_NOTE_ON:
 297                 case SONG_EV_NOTE_OFF:
 298                 case SONG_EV_END:
 299
 300                         /* never found in generic song streams */
 301                         break;
 302                 }
 303
 304                 /* store the further time seen */
 305                 if(f_msecs < msecs) f_msecs = msecs;
 306         }
 307
 308         /* generates an end of event mark, a time after the last one */
 309         me.generic.type = SONG_EV_END;
 310         me.generic.msecs = f_msecs + 1000;
 311         add_midi_ev(&me);
 312
 313         /* return the number of tracks */
 314         return(b_track + 1);
 315 }
 316
 317
 318 int midi_song_play(int skip_secs)
 319 {
 320         union midi_ev * e;
 321         int msecs, msecs_p, msecs_d;
 322         int go;
 323         int n_tracks;
 324         struct timespec ts;
 325         unsigned char midimsg[1024];
 326         int mi;
 327         int skip_msecs;
 328
 329         /* convert the song to MIDI events */
 330         n_tracks = midi_song_convert_events();
 331
 332         /* sort by time */
 333         qsort(midi_song, n_midi_ev, sizeof(union midi_ev), midi_ev_cmp_by_time);
 334
 335         msecs = msecs_p = 0;
 336         go = 1;
 337         e = midi_song;
 338
 339         /* calculate the millisecond to start playing */
 340         skip_msecs = skip_secs * 1000;
 341
 342         /* loop the events */
 343         while(go)
 344         {
 345                 /* clear buffer */
 346                 mi = 0;
 347
 348                 if(verbose >= 1)
 349                 {
 350                         if(msecs % 1000 == 0)
 351                         {
 352                                 int m = msecs / 1000;
 353                                 printf("[%02d:%02d]\r", m / 60, m % 60);
 354                                 fflush(stdout);
 355                         }
 356                 }
 357
 358                 /* process all events for this exact time */
 359                 while(e->generic.msecs == msecs)
 360                 {
 361                         switch(e->generic.type)
 362                         {
 363                         case SONG_EV_NOTE_ON:
 364
 365                                 midimsg[mi++] = MIDI_MSG_NOTE_ON|e->note_on.channel;
 366                                 midimsg[mi++] = e->note_on.note;
 367                                 midimsg[mi++] = e->note_on.vel;
 368
 369                                 break;
 370
 371                         case SONG_EV_NOTE_OFF:
 372
 373                                 midimsg[mi++] = MIDI_MSG_NOTE_OFF|e->note_off.channel;
 374                                 midimsg[mi++] = e->note_off.note;
 375                                 midimsg[mi++] = 0;
 376
 377                                 break;
 378
 379                         case SONG_EV_MIDI_PROGRAM:
 380
 381                                 midimsg[mi++] = MIDI_MSG_PROGRAM|e->midi_program.channel;
 382                                 midimsg[mi++] = e->midi_program.program;
 383
 384                                 break;
 385
 386                         case SONG_EV_END:
 387
 388                                 go = 0;
 389                                 break;
 390
 391                         default:
 392                                 /* ignore the rest */
 393                                 break;
 394                         }
 395
 396                         /* next event */
 397                         e++;
 398                 }
 399
 400                 if(!go)
 401                         break;
 402
 403                 /* get time of next event */
 404                 msecs_p = msecs;
 405                 msecs = e->generic.msecs;
 406                 msecs_d = msecs - msecs_p;
 407
 408                 if(msecs >= skip_msecs)
 409                 {
 410                         /* if there are pending messages, write them */
 411                         if(mi)
 412                                 write(midi_fd, midimsg, mi);
 413
 414                         /* calculate the time to sleep */
 415                         ts.tv_sec = (time_t) msecs_d / 1000;
 416                         ts.tv_nsec = (long) ((msecs_d * 1000000) % 1000000000);
 417
 418                         nanosleep(&ts, NULL);
 419                 }
 420         }
 421
 422         if(verbose >= 1) printf("\n");
 423
 424         return(0);
 425 }
 426
 427
 428 int midi_device_open(char * devfile)
 429 {
 430         if(devfile == NULL)
 431                 devfile = "/dev/midi";
 432
 433         return((midi_fd = open(devfile, O_WRONLY)));
 434 }
 435
 436
 437 void midi_device_close(void)
 438 {
 439         close(midi_fd);
 440 }