midi_song.c

   1 /*
   2
   3     Ann Hell Ex Machina - Music Software
   4     Copyright (C) 2003/2005 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 "annhell.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         /* reallocs */
 121         midi_song=(union midi_ev *)realloc(midi_song,
 122                 (n_midi_ev + 1) * sizeof(union midi_ev));
 123
 124         /* store */
 125         memcpy(&midi_song[n_midi_ev], e, sizeof(union midi_ev));
 126
 127         n_midi_ev++;
 128 }
 129
 130
 131 static int midi_ev_cmp_by_time(const void * v1, const void * v2)
 132 /* MIDI song event compare function for qsort(), by time (for playing) */
 133 {
 134         struct midi_ev_generic * e1;
 135         struct midi_ev_generic * e2;
 136
 137         e1=(struct midi_ev_generic *)v1; e2=(struct midi_ev_generic *)v2;
 138
 139         if(e1->msecs == e2->msecs)
 140                 return(e1->type - e2->type);
 141
 142         return(e1->msecs - e2->msecs);
 143 }
 144
 145
 146 static int midi_song_convert_events(void)
 147 /* converts generic song_ev events to MIDI events */
 148 {
 149         union song_ev * e;
 150         union midi_ev me;
 151         int msecs, msecs_ac, f_msecs;
 152         double time_ac, time_ac_m;
 153         int num, den;
 154         double mspw;
 155         int n;
 156         int b_track=-1;
 157
 158         /* resets the MIDI stream */
 159         if(midi_song != NULL)
 160         {
 161                 free(midi_song);
 162                 midi_song=NULL;
 163         }
 164
 165         n_midi_ev=0;
 166
 167         /* sorts the song */
 168         song_sort();
 169
 170         mspw=0;
 171         msecs=msecs_ac=f_msecs=0;
 172         time_ac=time_ac_m=0;
 173         num=den=4;
 174
 175         /* by default, all channels are 'mute' until
 176            a channel is explicitly set */
 177         for(n=0;n < MIDI_TRACK_NUM;n++)
 178                 track_channel[n]=-1;
 179
 180         /* travels the song events generating MIDI song events */
 181         for(n=0;n < n_song_ev;n++)
 182         {
 183                 /* gets the song event */
 184                 e=&song[n];
 185
 186                 /* calculates the msecs */
 187                 msecs=((e->generic.time - time_ac) * mspw) + msecs_ac;
 188
 189                 /* generic event data */
 190                 me.generic.type=e->generic.type;
 191                 me.generic.msecs=msecs;
 192                 me.generic.trk_id=e->generic.trk_id;
 193
 194                 /* if it's not a generic message, set MIDI channel */
 195                 if(e->generic.trk_id >= 0)
 196                         me.generic.channel=track_channel[e->generic.trk_id];
 197
 198                 /* account the biggest track number seen */
 199                 if(b_track < e->generic.trk_id) b_track=e->generic.trk_id;
 200
 201                 switch(e->generic.type)
 202                 {
 203                 case SONG_EV_TEMPO:
 204
 205                         /* updates accumulations */
 206                         msecs_ac += msecs;
 207                         time_ac += e->generic.time;
 208
 209                         /* calculates milliseconds-per-whole based on new tempo */
 210                         mspw = 1000.0 * 60.0;
 211                         mspw /= (e->tempo.tempo / 4.0);
 212
 213                         break;
 214
 215                 case SONG_EV_METER:
 216
 217                         /* just store the values */
 218                         num=e->meter.num;
 219                         den=e->meter.den;
 220                         time_ac_m=e->meter.time;
 221
 222                         break;
 223
 224                 case SONG_EV_MEASURE:
 225
 226                         song_test_measure_boundary(e->measure.time - time_ac_m,
 227                                 num, den, e->measure.line);
 228                         break;
 229
 230                 case SONG_EV_MIDI_CHANNEL:
 231
 232                         /* stores the channel for this track */
 233                         track_channel[e->midi_channel.trk_id]=
 234                                 e->midi_channel.channel;
 235                         break;
 236
 237                 case SONG_EV_NOTE:
 238
 239                         /* convert to note on / off pairs */
 240
 241                         me.note_on.type=SONG_EV_NOTE_ON;
 242                         me.note_on.note=e->note.note;
 243                         me.note_on.vel=(int)(e->note.vol * 127.0);
 244
 245                         add_midi_ev(&me);
 246
 247                         msecs += (int)(e->note.len * mspw);
 248
 249                         me.note_off.type=SONG_EV_NOTE_OFF;
 250                         me.note_off.msecs=msecs;
 251
 252                         add_midi_ev(&me);
 253                         break;
 254
 255                 case SONG_EV_MIDI_PROGRAM:
 256
 257                         /* set MIDI program (instrument) */
 258                         me.midi_program.program=e->midi_program.program;
 259
 260                         add_midi_ev(&me);
 261                         break;
 262
 263                 case SONG_EV_SS_PITCH_STRETCH:
 264                 case SONG_EV_SS_PRINT_WAVE_TEMPO:
 265                 case SONG_EV_SS_WAV:
 266                 case SONG_EV_SS_PAT:
 267                 case SONG_EV_SS_SUSTAIN:
 268                 case SONG_EV_SS_VIBRATO:
 269                 case SONG_EV_SS_CHANNEL:
 270                 case SONG_EV_SS_EFF_DELAY:
 271                 case SONG_EV_SS_EFF_ECHO:
 272                 case SONG_EV_SS_EFF_COMB:
 273                 case SONG_EV_SS_EFF_ALLPASS:
 274                 case SONG_EV_SS_EFF_FLANGER:
 275                 case SONG_EV_SS_EFF_WOBBLE:
 276                 case SONG_EV_SS_EFF_SQWOBBLE:
 277                 case SONG_EV_SS_EFF_FADER:
 278                 case SONG_EV_SS_EFF_REVERB:
 279                 case SONG_EV_SS_EFF_OFF:
 280
 281                         /* softsynth events are ignored */
 282                         break;
 283
 284                 case SONG_EV_NOTE_ON:
 285                 case SONG_EV_NOTE_OFF:
 286                 case SONG_EV_END:
 287
 288                         /* never found in generic song streams */
 289                         break;
 290                 }
 291
 292                 /* store the further time seen */
 293                 if(f_msecs < msecs) f_msecs=msecs;
 294         }
 295
 296         /* generates an end of event mark, a time after the last one */
 297         me.generic.type=SONG_EV_END;
 298         me.generic.msecs=f_msecs + 1000;
 299         add_midi_ev(&me);
 300
 301         /* return the number of tracks */
 302         return(b_track + 1);
 303 }
 304
 305
 306 int midi_song_play(int skip_secs)
 307 {
 308         union midi_ev * e;
 309         int msecs, msecs_p, msecs_d;
 310         int go;
 311         int n_tracks;
 312         struct timespec ts;
 313         unsigned char midimsg[1024];
 314         int mi;
 315         int skip_msecs;
 316
 317         /* convert the song to MIDI events */
 318         n_tracks=midi_song_convert_events();
 319
 320         /* sort by time */
 321         qsort(midi_song, n_midi_ev, sizeof(union midi_ev), midi_ev_cmp_by_time);
 322
 323         msecs=msecs_p=0;
 324         go=1;
 325         e=midi_song;
 326
 327         /* calculate the millisecond to start playing */
 328         skip_msecs=skip_secs * 1000;
 329
 330         /* loop the events */
 331         while(go)
 332         {
 333                 /* clear buffer */
 334                 mi=0;
 335
 336                 /* process all events for this exact time */
 337                 while(e->generic.msecs == msecs)
 338                 {
 339                         switch(e->generic.type)
 340                         {
 341                         case SONG_EV_NOTE_ON:
 342
 343                                 midimsg[mi++]=MIDI_MSG_NOTE_ON|e->note_on.channel;
 344                                 midimsg[mi++]=e->note_on.note;
 345                                 midimsg[mi++]=e->note_on.vel;
 346
 347                                 break;
 348
 349                         case SONG_EV_NOTE_OFF:
 350
 351                                 midimsg[mi++]=MIDI_MSG_NOTE_OFF|e->note_off.channel;
 352                                 midimsg[mi++]=e->note_off.note;
 353                                 midimsg[mi++]=0;
 354
 355                                 break;
 356
 357                         case SONG_EV_MIDI_PROGRAM:
 358
 359                                 midimsg[mi++]=MIDI_MSG_PROGRAM|e->midi_program.channel;
 360                                 midimsg[mi++]=e->midi_program.program;
 361
 362                                 break;
 363
 364                         case SONG_EV_END:
 365
 366                                 go=0;
 367                                 break;
 368
 369                         default:
 370                                 /* ignore the rest */
 371                                 break;
 372                         }
 373
 374                         /* next event */
 375                         e++;
 376                 }
 377
 378                 if(!go)
 379                         break;
 380
 381                 /* get time of next event */
 382                 msecs_p=msecs;
 383                 msecs=e->generic.msecs;
 384                 msecs_d=msecs - msecs_p;
 385
 386                 if(msecs >= skip_msecs)
 387                 {
 388                         /* if there are pending messages, write them */
 389                         if(mi)
 390                                 write(midi_fd, midimsg, mi);
 391
 392                         /* calculate the time to sleep */
 393                         ts.tv_sec=(time_t) msecs_d / 1000;
 394                         ts.tv_nsec=(long) ((msecs_d * 1000000) % 1000000000);
 395
 396                         nanosleep(&ts, NULL);
 397                 }
 398         }
 399
 400         return(0);
 401 }
 402
 403
 404 int midi_device_open(char * devfile)
 405 {
 406         if(devfile == NULL)
 407                 devfile="/dev/midi";
 408
 409         return((midi_fd=open(devfile, O_WRONLY)));
 410 }
 411
 412
 413 void midi_device_close(void)
 414 {
 415         close(midi_fd);
 416 }