3 Ann Hell Ex Machina - Music Software
4 Copyright (C) 2003/2005 Angel Ortega <angel@triptico.com>
6 midi_song.c - MIDI song event stream management
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.
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.
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.
22 http://www.triptico.com
35 #include "ss_core.h" /* for CHANNELS */
42 struct midi_ev_generic
44 song_ev_type type
; /* event type */
45 int msecs
; /* time in milliseconds */
46 int trk_id
; /* track id */
47 int channel
; /* MIDI channel */
50 struct midi_ev_program
52 song_ev_type type
; /* SONG_EV_MIDI_PROGRAM */
56 int program
; /* MIDI program number */
59 struct midi_ev_note_off
61 song_ev_type type
; /* SONG_EV_NOTE_OFF */
65 int note
; /* MIDI note */
68 struct midi_ev_note_on
70 song_ev_type type
; /* SONG_EV_NOTE_ON */
74 int note
; /* MIDI note */
75 int vel
; /* velocity (volume) */
80 struct midi_ev_generic generic
;
81 struct midi_ev_program midi_program
;
82 struct midi_ev_note_on note_on
;
83 struct midi_ev_note_off note_off
;
87 /* the MIDI song stream */
89 static union midi_ev
* midi_song
=NULL
;
90 static int n_midi_ev
=0;
92 /* the MIDI tracks: just a track/channel table */
94 #define MIDI_TRACK_NUM 256
95 static int track_channel
[MIDI_TRACK_NUM
];
97 /* MIDI message types */
99 #define MIDI_MSG_NOTE_ON 0x90
100 #define MIDI_MSG_NOTE_OFF 0x80
101 #define MIDI_MSG_CONTROLLER 0xB0
102 #define MIDI_MSG_PROGRAM 0xC0
110 ********************/
112 static void add_midi_ev(union midi_ev
* e
)
113 /* adds a MIDI song event */
118 midi_song
=(union midi_ev
*)realloc(midi_song
,
119 n_midi_ev
* sizeof(union midi_ev
));
122 memcpy(&midi_song
[n_midi_ev
- 1], e
, sizeof(union midi_ev
));
126 static int midi_ev_cmp_by_time(const void * v1
, const void * v2
)
127 /* MIDI song event compare function for qsort(), by time (for playing) */
129 struct midi_ev_generic
* e1
;
130 struct midi_ev_generic
* e2
;
132 e1
=(struct midi_ev_generic
*)v1
; e2
=(struct midi_ev_generic
*)v2
;
134 if(e1
->msecs
== e2
->msecs
)
135 return(e1
->type
- e2
->type
);
137 return(e1
->msecs
- e2
->msecs
);
141 static int midi_song_convert_events(void)
142 /* converts generic song_ev events to MIDI events */
153 /* resets the MIDI stream */
154 if(midi_song
!= NULL
)
170 /* sets the default track channels sparsely */
171 for(n
=0;n
< MIDI_TRACK_NUM
;n
++)
172 track_channel
[n
]=n
% 16;
174 /* travels the song events generating MIDI song events */
175 for(n
=0;n
< _n_song_ev
;n
++)
177 /* gets the song event */
180 /* calculates the msecs */
181 msecs
=((e
->generic
.time
- time_ac
) * mspw
) + msecs_ac
;
183 /* generic event data */
184 me
.generic
.type
=e
->generic
.type
;
185 me
.generic
.msecs
=msecs
;
186 me
.generic
.trk_id
=e
->generic
.trk_id
;
188 /* if it's not a generic message, set MIDI channel */
189 if(e
->generic
.trk_id
>= 0)
190 me
.generic
.channel
=track_channel
[e
->generic
.trk_id
];
192 /* account the biggest track number seen */
193 if(b_track
< e
->generic
.trk_id
) b_track
=e
->generic
.trk_id
;
195 switch(e
->generic
.type
)
199 /* updates accumulations */
201 time_ac
+= e
->generic
.time
;
203 /* calculates milliseconds-per-whole based on new tempo */
204 mspw
= 1000.0 * 60.0;
205 mspw
/= (e
->tempo
.tempo
/ 4.0);
211 /* just store the values */
217 case SONG_EV_MEASURE
:
219 printf("measure boundary check (must be 0): %d\n",
220 ((int) e
->generic
.time
* num
) % den
);
224 case SONG_EV_MIDI_CHANNEL
:
226 /* stores the channel for this track */
227 track_channel
[e
->midi_channel
.trk_id
]=
228 e
->midi_channel
.channel
- 1;
233 /* convert to note on / off pairs */
235 me
.note_on
.type
=SONG_EV_NOTE_ON
;
236 me
.note_on
.note
=e
->note
.note
;
237 me
.note_on
.vel
=(int)(e
->note
.vol
* 127.0);
241 msecs
+= (int)(e
->note
.len
* mspw
);
243 me
.note_off
.type
=SONG_EV_NOTE_OFF
;
244 me
.note_off
.msecs
=msecs
;
249 case SONG_EV_MIDI_PROGRAM
:
251 /* set MIDI program (instrument) */
252 me
.midi_program
.program
=e
->midi_program
.program
;
257 case SONG_EV_SS_NOTE_ON_BY_TIME
:
260 case SONG_EV_SS_SUSTAIN
:
261 case SONG_EV_SS_CHANNEL_MAP
:
262 case SONG_EV_SS_EFF_DELAY
:
263 case SONG_EV_SS_EFF_ECHO
:
264 case SONG_EV_SS_EFF_COMB
:
265 case SONG_EV_SS_EFF_ALLPASS
:
266 case SONG_EV_SS_EFF_FLANGER
:
267 case SONG_EV_SS_EFF_WOBBLE
:
268 case SONG_EV_SS_EFF_SQWOBBLE
:
269 case SONG_EV_SS_EFF_FADER
:
270 case SONG_EV_SS_EFF_REVERB
:
272 /* softsynth events are ignored */
275 case SONG_EV_NOTE_ON
:
276 case SONG_EV_NOTE_OFF
:
279 /* never found in generic song streams */
284 /* generates an end of event mark, a time after the last one */
285 me
.generic
.type
=SONG_EV_END
;
286 me
.generic
.msecs
=msecs
+ 1000;
289 /* return the number of tracks */
294 int midi_song_play(void)
297 int msecs
, msecs_p
, msecs_d
;
301 unsigned char midimsg
[10];
303 /* convert the song to MIDI events */
304 n_tracks
=midi_song_convert_events();
307 qsort(midi_song
, n_midi_ev
, sizeof(union midi_ev
), midi_ev_cmp_by_time
);
313 /* loop the events */
316 /* process all events for this exact time */
317 while(e
->generic
.msecs
== msecs
)
319 switch(e
->generic
.type
)
321 case SONG_EV_NOTE_ON
:
323 midimsg
[0]=MIDI_MSG_NOTE_ON
|e
->note_on
.channel
;
324 midimsg
[1]=e
->note_on
.note
;
325 midimsg
[2]=e
->note_on
.vel
;
327 write(midi_fd
, midimsg
, 3);
331 case SONG_EV_NOTE_OFF
:
333 midimsg
[0]=MIDI_MSG_NOTE_OFF
|e
->note_off
.channel
;
334 midimsg
[1]=e
->note_off
.note
;
337 write(midi_fd
, midimsg
, 3);
341 case SONG_EV_MIDI_PROGRAM
:
343 midimsg
[0]=MIDI_MSG_PROGRAM
|e
->midi_program
.channel
;
344 midimsg
[1]=e
->midi_program
.program
;
346 write(midi_fd
, midimsg
, 2);
356 /* ignore the rest */
367 /* get time of next event */
369 msecs
=e
->generic
.msecs
;
370 msecs_d
=msecs
- msecs_p
;
372 /* calculate the time to sleep */
373 ts
.tv_sec
=(time_t) msecs_d
/ 1000;
374 ts
.tv_nsec
=(long) ((msecs_d
* 1000000) % 1000000000);
376 nanosleep(&ts
, NULL
);