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Here's a collection of the C type definitions in this memo. In the
"struct" type definitions, fields are filed in the order shown. A UBYTE
field is packed into an 8-bit byte. Programs should set all "pad" fields
to 0.
#define ID_SMUS MakeID('S', 'M', 'U', 'S')
#define ID_SHDR MakeID('S', 'H', 'D', 'R')
typedef struct {
UWORD tempo; /* tempo, 128ths quarter note/minute */
UBYTE volume; /* overall playback volume 0 through 127 */
UBYTE ctTrack; /* count of tracks in the score */
} SScoreHeader;
#define ID_NAME MakeID('N', 'A', 'M', 'E')
/* NAME chunk contains a CHAR[], the musical score's name. */
#define ID_Copyright MakeID('(', 'c', ')', ' ')
/* "(c) " chunk contains a CHAR[], the FORM's copyright notice. */
#define ID_AUTH MakeID('A', 'U', 'T', 'H')
/* AUTH chunk contains a CHAR[], the name of the score's author. */
#define ID_ANNO MakeID('A', 'N', 'N', 'O')
/* ANNO chunk contains a CHAR[], author's text annotations. */
#define ID_INS1 MakeID('I', 'N', 'S', '1')
/* Values for the RefInstrument field "type". */
#define INS1_Name 0 /* just use the name; ignore data1, data2 */
#define INS1_MIDI 1 /* <data1, data2> = MIDI <channel, preset> */
typedef struct {
UBYTE register; /* set this instrument register number */
UBYTE type; /* instrument reference type */
UBYTE data1, data2; /* depends on the "type" field */
CHAR name[]; /* instrument name */
} RefInstrument;
#define ID_TRAK MakeID('T', 'R', 'A', 'K')
/* TRAK chunk contains an SEvent[]. */
/* SEvent: Simple musical event. */
typedef struct {
UBYTE sID; /* SEvent type code */
UBYTE data; /* sID-dependent data */
} SEvent;
/* SEvent type codes "sID". */
#define SID_FirstNote 0
#define SID_LastNote 127 /* sIDs in the range SID_FirstNote through
* SID_LastNote (sign bit = 0) are notes.
* sID is the MIDI tone number (pitch). */
#define SID_Rest 128 /* a rest (same data format as a note). */
#define SID_Instrument 129 /* set instrument number for this track.*/
#define SID_TimeSig 130 /* set time signature for this track. */
#define SID_KeySig 131 /* set key signature for this track. */
#define SID_Dynamic 132 /* set volume for this track. */
#define SID_MIDI_Chnl 133 /* set MIDI channel number (sequencers) */
#define SID_MIDI_Preset 134 /* set MIDI preset number (sequencers) */
#define SID_Clef 135 /* inline clef change. *
* 0=Treble, 1=Bass, 2=Alto, 3=Tenor. */
#define SID_Tempo 136 /* Inline tempo in beats per minute. */
/* SID values 144 through 159: reserved for Instant Music SEvents. */
/* Remaining sID values up through 254: reserved for future
* standardization. */
#define SID_Mark 255 /* sID reserved for an end-mark in RAM. */
/* SID_FirstNote..SID_LastNote, SID_Rest SEvents */
typedef struct {
UBYTE tone; /* MIDI tone number 0 to 127; 128 = rest */
unsigned chord :1, /* 1 = a chorded note */
tieOut :1, /* 1 = tied to the next note or chord */
nTuplet :2, /* 0 = none, 1 = triplet, 2 = quintuplet,
* 3 = septuplet */
dot :1, /* dotted note; multiply duration by 3/2 */
division :3; /* basic note duration is 2-division:
* 0 = whole note, 1 = half note,
* 2 = quarter note, 7 = 128th note */
} SNote;
#define noteChord (1<<7) /* note is chorded to next note */
#define noteTieOut (1<<6) /* tied to next note/chord */
#define noteNShift 4 /* shift count for nTuplet field */
#define noteN3 (1<<noteNShift) /* note is a triplet */
#define noteN5 (2<<noteNShift) /* note is a quintuplet */
#define noteN7 (3<<noteNShift) /* note is a septuplet */
#define noteNMask noteN7 /* bit mask for the nTuplet field */
#define noteDot (1<<3) /* note is dotted */
#define noteD1 0 /* whole note division */
#define noteD2 1 /* half note division */
#define noteD4 2 /* quarter note division */
#define noteD8 3 /* eighth note division */
#define noteD16 4 /* sixteenth note division */
#define noteD32 5 /* thirty-secondth note division */
#define noteD64 6 /* sixty-fourth note division */
#define noteD128 7 /* 1/128 note division */
#define noteDMask noteD128 /* bit mask for the division field */
#define noteDurMask 0x3F /* mask for combined duration fields */
/* SID_Instrument SEvent */
/* "data" value is an instrument register number 0 through 255. */
/* SID_TimeSig SEvent */
typedef struct {
UBYTE type; /* = SID_TimeSig */
unsigned timeNSig :5, /* time sig. "numerator" is timeNSig + 1 */
timeDSig :3; /* time sig. "denominator" is 2^timeDSig: *
* 0 = whole note, 1 = half note, 2 = *
* quarter note,.... 7 = 128th note */
} STimeSig;
#define timeNMask 0xF8 /* bit mask for the timeNSig field */
#define timeNShift 3 /* shift count for timeNSig field */
#define timeDMask 0x07 /* bit mask for the timeDSig field */
/* SID_KeySig SEvent */
/* "data" value 0 = Cmaj; 1 through 7 = G,D,A,E,B,F#,C#; *
* 8 through 14 = F,Bb,Eb,Ab,Db,Gb,Cb. */
/* SID_Dynamic SEvent */
/* "data" value is a MIDI key velocity 0..127. */