forked from WerWolv/ImHex-Patterns
-
Notifications
You must be signed in to change notification settings - Fork 0
/
midi.hexpat
298 lines (278 loc) · 8.02 KB
/
midi.hexpat
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
#include <std/core.pat>
#pragma MIME audio/midi
#pragma endian big
// Only supports format 0
// https://www.music.mcgill.ca/~ich/classes/mumt306/StandardMIDIfileformat.html
bool g_has_more_messages = true;
bool g_has_more_tracks = true;
fn signed14(s16 n) {
// Converts to 14-bit in range 0..16383. Note that MIDI data bytes
// have their first (most significant) bit clear (0), thus each byte
// is in range 0..127
n = ((n & 0x7f) << 7) | ((n >> 8) & 0x7f);
if (n >= 0) {
n -= 0x2000;
}
return n;
};
fn u32ify(u32 vlq) {
// Converts from variable-length quantity to u32. These numbers are
// represented 7 bits per byte, most significant bits first. All bytes
// except the last have bit 7 set, and the last byte has bit 7 clear.
// If the number is in range 0..127, it is thus represented exactly
// as one byte.
u32 n = vlq & 0x7f;
if (vlq & 0x8000 == 0x8000) {
n += ((vlq & 0x7f00) >> 8) * 0x80;
}
if (vlq & 0x800000 == 0x800000) {
n += ((vlq & 0x7f0000) >> 8 * 2) * 0x80 * 0x80;
}
if (vlq & 0x80000000 == 0x80000000) {
n += ((vlq & 0x7f000000) >> 8 * 3) * 0x80 * 0x80 * 0x80;
}
return n;
};
enum Status : u8 {
NoteOff = 0x80 ... 0x8F,
NoteOn = 0x90 ... 0x9F,
PolyphonicAfterTouch = 0xA0 ... 0xAF,
ControlChange = 0xB0 ... 0xBF,
ProgramChange = 0xC0 ... 0xCF,
ChannelAfterTouch = 0xD0 ... 0xDF,
PitchWheel = 0xE0 ... 0xEF,
SysEx = 0xF0,
TimeCodeQtrFrame = 0xF1,
SongPositionPointer = 0xF2,
SongSelect = 0xF3,
Undefined = 0xF4 ... 0xF5,
TuneRequest = 0xF6,
EndOfSysEx = 0xF7,
TimingClock = 0xF8,
Undefined = 0xF9,
Start = 0xFA,
Continue = 0xFB,
Stop = 0xFC,
Undefined = 0xFD,
ActiveSensing = 0xFE,
MetaEvent = 0xFF,
};
Status g_next_status;
enum MetaType : u8 {
SequenceNumber = 0x00,
Text = 0x01,
CopyrightNotice = 0x02,
TrackName = 0x03,
InstrumentName = 0x04,
Lyric = 0x05,
Marker = 0x06,
CuePoint = 0x07,
ChannelPrefix = 0x20,
EndOfTrack = 0x2F,
SetTempo = 0x51,
SMPTEOffset = 0x54,
TimeSignature = 0x58,
KeySignature = 0x59,
SequencerSpecific = 0x7F
};
enum ControlChangeType : u8 {
Bank_Select_MSB = 0,
Modulation_Wheel_MSB = 1,
Breath_Controller_MSB = 2,
Undefined_MSB = 3,
Foot_Pedal_MSB = 4,
Portamento_Time_MSB = 5,
Data_Entry_MSB = 6,
Volume_MSB = 7,
Balance_MSB = 8,
Undefined_MSB = 9,
Pan_MSB = 10,
Expression_MSB = 11,
Effect_Controller_1_MSB = 12,
Effect_Controller_2_MSB = 13,
Undefined_MSB = 14,
Undefined_MSB = 15,
General_Purpose_MSB = 16 ... 19,
Undefined_MSB = 20 ... 31,
Bank_Select_LSB = 32,
Modulation_Wheel_LSB = 33,
Breath_Controller_LSB = 34,
Undefined_LSB = 35,
Foot_Pedal_LSB = 36,
Portamento_Time_LSB = 37,
Data_Entry_LSB = 38,
Volume_LSB = 39,
Balance_LSB = 40,
Undefined_LSB = 41,
Pan_LSB = 42,
Expression_LSB = 43,
Effect_Controller_1_LSB = 44,
Effect_Controller_2_LSB = 45,
Undefined_LSB = 46,
Undefined_LSB = 47,
General_Purpose_LSB = 48 ... 51,
Undefined_LSB = 52 ... 63,
Damper_Pedal = 64,
Portamento = 65,
Sostenuto_Pedal = 66,
Soft_Pedal = 67,
Legato_FootSwitch = 68,
Hold_2 = 69,
Sound_Controller_1 = 70,
Sound_Controller_2 = 71,
Sound_Controller_3 = 72,
Sound_Controller_4 = 73,
Sound_Controller_6 = 75,
Sound_Controller_7 = 76,
Sound_Controller_8 = 77,
Sound_Controller_9 = 78,
Sound_Controller_10 = 79,
General_Purpose_CC_Control = 80 ... 83,
Portamento_CC_Control = 84,
Undefined = 85 ... 87,
High_Resolution_Velocity_Prefix = 88,
Effect_2_Depth = 92,
Effect_3_Depth = 93,
Effect_4_Depth = 94,
Effect_5_Depth = 95,
Data_Increment = 96,
Data_Decrement = 97,
Non_Registered_Parameter_Number_LSB = 98,
Non_Registered_Parameter_Number_MSB = 99,
Registered_Parameter_Number_LSB = 100,
Registered_Parameter_Number_MSB = 101,
Undefined = 102 ... 119,
All_Sound_Off = 120,
Reset_All_Controllers = 121,
Local_Switch = 122,
All_Notes_Off = 123,
Omni_Mode_Off = 124,
Omni_Mode_On = 125,
Mono_Mode = 126,
Poly_Mode = 127,
};
enum HeaderFlag : u32 {
MThd = 0x4D546864
};
enum TrackFlag : u32 {
MTrk = 0x4D54726B
};
struct VariableLengthQuantity<auto name> {
if (std::mem::read_unsigned($, 1) & 0x80 == 0x80) {
if (std::mem::read_unsigned($ + 1, 1) & 0x80 == 0x80) {
if (std::mem::read_unsigned($ + 2, 1) & 0x80 == 0x80) {
u32 value [[format("u32ify"), name(name)]];
} else {
u24 value [[format("u32ify"), name(name)]];
}
} else {
u16 value [[format("u32ify"), name(name)]];
}
} else {
u8 value [[format("u32ify"), name(name)]];
}
};
struct MessageData {
match (u8(g_next_status) & 0xf0) {
(Status::NoteOff | Status::NoteOn): {
u8 note_number;
u8 velocity;
}
(Status::PolyphonicAfterTouch): {
u8 note_number;
u8 amount;
}
(Status::ControlChange): {
ControlChangeType cc_number;
u8 value;
}
(Status::ProgramChange): {
u8 program_number;
}
(Status::ChannelAfterTouch): {
u8 amount;
}
(Status::PitchWheel): {
s16 value [[format("signed14")]];
}
}
match (g_next_status) {
(Status::SysEx | Status::EndOfSysEx): {
// "EndOfSysEx" can appear as the last data byte in a
// system exclusive message, or as the starting byte in
// multi-packet messages
VariableLengthQuantity<"sysex_length"> sysex_length [[inline]];
u8 sysex_data[sysex_length.value];
}
(Status::SongPositionPointer): {
u8 lsb;
u8 msb;
}
(Status::SongSelect): {
u8 song_number;
}
(Status::MetaEvent): {
MetaType meta_type;
VariableLengthQuantity<"meta_length"> meta_length [[inline]];
match (meta_type) {
(MetaType::EndOfTrack): {
g_has_more_messages = false;
g_has_more_tracks = std::mem::read_unsigned($, 4) == le u32(TrackFlag::MTrk);
}
(MetaType::Text
| MetaType::CopyrightNotice
| MetaType::TrackName
| MetaType::InstrumentName
| MetaType::Lyric
| MetaType::Marker
| MetaType::CuePoint): {
char text[meta_length.value];
}
(MetaType::TimeSignature): {
u8 numerator;
u8 denominator;
u8 ticks_per_click;
u8 thirty_second_notes_per_crotchet;
}
(MetaType::KeySignature): {
u8 key;
u8 mode;
}
(MetaType::SetTempo): {
u24 micro_seconds_per_click; // default 1 million
}
(_): {
u8 meta_data[meta_length.value];
}
}
}
}
};
struct Message {
VariableLengthQuantity<"delta"> delta [[inline]];
// Status bytes of MIDI channel messages may be omitted if the
// preceding event is a MIDI channel message with the same status
if (std::mem::read_unsigned($, 1) > 0x7f) {
Status status;
g_next_status = status;
}
MessageData data [[inline]];
};
struct HeaderChunk {
HeaderFlag flag;
u32 length;
u16 mode;
u16 num_tracks;
u16 ticks_per_quarter;
};
struct TrackChunk {
TrackFlag flag;
u32 length;
g_has_more_messages = true;
Message messages[while(g_has_more_messages)];
};
struct MidiFile {
HeaderChunk header;
TrackChunk tracks[while(g_has_more_tracks)];
};
MidiFile midi_file @ 0x00;