File size: 8,414 Bytes
b2f2f57 | 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 | export interface HendrixNote {
onset: number;
offset: number;
pitch: number;
program: number;
isDrum: boolean;
velocity: number;
}
interface Event {
type: "PAD" | "EOS" | "UNK" | "shift" | "pitch" | "velocity" | "tie" | "program" | "drum";
value: number;
}
interface NoteEvent {
isDrum: boolean;
program: number;
time: number | null;
velocity: number;
pitch: number;
}
interface DecodedWindow {
notes: NoteEvent[];
ties: NoteEvent[];
lastActivity: Array<[number, number]>;
start: number;
}
const PROGRAM_GROUPS: Array<[string, number[]]> = [
["acoustic_piano", [0, 1, 3, 6, 7]],
["electric_piano", [2, 4, 5]],
["chromatic_percussion", range(8, 16)],
["organ", range(16, 24)],
["acoustic_guitar", [24, 25]],
["clean_electric_guitar", [26, 27, 28]],
["distorted_electric_guitar", [29, 30, 31]],
["acoustic_bass", [32, 35]],
["electric_bass", [33, 34, 36, 37, 38, 39]],
["violin", [40]], ["viola", [41]], ["cello", [42]], ["contrabass", [43]],
["orchestral_harp", [46]], ["timpani", [47]],
["string_ensemble", [48, 49, 44, 45]], ["synth_strings", [50, 51]],
["voice", [52, 53, 54, 100, 101]], ["orchestra_hit", [55]],
["trumpet", [56, 59]], ["trombone", [57]], ["tuba", [58]],
["french_horn", [60]], ["brass_section", [61, 62, 63]],
["soprano_and_alto_sax", [64, 65]], ["tenor_sax", [66]],
["baritone_sax", [67]], ["oboe", [68]], ["english_horn", [69]],
["bassoon", [70]], ["clarinet", [71]], ["flutes", range(72, 80)],
["synth_lead", range(80, 88)], ["synth_pad", range(88, 96)],
];
function range(start: number, end: number): number[] {
return Array.from({ length: end - start }, (_, index) => start + index);
}
const programNames = new Map<number, string>();
for (const [name, programs] of PROGRAM_GROUPS) {
for (const program of programs) programNames.set(program, name);
}
export function instrumentName(note: HendrixNote): string {
if (note.isDrum) return "drums";
return programNames.get(note.program) ?? `program_${note.program}`;
}
function decodeToken(token: number): Event {
if (token === 0) return { type: "PAD", value: 0 };
if (token === 1) return { type: "EOS", value: 0 };
if (token === 2) return { type: "UNK", value: 0 };
if (token <= 208) return { type: "shift", value: token - 3 };
if (token <= 336) return { type: "pitch", value: token - 209 };
if (token <= 338) return { type: "velocity", value: token - 337 };
if (token === 339) return { type: "tie", value: 0 };
if (token <= 467) return { type: "program", value: token - 340 };
if (token <= 595) return { type: "drum", value: token - 468 };
throw new Error(`unknown token ${token}`);
}
function decodeWindow(tokens: number[], start: number): DecodedWindow {
const events = tokens.map(decodeToken);
let program: number | null = null;
const ties: NoteEvent[] = [];
const lastActivity: Array<[number, number]> = [];
let tieIndex = -1;
for (let i = 0; i < events.length; i++) {
const event = events[i];
if (event.type === "tie") {
tieIndex = i;
break;
}
if (event.type === "shift") break;
if (event.type === "program") program = event.value;
if (event.type === "pitch" && program !== null) {
ties.push({ isDrum: false, program, time: null, velocity: 1, pitch: event.value });
lastActivity.push([program, event.value]);
}
}
if (tieIndex < 0) return { notes: [], ties: [], lastActivity: [], start };
const notes: NoteEvent[] = [];
const startTick = Math.round(start * 100);
let tick = startTick;
let velocity: number | null = null;
for (const event of events.slice(tieIndex + 1)) {
if (event.type === "shift") {
if (event.value > 0) tick = startTick + event.value;
} else if (event.type === "drum") {
notes.push({ isDrum: true, program: 128, time: tick / 100, velocity: 1, pitch: event.value });
} else if (event.type === "program") {
program = event.value;
} else if (event.type === "velocity") {
velocity = event.value;
} else if (event.type === "pitch" && program !== null && velocity !== null) {
const key = `${program}:${event.value}`;
if (velocity > 0) {
lastActivity.push([program, event.value]);
} else {
const index = lastActivity.findIndex(([p, pitch]) => `${p}:${pitch}` === key);
if (index < 0) continue;
lastActivity.splice(index, 1);
}
notes.push({ isDrum: false, program, time: tick / 100, velocity, pitch: event.value });
} else if (event.type === "EOS") {
break;
}
}
notes.sort((a, b) => (a.time ?? 0) - (b.time ?? 0) || Number(a.isDrum) - Number(b.isDrum) || a.program - b.program || a.velocity - b.velocity || a.pitch - b.pitch);
ties.sort((a, b) => Number(a.isDrum) - Number(b.isDrum) || a.program - b.program || a.pitch - b.pitch);
return { notes, ties, lastActivity, start };
}
function notesFromEvents(events: NoteEvent[]): HendrixNote[] {
const active = new Map<string, NoteEvent>();
const notes: HendrixNote[] = [];
events.sort((a, b) => (a.time ?? 0) - (b.time ?? 0) || Number(a.isDrum) - Number(b.isDrum) || a.pitch - b.pitch || a.velocity - b.velocity || a.program - b.program);
for (const event of events) {
if (event.time === null) continue;
if (event.isDrum) {
notes.push({ onset: event.time, offset: event.time + 0.01, pitch: event.pitch, program: 128, isDrum: true, velocity: 1 });
continue;
}
const key = `${event.pitch}:${event.program}`;
if (event.velocity === 1) {
const previous = active.get(key);
if (previous !== undefined && previous.time !== null) {
notes.push({ onset: previous.time, offset: event.time, pitch: event.pitch, program: event.program, isDrum: false, velocity: previous.velocity });
}
active.set(key, event);
} else {
const previous = active.get(key);
active.delete(key);
if (previous !== undefined && previous.time !== null) {
notes.push({ onset: previous.time, offset: event.time, pitch: event.pitch, program: event.program, isDrum: false, velocity: previous.velocity });
}
}
}
for (const event of active.values()) {
if (event.time !== null) notes.push({ onset: event.time, offset: event.time + 0.01, pitch: event.pitch, program: event.program, isDrum: false, velocity: 1 });
}
return notes;
}
function trimOverlaps(notes: HendrixNote[]): HendrixNote[] {
const groups = new Map<string, HendrixNote[]>();
for (const note of notes) {
const key = `${note.pitch}:${note.program}:${Number(note.isDrum)}`;
const group = groups.get(key) ?? [];
group.push(note);
groups.set(key, group);
}
const result: HendrixNote[] = [];
for (const group of groups.values()) {
group.sort((a, b) => a.onset - b.onset);
for (let i = 1; i < group.length; i++) {
if (group[i - 1].offset > group[i].onset) group[i - 1].offset = group[i].onset;
}
result.push(...group.filter((note) => note.onset < note.offset));
}
return result.sort((a, b) => a.onset - b.onset || Number(a.isDrum) - Number(b.isDrum) || a.program - b.program || a.velocity - b.velocity || a.pitch - b.pitch);
}
/** Decode [window][channel][token] output with the upstream tie merge rules. */
export function decodeTrackTokens(
windows: number[][][],
segmentSeconds: number,
duration: number,
): HendrixNote[] {
const channelNotes: HendrixNote[][] = [];
for (let channel = 0; channel < 13; channel++) {
const decoded = windows.map((window, index) => decodeWindow(window[channel], index * segmentSeconds));
const merged: NoteEvent[] = [];
let previousActivity: Array<[number, number]> | null = null;
for (const current of decoded) {
if (previousActivity !== null) {
const ties = new Set(current.ties.map((event) => `${event.program}:${event.pitch}`));
for (const [program, pitch] of previousActivity) {
if (!ties.has(`${program}:${pitch}`)) {
merged.push({ isDrum: false, program, time: current.start, velocity: 0, pitch });
}
}
}
merged.push(...current.notes);
previousActivity = current.lastActivity;
}
channelNotes.push(notesFromEvents(merged));
}
return trimOverlaps(channelNotes.flat())
.filter((note) => note.onset < duration)
.map((note) => ({ ...note, offset: Math.min(duration, Math.max(note.offset, note.onset + 0.01)) }));
}
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