@midim/shared

Shared utilities for MIDIM OSS tools: MIDI parsing, hashing, canonical JSON, types, error classes, and synthetic MIDI fixtures for testing.

Install

pnpm add @midim/shared

API Usage

import { parseMidi, hashBlake3, hashSha256, canonicalJson } from "@midim/shared";
import { readFileSync } from "node:fs";

// Parse a MIDI file
const buffer = new Uint8Array(readFileSync("song.mid"));
const parsed = parseMidi(buffer);
console.log(parsed.allNotes.length, "notes in", parsed.durationSeconds, "seconds");

// Hash it
const blake3Hash = hashBlake3(buffer);
const sha256Hash = hashSha256(buffer);

// Canonical JSON (RFC 8785)
const canonical = canonicalJson({ z: 1, a: 2 }); // → '{"a":2,"z":1}'

Types

import type { MidiNote, MidiTrack, ParsedMidi, FingerprintResult, DiffResult } from "@midim/shared";

// MidiNote
interface MidiNote {
  pitch: number;       // MIDI pitch 0–127
  startTick: number;   // absolute tick position
  durationTicks: number;
  velocity: number;    // 0–127
  channel: number;
  trackIndex: number;
}

Test Fixtures

Synthetic MIDI generators for unit tests — no .mid files needed:

import { buildScaleMidi, buildChordMidi, buildSyntheticMidi } from "@midim/shared";

const cMajorScale = buildScaleMidi(60, 8);           // 8-note C-major scale
const chords = buildChordMidi([[60,64,67],[65,69,72]]); // two chords

Disclaimer

This package is part of MIDIM OSS tools. It provides local-only analysis utilities. For registry-backed POIM, corpus similarity search, rights registry lookup, and marketplace eligibility, visit MIDIM.net.

License

MIT