// Get ticks per quarter from MIDI function getTicksPerQuarter(midiFile)
// Parse MIDI file from ArrayBuffer async function parseMidiFromBuffer(buffer) try // MidiFile library expects Uint8Array or ArrayBuffer const midiFile = new MidiFile(buffer); // ensure parsing await midiFile.parse(); return midiFile; catch (err) console.error(err); throw new Error("Invalid MIDI structure or unsupported format"); midi to thirty dollar website
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes"> <title>MIDI to Sheet Music - $30 Web Tool</title> <!-- Google Fonts + simple reset --> <link href="https://fonts.googleapis.com/css2?family=Inter:opsz,wght@14..32,400;14..32,500;14..32,600&display=swap" rel="stylesheet"> <!-- AlphaVantage for free audio visual? No need. We use MIDI.js + VexFlow style rendering --> <script src="https://cdn.jsdelivr.net/npm/midifile@1.2.1/dist/MidiFile.min.js"></script> <!-- For rendering piano roll & notation: we'll use canvas & VexFlow (free) --> <script src="https://unpkg.com/vexflow@4.2.5/build/cjs/vexflow.js"></script> <!-- html2canvas for PDF generation (free, client-side) --> <script src="https://cdnjs.cloudflare.com/ajax/libs/html2canvas/1.4.1/html2canvas.min.js"></script> <style> * box-sizing: border-box; body font-family: 'Inter', sans-serif; background: #f6f9fc; margin: 0; padding: 24px 20px; color: #1e2a3e; // Get ticks per quarter from MIDI function
.upload-icon font-size: 48px; margin-bottom: 12px; // ensure parsing await midiFile.parse()
// Build simplified events for VexFlow: quantized to quarter notes, limit bars function buildVexFlowNotation(notes, ticksPerQuarter, maxMeasures = 4) if (!notes.length) return []; const ticksPerMeasure = ticksPerQuarter * 4; // 4/4 time sig default const maxTickLimit = ticksPerMeasure * maxMeasures; // filter notes within first N bars const filtered = notes.filter(n => n.startTick < maxTickLimit); // group by startTick and convert to VexFlow stave notes // we'll create an array of objects: keys: [pitchName], duration: string, startTick const pitchToNoteName = (pitch) => const notes = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B']; let octave = Math.floor(pitch / 12) - 1; let noteIndex = pitch % 12; return notes[noteIndex] + '/' + octave; ;
<script> // ---------- GLOBALS ---------- let currentMidiData = null; // raw array buffer let parsedMidi = null; // MidiFile object let currentTrackEvents = []; // simplified notes for piano roll + notation let activeTrackIndex = 0; // we'll merge first non-empty track