MISSING SHORT NOTES
A short sound is not automatically a MIDI note. In this converter, an audio frame must pass the silence check and yield a usable pitch; adjacent frames of the same detected pitch must then form a note long enough to pass Minimum note. A quiet, noisy, out-of-range, or very brief sound can fail before a note is exported. Test the same file below and change only one control at a time.
PROCESS ON THIS DEVICE
Use one clear recording. Compare the piano-roll preview and note count after each single-control change, then download the .mid file.
INPUT MP3 / WAV / M4A / FLAC / OGG → OUTPUT .MID
or click to choose audio from your device
MP3, WAV, M4A, FLAC, or OGG · one file · up to 50 MB / 5 minutesRESULT
Your audio stays on your device. All processing happens in this browser. No file is uploaded to a server.
SOURCE-CODE CHECK
The script measures frame level against Silence threshold, searches for a pitch inside Pitch range, and groups consecutive accepted pitch frames. It only keeps a grouped note if its duration reaches Minimum note. A lower duration setting helps only at the last gate; it cannot repair a frame that never produced a pitch.
DO NOT CONFUSE
Quantize changes the timing of MIDI events after notes have been detected. It cannot bring back an omitted note. Tempo changes how a beat grid is interpreted; neither control repairs a failed audio detection step.
| Part of this converter | Current source-code value | What it means |
|---|---|---|
| Analysis sample rate | 12,000 samples/second | Decoded audio is downsampled before pitch analysis. |
| Analysis frame | 2,048 samples, about 171 ms | Pitch is estimated from a window, not from an instantaneous point. |
| Frame hop | 512 samples, about 43 ms | Neighboring windows overlap; this is not a hard minimum note length. |
| Default Minimum note | 90 ms | A grouped detected note shorter than this is discarded. |
The time conversions are arithmetic from app.js: samples ÷ 12,000 × 1,000. They are implementation facts, not a promise that any particular real-world note will be recovered.
ONE-CHANGE TEST
Keep the recording fixed. First run the defaults and write down the note count and where the expected note should appear. Lower Minimum note one step and convert again. If it is still absent, reset that control; try a lower Silence threshold. Finally widen only the relevant end of Pitch range. Keep a change only when the intended note appears without unwanted fragments.
SOURCE QUALITY
A dense mix, drum hit, room echo, or pitch slide can confuse a monophonic pitch estimate. Trim to an isolated phrase if possible. Do not rename an audio file to a different extension; a failed decode is separate from a missing detected note.
Use this original short-note test sheet to record what changed and what stayed fixed. For a broader symptom map, see conversion troubleshooting; for a fair A/B test, see compare two results.
QUICK ANSWERS
In this tool, it may fail the loudness check, yield no stable pitch in the selected range, or form a detected note shorter than Minimum note. Test those gates one at a time with the same file.
No. That filter acts only after pitch frames have been grouped into a note. Lowering it can also retain unwanted fragments.
No. Quantize moves the timing of retained notes; it does not analyze the original audio again or add missing pitches.
No. It is this script's analysis-window duration. Overlapping windows and the duration filter are separate mechanisms, so it is not a guaranteed recoverability cutoff.