MP3 to MIDI Pre-Flight Check: Can This File Be Transcribed?
Six checks decide whether a file can be transcribed at all. Four take under a minute and cost nothing. Two are ceilings built into the file: if the note you need sits above one of them, that information is not in the file and no converter can put it back. Every threshold below comes from a published limit or specification.
The short answer
- Run the format and ceiling checks first. They are the two that can return a flat no, and neither can be rescued by a later step.
- Two checks are about the recording, not the file: how many notes sound at once, and how long the reverb tail runs against the shortest note you need.
- The cap check is the only one that can cost money if you leave it last: one path charges a credit per song, another per started five-second block with a minimum per job.
- None of this predicts accuracy. The checks separate "this cannot work" from "this can work, and here is what to expect afterwards".
The six checks, in order
1. Is the format accepted as it stands?
jukeblocks' browser tool takes MP3 and WAV and states that FLAC, OGG, AIFF and M4A must be converted first. ai-midi accepts FLAC, MP3, OGG and WAV. A format the tool does not list is a no until it is converted.
2. Does the file's ceiling sit above the notes you need?
Sampling sets the first ceiling: a file carries frequencies up to half its sample rate, so a 22.05 kHz file stops at 11.025 kHz, below the top of the MIDI note range. jukeblocks states that MP3 encoding removes high-frequency detail above 16 kHz. Anything above that ceiling is not in the file.
3. How many notes sound at the same time?
songscription separates monophonic sources, one note at a time, from polyphonic ones where several notes sound together, and states that polyphonic is much harder because the model must identify each pitch in a chord. Count them.
4. Is the reverb tail shorter than the shortest note you need?
ai-midi lists strong reverb among the conditions that lower accuracy. The check is a comparison, not a threshold. Measure how long the tail rings after a note stops, then the shortest note you need to keep. If the tail outlasts the note, adjacent notes overlap.
5. Is there a click inside the file?
jukeblocks states that material played to a click transcribes best and that live or rubato recordings drift against a fixed grid. A click in the performer's headphones is not in the file; a click that bled into the recording is.
6. Does the file fit the cap you are about to use?
Three published caps: jukeblocks' browser tool takes 100 MB and 3 minutes, ai-midi's free tier 50 MB and 5 minutes, jukeblocks' Recreate path 100 MB and 8 minutes. jukeblocks states a stereo WAV at 44.1 kHz and 16-bit runs roughly 10 MB per minute, around 15 MB at 24-bit, so a four-minute 24-bit WAV arrives at about 60 MB.
Why the order matters
Check six is the only one that can cost anything. jukeblocks charges one converter credit per song on its Recreate path and refunds the credit when a job fails. ai-midi charges one credit per started five-second block with a 12-credit minimum per job.
What the six checks do not do
They do not predict accuracy, and none of the three sites publishes a figure with a test method behind it. One does publish a planning number: songscription suggests budgeting 10 to 20 minutes of editing per song, and names the errors to look for.
Questions
- What rules a file out fastest?
- The format check. If the tool does not list your container, nothing else matters until it is converted.
- Is this page a converter?
- No. This site publishes written guides and accepts no uploads.