Skip to content

Downbeat engine

Shotwork finds the beats in every song on its own. To find real downbeats, the first beat of each bar, it needs the downbeat engine: an optional download of beat_this, an open-source model under the MIT license.

The Downbeat Engine dialog describing beat_this and what the download installs, the status line Not installed, and Download and Close buttons.

Downbeat Engine, before the download

Before you start

  • An internet connection.
  • About 300 to 400 MB of free disk space.

Install it

  1. Choose Settings › Downbeat Engine….
  2. Choose Download. The status line shows each step, and the bar keeps moving until the download is done.
  3. Wait for the short test analysis the download ends with. When the status reads Installed and verified., choose Close.

Ticking Downbeats on a song opens this dialog too, when the engine is not installed. Close it without downloading and the box unticks itself.

What happens

  • The engine goes into its own folder, beat_this_engine, in Shotwork's app data, together with the PyTorch it runs on (BSD-3-Clause license, the CPU-only build). Nothing outside that folder is touched.
  • It runs in a process of its own, never inside Shotwork.
  • Songs you add from now on start with Downbeats on. On a song already on a reel, tick Downbeats to analyze it again with the engine.

Check that it still works

Choose Verify. It runs the short test analysis again. The status reads Installed and verified. when it passes, or Verify failed -- see details below. with the error in a box underneath.

Remove it

  1. Choose Remove.
  2. Choose Yes to confirm.

The whole engine folder is deleted. Choose Download to install it again at any time.

If something goes wrong

  • The download fails. The status reads Failed -- see details below., the error appears in a box underneath, and the partial download is removed, so nothing half-installed is left behind. Choose Download to try again. If it keeps failing, copy the text in the box: it is the exact error.
  • You close the dialog during a download. The download is canceled and removed.
  • One song shows Downbeats unavailable for this track. Showing beats only. The engine could not place that song's downbeats, so it shows beats only. Shotwork remembers this for the file and does not retry it every time the reel opens. Manual downbeats gives that song downbeats by count.