Show HN: Android guitar looper app for creating seamless practice loops

[ralph_sc]

I’m a developer and hobby guitarist, and I built a small Android app to help with practicing.

I always wanted to make a cross-platform native app in C (C99), and this is my attempt. I started on macOS and then moved to Android. The hardest parts so far have been JNI integration and handling permissions. The GUI is custom and rendered with OpenGL ES.

The app records seamless, bar-perfect loops with a precount click, so you can strum chord changes and improvise over them.

Happy to answer questions or get feedback.

[wordglyph]

It worked well! Super handy to have a looper in my pocket! I do wish I could play a riff one time and just say loop it. I think you could use TarsosDSP for onset/beat detection, aubio for more advanced tempo and onset analysis and Superpowered for high-quality time-stretching and actual loop creation.

[jeffreygoesto]

If you want ideas what to play with it, search for "Jarle Bernhoft Bauhaus" on YouTube...

[0] https://youtu.be/lAvFhhl0U0I?feature=shared

[ralph_sc]

Looks like he is using a looper pedal. I have one of those too, but for a quick practice/jam session it's great to just pull out your phone and record a backing loop.

[wordglyph]

Are you saying it automatically fixes the loop so it makes it seamless? Or I still have to physically time it with the click?

[ralph_sc]

Right now it doesn’t "auto-fix" a recording after the fact. Instead, you set BPM, time signature, and number of bars before recording, and the app records exactly that length. Because the duration is defined up front, the loop lines up perfectly with the click without any drift.