Aubio Misnamed Beat Juggling

Summary

Status: There is a branch which has most of these features implemented. Testing is still needed.

Mixxx has BPM detection but not beat detection. Beat detection would allow us to do man cool tricks including:

• Jump from beat to beat
• Quantize Effects
• Create Beat Quantized loops
• Do full Automatic Beat Syncing
• Beat Smashing/Splicing (ala Aphex Twin)

Current Status

There is currently a branch at https://code.launchpad.net/~mixxxdevelopers/mixxx/features_trackbeats.

Currently it does:

• Rendering of the Beats on the Waveform
• Saving Tracked beats (column in library table as a bitmap)

Using beat markers to quantize cues, hotcues and loops is done by the branch features_beatcontrols; https://code.launchpad.net/~mixxxdevelopers/mixxx/features_beatcontrols.

Design

Current Issues

• TrackInfoBeats is not stored in the Database Implemented in the latest changes.
• Analysis takes 90%+ CPU and around 15 seconds for a typical Psytrance Song (not good for live performance).

Notes

• We could easily avoid the CPU and time penalty for analysis by only using aubio in the analysis section.
• Although the implementation so far deals with beat detection and quantization aubio also does other forms of analysis.
• We could color waveforms on peaks (onset detection)
• We could color waveforms according to pitch (pitch detection)