Dynamic playlist based on BPM calculation

[enso-media]

Right now the playlist is very static. Its only possible to define a fixed interval to step over to the next scene.
It would be awesome to have more options to make the playlist really react on the music.

A first massive improvement could be to use the already available BPM calculation. So instead setting a fixed time in seconds, it should be possible to set an amount of beats before moving to the next scene. This way an automatic light show will already look way more "on purpose", as the scene changes happen on the beat.

More advanced options could be to define conditions like:

• Enable a scene when volume is above/below X (for example to set a static light when the band/DJ make a break)
• Enable a scene when BPM is above/below X (for example some kind of strobe effect scene for fast electronic music, but a warm fades scene for slow music)
• Enable scene on specific energy thresholds (that are also available in the spectral description analyses of the aubio library)