I have uploaded the last version of my audio beat detection code on Github
It is still perfectible but for my use it is enough especially with techno. If you have questions don’t hesitate to ask.
Demo video: https://www.youtube.com/watch?v=SuUXksobkH0
An animation using it: https://www.youtube.com/watch?v=NGrln2cJkeA
It would work better with a derivative filter but I could not add it to the audio library. Does somebody knows if FMOD has this filter?