beatdetection

Experiment to create beat detection algorithm in cables.gl

If you can help to improve the detection algorithms please let me know.

Usage

The patch uses the MicrophoneIn operator to get audio input.

Go to the visualizer page

Open a browser and go to the Patch.

Accept michophone usage

Accept that the browser want to use the microphone, e.g. click on "Allow". The visualizer will render stuff based on the sound from the computer microhone.

Start the music

So start to play some music on your computer, e.g. open a browser and start playing the SHS31 mix from YouTube or SoundCloud: SHS31.

Start patch

Press play on the play button to start the patch.

Output

The patch renders a graph and three circles:

• The graph is the FFT audio analyzer array
• The gray circle is the audio analyzer avg. volume
• The green circle is beat detection algorithm #1
• The blue circle is beat detection algorithm #2

Algorithms

Adhoc Algorithm 1

Calculate FFT array

The AudioAnalyser operator produces an FFT array with parameters:

• Size = 256
• Smoothing = 0.3

The values in the array are between 0..1.

Get average volume (AV) for select frequencies

The average volume (AV) is calulated using the FFTAreaAverage operator.

Drums and beats then to have a low frequency. So the average volume is calculated from "the upper left" corner of the FFT array using these parameters:

• X pos = 0
• Y pos = 0
• Width = 0.2
• Height = 0.7

The value for AV is between 0..1.

Calculate Delta of average volume

Calculate delta from previous AV.

The value for AV is between 0..1.

Register single beat for sequence positive deltas

If delta is postive...

Inspiration

• http://archive.gamedev.net/archive/reference/programming/features/beatdetection/index.html
• https://github.com/michaelkrzyzaniak/Beat-and-Tempo-Tracking