bpmLover

bpmLover is an online BPM Analyzer that allows you to analyze tempo of a song by selecting a file or by tapping with your mouse. File processing is entirely done in Javascript, so there's no data sent to a remote server.

Website: http://bpmlover.com

Screenshots

About the source code

Library used

• For sound processing:

  • DSP.js
  • BeatDetektor.js

• For website stuff

  • Boostrap
  • jQuery
  • underscore.js

bpmLover's code

• App takes care of the UI
• AudioFile is a simple wrapper around File that provides utility functions such as getAudioBuffer or getAudioData.
• BPMWorker takes audio data and computes the BPM using DSP.js and BeatDetektor.js.

How it works

• The main app (UI) is in App.js
• When a file is selected, a new AudioFile is created.
• App creates a web worker: BPMWorker.js and sends it the audio data.
• BPMWorker cuts the audio data into 512-sample frames, and for each of them, applies FFT and sends it to an instance of BeatDetektor.
• When this is complete, the web worker sends the bpm back to App, which then updates the UI.

License

This code is under GPL-License.