kaumudpa / beats

Nodejs (javascript) app to extract amplitude data from sound file and infer beats.

Extract Peaks from Audio File

Nodejs app to process a sound file, identify peaks

Blog post here

This project provides Node.js code to decode a sound file, identify peaks, and identify beats. There are some sample code available that demonstrate this using HTML5 webaudio api, but this uses a nodejs port of same api.

How It Works

• Decode audio file (add one to your sounds folder)
• Identify peaks
• Identify beats

##Running

Note: To ensure correctness, the sound file is played back while being analyzed. ffmpeg is used to play back sound, and this must be installed.

To install ffmpeg on a mac

brew install ffmpeg

Start the application. (Note: you need sudo access)

node beats.js     

Dependencies List

• web-audio-api : implementation (partial) of the HTML5 web audio api, used to decode sound files.
• underscorejs : functional programming helper library for data manipulation.

Next Steps

Beat extraction. The general approach is to identify peaks most repetitive peaks to be indicative of a beat, and then compute inter-peak interval. Two 60 peaks within a 60 second interval might correspond to 60 beats per minute.

License

MIT License