Beefy Boxes and Bandwidth Generously Provided by pair Networks
The stupid question is the question not asked

Re: calculating the bpm of a song in mp3 format

by kvale (Monsignor)
on Apr 16, 2006 at 00:32 UTC ( #543604=note: print w/replies, xml ) Need Help??

in reply to calculating the bpm of a song in mp3 format

The algorithm I would use to calculate BPM is to
  1. calculate the modulation envelope of the waveform using either a Hilbert transform or rectification and smoothing
  2. compute the Fast Fourier Transform (FFT) of the modulation envelope
  3. look for the strongest peak in the 0.2-5Hz range (depending on the music)
  4. Assign the center of the peak to be the BPM.
Note that most music is approximately scale-free (or fractal, to use a more popular term) so that there will be energy at all time scales. But for some kinds of music there will be a prominent peak in the above range that people usually associate with BPM.

How to do all of this in perl? I would use PDL. It is very efficient in manipulating vector quantities like sound waveforms and has a built in FFT function.


  • Comment on Re: calculating the bpm of a song in mp3 format

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://543604]
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others musing on the Monastery: (5)
As of 2016-10-24 22:27 GMT
Find Nodes?
    Voting Booth?
    How many different varieties (color, size, etc) of socks do you have in your sock drawer?

    Results (310 votes). Check out past polls.