How to find the tempo of a .wav with aubio?

Question

I'm looking to detect the tempo of an audio file in python 3.6, but I don't really understand the doc about aubio. Would someone please indicate how to extract the tempo with aubio or another library?

Answer 1

Updated

This command will give you the tempo estimate of the entire file (available in 0.4.5):

aubio tempo foo.wav

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There is a simple demo in aubio's python/demos: demo_bpm_extract.py.

The most important part is the following two lines, which compute the periods between each consecutive beats (np.diff), convert these periods in bpm (60./), and takes the median (np.median) as the most likely bpm candidate for this series of beats:

#!/usr/bin/env python
import numpy as np
bpms = 60./np.diff(beats)
median_bpm = np.median(bpms)

Note how the median is better suited than the mean here, since it will always give an estimate which exists in the original population bpms.