CODEWITHSUNDEEP
pythonaudioanalysistempoaubio
P G
P G

Reputation: 31

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

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?

Upvotes: 3

Views: 5331

Answers (2)

piem
piem

Reputation: 390

Updated

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

aubio tempo foo.wav

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.

Upvotes: 9

Liam
Liam

Reputation: 6449

I found this code by Paul Brossier that could help you, here it is:

#! /usr/bin/env python

from aubio import source, tempo
from numpy import median, diff

def get_file_bpm(path, params = None):
    """ Calculate the beats per minute (bpm) of a given file.
        path: path to the file
        param: dictionary of parameters
    """
    if params is None:
        params = {}
    try:
        win_s = params['win_s']
        samplerate = params['samplerate']
        hop_s = params['hop_s']
    except KeyError:
        """
        # super fast
        samplerate, win_s, hop_s = 4000, 128, 64 
        # fast
        samplerate, win_s, hop_s = 8000, 512, 128
        """
        # default:
        samplerate, win_s, hop_s = 44100, 1024, 512

    s = source(path, samplerate, hop_s)
    samplerate = s.samplerate
    o = tempo("specdiff", win_s, hop_s, samplerate)
    # List of beats, in samples
    beats = []
    # Total number of frames read
    total_frames = 0

    while True:
        samples, read = s()
        is_beat = o(samples)
        if is_beat:
            this_beat = o.get_last_s()
            beats.append(this_beat)
            #if o.get_confidence() > .2 and len(beats) > 2.:
            #    break
        total_frames += read
        if read < hop_s:
            break

    # Convert to periods and to bpm 
    if len(beats) > 1:
        if len(beats) < 4:
            print("few beats found in {:s}".format(path))
        bpms = 60./diff(beats)
        b = median(bpms)
    else:
        b = 0
        print("not enough beats found in {:s}".format(path))
    return b

if __name__ == '__main__':
    import sys
    for f in sys.argv[1:]:
        bpm = get_file_bpm(f)
print("{:6s} {:s}".format("{:2f}".format(bpm), f))

this is the key part:

bpms = 60./np.diff(beats)
median_bpm = np.median(bpms)

Upvotes: 3

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