ref: a8752a8001c12336ee57bddf958b0da86df66634
dir: /python/demos/demo_beats_and_tempo.py/
#! /usr/bin/env python
import sys
from aubio import tempo, source
win_s = 512 # fft size
hop_s = win_s / 2 # hop size
samplerate = 44100
if len(sys.argv) < 2:
print "Usage: %s <filename>" % sys.argv[0]
sys.exit(1)
filename = sys.argv[1]
beats = []
s = source(filename, samplerate, hop_s)
t = tempo("default", win_s, hop_s)
block_read = 0
while True:
samples, read = s()
isbeat = t(samples)
if isbeat:
thisbeat = (block_read * hop_s + isbeat[0]) / samplerate
print "%.4f" % thisbeat
beats.append (thisbeat)
block_read += 1
if read < hop_s: break
periods = [60./(b - a) for a,b in zip(beats[:-1],beats[1:])]
from numpy import mean, median
print 'mean period:', mean(periods), 'bpm'
print 'median period:', median(periods), 'bpm'
from pylab import plot, show
plot(beats[1:], periods)
show()