ref: 8dbff94cd09295e81aea4b8418cfe47db0739377
dir: /python/demos/demo_tempo_plot.py/
#! /usr/bin/env python
import sys
from aubio import tempo, source
win_s = 512 # fft size
hop_s = win_s / 2 # hop size
if len(sys.argv) < 2:
print "Usage: %s <filename> [samplerate]" % sys.argv[0]
sys.exit(1)
filename = sys.argv[1]
samplerate = 0
if len( sys.argv ) > 2: samplerate = int(sys.argv[2])
s = source(filename, samplerate, hop_s)
samplerate = s.samplerate
o = tempo("default", win_s, hop_s, samplerate)
# tempo detection delay, in samples
# default to 4 blocks delay to catch up with
delay = 4. * hop_s
# 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)
total_frames += read
if read < hop_s: break
if len(beats) > 1:
# do plotting
from numpy import array, arange, mean, median, diff
import matplotlib.pyplot as plt
bpms = 60./ diff(beats)
print 'mean period:', "%.2f" % mean(bpms), 'bpm', 'median', "%.2f" % median(bpms), 'bpm'
print 'plotting', filename
plt1 = plt.axes([0.1, 0.75, 0.8, 0.19])
plt2 = plt.axes([0.1, 0.1, 0.8, 0.65], sharex = plt1)
plt.rc('lines',linewidth='.8')
for stamp in beats: plt1.plot([stamp, stamp], [-1., 1.], '-r')
plt1.axis(xmin = 0., xmax = total_frames / float(samplerate) )
plt1.xaxis.set_visible(False)
plt1.yaxis.set_visible(False)
# plot actual periods
plt2.plot(beats[1:], bpms, '-', label = 'raw')
# plot moving median of 5 last periods
median_win_s = 5
bpms_median = [ median(bpms[i:i + median_win_s:1]) for i in range(len(bpms) - median_win_s ) ]
plt2.plot(beats[median_win_s+1:], bpms_median, '-', label = 'median of %d' % median_win_s)
# plot moving median of 10 last periods
median_win_s = 20
bpms_median = [ median(bpms[i:i + median_win_s:1]) for i in range(len(bpms) - median_win_s ) ]
plt2.plot(beats[median_win_s+1:], bpms_median, '-', label = 'median of %d' % median_win_s)
plt2.axis(ymin = min(bpms), ymax = max(bpms))
#plt2.axis(ymin = 40, ymax = 240)
plt.xlabel('time (mm:ss)')
plt.ylabel('beats per minute (bpm)')
plt2.set_xticklabels([ "%02d:%02d" % (t/60, t%60) for t in plt2.get_xticks()[:-1]], rotation = 50)
#plt.savefig('/tmp/t.png', dpi=200)
plt2.legend()
plt.show()
else:
print 'mean period:', "%.2f" % 0, 'bpm', 'median', "%.2f" % 0, 'bpm',
print 'nothing to plot, file too short?'