ref: 1ec59e4cfdfcbe36295620926a7095e71b7d8066
dir: /python/demos/demo_waveform_plot.py/
#! /usr/bin/env python
import sys
from aubio import source
from numpy import zeros, hstack
def get_waveform_plot(filename, samplerate = 0, block_size = 4096, ax = None, downsample = 2**4):
import matplotlib.pyplot as plt
if not ax:
fig = plt.figure()
ax = fig.add_subplot(111)
hop_s = block_size
allsamples_max = zeros(0,)
downsample = downsample # to plot n samples / hop_s
a = source(filename, samplerate, hop_s) # source file
if samplerate == 0: samplerate = a.samplerate
total_frames = 0
while True:
samples, read = a()
# keep some data to plot it later
new_maxes = (abs(samples.reshape(hop_s//downsample, downsample))).max(axis=0)
allsamples_max = hstack([allsamples_max, new_maxes])
total_frames += read
if read < hop_s: break
allsamples_max = (allsamples_max > 0) * allsamples_max
allsamples_max_times = [ ( float (t) / downsample ) * hop_s for t in range(len(allsamples_max)) ]
ax.plot(allsamples_max_times, allsamples_max, '-b')
ax.plot(allsamples_max_times, -allsamples_max, '-b')
ax.axis(xmin = allsamples_max_times[0], xmax = allsamples_max_times[-1])
set_xlabels_sample2time(ax, allsamples_max_times[-1], samplerate)
return ax
def set_xlabels_sample2time(ax, latest_sample, samplerate):
ax.axis(xmin = 0, xmax = latest_sample)
if latest_sample / float(samplerate) > 60:
ax.set_xlabel('time (mm:ss)')
ax.set_xticklabels([ "%02d:%02d" % (t/float(samplerate)/60, (t/float(samplerate))%60) for t in ax.get_xticks()[:-1]], rotation = 50)
else:
ax.set_xlabel('time (ss.mm)')
ax.set_xticklabels([ "%02d.%02d" % (t/float(samplerate), 100*((t/float(samplerate))%1) ) for t in ax.get_xticks()[:-1]], rotation = 50)
if __name__ == '__main__':
import matplotlib.pyplot as plt
if len(sys.argv) < 2:
print("Usage: %s <filename>" % sys.argv[0])
else:
for soundfile in sys.argv[1:]:
get_waveform_plot(soundfile)
# display graph
plt.show()