ref: e5afd475bc606e5c78a5dda82863bc412b6580f0
parent: d83ac74b8a0f79d64680674d287aa053b70cf5f1
author: Paul Brossier <piem@piem.org>
date: Fri Mar 22 07:51:10 EDT 2013
python/demos/demo_mel-energy.py: added simple mel energy bands demo
--- /dev/null
+++ b/python/demos/demo_mel-energy.py
@@ -1,0 +1,70 @@
+#! /usr/bin/env python
+
+import sys
+from aubio import fvec, source, pvoc, filterbank
+from numpy import vstack, zeros
+from demo_waveform_plot import set_xlabels_sample2time
+
+win_s = 512 # fft size
+hop_s = win_s / 4 # 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
+
+pv = pvoc(win_s, hop_s)
+
+f = filterbank(40, win_s)
+f.set_mel_coeffs_slaney(samplerate)
+
+energies = zeros((40,))
+o = {}+
+total_frames = 0
+downsample = 2
+
+while True:
+ samples, read = s()
+ fftgrain = pv(samples)
+ new_energies = f(fftgrain)
+ print '%f' % (total_frames / float(samplerate) ),
+ print ' '.join(['%f' % b for b in new_energies])
+ energies = vstack( [energies, new_energies] )
+ total_frames += read
+ if read < hop_s: break
+
+if 1:
+ print "done computing, now plotting"
+ import matplotlib.pyplot as plt
+ from demo_waveform_plot import get_waveform_plot
+ fig = plt.figure()
+ plt.rc('lines',linewidth='.8')+ wave = plt.axes([0.1, 0.75, 0.8, 0.19])
+ get_waveform_plot(filename, samplerate, block_size = hop_s, ax = wave )
+ wave.yaxis.set_visible(False)
+ wave.xaxis.set_visible(False)
+
+ n_plots = len(energies.T)
+ all_desc_times = [ x * hop_s for x in range(len(energies)) ]
+ for i, band in enumerate(energies.T):
+ ax = plt.axes ( [0.1, 0.75 - ((i+1) * 0.65 / n_plots), 0.8, 0.65 / n_plots], sharex = wave )
+ ax.plot(all_desc_times, band, '-', label = 'band %d' % i)
+ #ax.set_ylabel(method, rotation = 0)
+ ax.xaxis.set_visible(False)
+ ax.yaxis.set_visible(False)
+ ax.axis(xmax = all_desc_times[-1], xmin = all_desc_times[0])
+ ax.annotate('band %d' % i, xy=(-10, 10), xycoords='axes points',+ horizontalalignment='right', verticalalignment='bottom',
+ )
+ set_xlabels_sample2time( ax, all_desc_times[-1], samplerate)
+ #plt.ylabel('spectral descriptor value')+ ax.xaxis.set_visible(True)
+ plt.show()