ref: 2d88f41a60d975ba715b964454c500a6c2de2c83
parent: c911b121883f3deff01e97fd5bf11a28d056f06b
author: Paul Brossier <piem@piem.org>
date: Tue Dec 3 12:17:52 EST 2013
python/demos/demo_simple_spectral_weighting.py: added simple spectral weighting
--- /dev/null
+++ b/python/demos/demo_simple_spectral_weighting.py
@@ -1,0 +1,55 @@
+#! /usr/bin/env python
+
+import sys
+from aubio import source, sink, pvoc
+from numpy import arange, exp, hstack, zeros, cos
+from math import pi
+
+def gauss(size):
+ return exp(- 1.0 / (size * size) * pow(2.0* arange(size) - 1. *size, 2.));
+
+def hanningz(size):
+ return 0.5 * (1. - cos(2.*pi*arange(size) / size))
+
+if __name__ == '__main__':
+ if len(sys.argv) < 2:
+ print 'usage: %s <inputfile> <outputfile>' % sys.argv[0]
+ sys.exit(1)
+ samplerate = 0
+ if len(sys.argv) > 3: samplerate = int(sys.argv[3])
+ f = source(sys.argv[1], samplerate, 256)
+ samplerate = f.samplerate
+ g = sink(sys.argv[2], samplerate)
+
+ win_s = 512 # fft size
+ hop_s = win_s / 2 # hop size
+ pv = pvoc(win_s, hop_s) # phase vocoder
+
+ # spectral weighting vector
+ spec_weight = hstack ( [
+ .8 * hanningz(80)[40:],
+ zeros( 50 ),
+ 1.3 * hanningz(100),
+ zeros (win_s / 2 + 1 - 40 - 50 - 100),
+ ] )
+
+ if 0:
+ from pylab import plot, show
+ plot(spec_weight)
+ show()
+
+ total_frames, read = 0, hop_s
+ while read:
+ # get new samples
+ samples, read = f()
+ # compute spectrum
+ spectrum = pv(samples)
+ # apply weight to spectral amplitudes
+ spectrum.norm *= spec_weight
+ # resynthesise modified samples
+ new_samples = pv.rdo(spectrum)
+ # write to output
+ g(new_samples, read)
+ total_frames += read
+
+ print "read", total_frames / float(samplerate), "seconds from", f.uri