From: Paul Brossier <piem@piem.org>
Date: Tue, 3 Dec 2013 22:17:52 +0000 (-0500)
Subject: python/demos/demo_simple_spectral_weighting.py: added simple spectral weighting
X-Git-Tag: 0.4.0-beta1~57
X-Git-Url: https://git.aubio.org/?a=commitdiff_plain;h=2d88f41a60d975ba715b964454c500a6c2de2c83;p=aubio.git

python/demos/demo_simple_spectral_weighting.py: added simple spectral weighting
---

diff --git a/python/demos/demo_simple_spectral_weighting.py b/python/demos/demo_simple_spectral_weighting.py
new file mode 100755
index 00000000..b84f7d8d
--- /dev/null
+++ b/python/demos/demo_simple_spectral_weighting.py
@@ -0,0 +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