1 files changed, 57 insertions, 0 deletions
diff --git a/python/demos/demo_sink_create_woodblock.py b/python/demos/demo_sink_create_woodblock.py
new file mode 100755
index 0000000..5a42adc
--- /dev/null
+++ b/python/demos/demo_sink_create_woodblock.py
@@ -0,0 +1,57 @@
+#! /usr/bin/env python
+
+import sys
+from math import pi, e
+from aubio import sink, float_type
+from numpy import arange, sin, exp, zeros
+
+if len(sys.argv) < 2:
+    print('usage: %s <outputfile> [samplerate]' % sys.argv[0])
+    sys.exit(1)
+
+samplerate = 44100 # samplerate in Hz
+if len( sys.argv ) > 2: samplerate = int(sys.argv[2])
+
+pitch = 2200            # in Hz
+blocksize = 256         # in samples
+duration = 0.02         # in seconds
+
+twopi = pi * 2.
+
+duration = int ( samplerate * duration ) # convert to samples
+attack = int (samplerate * .001 )
+decay = .5
+
+period = float(samplerate) /  pitch
+# create a sine lookup table
+tablelen = 1000
+sinetable = arange(tablelen + 1, dtype = float_type)
+sinetable = 0.7 * sin(twopi * sinetable/tablelen)
+sinetone = zeros((duration,), dtype = float_type)
+
+# compute sinetone at floating point period
+for i in range(duration):
+    x = int((i % period) / float(period) * tablelen)
+    idx = int(x)
+    frac = x - idx
+    a = sinetable[idx]
+    b = sinetable[idx + 1]
+    sinetone[i] = a + frac * (b -a)
+
+# apply some envelope
+float_ramp = arange(duration, dtype = float_type)
+sinetone *= exp( - e * float_ramp / duration / decay)
+sinetone[:attack] *= exp( e * ( float_ramp[:attack] / attack - 1 ) )
+
+if 1:
+    import matplotlib.pyplot as plt
+    plt.plot(sinetone)
+    plt.show()
+
+my_sink = sink(sys.argv[1], samplerate)
+
+total_frames = 0
+while total_frames + blocksize < duration:
+    my_sink(sinetone[total_frames:total_frames+blocksize], blocksize)
+    total_frames += blocksize
+my_sink(sinetone[total_frames:duration], duration - total_frames)