ref: 714d05eaeac1b18e412051cfba429fd240e0f2e4
dir: /python/demos/demo_sink_create_woodblock.py/
#! /usr/bin/env python
import sys
from math import sin, pi
from aubio import sink
from numpy import array
if len(sys.argv) != 2:
print 'usage: %s <outputfile>' % sys.argv[0]
sys.exit(1)
samplerate = 44100 # in Hz
pitch = 2200 # in Hz
blocksize = 256 # in samples
duration = 0.02 # in seconds
twopi = pi * 2.
duration = int ( 44100 * duration ) # convert to samples
attack = 3
period = int ( float(samplerate) / pitch )
sinetone = [ 0.7 * sin(twopi * i/ period) for i in range(period) ]
sinetone *= int ( duration / period )
sinetone = array(sinetone, dtype = 'float32')
from math import exp, e
for i in range(len(sinetone)):
sinetone[i] *= exp( - e * float(i) / len(sinetone))
for i in range(attack):
sinetone[i] *= exp( e * (float(i) / attack - 1 ) )
my_sink = sink(sys.argv[1], 44100)
i = 0
while i + blocksize < duration:
my_sink(sinetone[i:i+blocksize], blocksize)
i += blocksize