pyjack-0.5.2/demos/testtone.py

   1 #!/usr/bin/python
   2 # -*- coding: utf-8 -*-
   3 # Plays a 440.0 Hz test tone for 3 seconds to alsa_pcm:playback_1.
   4 #
   5 # Copyright 2003, Andrew W. Schmeder
   6 # This source code is released under the terms of the GNU Public License.
   7 # See LICENSE for the full text of these terms.
   8
   9 import numpy
  10 import jack
  11
  12 jack.attach("testtone")
  13 jack.register_port("in_1", jack.IsInput)
  14 jack.register_port("out_1", jack.IsOutput)
  15 jack.activate()
  16 jack.connect("testtone:out_1", "alsa_pcm:playback_1")
  17
  18 N = jack.get_buffer_size()
  19 Sr = float(jack.get_sample_rate())
  20 print "Buffer Size:", N, "Sample Rate:", Sr
  21 sec = 3.0
  22
  23 input = numpy.zeros((1,N), 'f')
  24 output = numpy.reshape(
  25     numpy.sin(
  26         2*numpy.pi*440.0 * (numpy.arange(0, sec, 1.0/(Sr), 'f')[0:int(Sr*sec)])
  27     ), (1, Sr*sec)).astype('f')
  28
  29 i = 0
  30 while i < output.shape[1] - N:
  31     try:
  32         jack.process(output[:,i:i+N], input)
  33         i += N
  34     except jack.InputSyncError:
  35         pass
  36     except jack.OutputSyncError:
  37         pass
  38
  39 jack.deactivate()
  40
  41 jack.detach()