[Discuss-gnuradio] Problem with Audio

Dear All,

I am trying my hands at GNU Radio on Ubuntu 10.1. I have been successful in installing GNU but am not able to use Audio sink in GRC. The error message is:

audio_alsa_sink[hw:0,0]: Device or resource busy
Traceback (most recent call last):
  File "/home/praphul/top_block.py", line 42, in <module>
    tb = top_block()
  File "/home/praphul/top_block.py", line 28, in __init__
    self.audio_sink_0 = audio.sink(48000, "", True)
  File "/usr/lib/python2.6/dist-packages/gnuradio/audio_alsa.py", line 321, in sink
    return _audio_alsa.sink(*args, **kwargs)
RuntimeError: audio_alsa_sink

I have tried several sampling frequencies for Audio sink and error is similar. Also, the dial_tone.py is returning following error:

gr_vmcircbuf_createfilemapping: createfilemapping is not available

Please help and suggest solutions

-- Praphul