Choppy audio and underrun (aUaU) with simple audio test

I am using gnuradio companion to run a simple test, in which I just
connect
a signal source to an audio sink. They have the same sample rate, and
the
signal source is a sine wave, amplitude is 0.1, frequency 1kHz, offset
0.
When I make the sample rate for both to be 48kHz, the audio is very
choppy
and sounds pretty bad. When make the sample rate for both equal to
16kHz,
it sounds much better but is still skipping at a period that is less
than a
second I think. In both cases I see the aUaUaU, indicating underrun.
What
can cause the underrun in this case?

I’m running Centos 6.4 in a virtual machine. I left the audio device
field
blank in the audio sink block in grc, and I believe it is using Pulse,
or
at least putting “pulse” in that field produces the same effect.

I have been able to capture data from the rtl-sdr and scroll through its
spectrum using WX widgets in grc, so everything else seems to be
working.

Thanks,
Curt


Discuss-gnuradio mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio