Test Branch for OSX Audio Sink Changes

I’ve created a branch for folks to try out with changes to the
gr-audio-osx code, the sink only for now. Hopefully this branch
addresses GR issue #623 < http://gnuradio.org/redmine/issues/623 > for
the sink (I’m working on the source separately; it’s more involved not
just for this bug but overall).

< https://github.com/michaelld/gnuradio/tree/fix_gr_audio_osx_sink >

My commit (7571ef40) entry reads as follows:
{{{
Fix OSX Audio Sink:

  • remove extra instantiation arguments;
  • search for and use the device name, if found;
  • if the device name is not found, print out a list of known device
    names and use the default audio output device;
  • dynamically handle the number of output channels, depending on graph
    topology;
  • various whitespace and comment changes;
  • various CamelCase to lower_case changes;
  • WIP: when using the default output device, set up a listener, which
    will (eventually) tear down and bring back up audio output to match the
    new output device.
    }}}

On my Mac, I have just 1 audio output device: “Built-in Output”. I can
select this device when running a audio sink (e.g., dial_tone.py -O
“Built-in Output”), but that’s sort of silly since there’s just 1 device
from which to do selection. I’ve ordered a couple rtl-sdr hardware
devices which should provide another option, but until they get here
there’s not much more I can do to test out this branch. The audio
output works just as before, with whatever sample rate I throw at it. I
have not tried start / stop, but they should now work correctly too & I
will test this sooner or later.

I’m hoping other OSX users can help me out here, by building and
installing this branch and testing the audio output capabilities.

I’ll now move on to working on the audio source, and post another email
like this once it’s done.

Thanks! - MLD

Michael D., OSX Programmer
Ettus R. Technical Support
Email: [email protected]
Web: http://www.ettus.com