[Discuss-gnuradio] gr-audio OSX fixes test branch (take 2)

[Michael Dickens]

I just pushed the latest changes to my gr-audio OSX test branch:
< https://github.com/michaelld/gnuradio/tree/fix_gr_audio_osx >

fix gr-audio osx:
+ use GNU Radio preferences file to set default input and output audio device, 
if provided;
+ use gr::logger for all non-debug messages;
+ case-insensitive string find with desired audio device name;
+ fixes buffer allocation bug with low sample rates;
+ allows using a specific (named) audio device, or the default;
+ handles the case when the selected audio device becomes unavailable (e.g., a 
USB stick is removed while in use);
+ if no audio device name is provided, uses the default audio device as found 
in System Preferences::Sound;
+ handles the case when the default audio device is in use, and the user 
changes that audio device in System Preferences::Sound, by internally resetting 
to use the newly selected audio device;
+ all non-Apple names are now lower_case, not CamelCase.

I believe the behavior is now as discussed by Kevin, Tom, myself, and others.  
And, at least for me, everything works as desired on OSX 10.8.  These changes 
should work back to at least OSX 10.4, maybe even earlier.

If you want do use MacPorts to test out these changes, here's what I recommend 
you do:

1) make sure the gnuradio-devel port is installed and up to date
{{{
sudo port -f deactivate installed and "gnuradio*"
sudo port install gnuradio-devel
sudo port selfupdate
sudo port upgrade gnuradio-devel
}}}

2) Download the patch for these fixes; you can get them via my github branch 
above (commit 55eaa7da48), and I've also put them into my public DropBox folder:
< https://dl.dropboxusercontent.com/u/16655336/gr-audio-osx-wip-2014-03-01.diff 
>

3) Patch gnuradio-devel; change "/PATH/TO" to be the correct path to the patch:
{{{
sudo port patch gnuradio-devel
cd `port work gnuradio-devel`/gnuradio*
sudo patch -p1 < /PATH/TO/gr-audio-osx-wip-2014-03-01.diff
}}}

4) build gnuradio-devel:
{{{
sudo port build gnuradio-devel
}}}

5) install the new gr audio library (assuming PREFIX=/opt/local; if not, change 
the "cp" destination):
{{{
cd `port work gnuradio-devel`/build/gr-audio/lib
sudo cp libgnuradio-audio.3.7.3git.dylib /opt/local/lib
}}}

6) Try it out!  For example:
{{{
/opt/local/share/gnuradio/examples/audio/audio_fft.py -r 96000 -I FUN
/opt/local/share/gnuradio/examples/audio/dial_tone.py -r 1200 -O BuIlT
}}}

Try different rates, and different I/O devices.  You should see LOG printouts 
from "audio_osx_source" and "audio_osx_sink" with information about what it's 
doing.

Let me know what you think! - MLD

ps> I intentionally am having you install gnuradio-devel then create a patched 
version in case things got messed up, for 2 reasons:

a) If things get messed up either building or after copying libgnuradio-audio, 
you can clean it up by doing
{{{
sudo port -f deactivate gnuradio-devel
sudo port activate gnuradio-devel
}}}
and start from go.

b) Sometimes 'port' thinks it is being smart by looking at the available 
(deactivated) versions of a port, comparing to what is being requested, and 
then activating a port instead of finishing the install of what you already 
have being compiled.  Adding in the "-s" (from source) does not always help.  
Hence, my having you copy the library by hand -- it's not difficult, and it's 
easy to clean up if things don't work right.