Greetings, While working on the Mac OS X app bundle for Gqrx 2.2, (available here http://gqrx.dk/download), I encountered several issues with the OS X audio support in gnuradio. These are my notes and how I worked around it.
My setup consists of Mac OS X 10.7, UHD and gnuradio-devel installed via macports with minimal python et al. (only interested in C++ for gqrx). rtl-sdr, hackrf, gr-fcdproplus, osmosdr and gr-osmosdr installed separately from source. Using the Qt4 package installed via macports I could readily build gqrx, which was a huge step forward compared to my previous attempts. This allowed me to check functionality using USRP, rtlssdr and hackrf. Then I moved on to trying the Funcube Dongle Pro and Pro+ devices which, as you may know, look like audio input devices. The Pro comes with 96 ksps the Pro+ with 192 ksps. Anyway, this is where things started to behave strange. First the audio sink seems to work in the sense that I could get stable 48 kHz audio out through the default device selected in the system preferences. I did not try to change sample rate or output device from within the application, but I suspect the audio sink has the same shortcomings as the source (see below). Next step was to try to get input from the Funcube Dongle, i.e. using the osx-audio source. This is where things got weird in that (1) I could not select audio input device from within the application; the source was always reading from the default input source and (2) even when I selected the FCD as input source the sample rate was limited to 96 kHz even for the Pro+. Finally, the input source was not working at all. Every time I started the application it would read samples for a few seconds then the data would "go through the roof" as illustrated on this screen capture: https://www.youtube.com/watch?v=W2XCk_drZ48 This behavior happened with all available input devices. Before giving up I noticed that Michael also included the portaudio backend in the gnuradio-devel package. I gave that a try and suddenly everything was working perfectly! As a bonus, portaudio has a very simple API that I could use to enumerate available audio devices and implement device discovery for the Funcube Dongle on OS X. So, if you have problems with gnuradio-audio on Mac OS X, try switching to the portaudio backend. Alex _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio