Notes on Pulseaudio setup

This applies to Linux.

The audio devices with Qt are supported through pulseaudio and unless you are using a single sound chip (or card) with a single output port or you are an expert with pulseaudio config files you may get into trouble when trying to route the audio to a different output port. These notes are a follow-up of issue #31 with my own experiments with HDMI audio output on the Udoo x86 board. So using this example of HDMI output you can do the following:

• Install pavucontro: sudo apt-get install pavucontrol
• Check the audio config with alsamixer. On the Udoo x86 the HDMI output depends on the S/PDIF control and it occasionally gets muted when the HDMI monitor is turned off or goes to sleep. So in any case make sure nothing is muted there.
• Open pavucontrol and open the last tab (rightmost) called 'Configuration'
• Select HDMI from the profiles list in the 'Configuration' tab
• Then in the 'Output devices' tab the HDMI / display port is selected as it is normally the only one. Just double check this
• In SDRangel's Preferences/Audio menu make sure something like alsa_output.pci-0000_00_1b.0.hdmi-stereo is selected. The default might also work after the pulseaudio configuration you just made.

In case you cannot see anything related to HDMI or your desired audio device in pavucontrol just restart pulseaudio with pulseaudio -k (-k kills the previous instance before restarting) and do the above steps again.