examples/multimedia/audiorecorder example does not work on Linux (kubuntu)

Trying to record something with the audiorecorder example on
kubuntu.

Depending on what codec I am using, it seems I get different errors. For example, if I use
the audio codec audio/vorbis and file container ogg, I get
"Failed to build media capture pipeline."

but if I use audio/mpeg and mp4, and try to save to test.mp4, I get
"Could not open file "file:///home/ezust/tmp/test.mp4" for writing."

Likewise, if I use PCM as my codec and .wav as my container and
try to save to test.wav, I get the same "could not open file" error.

Interestingly, I get a different error message "could not get/set settings from/on device" from the Ubuntu build of qt 5.1's audiorecorder example.

I can not reproduce this issue on windows.