Comment # 5 on bug 91253 from Richard Bradfield

I believe that the patch proposed in 91041 [1,2] will resolve this.

This bug seems to be caused by an early attempt to access the afmt property of
the encoder before it has been initialised. The audio detection rework in [2]
looks like it should avoid this corner case.

Andreas, can you try the patch linked as [2]?

[1] https://bugs.freedesktop.org/show_bug.cgi?id=91041
[2] https://bugs.freedesktop.org/attachment.cgi?id=117395