Save audio opus audio track

[guju]

I recently had a movie (mkv container) with an opus audio track.

When I try to save the audio track ("Audio / Save Audio")
a dialog pops and offers to save the track as "fileName.*".
If I change the "*" to "opus" and have a look at the generated file
it is of none identifyable content.

[eumagga0x2a]

Raw opus streams are useless, we don't have means to encapsulate it into an Ogg container as it should be. A nice-to-have, sure.

[guju]

But for... say... aac streams it does well? ... Saves as aac file...

[eumagga0x2a]

AAC streams (AAC LC only) are exported as ADTS (audio data transport stream) which is a very simple format. Ogg is much more complex, will need to use libogg for that.