Record A/V: MP3, Opus and Vorbis codecs fail to initialize

[SuperSamus]

When trying to record A/V using either the MP3, Opus or Vorbis audio codec, mGBA will show an error dialogue saying: "Failed to open video file: <file>".
By looking at the logs, however, it seems to be an error with ffmpeg. Respectively:

[libmp3lame @ 0x1c83000] Specified sample rate 65536 is not supported
[libopus @ 0x15bb340] Specified sample rate 65536 is not supported
[libvorbis @ 0x1c83f00] encoder setup failed

Linux NixOS unstable.
Tested with latest master (45762c8).
(Related #2731)

[endrift]

Can you confirm if this happens with 0.10.1?

[SuperSamus]

Yes.

[endrift]

Thanks for finding this; glad I got it fixed before 0.10.2.