Audio

https://xiph.org/

Generally don't re-encode the audio with a different codec unless you are using the original lossless.

Quality

Ogg is a container format for Vorbis and Opus codecs.

• Vorbis is deprecated. Opus generally beats it.
• Opus is low-latency, switches between speech and music, very good and low bitrates.

See comparison: https://opus-codec.org/comparison/