How hard an encoder compresses. Each field belongs to one codec and the others ignore it: FLAC is lossless and takes neither. An encoder that has no use for them may leave the parameter out.
Optional
target bitrate in kbit/s for Opus (6 to 510); the encoder's own default when absent
quality level for Vorbis, -1 (smallest) to 10 (best); the encoder's own default when absent
How hard an encoder compresses. Each field belongs to one codec and the others ignore it: FLAC is lossless and takes neither. An encoder that has no use for them may leave the parameter out.