Mp3Settings interface
Settings for an MP3 (MPEG-1/2 Layer III) encode, constant bitrate, mono or stereo (channel layout and bitrate are on AudioEncodeSettings).
A constant-bitrate MP3 can only have one of a fixed set of bitrates, and which set depends on the sample rate - so the two are typed together, see AudioEncodeSettings. Anything else is rejected rather than encoded at some other bitrate. see: NorskTransform.audioEncode()
Signature:
export interface Mp3Settings<SampleRateT extends Mp3SampleRate = Mp3SampleRate>