Values.OpusSettingsSourceRequired when you set Codec, under AudioDescriptions>CodecSettings, to the value OPUS.
type nonrec t = {bitrate : int option;Optional. Specify the average bitrate in bits per second. Valid values are multiples of 8000, from 32000 through 192000. The default value is 96000, which we recommend for quality and bandwidth.
*)channels : int option;Specify the number of channels in this output audio track. Choosing Follow input will use the number of channels found in the audio source; choosing Mono gives you 1 output channel; choosing Stereo gives you 2. In the API, valid values are 0, 1, and 2.
*)sampleRate : int option;Optional. Sample rate in Hz. Valid values are 16000, 24000, and 48000. The default value is 48000.
*)}