&proaudioto the URL will apply audio-specific setting presets. For inbound audio streams, it can be used to increase the audio bitrate from 32-kbps to 256-kbps. For outbound streams, it will disable echo-cancellation and noise-reduction. When applied to both the outbound and inbound sides of an audio stream, it will also enable stereo audio if available.
&proaudiocurrently do the same thing, so they are just aliases of each other. When used, they can be used to setup the audio transfer pipeline to allow for unprocessed, high-bitrate, stereo audio.
&proaudioflag add to their URL.
proaudio=1, which if enabled:
&proaudiois used alone is
&proaudio=5, which acts like either
&proaudio=1, depending on whether the link its applied to is a room guest or not. This option will make the most sense for most users.
&proaudioparameter but wish the output to still be mono (1-channel), there's some options.