Interface AdapterInput

The gain this input's preamp is KNOWN to come up at, and how the adapter knows it — see GainDefault. Absent means the adapter has not measured or been told one, and gainDefaultOf resolves the house mic default for it; absent alongside an absent gainRange means the REAC preamp, whose come-up gain IS measured.

DECLARED here rather than derived from the travel, because a travel says how far a control goes and never where it starts. Only meaningful alongside sensCapable.

How far this input's gain control reaches, in dB of gain, when it differs from the REAC span — see HeadAmpGainRange. Absent (every REAC / console input) means 0..55. Only meaningful alongside sensCapable.

The adapter's own input reference (matches SourcePatch.input).

Human label for the input (e.g. "Stagebox 1 / In 3", "X32 Local 5").

Free-form adapter-specific metadata (port name, channel index, stagebox id, …).

Whether the input implements the −20 dB analog pad (a REAC box control). Absent = not capable: a software / non-REAC input has no pad, so the UI must not offer one.

Whether the input can supply +48 V phantom (a head-amp capability). When false/absent a source on this input cannot enable phantom (e.g. a line input or a software node).

Whether the input exposes a settable analog GAIN — a REAC box's SENS control, an RME mic input's Mic-AN<n> Gain. Absent = not capable: a software input has no preamp to set. The travel it covers is AdapterInput.gainRange; the unit is always dB of gain.