voice-goio docs

Recognition

stt/sapi is written but has never run against a live engine, and no current consumer uses it. See Platform status.

Recognition, on Windows:

rec, err := sapi.New(sapi.Options{MinConfidence: 0.5})
rec.SetCallsigns(aircraftOnFrequency)   // on every roster change
rec.Start()                             // PTT pressed
rec.Stop()                              // PTT released
r := <-rec.Results()                    // exactly one result per cycle
switch r.Tags[voicegoio.TagIntent] { ... }

On macOS use stt/fake (typed input or a script) — the same interface.

The dynamic callsign rule

Restricting recognition to the aircraft actually on frequency is worth more than any acoustic tuning. SetCallsigns clears and rebuilds the grammar’s callsign rule, adding one word transition per phraseology variant, so a pilot may say “tree” or “three” for the same aircraft. normalise.SpokenVariants(spoken) gives every phraseology variant of a spoken callsign, for a recogniser’s callsign list.

Grammars of your own

The ATC grammar is the default, not the only one. An application listening for its own phrases (cockpit commands: “request taxi”, “gear up”, “doors closed”) builds a grammar from them and hands it to SAPI; each phrase comes back as its intent. grammar.Match is the same matching for typed input and away from Windows.

cmds := []grammar.Command{
    {Intent: "gear_up", Phrases: []string{"gear up", "landing gear up"}},
    {Intent: "doors_closed", Phrases: []string{"doors closed"}},
}
g, _ := grammar.Commands(cmds)
rec, err := sapi.New(sapi.Options{Grammar: g}) // r.Tags["intent"] == "gear_up"
intent, ok := grammar.Match(cmds, "Gear up")  // typed: "gear_up", true

A hand-written SRGS file works too (Options.GrammarPath): its public root rule must be transmission, its tags set out.intent, and a callsign rule is what SetCallsigns rebuilds.

Distress and urgency

MAYDAY and PAN PAN are recognised by both backends and outrank every other intent, including say_again: a transmission containing “mayday” is a mayday whatever else is in it. The callsign is matched anywhere in the transmission, because a distress call puts the signal first, and it is reported confidently even when the aircraft is not on the roster — an aircraft in trouble may have just arrived on the frequency. Tags[value] carries the nature (engine_failure, low_fuel, medical, …) on a best effort basis; an unrecognised nature never downgrades the intent.

Typing shortcuts

As a typing convenience, stt/fake also accepts the identifier and plain digits: CSA1234 with you, 15000 and DLH4EK request climb FL370 tag exactly as their spoken equivalents do. Speech never produces those forms, so nothing in the Windows backend has to cope with them.