How late the clicks reach the microphone, once the count-in has shown it; null until then, or when they were not heard
Where an attack heard at onsetMs began, when a silenced click hid its
start: a note that comes in during the blanked span is first heard where
the span ends, and is taken to have started on the click — as near as can
be told, it was played on the beat. null for an attack not heard at the
end of a span, or before the clicks have been found. marginMs is how far
past the span's end the onset detector may report such an attack: its
time resolution.
Take the next chunk of the stream, startFrame being the index of its
first sample. Returns the chunk with any click in it blanked — a copy
when something was blanked, the chunk itself otherwise.
Forget everything, as at the start of a stream.
Count-in clicks recognised so far