Frames skipped since the previous read because the ring overwrote them or a retry shrank the window.
Host Unix time in milliseconds of the write that produced the newest frame.
One array per channel, frames samples each, oldest first.
The frames cut into runs of continuous media time, in offset order,
the first at offset 0. A version-1 buffer has no segment table and
always reports one unknown run.
Frames returned by one PcmRingReader.read call.