Notification of new latency adjustment.
The event is sent upstream from the sinks and
notifies elements that they should add an additional latency to the
timestamps before synchronising against the clock.
The latency is mostly used in live sinks and is always expressed in
the time format.
This constructor is for internal use only.
init initialization data.
Create a new latency event.
latency the new latency value to add to timestamps.
Gets the latency in the latency event.