5.3. Time and Time Types

All Rivendell log events have an associated time type, which controls what effect (if any) the passage of time will have on the event. There are two basic time types: relative and hard. Additionally, the hard time type has several additional options that further modify its behavior.

5.3.1. The Relative Time Type

The default time type for log events, a relative time type simply means that the event is assumed to have a start time of whenever the previous event ends (if it has a PLAY or SEGUE transition) or whenever it is started (if it has a STOP transition).

5.3.2. The Hard Time Type

A hard time type causes the event to be executed or otherwise acted upon when the wall clock equals the time associated with the event. Hard times are a powerful feature that can be used to synchronize the log to various external events. An event can be assigned a hard time by clicking the Start at check box in the Edit Log Entry and filling in the desired time, and will show up with the letter T appearing at the beginning of its listed time in the Time column of the Edit Log dialog.

The specific action that is performed when the time matches is determined by the option parameters supplied as part of the event. Three basic actions are possible:

  • Start the event immediately
  • Cue to the event ("Make Next")
  • Wait up to some period of time, then start the event Start Immediately

As implied by the name, if the event is set to start immediately, it will be started as soon as the hard time is reached. Any currently playing events in the log will be simultaneously stopped down. Cue to the Event ("Make Next")

If set to 'Make Next', the event will be cued up to become the next event to be executed in the log, bypassing any intervening events in the log between the currently playing event and the hard timed one. Any currently playing events are unaffected. Wait up to some period of time, then start the event

Very similar to "start immediately", with the difference that, if one or more events are currently playing, the log will wait up to the specified amount of time before stopping them and starting the new event. If the currently playing event(s) finish before the specified time period has elapsed, then the event is started immediately.

5.3.3. Estimated vs. Scheduled Start Times

When viewing log events in rdlogedit(1), the displayed start time style for each event can be either Estimated or Scheduled, as selected in the Show Start Times As dropdown box. Estimated will give start time values based on any hard start times in the log, taking the known lengths of the relevant carts, while Scheduled will display the start times as provided by an external music and/or traffic scheduling system.

The optimum style to use is largely dependent on how a particular log was assembled. If the log was generated using rdlogmanager(1) and largely populated with events from external music and traffic systems, the Scheduled style will usually be preferred as this permits the start times provided by those external schedulers to be visible. On the other hand, if the log was mostly assembled "on the fly" in rdlogedit(1), the Estimated style will usually provide more insight on a log will actually time out when played.