Time capsules: an abstraction for access to continuous-media data

The author presents the time capsule abstraction to describe how timed data shall be stored, exchanged, and accessed in a real-time system. When data are written into a time capsule, a time stamp and a duration are associated with the data item. When it is read, a time stamp is used to select the data item. The time capsule abstraction includes the notion of clocks that ensure periodic data access that is typical for continuous-media applications. By modifying the parameters of a clock, effects such as time lapses or slow motion can be achieved