The StreamExporter interface requires of its implementations to contain among others
the following methods:
registerStream(). This method adds a new entry to the StreamExporter's list
of Stream objects, to which the StreamExporter exports Chunk objects.
exportChunk(). An invocation of this method triggers the data export mechanism.
The StreamExporter is intended at least to invoke the importChunk() method of
all its registered Stream objects. Further actions, such as network transmission, depend on
the particular implementation class.
createSlaveClock(). Stream implementations call this method to obtain a
Clock object. It is initialised with the timestamp--to--wall-clock-time ratio that the
StreamExporter's Master_Clock uses. Each Stream object uses a
Clock object to calculate playout synchronisation delays.