org.dvb.dsmcc

Class StreamEvent

java.lang.Object

java.util.EventObject

org.dvb.dsmcc.StreamEvent

All Implemented Interfaces:

Serializable

public class StreamEvent
extends EventObject

This class describes a Stream event which is used to synchronize an application with an MPEG Stream.

NOTE: The NPT mechanism and scheduled stream events that depend on it are known to be vulnerable to disruption in many digital TV distribution networks. Existing deployed network equipment that re-generates the STC is unlikely to be aware of NPT and hence will not make the necessary corresponding modification to STC values inside NPT reference descriptors. This may cause stream events scheduled against NPT to fire at the wrong time or to never fire at all. Applications should only use scheduled stream events with NPT where they are confident that the network where they are to be used does not have this problem. DVB Timeline, DSM-CC "do it now" events and events carried within DVB synchronised auxiliary data offer more reliable alternatives to NPT.

See Also:

Serialized Form

Field Summary

Fields inherited from class java.util.EventObject

source

Constructor Summary

Constructors

Constructor and Description
StreamEvent(DSMCCStreamEvent source, long npt, String name, int eventId, byte[] eventData) Creates a StreamEvent object.

Method Summary

Methods

Modifier and Type	Method and Description
byte[]	getEventData() This method is used to retrieve the private data associated with the event.
int	getEventId() This method is used to get the identifier of the StreamEvent.
String	getEventName() This method is used to get the name of the StreamEvent
long	getEventNPT() This method is used to get the value of the timeline when the event was triggered
Object	getSource() This method returns the DSMCCStreamEvent that generated the event.

Methods inherited from class java.util.EventObject

toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

StreamEvent

public StreamEvent(DSMCCStreamEvent source,
           long npt,
           String name,
           int eventId,
           byte[] eventData)

Creates a StreamEvent object.

Parameters:

source - The DSMCCStreamEvent that has generated the event.

npt - The value of the timeline when the event is triggered. For NPT based timelines, this value is equal to the field eventNPT in the DSMCC StreamEventDescriptor except where the event is a "do it now" event in which case the value -1 is returned (as the value of NPT may not be meaningful). For DVB timelines, this value is the to-be-completed

name - The name of this event. The list of event names is located in the DSMCC StreamEvent object. This list is returned by the method DSMCCStreamEvent.getEventList.

eventId - The eventId of this event. The list of event IDs is located in the DSMCC StreamEvent object.

eventData - The application specific data found in the DSMCC StreamEventDescriptor.

Method Detail

getSource

public Object getSource()

This method returns the DSMCCStreamEvent that generated the event.

Overrides:

getSource in class EventObject

Returns:

the DSMCCStreamEvent that generated the event.

getEventName

public String getEventName()

This method is used to get the name of the StreamEvent

Returns:

the name of the StreamEvent

getEventId

public int getEventId()

This method is used to get the identifier of the StreamEvent.

Returns:

The identifier of the StreamEvent.

getEventNPT

public long getEventNPT()

This method is used to get the value of the timeline when the event was triggered

Returns:

The value of the timeline in milliseconds.

getEventData

public byte[] getEventData()

This method is used to retrieve the private data associated with the event. For events signalled by a DVB synchronised event descriptor, these are the bytes carried in the synchronised_event_data_byte field. For events signalled by a DSMCC stream event descriptor, these are the contents of the privateDataByte field.

Returns:

The private data associated with the event.