org.dvb.dsmcc.DSMCCStream Maven / Gradle / Ivy
package org.dvb.dsmcc;
import java.lang.*;
import java.io.*;
import org.davic.net.*;
import javax.media.Time;
import javax.media.Clock;
/**
* The DSMCCStream class is used to manage DSMCC Stream Objects.
* The BIOP::Stream message shall be read from the network once only, before the constructor
* of this class returns. Hence methods which return information from that message shall not
* be affected by any subsequent changes to that information.
* The methods in this class relating to the NPT mechanism shall also be
* mapped onto the DVB timeline as defined in the main part of this specification.
* 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. Applications
* should only use NPT where they are confident that the network where they are
* to be used does not have this problem.
* @see org.dvb.dsmcc.DSMCCObject
*/
public class DSMCCStream {
/**
* Creates a Stream Object from a DSMCC Object. The BIOP message
* referenced by the DSMCCObject has to be a Stream or StreamEvent BIOP message.
* @param aDSMCCObject the DSMCC object which describes the stream
* @exception NotLoadedException the DSMCCObject is not loaded.
* @exception IllegalObjectTypeException the DSMCCObject is
neither a DSMCC Stream nor a DSMCCStreamEvent
*/
public DSMCCStream(DSMCCObject aDSMCCObject)
throws NotLoadedException, IllegalObjectTypeException
{
}
/**
* Create a Stream Object from its pathname. For an object Carousel, this
* method will block until the module which contains the object is loaded.
* The BIOP message referenced by the DSMCCObject pointed to by the parameter
* path has to be a Stream or StreamEvent BIOP message.
* @param path the pathname of the DSMCCStream Object.
* @exception IOException If an IO error occurred.
* @exception IllegalObjectTypeException the DSMCCObject is
neither a DSMCC Stream nor a DSMCCStreamEvent
*/
public DSMCCStream(String path) throws IOException, IllegalObjectTypeException
{
}
/**
* Create a DSMCCStream from its pathname. For an object Carousel, this
* method will block until the module which contains the object is loaded.
* The BIOP message referenced by the DSMCCObject pointed to be the
* parameters path and name has to be a Stream or StreamEvent BIOP message.
* @param path the directory path.
* @param name the name of the DSMCCStream Object.
* @exception IOException If an IO error occurred.
* @exception IllegalObjectTypeException the DSMCCObject is
neither a DSMCC Stream nor a DSMCCStreamEvent
*/
public DSMCCStream(String path, String name)
throws IOException, IllegalObjectTypeException
{
}
/**
* This function returns the duration in milliseconds of the DSMCC Stream.
* If the DSMCCStream BIOP message does not specify duration, zero will be returned.
* @return The duration in milliseconds of the DSMCC Stream.
*/
public long getDuration()
{ return (long)0;
}
/**
* This function is used to get value of the current timeline in milliseconds.
* Implementations are not required to continuously monitor for
* the timeline descriptors.
* In implementations which do not continuously monitor, this method will block while
* the current timeline is retrieved from the stream.
* @return the current time in milliseconds or zero if the DSMCC Stream object BIOP
* message does not contain any taps pointing to a timeline.
* @exception MPEGDeliveryException if there is an error in retrieving the timeline descriptors
*/
public long getNPT() throws MPEGDeliveryException
{ return (long)0;
}
/**
* This function returned a Locator referencing the streams of
* this collection. The interpretation of the return value
* is determined by the isMPEGProgram method.
* @return a locator.
*/
public org.davic.net.Locator getStreamLocator()
{return null;
}
/**
* This method will return true if the Stream(Event) BIOP message contains a
* tap with use field BIOP_PROGRAM_USE, otherwise it will return false.
* @return true only if the Stream(Event) BIOP message is as described above
*/
public boolean isMPEGProgram()
{return true;
}
/**
* This function returns a boolean indicating if the Stream Object
* refers to an audio stream. This is the case if the audio field in the Stream(Event)
* BIOP message has a value different from zero.
* @return true only if the Stream object refers to an audio stream
*/
public boolean isAudio()
{return false ;
}
/**
* This function returns a boolean indicating if the Stream Object
* refers to an video stream.
* This is the case if the `video' field in the Stream(Event) BIOP message
* has a value different from zero otherwise false is returned.
* @return true only if the Stream object refers to an video stream
*/
public boolean isVideo()
{return false;
}
/**
* This function returns a boolean indicating if the Stream Object
* refers to a data stream. This is the case if the data field in the
* Stream(Event) BIOP message has a value different from zero.
* @return true only if the Stream object refers to a data stream
*/
public boolean isData() {return true; }
/**
* Get the rate for the timeline referenced in the DSMCCStream object.
* Where the timeline is NPT, the NPT rate is returned.
* Where the timeline is the DVB timeline, 0/1 is returned if it is paused
* and 1/1 is returned if it is advancing.
* The method returns null if no timeline is referenced by the DSMCCStream
* object, (i.e. for NPT, no STR_NPT_USE tap in the list
* of taps).
* @return the NPT rate or null
* @exception throws MPEGDeliveryException if there is an error in retrieving NPT reference descriptors
* @since MHP 1.0.1
*/
public NPTRate getNPTRate() throws MPEGDeliveryException { return null; }
/**
* Add a listener for timeline events on the DSMCCStream object.
* Adding the same listener a second time has no effect.
* @param l the listener
* @since MHP 1.0.1
*/
public void addNPTListener(NPTListener l){};
/**
* Remove a listener for timeline events on the DSMCCStream object.
* Removing a non-subscribed listener has no effect.
* @param l the listener to remove
* @since MHP 1.0.1
*/
public void removeNPTListener(NPTListener l) {};
/**
* Convert a time measured according to a timeline in the stream
* into a JMF media time measured in a specified clock.
* @param time the time measured according to the timeline in the stream
* @param c the clock to express the media time
* @return the JMF media time corresponding to the specified time
* @throws IllegalArgumentException if the Clock is not a Player which is
* presenting at least one of the streams of this collection
* (as returned by getStreamLocator).
*/
public Time getMediaTimeFromStream(long time, Clock c) {return null;}
}