demuxnode.java

FMJ（freedom media for java)是java视频开发的新选择

/**
 * 
 */
package net.sf.fmj.filtergraph;

import java.io.IOException;

import javax.media.Buffer;
import javax.media.Demultiplexer;
import javax.media.Format;
import javax.media.ResourceUnavailableException;
import javax.media.Track;

/**
 * A node in a filter graph for a Demultiplexer.
 * @author Ken Larson
 *
 */
public class DemuxNode extends FilterGraphNode
{	
	private final Format inputFormat;
	private final Demultiplexer demux;
	/**
	 * Must have the same number of entries as dest.
	 */
	private Track[] tracks;
	
	public long sequenceNumber = 0L;	// TODO: 1 per track
	
	
	public DemuxNode(Format format, Demultiplexer demux, Track[] tracks)
	{
		super(demux);
		this.inputFormat = format;
		this.demux = demux;
		this.setTracks(tracks);
	}
	
	

	public FilterGraphNode duplicate()
	{
		return propagateDuplicate(new DemuxNode(getInputFormat(), getDemux(), getTracks()));
		
	}



	public void setTracks(Track[] tracks)
	{
		this.tracks = tracks;
	}



	public Track[] getTracks()
	{
		return tracks;
	}



	public Format getInputFormat()
	{
		return inputFormat;
	}



	public Demultiplexer getDemux()
	{
		return demux;
	}
	
	public void open() throws ResourceUnavailableException
	{
		getDemux().open();
	}
	
	@Override
	public void start() throws IOException
	{
		getDemux().start();	// TODO: what if already started?
	}



	@Override
	public void stop() 
	{
		getDemux().stop();
	}



	public int process(final Buffer input, final int sourceTrackNumber, final int destTrackNumber, final int flags)
	{
		for (int i = 0; i < getTracks().length; ++i)
		{	
			if (sourceTrackNumber >= 0 && i != sourceTrackNumber)
			{	//nCast.setBuffer(i, null);
				continue;
			}					
			final FilterGraphLink destLink = getDestLink(i);
			if (destLink == null)
			{	//nCast.setBuffer(i, null);
				continue;
			}
			
			if ((flags & FilterGraph.SUPPRESS_TRACK_READ) == 0)
			{
				// JMF re-uses the previous buffer
				if (getOutputBuffer(i) == null)
				{
					setOutputBuffer(i, new Buffer());
				}
				final Buffer buffer1 = (Buffer) getOutputBuffer(i);
				buffer1.setLength(0);
				buffer1.setSequenceNumber(sequenceNumber++); // TODO: 1 seq # per track is needed
				buffer1.setFlags(0);	// clear all flags. TODO: does JMF do this?  Or must the demux itself clear the flags?
				
//				// It does not appear that JMF sets the timestamp to what it thinks it is going to be.
				// although this is theoretically possible knowing the frame/buffer # and the framerate.

				// according to the docs,  Each track has a sequence number that is updated by the Demultiplexer for each frame
				// however, the OggDemux does not do this, and it appears that JMF sets the sequence number before giving it to the demux.
//				 TODO: other fields to clear?
				
				
				getTracks()[i].readFrame(buffer1);
				if (buffer1.getFormat() == null)
					buffer1.setFormat(getTracks()[i].getFormat());  // TODO: is this right?  JMF appears to set the format in between demux track read adnd codec process.

			}

		}
		

		return Demultiplexer.BUFFER_PROCESSED_OK;	// not really meaningful here
		
	}
	

}