filtergraphnode.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 java.util.ArrayList;
import java.util.List;
import java.util.logging.Logger;

import javax.media.Buffer;
import javax.media.Format;
import javax.media.PlugIn;
import javax.media.ResourceUnavailableException;

import net.sf.fmj.utility.LoggerSingleton;

/**
 * Base class for all filter graph nodes.
 * @author Ken Larson
 *
 */
public abstract class FilterGraphNode
{

	protected static final Logger logger = LoggerSingleton.logger;

	/**
	 * Destination nodes.
	 */
	private List/*<FilterGraphLink>*/ destLinks = new ArrayList/*<FilterGraphLink>*/();
	
	// processing state:
	/**
	 * Output buffer n is for destination node n.
	 * For a node which is a renderer node, the corresponding buffer will be null.
	 * Also, if a particular track/dest is not being processed at all by a graph,
	 * the corresponding buffer will be null.
	 */
	private List/*<Buffer>*/ outputBuffers = new ArrayList();
	
	private final PlugIn plugIn;
	
	public FilterGraphNode(final PlugIn plugIn)
	{
		super();
		this.plugIn = plugIn;
	}

	public int getNumDestLinks()
	{	return destLinks.size();
	}
	
	public FilterGraphLink getDestLink(int i)
	{
		try {
			return (FilterGraphLink) destLinks.get(i);
		}
		catch (IndexOutOfBoundsException e) {
			return null;
		}
	}
	
	public Buffer getOutputBuffer(int i)
	{
		try {
			return (Buffer) outputBuffers.get(i);
		}
		catch (IndexOutOfBoundsException e) {
			return null;
		}
	}
	
	public void setOutputBuffer(int i, Buffer b)
	{
		outputBuffers.set(i, b);
	}
	
	public void addDestLink(FilterGraphLink n)
	{
		destLinks.add(n);
		outputBuffers.add(null);
	}
	
	public abstract FilterGraphNode duplicate();
	public abstract void open() throws ResourceUnavailableException;
	// TODO: close() method
	/** sourceTrackNumber only used for demux, and destTrackNumber only used for mux. */
	public abstract int process(Buffer input, int sourceTrackNumber, int destTrackNumber, int flags);
	
	/**
	 * Intended to be called by subclass implementations of duplicate, to duplicate the destinations.
	 * @param result FilterGraphNode that is to be returned by duplicate();
	 */
	protected FilterGraphNode propagateDuplicate(FilterGraphNode result)
	{
		for (int i = 0; i < getNumDestLinks(); ++i)
		{
			FilterGraphLink link = getDestLink(i);
			if (link != null) {
				result.addDestLink(new FilterGraphLink(link.getDestNode().duplicate(), link.getDestTrack()));
			}
		}
		return result;
	}
	
	public void print(Logger logger, String prefix)
	{
		final String inputFormatStr = getInputFormat() == null ? "" : (getInputFormat().getClass().getSimpleName() + " [" + getInputFormat() + "]");
		logger.info(prefix + inputFormatStr);
		logger.info(prefix + getPlugIn().getClass().getName());
	}
	public abstract Format getInputFormat();
	public PlugIn getPlugIn()
	{	return plugIn;
	}

	public void start() throws IOException
	{	// do nothing by default
	}
	
	public void stop()
	{	// do nothing by default
	}
	
}