depacketizer.java

来自「FMJ（freedom media for java)是java视频开发的新选择」· Java 代码 · 共 82 行

package net.sf.fmj.media.codec.audio.alaw;

import java.util.logging.Logger;

import javax.media.Format;
import javax.media.format.AudioFormat;

import net.sf.fmj.media.AbstractDePacketizer;
import net.sf.fmj.media.BonusAudioFormatEncodings;
import net.sf.fmj.utility.LoggerSingleton;

/**
 * 
 * DePacketizer for ALAW/RTP.  Doesn't have to do much, just copies input to output.  Uses buffer-swapping observed in debugging
 * and seen in other open-source DePacketizer implementations.
 * @author Ken Larson
 *
 */
public class DePacketizer extends AbstractDePacketizer
{
	private static final Logger logger = LoggerSingleton.logger;

	public String getName()
	{
		return "ALAW DePacketizer";
	}
	
	public DePacketizer()
	{
		super();
		this.inputFormats = new Format[] {new AudioFormat(BonusAudioFormatEncodings.ALAW_RTP, -1.0, -1, -1, -1, -1, -1, -1.0, Format.byteArray)};
	}
	
	// TODO: move to base class?
	protected Format[] outputFormats = new Format[] {new AudioFormat(AudioFormat.ALAW, -1.0, -1, -1, -1, -1, -1, -1.0, Format.byteArray)};
	
	public Format[] getSupportedOutputFormats(Format input)
	{
		if (input == null)
			return outputFormats;
		else
		{	
			if (!(input instanceof AudioFormat))
			{	logger.warning(this.getClass().getSimpleName() + ".getSupportedOutputFormats: input format does not match, returning format array of {null} for " + input); // this can cause an NPE in JMF if it ever happens.
				return new Format[] {null};
			}
			final AudioFormat inputCast = (AudioFormat) input;
			if (!inputCast.getEncoding().equals(BonusAudioFormatEncodings.ALAW_RTP))
			{	
				logger.warning(this.getClass().getSimpleName() + ".getSupportedOutputFormats: input format does not match, returning format array of {null} for " + input); // this can cause an NPE in JMF if it ever happens.
				return new Format[] {null};
			}
			final AudioFormat result = new AudioFormat(AudioFormat.ALAW, inputCast.getSampleRate(), inputCast.getSampleSizeInBits(),
					inputCast.getChannels(), inputCast.getEndian(), inputCast.getSigned(), inputCast.getFrameSizeInBits(), 
					inputCast.getFrameRate(), inputCast.getDataType());

			return new Format[] {result};
		}
	}

	public void open()
	{
	}
	
	public void close()
	{
	}


	public Format setInputFormat(Format arg0)
	{
		return super.setInputFormat(arg0);
	}

	public Format setOutputFormat(Format arg0)
	{
		return super.setOutputFormat(arg0);
	}

	
}