basiccodec.java

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

package com.sun.media;

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


/**
 * TODO: incomplete.
 * @author Ken Larson
 */
public abstract class BasicCodec extends BasicPlugIn implements Codec
{
// TODO: it is really hard to figure out comprehensively what is being done with these various methods.
	// I think we may have enough for FFMPEG.
	
	/* ffmpeg uses: inputFormat, outputFormat, inputFormats, outputFormats, 
//	   if (isEOM(inBuffer)) {
//           propagateEOM(outBuffer); 
	
	        Object inData = getInputData(inBuffer);
        long inDataBytes = getNativeData(inData);

        Object outData = getOutputData(outBuffer);
        
              outData = validateData(outBuffer, outputH263Length, true / *allow native* /);
        long outDataBytes = getNativeData(outData);
        
        opened

	*/
	
	private static final boolean DEBUG = true;
	protected Format inputFormat = null;
	protected Format outputFormat = null;
	protected boolean opened = false;
	protected Format[] inputFormats = new Format[0];
	protected Format[] outputFormats = new Format[0];
	protected boolean pendingEOM = false;
	
	public BasicCodec()
	{
		super();
	}
	public Format setInputFormat(Format input)
	{
		this.inputFormat = input;
		return this.inputFormat;
	}
	public Format setOutputFormat(Format output)
	{
		this.outputFormat = output;
		return this.outputFormat;
	}
	protected Format getInputFormat()
	{	return inputFormat;
	}
	protected Format getOutputFormat()
	{	return outputFormat;
	}	
	public void reset()
	{
		// TODO: does not appear to do anything.
	}
	public Format[] getSupportedInputFormats()
	{
		return inputFormats;
	}
	protected boolean isEOM(Buffer inputBuffer)
	{
		return inputBuffer.isEOM();
	}
	protected void propagateEOM(Buffer outputBuffer)
	{
		outputBuffer.setFormat(outputFormat);
		outputBuffer.setLength(0);
		outputBuffer.setOffset(0);
		outputBuffer.setEOM(true);
	
	}
	protected void updateOutput(Buffer outputBuffer, Format format, int length, int offset)
	{
		outputBuffer.setFormat(format);
		outputBuffer.setLength(length);
		outputBuffer.setOffset(offset);
		
	}
	protected boolean checkInputBuffer(Buffer inputBuffer)
	{
		// JMF appears to call isEOM on the buffer.  
		if (inputBuffer.isEOM())
			return true;
		
		final Format f = inputBuffer.getFormat();
		
		inputBuffer.getFormat();	// TODO: why does JMF call this twice?
		
		// JMF appears to call checkFormat
		return  f != null && checkFormat(f);	// TODO: anything else to check?
	}
	protected boolean checkFormat(Format format)
	{
		return true;	// TODO: anything to check? does not appear to check anything.
	}
	protected int checkEOM(Buffer inputBuffer, Buffer outputBuffer)
	{
		throw new UnsupportedOperationException();	// TODO
	}
	protected int processAtEOM(Buffer inputBuffer, Buffer outputBuffer)
	{
		throw new UnsupportedOperationException();	// TODO
	}
	protected int getArrayElementSize(Class type)
	{
		if (type == byte[].class)
			return 1;
		else if (type == short[].class)
			return 2;
		else if (type == int[].class)
			return 4;
		else
			return 0;
		
	}

	public abstract int process(Buffer input, Buffer output);
	
	
	public abstract Format[] getSupportedOutputFormats(Format input);
	//@Override
	public void close()
	{	opened = false;
	}

	//@Override
	public void open() throws ResourceUnavailableException
	{	opened = true;
	}
	
}