jpegencoder.java

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

package net.sf.fmj.media.codec.video.jpeg;

import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

import javax.media.Buffer;
import javax.media.Codec;
import javax.media.Format;
import javax.media.format.VideoFormat;

import net.sf.fmj.media.AbstractCodec;
import net.sf.fmj.media.util.BufferToImage;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

/**
 * Interesting that JMF doesn't include such an encoder in cross-platform JMF.
 * @author Ken Larson
 *
 */
public class JpegEncoder extends AbstractCodec implements Codec
{
	private final Format[] supportedInputFormats = new Format[] {
			new VideoFormat(VideoFormat.RGB, null, -1, Format.byteArray, -1.0f),
			new VideoFormat(VideoFormat.RGB, null, -1, Format.intArray, -1.0f),
		};
	private final Format[] supportedOutputFormats = new Format[] {
			new VideoFormat(VideoFormat.JPEG, null, -1, Format.byteArray, -1.0f),
		};

	public Format[] getSupportedInputFormats()
	{
		return supportedInputFormats;
	}

	public Format[] getSupportedOutputFormats(Format input)
	{
		if (input == null)
			return supportedOutputFormats;
		VideoFormat inputCast = (VideoFormat) input;
		final Format[] result = new Format[] {
				new VideoFormat(VideoFormat.JPEG, inputCast.getSize(), -1, Format.byteArray, -1.0f)};
	
		return result;
	}

	private BufferToImage bufferToImage;
	
	public Format setInputFormat(Format format)
	{
		final VideoFormat videoFormat = (VideoFormat) format;
		if (videoFormat.getSize() == null)
			return null;	// must set a size.
//		logger.fine("FORMAT: " + MediaCGUtils.formatToStr(format));
		// TODO: check VideoFormat and compatibility
		bufferToImage = new BufferToImage((VideoFormat) format);
		return super.setInputFormat(format);
	}
	
	public int process(Buffer input, Buffer output) 
	{
		final BufferedImage image = (BufferedImage) bufferToImage.createImage(input);
		
		try
		{
			// TODO: this is very inefficient - it allocates a new byte array (or more) every time
			
			final ByteArrayOutputStream os = new ByteArrayOutputStream();
			final JPEGEncodeParam param = JPEGCodec.getDefaultJPEGEncodeParam(image);
			// TODO: trying to get good compression of safexmas.avi frames, but they end up being
			// 10k each at 50% quality.  JMF sends them at about 3k each with 74% quality.
			// I think the reason is that JMF is probably encoding the YUV in the jpeg, rather
			// than the 24-bit RGB that FMJ would use when using the ffmpeg-java demux.
			
			// TODO: we should also use a JPEGFormat explicitly, and honor those params.
			
			param.setQuality(0.74f, true);
			final JPEGImageEncoder jpeg = JPEGCodec.createJPEGEncoder(os, param);
			jpeg.encode(image);
			os.close();
			
			final byte[] ba = os.toByteArray();
			output.setData(ba);
			output.setOffset(0);
			output.setLength(ba.length);
			//System.out.println("Encoded jpeg to len: " + ba.length);
			return BUFFER_PROCESSED_OK;

		}
		catch (IOException e)
		{	output.setDiscard(true);
			output.setLength(0);
			return BUFFER_PROCESSED_FAILED;
		}		
		
		
	}
}