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BufferToImage.javaAPI DocJMF 2.1.1e5674Mon May 12 12:20:34 BST 2003javax.media.util

BufferToImage

public class BufferToImage extends Object
This is a utility class to convert a video Buffer object to an AWT Image object that you can then render using AWT methods.

You can use this class in conjunction with the FrameGrabbingControl to grab frames from the video renderer and manipulate the image.

see
javax.media.control.FrameGrabbingControl
since
JMF 2.0

Fields Summary
private VideoFormat
format
private Codec
converter
private RGBFormat
prefFormat
private Buffer
outputBuffer
private Dimension
size
private boolean
converterNotRequired
Constructors Summary
public BufferToImage(VideoFormat format)
Instantiates a Buffer to Image conversion object for the specified format. The createImage method expects input buffers to have the format that is specified here.

param
format the format of incoming Buffer objects.


                                          
       
	if (!(format instanceof YUVFormat ||
	      format instanceof RGBFormat)) {
	    // Cant do
	} else {
	    this.format = format;
	    size = format.getSize();
	    prefFormat = new RGBFormat(size,
				       size.width * size.height, // maxDataLength
				       Format.intArray,       // type
				       format.getFrameRate(),
				       32,  // bpp
				       Format.NOT_SPECIFIED,  // masks
				       Format.NOT_SPECIFIED,
				       Format.NOT_SPECIFIED, 
				       1, Format.NOT_SPECIFIED, // strides
				       RGBFormat.FALSE, // flipped
				       Format.NOT_SPECIFIED); // endian
	    if (format.matches(prefFormat)) {
		converterNotRequired = true;
		return;
	    }
	    Codec codec = findCodec(format, prefFormat);
	    if (codec != null)
		converter = codec;
	    outputBuffer = new Buffer();
	}
Methods Summary
public java.awt.ImagecreateImage(javax.media.Buffer buffer)
Converts the input buffer to a standard AWT image and returns the image. The buffer should contain video data of the format specified in the constructor. If the input data is not valid or a suitable converter couldn't be found, the method returns null.

return
an AWT Image if the conversion was completed succesfully, else returns null.

	// check for bad values
	if (  buffer == null ||
	      (converter == null && converterNotRequired == false) ||
	      prefFormat == null ||
	      buffer.getFormat() == null ||
	      !buffer.getFormat().matches(format) ||
	      buffer.getData() == null ||
	      buffer.isEOM() ||
	      buffer.isDiscard()  )
	    return null;

	int [] outputData;
	RGBFormat vf;
	
	try {
	    if (converterNotRequired) {
		outputData = (int[]) buffer.getData();
		vf = (RGBFormat) buffer.getFormat();
		outputBuffer = buffer;
	    } else {
		int retVal = converter.process(buffer, outputBuffer);
		if (retVal != PlugIn.BUFFER_PROCESSED_OK)
		    return null;
		outputData = (int[]) outputBuffer.getData();
		vf = (RGBFormat) outputBuffer.getFormat();
	    }
	} catch (Exception ex) {
	    System.err.println("Exception " + ex);
	    return null;
	}

	Image outputImage = null;
	BufferToImage waFor2DBug = null;

	try {
	    Class cl = Class.forName("com.sun.media.util.BufferToBufferedImage");
	    waFor2DBug = (BufferToImage) cl.newInstance();
	} catch (Exception e) {
	    //System.err.println("Not JDK 1.2");
	}

	if (waFor2DBug != null) {
	    outputImage = waFor2DBug.createImage(outputBuffer);
	} else {
	    int redMask = vf.getRedMask();
	    int greenMask = vf.getGreenMask();
	    int blueMask = vf.getBlueMask();
	    
	    
	    DirectColorModel dcm = new DirectColorModel(32,
							redMask,
							greenMask,
							blueMask);
	    
	    MemoryImageSource sourceImage = new MemoryImageSource(size.width,
								  size.height,
								  dcm,
								  outputData,
								  0,
								  size.width);
	    outputImage = Toolkit.getDefaultToolkit().createImage(sourceImage);
	}
	
	return outputImage;
private javax.media.CodecfindCodec(javax.media.format.VideoFormat input, javax.media.format.VideoFormat output)

	Vector codecList = PlugInManager.getPlugInList(input, output, PlugInManager.CODEC);
	if (codecList == null || codecList.size() == 0)
	    return null;
	for (int i = 0; i < codecList.size(); i++) {
	    String codecName = (String) codecList.elementAt(i);
	    Class codecClass = null;
	    Codec codec = null;
	    try {
		codecClass = Class.forName(codecName);
		if (codecClass != null)
		    codec = (Codec) codecClass.newInstance();
	    } catch (ClassNotFoundException cnfe) {
	    } catch (IllegalAccessException iae) {
	    } catch (InstantiationException ie) {
	    } catch (ClassCastException cce) {
	    }
	    if (codec == null)
		continue;
	    if (codec.setInputFormat(input) == null)
		continue;
	    Format [] outputs = codec.getSupportedOutputFormats(input);
	    if (outputs == null || outputs.length == 0)
		continue;
	    for (int j = 0; j < outputs.length; j++) {
		if (outputs[j].matches(output)) {
		    Format out = codec.setOutputFormat(outputs[j]);
		    if (out != null && out.matches(output)) {
			try {
			    codec.open();
			    return codec;
			} catch (ResourceUnavailableException rue) {
			}
		    }
		}
	    }
	}
	return null;