org.vigia.server.driver.camera
Class JMFCapture

java.lang.Object
  org.vigia.server.driver.camera.JMFCapture

All Implemented Interfaces:

javax.media.ControllerListener

public class JMFCapture
extends java.lang.Object
implements javax.media.ControllerListener

Author:

Jesus

Field Summary

private javax.media.util.BufferToImage	bufferToImage BufferToImage object
private static java.lang.String	CAP_DEVICE Common name in WinXP/Vista
private boolean	closedDevice closed device indication
private javax.media.control.FrameGrabbingControl	fg FrameGrabbingControl object
private static int	MAX_TRIES tries used while waiting for the BufferToImage object to be initialized
private javax.media.Player	p Player object
private boolean	stateTransitionOK used for waiting until the player has started
private static int	TRY_PERIOD period used while waiting for the BufferToImage object to be initialized
private java.lang.Object	waitSync used for waiting until the player has started

Constructor Summary

JMFCapture()
JMFCapture constructor

Method Summary

void	close() close() and grabImage() are synchronized so that it's not possible to close down the player while a frame is being snapped.
void	controllerUpdate(javax.media.ControllerEvent evt) respond to events
java.awt.image.BufferedImage	grabImage() Capture an image/frame.
private boolean	hasBufferToImage() The BufferToImage object is initialized here, so that when grabImage() is called later, the snap can be quickly changed to an image.
boolean	isClosed() is closed the device?
private java.awt.image.BufferedImage	makeBIM(java.awt.Image im) Make a BufferedImage copy of im, assuming no alpha channel.
private void	waitForBufferToImage() Wait for the BufferToImage object to be initialized.
private boolean	waitForStart() wait for the player to enter its Started state

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CAP_DEVICE

private static final java.lang.String CAP_DEVICE

Common name in WinXP/Vista

See Also:

Constant Field Values

MAX_TRIES

private static final int MAX_TRIES

tries used while waiting for the BufferToImage object to be initialized

See Also:

Constant Field Values

TRY_PERIOD

private static final int TRY_PERIOD

period used while waiting for the BufferToImage object to be initialized

See Also:

Constant Field Values

p

private javax.media.Player p

Player object

fg

private javax.media.control.FrameGrabbingControl fg

FrameGrabbingControl object

bufferToImage

private javax.media.util.BufferToImage bufferToImage

BufferToImage object

closedDevice

private boolean closedDevice

closed device indication

waitSync

private java.lang.Object waitSync

used for waiting until the player has started

stateTransitionOK

private boolean stateTransitionOK

used for waiting until the player has started

Constructor Detail

JMFCapture

public JMFCapture()

JMFCapture constructor

Method Detail

waitForStart

private boolean waitForStart()

wait for the player to enter its Started state

Returns:

state

waitForBufferToImage

private void waitForBufferToImage()

Wait for the BufferToImage object to be initialized. May take several seconds to initialize this object, so this method makes up to MAX_TRIES attempts

hasBufferToImage

private boolean hasBufferToImage()

The BufferToImage object is initialized here, so that when grabImage() is called later, the snap can be quickly changed to an image. The object is initialized by taking a snap, which may be an actual picture or be 'empty'. An 'empty' snap is a Buffer object with no video information, as detected by examining its component VideoFormat data. An 'empty' snap is caused by the delay in the player, which although in its started state may still take several seconds to start capturing. The dimensions of the snap are used to calculate the scale factor from the original image size to size*size.

Returns:

state

grabImage

public java.awt.image.BufferedImage grabImage()

Capture an image/frame. The frame is converted from Buffer object to Image, and finally to BufferedImage.

Returns:

a BufferedImage object contains the frame

makeBIM

private java.awt.image.BufferedImage makeBIM(java.awt.Image im)

Make a BufferedImage copy of im, assuming no alpha channel. Resize it to fit into size dimensions.

Parameters:

im - Image object

Returns:

a BufferedImage object

close

public void close()

close() and grabImage() are synchronized so that it's not possible to close down the player while a frame is being snapped.

isClosed

public boolean isClosed()

is closed the device?

Returns:

true if device is closed

controllerUpdate

public void controllerUpdate(javax.media.ControllerEvent evt)

respond to events

Specified by:

controllerUpdate in interface javax.media.ControllerListener

See Also:

ControllerListener.controllerUpdate(javax.media.ControllerEvent)