couldntGetRequiredComponent in Quicktime For Java

I have to make a free software for children. It includes a webcam. I wanted to use « Quicktime for Java » but I have an error ‘couldntGetRequiredComponent’,

The only reason I found was on the forum "http://www.monkeybreadsoftware.de/realbasic/pluginhelp/quicktimesequencegrabber-qtgrabbermbs.shtml" :
“you have as a possible solution in case you really have recording hardware, that the QuickTime installation is without Authoring Support. The default QuickTime Installation installs only software needed for playing movies and displaying picture, but not to record them. You may need to do a custom installation to have the Authoring Support files installed.”.

My source code is :
QTSession.open();
myQTCanvas = new QTCanvas(QTCanvas.kPerformanceResize, 0.5F, 0.5F);
myQTCanvas.setMaximumSize(new Dimension(640, 480));
add("Center", myQTCanvas);
addNotify();
Insets insets = getInsets();
setBounds(0, 0, (insets.left + insets.right + kWidth),
(insets.top + insets.bottom + kHeight));
myGrabber = new SequenceGrabber();
SGVideoChannel myVideo =new SGVideoChannel(myGrabber);
myVideo.settingsDialog();
myVideo.setBounds(new QDRect(kWidth, kHeight));
myVideo.setUsage(seqGrabPreview | seqGrabRecord | seqGrabPlayDuringRecord);
mySGDrawer = new SGDrawer(myVideo);
myQTCanvas.setClient(mySGDrawer, true);
myGrabber.prepare(true,false);
myGrabber.startPreview();

Do you have a better code or do you know how to correct this error. Thanks for reply.