Display the camera frame in real time

[alex_lue]

I use a FireWire-Camera and i want to display the frame in real time (15 ~ 30fps) by Qt. I have tried to display it by QGraphicsview, e.g.:

graphicsview->scene()->addPixmap(pixmap);

graphicsview->scene()->addPixmap(pixmap);

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But it is too slow. And i have tried to use "setBackgroundBrush", e.g.:

graphicsview->scene()->setBackgroundBrush(QBrush::QBrush(qimage));

graphicsview->scene()->setBackgroundBrush(QBrush::QBrush(qimage));

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This is faster, but not real time.
Can anyone tell me some advices how to solve the tempo problem?

Thanks!