What is the fastest way to display an image in QT on X11 without OpenGL?

Posted by msh on Stack Overflow See other posts from Stack Overflow or by msh
Published on 2011-09-14T02:09:35Z Indexed on 2012/06/28 9:16 UTC
Read the original article Hit count: 280

Filed under:

linux

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qt

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qt4

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x11

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xlib

I need to display a raw image in a QT widget. I'm running X11 on a framebuffer, so OpenGL is not available.

Both the image and the framebuffer are in the same format - RGB565, but I can change it to any other format if needed. I don't need blending or scaling. I just need to display pixels as is.

I'm using QPainter::drawImage, but it converts QImage to QPixmap and this conversion seems to be very slow. Also it is backed by Xrender and I think there is unnecessary overhead required to support blending in Xrender which I don't really need

Is there any better way? If it is not available in QT, I can use Xlib or any other library or protocol. I can modify the driver, X server or anything else.

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