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Using accelerated cfb_imageblit and cfb_fillrect with linux frame buffer driver



  • Hello,

    We are developing a product that uses Qt 4.8.7 on a board with a frame buffer driver, without a graphics card and a very slow CPU. Therefore we want to try all options available to speed up rendering as much as possible. Digging into qt code I've found that (if I'm not mistaken) it uses the linux frame buffer screen class which mmaps the /dev/fb0 device and then copies the pixels to it normally (qscreenlinuxfb_qws.h/cpp).

    Our driver though also provides dma accelerated functions, namely cfb_imageblit to do that same job. Doing an lsmod on the board shows that these modules are up and running so I should be able to use them. Does qt provide any options to use them or would I have to patch the source code somehow? If I have to patch, do you have any suggestions on which parts of the code I should be looking at?


  • Lifetime Qt Champion

    Hi,

    I would start by looking at the gfxdrivers plugins.



  • That sounds promising, thanks @SGaist . I'll have a look at that.


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