DirectFB performance

[Jean]

Dear All,

I'm use QT 4.8.7 and broadcom board.

I want to use qt ui and directly call directfb api. (directfb version is 1.7.x)
I could find to use both but there is lower performance problem.

The performance is lower to call blit (directfb api) with QApplication.

I mean 1 is twice faster than 2.

1. call the blit function with QCoreApplication

int main(int argc, char *args[])
{
    QCoreApplication app(argc, args);
    DirectFBTest();
    return app.exec();
}

2. call the blit function with QApplication (-qws -display directfb)

int main(int argc, char *args[])
{
    int _argc = 4;
    char *_args[4] = {"test","-qws","-display","directfb"};

    QApplication app(_argc, _args);
    DirectFBTest();
    return app.exec();
}

Note: the function (DirectFBTest) is just rendering image and blit it to primary surface.

Could you advise for me to improve the performace?

Jean.

[SGaist]

Hi,

Just an educated guess:
Numer one is faster because there's nothing accessing the framebuffer at all while with number two there's QWS running which does use said framebuffer to do window management.

[Jean]

Dear SGaist,

Yes, I guessed it as you mentioned.
I just want to know how to optimize directfb performance why I asked the question.

Thanks for relpying it :)

[SGaist]

Can you give more details about your use case ?

[chengch512]

@SGaist said in DirectFB performance:

Can you give more details about your use case ?

Hi SGaist,
My issue is same with this, could you take a look at it? thansk!
https://forum.qt.io/topic/81151/qt-directfb-performance-issue