QVideoWidget::setBrightness doesn't have any effect

[timppajee]

I am developing on mac and QT5.7.

I am trying to do a small video playing application, but when trying to set contrast or brightness it looks like these setBrightness and setContrast doesn't have any effect to video playback whatsoever.

Maybe I am doing something stupid? Simplified code is like this:

MainWindow::MainWindow(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::MainWindow)
{
    QVideoWidget* vw = new QVideoWidget();

    inputPlayer->setVideoOutput(vw);
    inputPlayer->setMedia(QUrl::fromLocalFile("video.mp4"));

    vw->setBrightness(-100);
//    vw->setBrightness(100);
    vw->setContrast(-100);
//    vw->setContrast(100);

I tried to set it back and forth from 100 to 0 to -100, but I don't see any difference.
Is it a problem in my environment or code?

[SGaist]

Hi and welcome to devnet,

You're not doing anything stupid but I'd rather try to modify the brightness after the video has started running rather than in the constructor.

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