Adjust brightness for qvideowidget inserted in QGraphicsscene and QGraphicsView

Question

I play videos using Qgrpahicsscene, QgraphicsView, qvideowidget

videoWidget = new QVideoWidget; QGraphicsScene *scene = new QGraphicsScene; QGraphicsView *graphicsView = new QGraphicsView(scene); scene->addWidget(videoWidget); 

playing the video correctly, I need it when I adjust the brightness in the video call, it does not reflect, and I checked the brightness level of the video output that it sets. please share some ideas, thanks in advance

Answer 1

You can achieve almost all kinds of effects and corrections using shaders, in particular, brightness is a very simple fragment shader, just multiply each pixel brightness by a real factor. With QML, you can even use shader effects, as well as an example of QML video effects.

Brightness / Contrast

All ready to use effects.

QML Video Effects Example

You can use shaders even with widgets if you go for the basic QGLWidget widget and still get great performance.

Answer 2

Refresh the scene after changing the brightness. Like this:

 videoWidget->setBrightness(bright); scene->update(scene->sceneRect());