Qt MediaFX.RenderWindow

MediaFX.RenderWindow is a QML QQuickWindow subclass that supports offscreen rendering of its contents via QQuickRenderControl.

Given this QML

import QtQuick.Controls
import MediaFX.RenderWindow

RenderWindow {
    width: 160
    height: 160
    Button {
        text: "The Button"
    }
}

Instantiate a QQmlApplicationEngine, addImportPath the module, then invoke render(millis) on the RenderWindow to get a QByteArray of RGBA pixels.