QML叠加在摄像机视频上

Question

I am trying to draw some overlay on the frame captured by the Camera objet in Qt/QML. The camera itself is defined as:

Camera {
    id: camera
    captureMode: Camera.CaptureVideo
}
VideoOutput {
    source: camera
    focus : visible 
    anchors.fill: parent
}

Now when I call camera.videorecorder.record() , the camera starts recording and the current frame is displayed on the video output canvas. Now, what I would like to do is draw a rectangle at some arbitrary location on the frame.

I see that there are some shader effects example ( http://doc.qt.io/qt-5/qtmultimedia-multimedia-video-qmlvideofx-example.html ) but they look really complicated for what I want to do and I am not versed with GLSL.

Answer 1

Something like this?

Camera {
    id: camera
    captureMode: Camera.CaptureVideo
}

VideoOutput {
    source: camera
    focus : visible
    anchors.fill: parent
    Rectangle {
            color: "red";
            width: parent.width / 2;
            height: parent.height / 2;
            anchors.centerIn: parent;
   }
}

Edit: This will work too:

Camera {
    id: camera
    captureMode: Camera.CaptureVideo
}
VideoOutput {
    source: camera
    focus : visible
    anchors.fill: parent
}
Rectangle {
        color: "red";
        width: parent.width / 2;
        height: parent.height / 2;
        anchors.centerIn: parent;
}