On the right side of the dialog is a Button frame for control, on the left side I will sie the video.

I tried 3 methods, but every had problems.

1. Manipulate Vidoestream:

   VideoSurface = new TMyVideoSurface(this); // derived from QAbstractVideoSurface
    connect(VideoSurface, &TMyVideoSurface::frameReceived,
    this, &Camera_Frame::updateVideoPicture);

This worked on Windows very good, but on Android its to slow - the video is delayed.
The slow part should be, datatransfer from "Camera-RAM" to nommal RAM.

2. Widget over the QVideoWidget

m_overlay= new TMyCameraOverlay(m_videoWidget);

I see no overlay. I heared that the QVideoWidget "overdraws" all.

3. Use QGraphicsScene:

//  Main part of the code
m_graphicsScene = new QGraphicsScene(this);
   m_graphicsView = new QGraphicsView(m_graphicsScene, this);
   m_graphicsView->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
   m_graphicsView->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

   m_videoItem = new QGraphicsVideoItem();
   m_graphicsScene->addItem(m_videoItem);
   // 3. Create  Custom-Overlay and put it in the Szene
   m_overlay = new TCameraOverlay();
   // Proxy makes normal Widget visible
   QGraphicsProxyWidget *proxy = m_graphicsScene->addWidget(m_overlay);
   proxy->setZValue(1); // Overlay in den forground !
   
   // Pack View in the Layout
   ui->ViewLayout->addWidget(m_graphicsView, 0, 0);

   // 4. Connect Camera (Set VideoItem as VideoOutput)
   m_captureSession = new QMediaCaptureSession(this);
   m_imageCapture = new QImageCapture(this);
   connect(m_imageCapture, &QImageCapture::imageCaptured,
           this, &Camera_Frame::processCapturedImage);

   m_captureSession->setCamera(m_camera);
   m_captureSession->setVideoOutput(m_videoItem); // Important: videoItem instead of videoWidget!
   m_captureSession->setImageCapture(m_imageCapture);

But here I get a very strange effect. The whole window especialy the control-buttons do react on touch evens no more.

Who has experiences with a camera modul on Android ?