Dealing with the disappearance of QVideoProbe and QCameraViewfinder in Qt 6.x

Francky033

Hello,
Under Qt 5.x, I was using QVideoProbe to get images from a camera. Unfortunately, this function has disappeared in version 6.x

const QList<QCameraInfo> cameras = QCameraInfo::availableCameras();

if (!cameras.empty())
{
	camera_sensor = new QCamera(QCamera::BackFace);

	if (camera_sensor)
	{
		viewfinder = new QCameraViewfinder();

		if (viewfinder)
	       {
			camera_sensor->setViewfinder(viewfinder);
		        camera_sensor->setCaptureMode(QCamera::CaptureStillImage);

			videoProbe = new QVideoProbe(this);

			if (videoProbe->setSource(camera_sensor)) {
				// Probing succeeded, videoProbe->isValid() should be true.
				connect(videoProbe, SIGNAL(videoFrameProbed(QVideoFrame)),
													this, SLOT(recupererImagesCamera(QVideoFrame)));
			}

			camera_sensor->start();
			// Viewfinder frames should now also be emitted by
			// the video probe, even in still image capture mode.
			// Another alternative is to install the probe on a
			// QMediaRecorder connected to the camera to get the
			// recorded frames, if they are different from the
			// viewfinder frames.
	}
}

I try painfully to go through the QVideoSink class but without success.

const QList<QCameraDevice> cameras = QMediaDevices::videoInputs();

if (!cameras.empty())
{
        camera_sensor = new QCamera(QCameraDevice::BackFace);

	if (camera_sensor)
	{
		viewfinder = new QVideoSink(this);

		if (viewfinder)
	       {
        		videoFrame = new QMediaCaptureSession();

			videoFrame->setCamera(camera_sensor);

			videoFrame->setVideoSink(viewfinder);

			connect(viewfinder, &QVideoSink::videoFrameChanged,
				this, &QWinStars3View::recupererImagesCamera2);
											
		}
     }
}

I try painfully to go through the QVideoSink class but without success.

Thanx !

Bonnie

Hello, have you checked the Camera Example came with Qt installation?
From my understanding, we use a QVideoWidget as the viewfinder (preview widget), and you don't need to create a QVideoSink because QVideoWidget already have one.
So should be something like

viewfinder = new QVideoWidget(this);
videoFrame = new QMediaCaptureSession();
videoFrame->setCamera(camera_sensor);
videoFrame->setVideoOutput(viewfinder);
connect(viewfinder->videoSink(), &QVideoSink::videoFrameChanged, this, &QWinStars3View::recupererImagesCamera2);
camera_sensor->start();

If you don't need a preview widget, then use QVideoSink only as in your code. Seems that should work after you start the camera.

Francky033

Thanks Bonnie!

It works perfectly (I will use QVideoSink )!

Have a great day!