QCamera/QCameraFocus Windows 10 tablet

addebito

Hi at all,

I bought an industrial tablet with a rear camera and I can use it by the QCamera + QAbstractVideoSurface without particular problems.
The only thing I care about now is how to disable the auto focus functionality because is extremely slow.

Before that I check by

QCameraFocus::isFocusModeSupported(QCameraFocus::FocusModes mode)
QCameraFocus::isFocusPointModeSupported(QCameraFocus::FocusPointMode mode)

...but all types give me a false as result.
But I'm sure, the rear camera has the auto focus functionality, I can see it during the video capture.

I'm using QT 5.12.6 and the tablet has Windows 10 LTSB 2016.

Follow the output of QCameraInfo "deviceName" and "description".

    foreach(QCameraInfo cam, cam_list)
        ui->textCamera->append(cam.deviceName() + " " + cam.description());

@device:pnp:\\?\usb#vid_5986&pid_0546&mi_00#8&2391f56a&0&0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\global USB2.0 Camera

Do you have any advice?
Thank you.

SGaist

Hi,

It might be a limitation of the Windows backend. You should check if the control itself is available.

addebito

Thank you @SGaist, how to do that?
What you mean with "control" is available?

In the meantime I trying a different approach. I'll post it.

addebito

As mentioned before I changed approach, I abandoned QCamera class, now I'm using VideoCapture from OpenCV.

        // turn the autofocus off
        bool ret = cap.set(CAP_PROP_AUTOFOCUS, 0); 
        if (!ret)
            qWarning() << "Error during disable auto focus";

        // set manual focus (0 to 255)
        ret = cap.set(CAP_PROP_FOCUS, 255);
        if (!ret)
            qWarning() << "Error during set focus to 255";

SGaist

@addebito said in QCamera/QCameraFocus Windows 10 tablet:

Thank you @SGaist, how to do that?
What you mean with "control" is available?

In the meantime I trying a different approach. I'll post it.

I meant if you can get a QCameraFocusControl but it looks like I misread your original post and you did get the control. So I think it's indeed a limitation of the backend or that it can't for some reason provide that control directly.

Out of curiosity, what type of camera is that ?

addebito

@SGaist I don't know exactly.
It's a 5Mpixels USB camera mounted on rear of an industrial tablet.