Why do I get a time out while getting a from a USB webcam?

How do I fix this problem. I webcam works fine on skype and I had all my chat apps off too. Preview gets me a window with a black image.

>> cam= webcam(1);
>> cam

cam = 

    webcam with properties:

                       Name: 'Logitech HD Pro Webcam C920'
                 Resolution: '640x480'
       AvailableResolutions: {1x17 cell}
               WhiteBalance: 4000
                 Saturation: 128
                   Exposure: -4
                       Zoom: 100
                       Gain: 0
                      Focus: 0
                 Brightness: 100
                       Tilt: 0
                   Contrast: 128
                  Sharpness: 128
                        Pan: 0
               ExposureMode: 'auto'
      BacklightCompensation: 0

>> img = snapshot(cam);
Error using matlab.webcam.internal.WebcamController/getCurrentFrame
Time out occured while trying to get a frame from the webcam.

Error in webcam/snapshot (line 227)
            [image, timestamp] = obj.CamController.getCurrentFrame();

I am using 2015b on Windows 10. I have skype and google hangouts installed. I have 2 webcams - the notebook inbuilt webcam and a C920 Logitech external camera.

The video chat app test shows the preview fine. I made sure that these apps were closed while trying to capture images.

The issue occurs with both cameras. Also, the problem persisted even after a reboot.

[Bharath Lohray]

The problem mysteriously vanished. I attached the webcam to my computer instead of the self powered USB3 hub. It worked. Then attached it back to the hub. It still worked.

Undetirministic Machine!

Answer 1

[Madhura Suresh]

Hi Bharath,

What version of MATLAB are you using and what OS are you on? Can you also confirm that other apps that might be using the webcam(like Skype/ Logitech software) are closed before you run this in MATLAB?

[Bharath Lohray]

I am using 2015b on Windows 10. I have skype and google hangouts installed. I have 2 webcams - the notebook inbuilt webcam and a C920 Logitech external camera.

The video chat app test shows the preview fine. I made sure that these apps were closed while trying to capture images.

The issue occurs with both cameras. Also, the problem persisted even after a reboot.

Answer 2

[Enoch]

I do it by running matlab as administrator