UBUNTU 14.04 cheese booth not detect webcam

Cheese Booth shows an error:

There was an error playing video from the webcam

I test if webcam works fine or not by opening google hangout, its works fine.

Please tell, what is the issue in cheese booth.

Note: Sometimes the cheese booth works fine but most of time not

1. Open Preferences, and change these resolutions to the lowest.

2.Now restart cheese.

3.The webcam should work. Keep increasing the resolution until it stops working again.For many webcams, this limit is 640x480.

I faced similar problem with cheese so I installed GTK UVC Video Viewer. It rich in terms of feature as compared to cheese. You can install it by entering following in terminal:

sudo apt-get install guvcview

UPDATE: Actually, I just found that you need to manually add your user to the audio and video groups. The easiest way is to launch the "users and groups" app and go to manage groups

Original answer: There seems to be an issue with the permissions on /dev/video*.

They are owned by root with no read/write permissions for regular users. My quick-and-dirty hack was a simple:

sudo chmod 777 /dev/video*

If you start cheese from the terminal you might see this error:

(cheese:7333): cheese-WARNING **: 09:47:54.438: Device '/dev/video0' is busy: gstv4l2object.c(3706): gst_v4l2_object_set_format_full (): /GstCameraBin:camerabin/GstWrapperCameraBinSrc:camera_source/GstBin:bin18/GstV4l2Src:v4l2src1: Call to S_FMT failed for YUYV @ 160x120: Device or resource busy

Closing the other app (for me it was a Chrome tab with Google Hangouts) is the work around.

Try sudo cheese if it is a permission problem this will let you open it with the super user privileges.