This might be a problem with OpenCV handling your webcam.
Some hints to solve it:
- Did you have the dev package of V4L2 installed when you compiled OpenCV? Try to recompile OpenCV from source after installing this package. This should solve the problem
- OpenCV of V4L2 might not be able to handle resolution changing on your device. This is a much less probable cause, but some time ago there still were some incompatible cameras. In this case you can change the resolution, but it will be hard-coded. Look for the definition of the default resolution in the highgui folder of the sources (
DEFAULT_V4L_HEIGHT/WIDTH in cap-v4l.cpp).
