Actually I have.
Regarding start and stop methods. I am using CameraDetector and if I call start and stop once everything works. But if I do it again in my application (workflow can be executed mutliple times), next time no images are grabbed from camera and there is an error
VIDIOC_STREAMON: Invalid file handle (translated from polish)
Example log from my app (Result updated means frame was captured by CameraDetector, "Błędny deskryptor pliku" means Invalid File Handle ):
HIGHGUI WARNING: V4L/V4L2: VIDIOC_S_CROP
HIGHGUI ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV
VIDIOC_STREAMON: Błędny deskryptor pliku
Unable to stop the stream.: Błędny deskryptor pliku
I searched the web and it looks like this happens, when camera is not properly released. And this might be the case, since camera is off before calling start, but stays on after stop is called. Could that be the case?
Additionally, why it is not possible to specify camera resolution in CameraDetector?