Using device name instead of ID in OpenCV method VideoCapture.open()

Question

I have a lot of video devices in my /dev folder (e.g. video1, video2, ..., video9) and one /dev/video which is always pointing to the valid device (which, of course, can change). I want to open the /dev/video device with OpenCV using cv::Videocapture and realized that there are only two ways to open it:

VideoCapture::VideoCapture(const string& filename)
VideoCapture::VideoCapture(int device)

The first one opens a file and the second one opens /dev/video[device].

Is there any way to do something like cap = cv::VideoCapture("/dev/video");?

Answer 1

with current OpenCV 3.2.0 you can create a new capture like this:

cv::VideoCapture cap("/dev/video20", cv::CAP_V4L);

its one of the additional constructors:

VideoCapture (const String &filename, int apiPreference)
Open video file or a capturing device or a IP video stream for video capturing with API Preference.

this is also possible with the open function:

cap.open("/dev/video20", cv::CAP_V4L);

i have tested this successfully under Kubuntu 16.10 with self compiled openCV from current git master.