A framework for drivers of video cameras, TV tuners etc. The device API for userland processes is commonly called v4l or v4l2 (v4l being deprecated in theory). Drivers written for this framework are normally compiled into the LinuxKernel as Modules. The devices are enumerated by UDev and appear as /dev/video0, /dev/video1 etc.

You must have the videodev Module loaded as well.

Some applications require a specific device name e.g. /dev/video. If this is the case then use mknod(1) to create a device entry or ln(1) to link one if it already exists. I suspect this could also be done with UDev as well but don't know much about that.

Also known as V4L.