"Video For Linux (V4L) is an API that provides unified access to
various video capturing devices, such as TV tuners, USB web
cameras, etc. The first version of this interface was implemented
in Linux 2.2, by Alan Cox. In 1999, development began on the
second-generation V4L2 interface, which fixed bugs found in V4L,
and supported a wider range of devices.
"General overview of Video4Linux2 interface (V4L2)
"V4L2 drivers are implemented as normal kernel modules that can
be loaded by an administrator, or loaded automatically when opening
a device file. Drivers use the base "videodev" kernel module, which
represents the corresponding kernel interface for working with a
"V4L2 API provides access to a device by means of standard Unix
character devices. V4L2 provides the following interfaces:"