Video in Linux
In a GNU/Linux-based system, all video devices are managed by a standard API called Video4Linux (Video for Linux), which is a collection of device drivers to support real-time video capture. It supports many USB webcams, TV tuners, and similar devices in such a way that they have a common interface so that users can get access to to the underlying hardware in the same manner independently and programmers can easily add video support to their applications. The Video4Linux (V4L2) API is currently in its second version, which can be referred as Video4Linux2. Using the name Video4Linux only is not erroneous since the first release of the API was dropped several years ago from the kernel main line.
In a GNU/Linux-based system, each Video4Linux device appears in the system as a /dev/video0, /dev/video1 file. For example, to our BeagleBone Black, we have connected a webcam, and the video file we get is as follows:
root@bbb:~# ls -l /dev/video* crw-rw---- 1 root video 81, 0 Oct 10...
