Video Output Overlay Interface
******************************
-
**Also known as On-Screen Display (OSD)**
+
Some video output devices can overlay a framebuffer image onto the
outgoing video signal. Applications can set up such an overlay using
this interface, which borrows structures and ioctls of the
The width and height of the framebuffer depends on the current video
standard. A V4L2 driver may reject attempts to change the video standard
(or any other ioctl which would imply a framebuffer size change) with an
-EBUSY error code until all applications closed the framebuffer device.
+``EBUSY`` error code until all applications closed the framebuffer device.
.. code-block:: c
+ :caption: Example 4.1. Finding a framebuffer device for OSD
#include <linux/fb.h>