1 .. Permission is granted to copy, distribute and/or modify this
2 .. document under the terms of the GNU Free Documentation License,
3 .. Version 1.1 or any later version published by the Free Software
4 .. Foundation, with no Invariant Sections, no Front-Cover Texts
5 .. and no Back-Cover Texts. A copy of the license is included at
6 .. Documentation/media/uapi/fdl-appendix.rst.
8 .. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
19 VIDIOC_OVERLAY - Start or stop video overlay
25 .. c:function:: int ioctl( int fd, VIDIOC_OVERLAY, const int *argp )
33 File descriptor returned by :ref:`open() <func-open>`.
36 Pointer to an integer.
42 This ioctl is part of the :ref:`video overlay <overlay>` I/O method.
43 Applications call :ref:`VIDIOC_OVERLAY` to start or stop the overlay. It
44 takes a pointer to an integer which must be set to zero by the
45 application to stop overlay, to one to start.
47 Drivers do not support :ref:`VIDIOC_STREAMON` or
48 :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` with
49 ``V4L2_BUF_TYPE_VIDEO_OVERLAY``.
55 On success 0 is returned, on error -1 and the ``errno`` variable is set
56 appropriately. The generic error codes are described at the
57 :ref:`Generic Error Codes <gen-errors>` chapter.
60 The overlay parameters have not been set up. See :ref:`overlay`
61 for the necessary steps.