Based on kernel version 6.8. Page generated on 2024-03-11 21:26 EST.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 |
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: V4L
.. _VIDIOC_OVERLAY:
********************
ioctl VIDIOC_OVERLAY
********************
Name
====
VIDIOC_OVERLAY - Start or stop video overlay
Synopsis
========
.. c:macro:: VIDIOC_OVERLAY
``int ioctl(int fd, VIDIOC_OVERLAY, const int *argp)``
Arguments
=========
``fd``
File descriptor returned by :c:func:`open()`.
``argp``
Pointer to an integer.
Description
===========
This ioctl is part of the :ref:`video overlay <overlay>` I/O method.
Applications call :ref:`VIDIOC_OVERLAY` to start or stop the overlay. It
takes a pointer to an integer which must be set to zero by the
application to stop overlay, to one to start.
Drivers do not support :ref:`VIDIOC_STREAMON` or
:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` with
``V4L2_BUF_TYPE_VIDEO_OVERLAY``.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
EINVAL
The overlay parameters have not been set up. See :ref:`overlay`
for the necessary steps.
|
