1 .. SPDX-License-Identifier: GFDL-1.1-no-invari !! 1 .. Permission is granted to copy, distribute and/or modify this
2 .. c:namespace:: V4L !! 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/userspace-api/media/fdl-appendix.rst.
>> 7 ..
>> 8 .. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
3 9
4 .. _VIDIOC_OVERLAY: 10 .. _VIDIOC_OVERLAY:
5 11
6 ******************** 12 ********************
7 ioctl VIDIOC_OVERLAY 13 ioctl VIDIOC_OVERLAY
8 ******************** 14 ********************
9 15
10 Name 16 Name
11 ==== 17 ====
12 18
13 VIDIOC_OVERLAY - Start or stop video overlay 19 VIDIOC_OVERLAY - Start or stop video overlay
14 20
>> 21
15 Synopsis 22 Synopsis
16 ======== 23 ========
17 24
18 .. c:macro:: VIDIOC_OVERLAY !! 25 .. c:function:: int ioctl( int fd, VIDIOC_OVERLAY, const int *argp )
>> 26 :name: VIDIOC_OVERLAY
19 27
20 ``int ioctl(int fd, VIDIOC_OVERLAY, const int <<
21 28
22 Arguments 29 Arguments
23 ========= 30 =========
24 31
25 ``fd`` 32 ``fd``
26 File descriptor returned by :c:func:`open( !! 33 File descriptor returned by :ref:`open() <func-open>`.
27 34
28 ``argp`` 35 ``argp``
29 Pointer to an integer. 36 Pointer to an integer.
30 37
>> 38
31 Description 39 Description
32 =========== 40 ===========
33 41
34 This ioctl is part of the :ref:`video overlay 42 This ioctl is part of the :ref:`video overlay <overlay>` I/O method.
35 Applications call :ref:`VIDIOC_OVERLAY` to sta 43 Applications call :ref:`VIDIOC_OVERLAY` to start or stop the overlay. It
36 takes a pointer to an integer which must be se 44 takes a pointer to an integer which must be set to zero by the
37 application to stop overlay, to one to start. 45 application to stop overlay, to one to start.
38 46
39 Drivers do not support :ref:`VIDIOC_STREAMON` 47 Drivers do not support :ref:`VIDIOC_STREAMON` or
40 :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` with 48 :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` with
41 ``V4L2_BUF_TYPE_VIDEO_OVERLAY``. 49 ``V4L2_BUF_TYPE_VIDEO_OVERLAY``.
>> 50
42 51
43 Return Value 52 Return Value
44 ============ 53 ============
45 54
46 On success 0 is returned, on error -1 and the 55 On success 0 is returned, on error -1 and the ``errno`` variable is set
47 appropriately. The generic error codes are des 56 appropriately. The generic error codes are described at the
48 :ref:`Generic Error Codes <gen-errors>` chapte 57 :ref:`Generic Error Codes <gen-errors>` chapter.
49 58
50 EINVAL 59 EINVAL
51 The overlay parameters have not been set u 60 The overlay parameters have not been set up. See :ref:`overlay`
52 for the necessary steps. 61 for the necessary steps.
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