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_G_INPUT: 10 .. _VIDIOC_G_INPUT:
5 11
6 ************************************ 12 ************************************
7 ioctl VIDIOC_G_INPUT, VIDIOC_S_INPUT 13 ioctl VIDIOC_G_INPUT, VIDIOC_S_INPUT
8 ************************************ 14 ************************************
9 15
10 Name 16 Name
11 ==== 17 ====
12 18
13 VIDIOC_G_INPUT - VIDIOC_S_INPUT - Query or sel 19 VIDIOC_G_INPUT - VIDIOC_S_INPUT - Query or select the current video input
14 20
>> 21
15 Synopsis 22 Synopsis
16 ======== 23 ========
17 24
18 .. c:macro:: VIDIOC_G_INPUT !! 25 .. c:function:: int ioctl( int fd, VIDIOC_G_INPUT, int *argp )
19 !! 26 :name: VIDIOC_G_INPUT
20 ``int ioctl(int fd, VIDIOC_G_INPUT, int *argp) <<
21 27
22 .. c:macro:: VIDIOC_S_INPUT !! 28 .. c:function:: int ioctl( int fd, VIDIOC_S_INPUT, int *argp )
>> 29 :name: VIDIOC_S_INPUT
23 30
24 ``int ioctl(int fd, VIDIOC_S_INPUT, int *argp) <<
25 31
26 Arguments 32 Arguments
27 ========= 33 =========
28 34
29 ``fd`` 35 ``fd``
30 File descriptor returned by :c:func:`open( !! 36 File descriptor returned by :ref:`open() <func-open>`.
31 37
32 ``argp`` 38 ``argp``
33 Pointer an integer with input index. 39 Pointer an integer with input index.
34 40
>> 41
35 Description 42 Description
36 =========== 43 ===========
37 44
38 To query the current video input applications 45 To query the current video input applications call the
39 :ref:`VIDIOC_G_INPUT <VIDIOC_G_INPUT>` ioctl w 46 :ref:`VIDIOC_G_INPUT <VIDIOC_G_INPUT>` ioctl with a pointer to an integer where the driver
40 stores the number of the input, as in the stru 47 stores the number of the input, as in the struct
41 :c:type:`v4l2_input` ``index`` field. This ioc 48 :c:type:`v4l2_input` ``index`` field. This ioctl will fail
42 only when there are no video inputs, returning 49 only when there are no video inputs, returning ``EINVAL``.
43 50
44 To select a video input applications store the 51 To select a video input applications store the number of the desired
45 input in an integer and call the :ref:`VIDIOC_ 52 input in an integer and call the :ref:`VIDIOC_S_INPUT <VIDIOC_G_INPUT>` ioctl with a pointer
46 to this integer. Side effects are possible. Fo 53 to this integer. Side effects are possible. For example inputs may
47 support different video standards, so the driv 54 support different video standards, so the driver may implicitly switch
48 the current standard. Because of these possibl 55 the current standard. Because of these possible side effects
49 applications must select an input before query 56 applications must select an input before querying or negotiating any
50 other parameters. 57 other parameters.
51 58
52 Information about video inputs is available us 59 Information about video inputs is available using the
53 :ref:`VIDIOC_ENUMINPUT` ioctl. 60 :ref:`VIDIOC_ENUMINPUT` ioctl.
>> 61
54 62
55 Return Value 63 Return Value
56 ============ 64 ============
57 65
58 On success 0 is returned, on error -1 and the 66 On success 0 is returned, on error -1 and the ``errno`` variable is set
59 appropriately. The generic error codes are des 67 appropriately. The generic error codes are described at the
60 :ref:`Generic Error Codes <gen-errors>` chapte 68 :ref:`Generic Error Codes <gen-errors>` chapter.
61 69
62 EINVAL 70 EINVAL
63 The number of the video input is out of bo 71 The number of the video input is out of bounds.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.