1 .. SPDX-License-Identifier: GFDL-1.1-no-invari 1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2 .. c:namespace:: V4L 2 .. c:namespace:: V4L
3 3
4 .. _VIDIOC_G_STD: 4 .. _VIDIOC_G_STD:
5 5
6 ********************************************** 6 **************************************************************************
7 ioctl VIDIOC_G_STD, VIDIOC_S_STD, VIDIOC_SUBDE 7 ioctl VIDIOC_G_STD, VIDIOC_S_STD, VIDIOC_SUBDEV_G_STD, VIDIOC_SUBDEV_S_STD
8 ********************************************** 8 **************************************************************************
9 9
10 Name 10 Name
11 ==== 11 ====
12 12
13 VIDIOC_G_STD - VIDIOC_S_STD - VIDIOC_SUBDEV_G_ 13 VIDIOC_G_STD - VIDIOC_S_STD - VIDIOC_SUBDEV_G_STD - VIDIOC_SUBDEV_S_STD - Query or select the video standard of the current input
14 14
15 Synopsis 15 Synopsis
16 ======== 16 ========
17 17
18 .. c:macro:: VIDIOC_G_STD 18 .. c:macro:: VIDIOC_G_STD
19 19
20 ``int ioctl(int fd, VIDIOC_G_STD, v4l2_std_id 20 ``int ioctl(int fd, VIDIOC_G_STD, v4l2_std_id *argp)``
21 21
22 .. c:macro:: VIDIOC_S_STD 22 .. c:macro:: VIDIOC_S_STD
23 23
24 ``int ioctl(int fd, VIDIOC_S_STD, const v4l2_s 24 ``int ioctl(int fd, VIDIOC_S_STD, const v4l2_std_id *argp)``
25 25
26 .. c:macro:: VIDIOC_SUBDEV_G_STD 26 .. c:macro:: VIDIOC_SUBDEV_G_STD
27 27
28 ``int ioctl(int fd, VIDIOC_SUBDEV_G_STD, v4l2_ 28 ``int ioctl(int fd, VIDIOC_SUBDEV_G_STD, v4l2_std_id *argp)``
29 29
30 .. c:macro:: VIDIOC_SUBDEV_S_STD 30 .. c:macro:: VIDIOC_SUBDEV_S_STD
31 31
32 ``int ioctl(int fd, VIDIOC_SUBDEV_S_STD, const 32 ``int ioctl(int fd, VIDIOC_SUBDEV_S_STD, const v4l2_std_id *argp)``
33 33
34 Arguments 34 Arguments
35 ========= 35 =========
36 36
37 ``fd`` 37 ``fd``
38 File descriptor returned by :c:func:`open( 38 File descriptor returned by :c:func:`open()`.
39 39
40 ``argp`` 40 ``argp``
41 Pointer to :c:type:`v4l2_std_id`. 41 Pointer to :c:type:`v4l2_std_id`.
42 42
43 Description 43 Description
44 =========== 44 ===========
45 45
46 To query and select the current video standard 46 To query and select the current video standard applications use the
47 :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` and :ref:`V 47 :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` and :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` ioctls which take a pointer to a
48 :ref:`v4l2_std_id <v4l2-std-id>` type as argum 48 :ref:`v4l2_std_id <v4l2-std-id>` type as argument. :ref:`VIDIOC_G_STD <VIDIOC_G_STD>`
49 can return a single flag or a set of flags as 49 can return a single flag or a set of flags as in struct
50 :c:type:`v4l2_standard` field ``id``. The flag 50 :c:type:`v4l2_standard` field ``id``. The flags must be
51 unambiguous such that they appear in only one 51 unambiguous such that they appear in only one enumerated
52 struct :c:type:`v4l2_standard` structure. 52 struct :c:type:`v4l2_standard` structure.
53 53
54 :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` accepts one 54 :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` accepts one or more flags, being a write-only ioctl it
55 does not return the actual new standard as :re 55 does not return the actual new standard as :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` does. When
56 no flags are given or the current input does n 56 no flags are given or the current input does not support the requested
57 standard the driver returns an ``EINVAL`` erro 57 standard the driver returns an ``EINVAL`` error code. When the standard set
58 is ambiguous drivers may return ``EINVAL`` or 58 is ambiguous drivers may return ``EINVAL`` or choose any of the requested
59 standards. If the current input or output does 59 standards. If the current input or output does not support standard
60 video timings (e.g. if :ref:`VIDIOC_ENUMINPUT` 60 video timings (e.g. if :ref:`VIDIOC_ENUMINPUT`
61 does not set the ``V4L2_IN_CAP_STD`` flag), th 61 does not set the ``V4L2_IN_CAP_STD`` flag), then ``ENODATA`` error code is
62 returned. 62 returned.
63 63
64 Calling ``VIDIOC_SUBDEV_S_STD`` on a subdev de 64 Calling ``VIDIOC_SUBDEV_S_STD`` on a subdev device node that has been registered
65 in read-only mode is not allowed. An error is 65 in read-only mode is not allowed. An error is returned and the errno variable is
66 set to ``-EPERM``. 66 set to ``-EPERM``.
67 67
68 Return Value 68 Return Value
69 ============ 69 ============
70 70
71 On success 0 is returned, on error -1 and the 71 On success 0 is returned, on error -1 and the ``errno`` variable is set
72 appropriately. The generic error codes are des 72 appropriately. The generic error codes are described at the
73 :ref:`Generic Error Codes <gen-errors>` chapte 73 :ref:`Generic Error Codes <gen-errors>` chapter.
74 74
75 EINVAL 75 EINVAL
76 The :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` par 76 The :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` parameter was unsuitable.
77 77
78 ENODATA 78 ENODATA
79 Standard video timings are not supported f 79 Standard video timings are not supported for this input or output.
80 80
81 EPERM 81 EPERM
82 ``VIDIOC_SUBDEV_S_STD`` has been called on 82 ``VIDIOC_SUBDEV_S_STD`` has been called on a read-only subdevice.
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