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_SUBDEV_ENUM_FRAME_INTERVAL: 4 .. _VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL:
5 5
6 *************************************** 6 ***************************************
7 ioctl VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL 7 ioctl VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL
8 *************************************** 8 ***************************************
9 9
10 Name 10 Name
11 ==== 11 ====
12 12
13 VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL - Enumerate 13 VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL - Enumerate frame intervals
14 14
15 Synopsis 15 Synopsis
16 ======== 16 ========
17 17
18 .. c:macro:: VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL 18 .. c:macro:: VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL
19 19
20 ``int ioctl(int fd, VIDIOC_SUBDEV_ENUM_FRAME_I 20 ``int ioctl(int fd, VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL, struct v4l2_subdev_frame_interval_enum * argp)``
21 21
22 Arguments 22 Arguments
23 ========= 23 =========
24 24
25 ``fd`` 25 ``fd``
26 File descriptor returned by :c:func:`open( 26 File descriptor returned by :c:func:`open()`.
27 27
28 ``argp`` 28 ``argp``
29 Pointer to struct :c:type:`v4l2_subdev_fra 29 Pointer to struct :c:type:`v4l2_subdev_frame_interval_enum`.
30 30
31 Description 31 Description
32 =========== 32 ===========
33 33
34 This ioctl lets applications enumerate availab 34 This ioctl lets applications enumerate available frame intervals on a
35 given sub-device pad. Frame intervals only mak 35 given sub-device pad. Frame intervals only makes sense for sub-devices
36 that can control the frame period on their own 36 that can control the frame period on their own. This includes, for
37 instance, image sensors and TV tuners. 37 instance, image sensors and TV tuners.
38 38
39 For the common use case of image sensors, the 39 For the common use case of image sensors, the frame intervals available
40 on the sub-device output pad depend on the fra 40 on the sub-device output pad depend on the frame format and size on the
41 same pad. Applications must thus specify the d 41 same pad. Applications must thus specify the desired format and size
42 when enumerating frame intervals. 42 when enumerating frame intervals.
43 43
44 To enumerate frame intervals applications init 44 To enumerate frame intervals applications initialize the ``index``,
45 ``pad``, ``which``, ``code``, ``width`` and `` 45 ``pad``, ``which``, ``code``, ``width`` and ``height`` fields of struct
46 :c:type:`v4l2_subdev_frame_interval_enum` 46 :c:type:`v4l2_subdev_frame_interval_enum`
47 and call the :ref:`VIDIOC_SUBDEV_ENUM_FRAME_IN 47 and call the :ref:`VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL` ioctl with a pointer
48 to this structure. Drivers fill the rest of th 48 to this structure. Drivers fill the rest of the structure or return an
49 EINVAL error code if one of the input fields i 49 EINVAL error code if one of the input fields is invalid. All frame
50 intervals are enumerable by beginning at index 50 intervals are enumerable by beginning at index zero and incrementing by
51 one until ``EINVAL`` is returned. 51 one until ``EINVAL`` is returned.
52 52
53 Available frame intervals may depend on the cu 53 Available frame intervals may depend on the current 'try' formats at
54 other pads of the sub-device, as well as on th 54 other pads of the sub-device, as well as on the current active links.
55 See :ref:`VIDIOC_SUBDEV_G_FMT` for more 55 See :ref:`VIDIOC_SUBDEV_G_FMT` for more
56 information about the try formats. 56 information about the try formats.
57 57
58 Sub-devices that support the frame interval en 58 Sub-devices that support the frame interval enumeration ioctl should
59 implemented it on a single pad only. Its behav 59 implemented it on a single pad only. Its behaviour when supported on
60 multiple pads of the same sub-device is not de 60 multiple pads of the same sub-device is not defined.
61 61
62 .. c:type:: v4l2_subdev_frame_interval_enum 62 .. c:type:: v4l2_subdev_frame_interval_enum
63 63
64 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm 64 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|
65 65
66 .. flat-table:: struct v4l2_subdev_frame_inter 66 .. flat-table:: struct v4l2_subdev_frame_interval_enum
67 :header-rows: 0 67 :header-rows: 0
68 :stub-columns: 0 68 :stub-columns: 0
69 :widths: 1 1 2 69 :widths: 1 1 2
70 70
71 * - __u32 71 * - __u32
72 - ``index`` 72 - ``index``
73 - Number of the format in the enumeratio 73 - Number of the format in the enumeration, set by the application.
74 * - __u32 74 * - __u32
75 - ``pad`` 75 - ``pad``
76 - Pad number as reported by the media co 76 - Pad number as reported by the media controller API.
77 * - __u32 77 * - __u32
78 - ``code`` 78 - ``code``
79 - The media bus format code, as defined 79 - The media bus format code, as defined in
80 :ref:`v4l2-mbus-format`. 80 :ref:`v4l2-mbus-format`.
81 * - __u32 81 * - __u32
82 - ``width`` 82 - ``width``
83 - Frame width, in pixels. 83 - Frame width, in pixels.
84 * - __u32 84 * - __u32
85 - ``height`` 85 - ``height``
86 - Frame height, in pixels. 86 - Frame height, in pixels.
87 * - struct :c:type:`v4l2_fract` 87 * - struct :c:type:`v4l2_fract`
88 - ``interval`` 88 - ``interval``
89 - Period, in seconds, between consecutiv 89 - Period, in seconds, between consecutive video frames.
90 * - __u32 90 * - __u32
91 - ``which`` 91 - ``which``
92 - Frame intervals to be enumerated, from 92 - Frame intervals to be enumerated, from enum
93 :ref:`v4l2_subdev_format_whence <v4l2- 93 :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
94 * - __u32 94 * - __u32
95 - ``stream`` 95 - ``stream``
96 - Stream identifier. 96 - Stream identifier.
97 * - __u32 97 * - __u32
98 - ``reserved``\ [7] 98 - ``reserved``\ [7]
99 - Reserved for future extensions. Applic 99 - Reserved for future extensions. Applications and drivers must set
100 the array to zero. 100 the array to zero.
101 101
102 Return Value 102 Return Value
103 ============ 103 ============
104 104
105 On success 0 is returned, on error -1 and the 105 On success 0 is returned, on error -1 and the ``errno`` variable is set
106 appropriately. The generic error codes are des 106 appropriately. The generic error codes are described at the
107 :ref:`Generic Error Codes <gen-errors>` chapte 107 :ref:`Generic Error Codes <gen-errors>` chapter.
108 108
109 EINVAL 109 EINVAL
110 The struct :c:type:`v4l2_subdev_frame_inte 110 The struct :c:type:`v4l2_subdev_frame_interval_enum` ``pad`` references a
111 non-existing pad, the ``which`` field has 111 non-existing pad, the ``which`` field has an unsupported value, one of the
112 ``code``, ``width`` or ``height`` fields a 112 ``code``, ``width`` or ``height`` fields are invalid for the given pad, or
113 the ``index`` field is out of bounds. 113 the ``index`` field is out of bounds.
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