Commit | Line | Data |
---|---|---|
5377d91f MH |
1 | .. -*- coding: utf-8; mode: rst -*- |
2 | ||
af4a4d0d | 3 | .. _VIDIOC_SUBDEV_G_SELECTION: |
5377d91f MH |
4 | |
5 | ********************************************************** | |
6 | ioctl VIDIOC_SUBDEV_G_SELECTION, VIDIOC_SUBDEV_S_SELECTION | |
7 | ********************************************************** | |
8 | ||
15e7d615 | 9 | Name |
586027ce | 10 | ==== |
5377d91f | 11 | |
586027ce | 12 | VIDIOC_SUBDEV_G_SELECTION - VIDIOC_SUBDEV_S_SELECTION - Get or set selection rectangles on a subdev pad |
5377d91f | 13 | |
15e7d615 MCC |
14 | |
15 | Synopsis | |
5377d91f MH |
16 | ======== |
17 | ||
41d80465 MCC |
18 | .. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_G_SELECTION, struct v4l2_subdev_selection *argp ) |
19 | :name: VIDIOC_SUBDEV_G_SELECTION | |
20 | ||
21 | .. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_SELECTION, struct v4l2_subdev_selection *argp ) | |
22 | :name: VIDIOC_SUBDEV_S_SELECTION | |
5377d91f | 23 | |
586027ce | 24 | |
15e7d615 | 25 | Arguments |
5377d91f MH |
26 | ========= |
27 | ||
28 | ``fd`` | |
29 | File descriptor returned by :ref:`open() <func-open>`. | |
30 | ||
5377d91f MH |
31 | ``argp`` |
32 | ||
33 | ||
15e7d615 | 34 | Description |
5377d91f MH |
35 | =========== |
36 | ||
37 | The selections are used to configure various image processing | |
38 | functionality performed by the subdevs which affect the image size. This | |
39 | currently includes cropping, scaling and composition. | |
40 | ||
41 | The selection API replaces | |
af4a4d0d | 42 | :ref:`the old subdev crop API <VIDIOC_SUBDEV_G_CROP>`. All the |
5377d91f MH |
43 | function of the crop API, and more, are supported by the selections API. |
44 | ||
45 | See :ref:`subdev` for more information on how each selection target | |
46 | affects the image processing pipeline inside the subdevice. | |
47 | ||
48 | ||
49 | Types of selection targets | |
50 | -------------------------- | |
51 | ||
52 | There are two types of selection targets: actual and bounds. The actual | |
53 | targets are the targets which configure the hardware. The BOUNDS target | |
54 | will return a rectangle that contain all possible actual rectangles. | |
55 | ||
56 | ||
57 | Discovering supported features | |
58 | ------------------------------ | |
59 | ||
60 | To discover which targets are supported, the user can perform | |
61 | ``VIDIOC_SUBDEV_G_SELECTION`` on them. Any unsupported target will | |
62 | return ``EINVAL``. | |
63 | ||
64 | Selection targets and flags are documented in | |
65 | :ref:`v4l2-selections-common`. | |
66 | ||
67 | ||
56683d7d | 68 | .. c:type:: v4l2_subdev_selection |
5377d91f | 69 | |
5bd4bb78 MCC |
70 | .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| |
71 | ||
5377d91f MH |
72 | .. flat-table:: struct v4l2_subdev_selection |
73 | :header-rows: 0 | |
74 | :stub-columns: 0 | |
75 | :widths: 1 1 2 | |
76 | ||
77 | ||
78 | - .. row 1 | |
79 | ||
80 | - __u32 | |
81 | ||
82 | - ``which`` | |
83 | ||
84 | - Active or try selection, from enum | |
0579e6e3 | 85 | :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. |
5377d91f MH |
86 | |
87 | - .. row 2 | |
88 | ||
89 | - __u32 | |
90 | ||
91 | - ``pad`` | |
92 | ||
93 | - Pad number as reported by the media framework. | |
94 | ||
95 | - .. row 3 | |
96 | ||
97 | - __u32 | |
98 | ||
99 | - ``target`` | |
100 | ||
101 | - Target selection rectangle. See :ref:`v4l2-selections-common`. | |
102 | ||
103 | - .. row 4 | |
104 | ||
105 | - __u32 | |
106 | ||
107 | - ``flags`` | |
108 | ||
109 | - Flags. See :ref:`v4l2-selection-flags`. | |
110 | ||
111 | - .. row 5 | |
112 | ||
e8be7e97 | 113 | - struct :c:type:`v4l2_rect` |
5377d91f MH |
114 | |
115 | - ``r`` | |
116 | ||
117 | - Selection rectangle, in pixels. | |
118 | ||
119 | - .. row 6 | |
120 | ||
121 | - __u32 | |
122 | ||
8968da9b | 123 | - ``reserved``\ [8] |
5377d91f MH |
124 | |
125 | - Reserved for future extensions. Applications and drivers must set | |
0579e6e3 | 126 | the array to zero. |
5377d91f MH |
127 | |
128 | ||
15e7d615 | 129 | Return Value |
5377d91f MH |
130 | ============ |
131 | ||
132 | On success 0 is returned, on error -1 and the ``errno`` variable is set | |
133 | appropriately. The generic error codes are described at the | |
134 | :ref:`Generic Error Codes <gen-errors>` chapter. | |
135 | ||
136 | EBUSY | |
137 | The selection rectangle can't be changed because the pad is | |
138 | currently busy. This can be caused, for instance, by an active video | |
139 | stream on the pad. The ioctl must not be retried without performing | |
140 | another action to fix the problem first. Only returned by | |
141 | ``VIDIOC_SUBDEV_S_SELECTION`` | |
142 | ||
143 | EINVAL | |
56683d7d | 144 | The struct :c:type:`v4l2_subdev_selection` |
5377d91f MH |
145 | ``pad`` references a non-existing pad, the ``which`` field |
146 | references a non-existing format, or the selection target is not | |
147 | supported on the given subdev pad. |