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_ENUM_FRAMESIZES: 4 .. _VIDIOC_ENUM_FRAMESIZES:
5 5
6 **************************** 6 ****************************
7 ioctl VIDIOC_ENUM_FRAMESIZES 7 ioctl VIDIOC_ENUM_FRAMESIZES
8 **************************** 8 ****************************
9 9
10 Name 10 Name
11 ==== 11 ====
12 12
13 VIDIOC_ENUM_FRAMESIZES - Enumerate frame sizes 13 VIDIOC_ENUM_FRAMESIZES - Enumerate frame sizes
14 14
15 Synopsis 15 Synopsis
16 ======== 16 ========
17 17
18 .. c:macro:: VIDIOC_ENUM_FRAMESIZES 18 .. c:macro:: VIDIOC_ENUM_FRAMESIZES
19 19
20 ``int ioctl(int fd, VIDIOC_ENUM_FRAMESIZES, st 20 ``int ioctl(int fd, VIDIOC_ENUM_FRAMESIZES, struct v4l2_frmsizeenum *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_frmsizeenu 29 Pointer to struct :c:type:`v4l2_frmsizeenum`
30 that contains an index and pixel format an 30 that contains an index and pixel format and receives a frame width
31 and height. 31 and height.
32 32
33 Description 33 Description
34 =========== 34 ===========
35 35
36 This ioctl allows applications to enumerate al 36 This ioctl allows applications to enumerate all frame sizes (i. e. width
37 and height in pixels) that the device supports 37 and height in pixels) that the device supports for the given pixel
38 format. 38 format.
39 39
40 The supported pixel formats can be obtained by 40 The supported pixel formats can be obtained by using the
41 :ref:`VIDIOC_ENUM_FMT` function. 41 :ref:`VIDIOC_ENUM_FMT` function.
42 42
43 The return value and the content of the ``v4l2 43 The return value and the content of the ``v4l2_frmsizeenum.type`` field
44 depend on the type of frame sizes the device s 44 depend on the type of frame sizes the device supports. Here are the
45 semantics of the function for the different ca 45 semantics of the function for the different cases:
46 46
47 - **Discrete:** The function returns success 47 - **Discrete:** The function returns success if the given index value
48 (zero-based) is valid. The application shou 48 (zero-based) is valid. The application should increase the index by
49 one for each call until ``EINVAL`` is retur 49 one for each call until ``EINVAL`` is returned. The
50 ``v4l2_frmsizeenum.type`` field is set to 50 ``v4l2_frmsizeenum.type`` field is set to
51 ``V4L2_FRMSIZE_TYPE_DISCRETE`` by the drive 51 ``V4L2_FRMSIZE_TYPE_DISCRETE`` by the driver. Of the union only the
52 ``discrete`` member is valid. 52 ``discrete`` member is valid.
53 53
54 - **Step-wise:** The function returns success 54 - **Step-wise:** The function returns success if the given index value
55 is zero and ``EINVAL`` for any other index 55 is zero and ``EINVAL`` for any other index value. The
56 ``v4l2_frmsizeenum.type`` field is set to 56 ``v4l2_frmsizeenum.type`` field is set to
57 ``V4L2_FRMSIZE_TYPE_STEPWISE`` by the drive 57 ``V4L2_FRMSIZE_TYPE_STEPWISE`` by the driver. Of the union only the
58 ``stepwise`` member is valid. 58 ``stepwise`` member is valid.
59 59
60 - **Continuous:** This is a special case of t 60 - **Continuous:** This is a special case of the step-wise type above.
61 The function returns success if the given i 61 The function returns success if the given index value is zero and
62 ``EINVAL`` for any other index value. The ` 62 ``EINVAL`` for any other index value. The ``v4l2_frmsizeenum.type``
63 field is set to ``V4L2_FRMSIZE_TYPE_CONTINU 63 field is set to ``V4L2_FRMSIZE_TYPE_CONTINUOUS`` by the driver. Of
64 the union only the ``stepwise`` member is v 64 the union only the ``stepwise`` member is valid and the
65 ``step_width`` and ``step_height`` values a 65 ``step_width`` and ``step_height`` values are set to 1.
66 66
67 When the application calls the function with i 67 When the application calls the function with index zero, it must check
68 the ``type`` field to determine the type of fr 68 the ``type`` field to determine the type of frame size enumeration the
69 device supports. Only for the ``V4L2_FRMSIZE_T 69 device supports. Only for the ``V4L2_FRMSIZE_TYPE_DISCRETE`` type does
70 it make sense to increase the index value to r 70 it make sense to increase the index value to receive more frame sizes.
71 71
72 .. note:: 72 .. note::
73 73
74 The order in which the frame sizes are retu 74 The order in which the frame sizes are returned has no special
75 meaning. In particular does it not say anyt 75 meaning. In particular does it not say anything about potential default
76 format sizes. 76 format sizes.
77 77
78 Applications can assume that the enumeration d 78 Applications can assume that the enumeration data does not change
79 without any interaction from the application i 79 without any interaction from the application itself. This means that the
80 enumeration data is consistent if the applicat 80 enumeration data is consistent if the application does not perform any
81 other ioctl calls while it runs the frame size 81 other ioctl calls while it runs the frame size enumeration.
82 82
83 Structs 83 Structs
84 ======= 84 =======
85 85
86 In the structs below, *IN* denotes a value tha 86 In the structs below, *IN* denotes a value that has to be filled in by
87 the application, *OUT* denotes values that the 87 the application, *OUT* denotes values that the driver fills in. The
88 application should zero out all members except 88 application should zero out all members except for the *IN* fields.
89 89
90 .. c:type:: v4l2_frmsize_discrete 90 .. c:type:: v4l2_frmsize_discrete
91 91
92 .. flat-table:: struct v4l2_frmsize_discrete 92 .. flat-table:: struct v4l2_frmsize_discrete
93 :header-rows: 0 93 :header-rows: 0
94 :stub-columns: 0 94 :stub-columns: 0
95 :widths: 1 1 2 95 :widths: 1 1 2
96 96
97 * - __u32 97 * - __u32
98 - ``width`` 98 - ``width``
99 - Width of the frame [pixel]. 99 - Width of the frame [pixel].
100 * - __u32 100 * - __u32
101 - ``height`` 101 - ``height``
102 - Height of the frame [pixel]. 102 - Height of the frame [pixel].
103 103
104 104
105 .. c:type:: v4l2_frmsize_stepwise 105 .. c:type:: v4l2_frmsize_stepwise
106 106
107 .. flat-table:: struct v4l2_frmsize_stepwise 107 .. flat-table:: struct v4l2_frmsize_stepwise
108 :header-rows: 0 108 :header-rows: 0
109 :stub-columns: 0 109 :stub-columns: 0
110 :widths: 1 1 2 110 :widths: 1 1 2
111 111
112 * - __u32 112 * - __u32
113 - ``min_width`` 113 - ``min_width``
114 - Minimum frame width [pixel]. 114 - Minimum frame width [pixel].
115 * - __u32 115 * - __u32
116 - ``max_width`` 116 - ``max_width``
117 - Maximum frame width [pixel]. 117 - Maximum frame width [pixel].
118 * - __u32 118 * - __u32
119 - ``step_width`` 119 - ``step_width``
120 - Frame width step size [pixel]. 120 - Frame width step size [pixel].
121 * - __u32 121 * - __u32
122 - ``min_height`` 122 - ``min_height``
123 - Minimum frame height [pixel]. 123 - Minimum frame height [pixel].
124 * - __u32 124 * - __u32
125 - ``max_height`` 125 - ``max_height``
126 - Maximum frame height [pixel]. 126 - Maximum frame height [pixel].
127 * - __u32 127 * - __u32
128 - ``step_height`` 128 - ``step_height``
129 - Frame height step size [pixel]. 129 - Frame height step size [pixel].
130 130
131 131
132 .. c:type:: v4l2_frmsizeenum 132 .. c:type:: v4l2_frmsizeenum
133 133
134 .. tabularcolumns:: |p{6.4cm}|p{2.8cm}|p{8.1cm 134 .. tabularcolumns:: |p{6.4cm}|p{2.8cm}|p{8.1cm}|
135 135
136 .. flat-table:: struct v4l2_frmsizeenum 136 .. flat-table:: struct v4l2_frmsizeenum
137 :header-rows: 0 137 :header-rows: 0
138 :stub-columns: 0 138 :stub-columns: 0
139 139
140 * - __u32 140 * - __u32
141 - ``index`` 141 - ``index``
142 - IN: Index of the given frame size in t 142 - IN: Index of the given frame size in the enumeration.
143 * - __u32 143 * - __u32
144 - ``pixel_format`` 144 - ``pixel_format``
145 - IN: Pixel format for which the frame s 145 - IN: Pixel format for which the frame sizes are enumerated.
146 * - __u32 146 * - __u32
147 - ``type`` 147 - ``type``
148 - OUT: Frame size type the device suppor 148 - OUT: Frame size type the device supports.
149 * - union { 149 * - union {
150 - (anonymous) 150 - (anonymous)
151 - OUT: Frame size with the given index. 151 - OUT: Frame size with the given index.
152 * - struct :c:type:`v4l2_frmsize_discrete` 152 * - struct :c:type:`v4l2_frmsize_discrete`
153 - ``discrete`` 153 - ``discrete``
154 - 154 -
155 * - struct :c:type:`v4l2_frmsize_stepwise` 155 * - struct :c:type:`v4l2_frmsize_stepwise`
156 - ``stepwise`` 156 - ``stepwise``
157 - 157 -
158 * - } 158 * - }
159 - 159 -
160 - 160 -
161 * - __u32 161 * - __u32
162 - ``reserved[2]`` 162 - ``reserved[2]``
163 - Reserved space for future use. Must be 163 - Reserved space for future use. Must be zeroed by drivers and
164 applications. 164 applications.
165 165
166 166
167 Enums 167 Enums
168 ===== 168 =====
169 169
170 .. c:type:: v4l2_frmsizetypes 170 .. c:type:: v4l2_frmsizetypes
171 171
172 .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.5cm 172 .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.5cm}|
173 173
174 .. flat-table:: enum v4l2_frmsizetypes 174 .. flat-table:: enum v4l2_frmsizetypes
175 :header-rows: 0 175 :header-rows: 0
176 :stub-columns: 0 176 :stub-columns: 0
177 :widths: 3 1 4 177 :widths: 3 1 4
178 178
179 * - ``V4L2_FRMSIZE_TYPE_DISCRETE`` 179 * - ``V4L2_FRMSIZE_TYPE_DISCRETE``
180 - 1 180 - 1
181 - Discrete frame size. 181 - Discrete frame size.
182 * - ``V4L2_FRMSIZE_TYPE_CONTINUOUS`` 182 * - ``V4L2_FRMSIZE_TYPE_CONTINUOUS``
183 - 2 183 - 2
184 - Continuous frame size. 184 - Continuous frame size.
185 * - ``V4L2_FRMSIZE_TYPE_STEPWISE`` 185 * - ``V4L2_FRMSIZE_TYPE_STEPWISE``
186 - 3 186 - 3
187 - Step-wise defined frame size. 187 - Step-wise defined frame size.
188 188
189 Return Value 189 Return Value
190 ============ 190 ============
191 191
192 On success 0 is returned, on error -1 and the 192 On success 0 is returned, on error -1 and the ``errno`` variable is set
193 appropriately. The generic error codes are des 193 appropriately. The generic error codes are described at the
194 :ref:`Generic Error Codes <gen-errors>` chapte 194 :ref:`Generic Error Codes <gen-errors>` chapter.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.