1 .. -*- coding: utf-8; mode: rst -*-
3 .. _VIDIOC_SUBDEV_ENUM_FRAME_SIZE:
5 ***********************************
6 ioctl VIDIOC_SUBDEV_ENUM_FRAME_SIZE
7 ***********************************
12 VIDIOC_SUBDEV_ENUM_FRAME_SIZE - Enumerate media bus frame sizes
18 .. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_ENUM_FRAME_SIZE, struct v4l2_subdev_frame_size_enum * argp )
19 :name: VIDIOC_SUBDEV_ENUM_FRAME_SIZE
26 File descriptor returned by :ref:`open() <func-open>`.
29 Pointer to struct :c:type:`v4l2_subdev_frame_size_enum`.
35 This ioctl allows applications to enumerate all frame sizes supported by
36 a sub-device on the given pad for the given media bus format. Supported
37 formats can be retrieved with the
38 :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE`
41 To enumerate frame sizes applications initialize the ``pad``, ``which``
42 , ``code`` and ``index`` fields of the struct
43 :c:type:`v4l2_subdev_mbus_code_enum` and
44 call the :ref:`VIDIOC_SUBDEV_ENUM_FRAME_SIZE` ioctl with a pointer to the
45 structure. Drivers fill the minimum and maximum frame sizes or return an
46 EINVAL error code if one of the input parameters is invalid.
48 Sub-devices that only support discrete frame sizes (such as most
49 sensors) will return one or more frame sizes with identical minimum and
52 Not all possible sizes in given [minimum, maximum] ranges need to be
53 supported. For instance, a scaler that uses a fixed-point scaling ratio
54 might not be able to produce every frame size between the minimum and
55 maximum values. Applications must use the
56 :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>` ioctl to try the
57 sub-device for an exact supported frame size.
59 Available frame sizes may depend on the current 'try' formats at other
60 pads of the sub-device, as well as on the current active links and the
61 current values of V4L2 controls. See
62 :ref:`VIDIOC_SUBDEV_G_FMT` for more
63 information about try formats.
66 .. c:type:: v4l2_subdev_frame_size_enum
68 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
70 .. flat-table:: struct v4l2_subdev_frame_size_enum
77 - Number of the format in the enumeration, set by the application.
80 - Pad number as reported by the media controller API.
83 - The media bus format code, as defined in
84 :ref:`v4l2-mbus-format`.
87 - Minimum frame width, in pixels.
90 - Maximum frame width, in pixels.
93 - Minimum frame height, in pixels.
96 - Maximum frame height, in pixels.
99 - Frame sizes to be enumerated, from enum
100 :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
103 - Reserved for future extensions. Applications and drivers must set
110 On success 0 is returned, on error -1 and the ``errno`` variable is set
111 appropriately. The generic error codes are described at the
112 :ref:`Generic Error Codes <gen-errors>` chapter.
116 :c:type:`v4l2_subdev_frame_size_enum`
117 ``pad`` references a non-existing pad, the ``code`` is invalid for
118 the given pad or the ``index`` field is out of bounds.