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linux-next/Documentation/media/uapi/v4l/vidioc-subdev-enum-frame-size.rst
Mauro Carvalho Chehab 56683d7dea [media] docs-rst: fix cross-references for videodev2.h
There are several broken references there, due to the conversion to
C domain. Fix them using this shell script and manually adjust what's
broken:

	# funcs is a file with the broken functions/references
	for i in $(cat funcs|sort|uniq|perl -ne 'print "$1\n" if (m/(\S+)$/)'); do
		i=${i//-/_}
		echo $i
		j=${i//_/-}
		for k in $(git grep -l "_$j:" Documentation/); do
			sed s,\_$j\:,"c\:type\:\: $i", <$k >a && mv a $k
		done
		for k in $(git grep -l "$j" Documentation/media/*.exceptions); do
			sed s,$j,":c\:type\:\`$i\`", <$k >a && mv a $k
		done
		for k in $(git grep -l "$j" Documentation/); do
			sed "s,:ref:\`$i <$j>\`,:c:type:\`$i\`," <$k >a && mv a $k
			sed "s,:ref:\`$j\`,:c:type:\`$i\`," <$k >a && mv a $k
			sed -E "s,:ref:\`(.*)<$j>\`,:c:type:\`\1<$i>\`," <$k >a && mv a $k
		done
		for k in $(git grep -l "<$j>" include/media); do
			sed -E "s,:ref:\`(.*)<$j>\`,enum \&$i," <$k >a && mv a $k
		done
	done

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-09-09 09:57:23 -03:00

163 lines
3.6 KiB
ReStructuredText

.. -*- coding: utf-8; mode: rst -*-
.. _VIDIOC_SUBDEV_ENUM_FRAME_SIZE:
***********************************
ioctl VIDIOC_SUBDEV_ENUM_FRAME_SIZE
***********************************
Name
====
VIDIOC_SUBDEV_ENUM_FRAME_SIZE - Enumerate media bus frame sizes
Synopsis
========
.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_ENUM_FRAME_SIZE, struct v4l2_subdev_frame_size_enum * argp )
:name: VIDIOC_SUBDEV_ENUM_FRAME_SIZE
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <func-open>`.
``argp``
Description
===========
This ioctl allows applications to enumerate all frame sizes supported by
a sub-device on the given pad for the given media bus format. Supported
formats can be retrieved with the
:ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE`
ioctl.
To enumerate frame sizes applications initialize the ``pad``, ``which``
, ``code`` and ``index`` fields of the struct
:c:type:`v4l2_subdev_mbus_code_enum` and
call the :ref:`VIDIOC_SUBDEV_ENUM_FRAME_SIZE` ioctl with a pointer to the
structure. Drivers fill the minimum and maximum frame sizes or return an
EINVAL error code if one of the input parameters is invalid.
Sub-devices that only support discrete frame sizes (such as most
sensors) will return one or more frame sizes with identical minimum and
maximum values.
Not all possible sizes in given [minimum, maximum] ranges need to be
supported. For instance, a scaler that uses a fixed-point scaling ratio
might not be able to produce every frame size between the minimum and
maximum values. Applications must use the
:ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>` ioctl to try the
sub-device for an exact supported frame size.
Available frame sizes may depend on the current 'try' formats at other
pads of the sub-device, as well as on the current active links and the
current values of V4L2 controls. See
:ref:`VIDIOC_SUBDEV_G_FMT` for more
information about try formats.
.. c:type:: v4l2_subdev_frame_size_enum
.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
.. flat-table:: struct v4l2_subdev_frame_size_enum
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- __u32
- ``index``
- Number of the format in the enumeration, set by the application.
- .. row 2
- __u32
- ``pad``
- Pad number as reported by the media controller API.
- .. row 3
- __u32
- ``code``
- The media bus format code, as defined in
:ref:`v4l2-mbus-format`.
- .. row 4
- __u32
- ``min_width``
- Minimum frame width, in pixels.
- .. row 5
- __u32
- ``max_width``
- Maximum frame width, in pixels.
- .. row 6
- __u32
- ``min_height``
- Minimum frame height, in pixels.
- .. row 7
- __u32
- ``max_height``
- Maximum frame height, in pixels.
- .. row 8
- __u32
- ``which``
- Frame sizes to be enumerated, from enum
:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
- .. row 9
- __u32
- ``reserved``\ [8]
- Reserved for future extensions. Applications and drivers must set
the array to zero.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
EINVAL
The struct
:c:type:`v4l2_subdev_frame_size_enum`
``pad`` references a non-existing pad, the ``code`` is invalid for
the given pad or the ``index`` field is out of bounds.