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.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: V4L
.. _VIDIOC_SUBDEV_ENUM_MBUS_CODE:
**********************************
ioctl VIDIOC_SUBDEV_ENUM_MBUS_CODE
**********************************
Name
====
VIDIOC_SUBDEV_ENUM_MBUS_CODE - Enumerate media bus formats
Synopsis
========
.. c:macro:: VIDIOC_SUBDEV_ENUM_MBUS_CODE
``int ioctl(int fd, VIDIOC_SUBDEV_ENUM_MBUS_CODE, struct v4l2_subdev_mbus_code_enum * argp)``
Arguments
=========
``fd``
File descriptor returned by :c:func:`open()`.
``argp``
Pointer to struct :c:type:`v4l2_subdev_mbus_code_enum`.
Description
===========
This call is used by the application to access the enumeration
of media bus formats for the selected pad.
The enumerations are defined by the driver, and indexed using the ``index`` field
of struct :c:type:`v4l2_subdev_mbus_code_enum`.
Each enumeration starts with the ``index`` of 0, and
the lowest invalid index marks the end of enumeration.
Therefore, to enumerate media bus formats available at a given sub-device pad,
initialize the ``pad``, and ``which`` fields to desired values,
and set ``index`` to 0.
Then call the :ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` ioctl
with a pointer to this structure.
A successful call will return with the ``code`` field filled in
with a mbus code value.
Repeat with increasing ``index`` until ``EINVAL`` is received.
``EINVAL`` means that either ``pad`` is invalid,
or that there are no more codes available at this pad.
The driver must not return the same value of ``code`` for different indices
at the same pad.
Available media bus formats may depend on the current 'try' formats at
other pads of the sub-device, as well as on the current active links.
See :ref:`VIDIOC_SUBDEV_G_FMT` for more
information about the try formats.
.. c:type:: v4l2_subdev_mbus_code_enum
.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|
.. flat-table:: struct v4l2_subdev_mbus_code_enum
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
* - __u32
- ``pad``
- Pad number as reported by the media controller API. Filled in by the
application.
* - __u32
- ``index``
- Index of the mbus code in the enumeration belonging to the given pad.
Filled in by the application.
* - __u32
- ``code``
- The media bus format code, as defined in
:ref:`v4l2-mbus-format`. Filled in by the driver.
* - __u32
- ``which``
- Media bus format codes to be enumerated, from enum
:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
* - __u32
- ``flags``
- See :ref:`v4l2-subdev-mbus-code-flags`
* - __u32
- ``stream``
- Stream identifier.
* - __u32
- ``reserved``\ [6]
- Reserved for future extensions. Applications and drivers must set
the array to zero.
.. raw:: latex
\footnotesize
.. tabularcolumns:: |p{8.8cm}|p{2.2cm}|p{6.3cm}|
.. _v4l2-subdev-mbus-code-flags:
.. flat-table:: Subdev Media Bus Code Enumerate Flags
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
* - V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE
- 0x00000001
- The driver allows the application to try to change the default colorspace
encoding. The application can ask to configure the colorspace of the
subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
See :ref:`v4l2-mbus-format` on how to do this.
* - V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC
- 0x00000002
- The driver allows the application to try to change the default transform function.
The application can ask to configure the transform function of
the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
See :ref:`v4l2-mbus-format` on how to do this.
* - V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC
- 0x00000004
- The driver allows the application to try to change the default Y'CbCr
encoding. The application can ask to configure the Y'CbCr encoding of the
subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
See :ref:`v4l2-mbus-format` on how to do this.
* - V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC
- 0x00000004
- The driver allows the application to try to change the default HSV
encoding. The application can ask to configure the HSV encoding of the
subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
See :ref:`v4l2-mbus-format` on how to do this.
* - V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION
- 0x00000008
- The driver allows the application to try to change the default
quantization. The application can ask to configure the quantization of
the subdevice when calling the :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>`
ioctl with :ref:`V4L2_MBUS_FRAMEFMT_SET_CSC <mbus-framefmt-set-csc>` set.
See :ref:`v4l2-mbus-format` on how to do this.
.. raw:: latex
\normalsize
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_mbus_code_enum`
``pad`` references a non-existing pad, or the ``index`` field is out
of bounds.
|
