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.