.. Permission is granted to copy, distribute and/or modify this
.. document under the terms of the GNU Free Documentation License,
.. Version 1.1 or any later version published by the Free Software
.. Foundation, with no Invariant Sections, no Front-Cover Texts
.. and no Back-Cover Texts. A copy of the license is included at
.. Documentation/media/uapi/fdl-appendix.rst.
..
.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections

.. _VIDIOC_DV_TIMINGS_CAP:

*********************************************************
ioctl VIDIOC_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP
*********************************************************

Name
====

VIDIOC_DV_TIMINGS_CAP - VIDIOC_SUBDEV_DV_TIMINGS_CAP - The capabilities of the Digital Video receiver/transmitter


Synopsis
========

.. c:function:: int ioctl( int fd, VIDIOC_DV_TIMINGS_CAP, struct v4l2_dv_timings_cap *argp )
    :name: VIDIOC_DV_TIMINGS_CAP

.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_DV_TIMINGS_CAP, struct v4l2_dv_timings_cap *argp )
    :name: VIDIOC_SUBDEV_DV_TIMINGS_CAP


Arguments
=========

``fd``
    File descriptor returned by :ref:`open() <func-open>`.

``argp``
    Pointer to struct :c:type:`v4l2_dv_timings_cap`.


Description
===========

To query the capabilities of the DV receiver/transmitter applications
initialize the ``pad`` field to 0, zero the reserved array of struct
:c:type:`v4l2_dv_timings_cap` and call the
``VIDIOC_DV_TIMINGS_CAP`` ioctl on a video node and the driver will fill
in the structure.

.. note::

   Drivers may return different values after
   switching the video input or output.

When implemented by the driver DV capabilities of subdevices can be
queried by calling the ``VIDIOC_SUBDEV_DV_TIMINGS_CAP`` ioctl directly
on a subdevice node. The capabilities are specific to inputs (for DV
receivers) or outputs (for DV transmitters), applications must specify
the desired pad number in the struct
:c:type:`v4l2_dv_timings_cap` ``pad`` field and
zero the ``reserved`` array. Attempts to query capabilities on a pad
that doesn't support them will return an ``EINVAL`` error code.


.. tabularcolumns:: |p{1.2cm}|p{3.0cm}|p{13.3cm}|

.. c:type:: v4l2_bt_timings_cap

.. flat-table:: struct v4l2_bt_timings_cap
    :header-rows:  0
    :stub-columns: 0
    :widths:       1 1 2

    * - __u32
      - ``min_width``
      - Minimum width of the active video in pixels.
    * - __u32
      - ``max_width``
      - Maximum width of the active video in pixels.
    * - __u32
      - ``min_height``
      - Minimum height of the active video in lines.
    * - __u32
      - ``max_height``
      - Maximum height of the active video in lines.
    * - __u64
      - ``min_pixelclock``
      - Minimum pixelclock frequency in Hz.
    * - __u64
      - ``max_pixelclock``
      - Maximum pixelclock frequency in Hz.
    * - __u32
      - ``standards``
      - The video standard(s) supported by the hardware. See
	:ref:`dv-bt-standards` for a list of standards.
    * - __u32
      - ``capabilities``
      - Several flags giving more information about the capabilities. See
	:ref:`dv-bt-cap-capabilities` for a description of the flags.
    * - __u32
      - ``reserved``\ [16]
      - Reserved for future extensions.
	Drivers must set the array to zero.



.. tabularcolumns:: |p{1.0cm}|p{4.0cm}|p{3.5cm}|p{9.2cm}|

.. c:type:: v4l2_dv_timings_cap

.. flat-table:: struct v4l2_dv_timings_cap
    :header-rows:  0
    :stub-columns: 0
    :widths:       1 1 2 1

    * - __u32
      - ``type``
      - Type of DV timings as listed in :ref:`dv-timing-types`.
    * - __u32
      - ``pad``
      - Pad number as reported by the media controller API. This field is
	only used when operating on a subdevice node. When operating on a
	video node applications must set this field to zero.
    * - __u32
      - ``reserved``\ [2]
      - Reserved for future extensions.

	Drivers and applications must set the array to zero.
    * - union
      -
      -
    * -
      - struct :c:type:`v4l2_bt_timings_cap`
      - ``bt``
      - BT.656/1120 timings capabilities of the hardware.
    * -
      - __u32
      - ``raw_data``\ [32]
      -

.. tabularcolumns:: |p{7.0cm}|p{10.5cm}|

.. _dv-bt-cap-capabilities:

.. flat-table:: DV BT Timing capabilities
    :header-rows:  0
    :stub-columns: 0

    * - Flag
      - Description
    * -
      -
    * - ``V4L2_DV_BT_CAP_INTERLACED``
      - Interlaced formats are supported.
    * - ``V4L2_DV_BT_CAP_PROGRESSIVE``
      - Progressive formats are supported.
    * - ``V4L2_DV_BT_CAP_REDUCED_BLANKING``
      - CVT/GTF specific: the timings can make use of reduced blanking
	(CVT) or the 'Secondary GTF' curve (GTF).
    * - ``V4L2_DV_BT_CAP_CUSTOM``
      - Can support non-standard timings, i.e. timings not belonging to
	the standards set in the ``standards`` field.


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.