Documentation/userspace-api/media/v4l/vidioc-enumoutput.rst

Source file repositories/reference/linux-study-clean/Documentation/userspace-api/media/v4l/vidioc-enumoutput.rst

File Facts

System
Linux kernel
Corpus path
Documentation/userspace-api/media/v4l/vidioc-enumoutput.rst
Extension
.rst
Size
4544 bytes
Lines
154
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: V4L

.. _VIDIOC_ENUMOUTPUT:

***********************
ioctl VIDIOC_ENUMOUTPUT
***********************

Name
====

VIDIOC_ENUMOUTPUT - Enumerate video outputs

Synopsis
========

.. c:macro:: VIDIOC_ENUMOUTPUT

``int ioctl(int fd, VIDIOC_ENUMOUTPUT, struct v4l2_output *argp)``

Arguments
=========

``fd``
    File descriptor returned by :c:func:`open()`.

``argp``
    Pointer to struct :c:type:`v4l2_output`.

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

To query the attributes of a video outputs applications initialize the
``index`` field of struct :c:type:`v4l2_output` and call
the :ref:`VIDIOC_ENUMOUTPUT` with a pointer to this structure.
Drivers fill the rest of the structure or return an ``EINVAL`` error code
when the index is out of bounds. To enumerate all outputs applications
shall begin at index zero, incrementing by one until the driver returns
``EINVAL``.

.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|

.. c:type:: v4l2_output

.. flat-table:: struct v4l2_output
    :header-rows:  0
    :stub-columns: 0
    :widths:       1 1 2

    * - __u32
      - ``index``
      - Identifies the output, set by the application.
    * - __u8
      - ``name``\ [32]
      - Name of the video output, a NUL-terminated ASCII string, for
	example: "Vout". This information is intended for the user,
	preferably the connector label on the device itself.
    * - __u32
      - ``type``
      - Type of the output, see :ref:`output-type`.
    * - __u32
      - ``audioset``
      - Drivers can enumerate up to 32 video and audio outputs. This field
	shows which audio outputs were selectable as the current output if
	this was the currently selected video output. It is a bit mask.
	The LSB corresponds to audio output 0, the MSB to output 31. Any
	number of bits can be set, or none.

	When the driver does not enumerate audio outputs no bits must be

Annotation

Implementation Notes