[deliverable/linux.git] / Documentation / linux_tv / media / v4l / vidioc-enumaudio.rst

.. -*- coding: utf-8; mode: rst -*-

.. _VIDIOC_ENUMAUDIO:

**********************
ioctl VIDIOC_ENUMAUDIO
**********************

*man VIDIOC_ENUMAUDIO(2)*

Enumerate audio inputs


Synopsis
========

.. c:function:: int ioctl( int fd, int request, struct v4l2_audio *argp )

Arguments
=========

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

``request``
    VIDIOC_ENUMAUDIO

``argp``


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

To query the attributes of an audio input applications initialize the
``index`` field and zero out the ``reserved`` array of a struct
:ref:`v4l2_audio <v4l2-audio>` and call the :ref:`VIDIOC_ENUMAUDIO`
ioctl 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 audio inputs applications shall begin at index
zero, incrementing by one until the driver returns EINVAL.

See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for a description of struct
:ref:`v4l2_audio <v4l2-audio>`.


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 number of the audio input is out of bounds.


.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
Commit	Line	Data
5377d91f MH	1	.. -- coding: utf-8; mode: rst --
5377d91f MH	2
af4a4d0d	3	.. _VIDIOC_ENUMAUDIO:
5377d91f MH	4
	5	**********************
	6	ioctl VIDIOC_ENUMAUDIO
	7	**********************
	8
	9	man VIDIOC_ENUMAUDIO(2)
	10
	11	Enumerate audio inputs
	12
	13
	14	Synopsis
	15	========
	16
	17	.. c:function:: int ioctl( int fd, int request, struct v4l2_audio *argp )
	18
	19	Arguments
	20	=========
	21
	22	``fd``
	23	File descriptor returned by :ref:`open() <func-open>`.
	24
	25	``request``
	26	VIDIOC_ENUMAUDIO
	27
	28	``argp``
	29
	30
	31	Description
	32	===========
	33
	34	To query the attributes of an audio input applications initialize the
	35	``index`` field and zero out the ``reserved`` array of a struct
2212ff25	36	:ref:`v4l2_audio <v4l2-audio>` and call the :ref:`VIDIOC_ENUMAUDIO`
5377d91f MH	37	ioctl with a pointer to this structure. Drivers fill the rest of the
	38	structure or return an EINVAL error code when the index is out of
	39	bounds. To enumerate all audio inputs applications shall begin at index
	40	zero, incrementing by one until the driver returns EINVAL.
	41
4e03cb76	42	See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for a description of struct
5377d91f MH	43	:ref:`v4l2_audio <v4l2-audio>`.
	44
	45
	46	Return Value
	47	============
	48
	49	On success 0 is returned, on error -1 and the ``errno`` variable is set
	50	appropriately. The generic error codes are described at the
	51	:ref:`Generic Error Codes <gen-errors>` chapter.
	52
	53	EINVAL
	54	The number of the audio input is out of bounds.
	55
	56
	57	.. ------------------------------------------------------------------------------
	58	.. This file was automatically converted from DocBook-XML with the dbxml
	59	.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
	60	.. from the linux kernel, refer to:
	61	..
	62	.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
	63	.. ------------------------------------------------------------------------------