706f8a9975
There are several notes and warning mesages in the middle of the media docbook. Use the ReST tags for that, as it makes them visually better and hightlights them. While here, modify a few ones to make them clearer. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
60 lines
1.4 KiB
ReStructuredText
60 lines
1.4 KiB
ReStructuredText
.. -*- coding: utf-8; mode: rst -*-
|
|
|
|
.. _VIDIOC_ENUMAUDOUT:
|
|
|
|
***********************
|
|
ioctl VIDIOC_ENUMAUDOUT
|
|
***********************
|
|
|
|
Name
|
|
====
|
|
|
|
VIDIOC_ENUMAUDOUT - Enumerate audio outputs
|
|
|
|
|
|
Synopsis
|
|
========
|
|
|
|
.. cpp:function:: int ioctl( int fd, int request, struct v4l2_audioout *argp )
|
|
|
|
|
|
Arguments
|
|
=========
|
|
|
|
``fd``
|
|
File descriptor returned by :ref:`open() <func-open>`.
|
|
|
|
``request``
|
|
VIDIOC_ENUMAUDOUT
|
|
|
|
``argp``
|
|
|
|
|
|
Description
|
|
===========
|
|
|
|
To query the attributes of an audio output applications initialize the
|
|
``index`` field and zero out the ``reserved`` array of a struct
|
|
:ref:`v4l2_audioout <v4l2-audioout>` and call the ``VIDIOC_G_AUDOUT``
|
|
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 outputs applications shall begin at index
|
|
zero, incrementing by one until the driver returns ``EINVAL``.
|
|
|
|
.. note:: Connectors on a TV card to loop back the received audio signal
|
|
to a sound card are not audio outputs in this sense.
|
|
|
|
See :ref:`VIDIOC_G_AUDIOout <VIDIOC_G_AUDOUT>` for a description of struct
|
|
:ref:`v4l2_audioout <v4l2-audioout>`.
|
|
|
|
|
|
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 output is out of bounds.
|