blob: c8dcaf92714c7895ae8d41750ac7c42ac247c2a5 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
.. _VIDIOC_ENUMAUDIO:
**********************
ioctl VIDIOC_ENUMAUDIO
**********************
Name
====
VIDIOC_ENUMAUDIO - Enumerate audio inputs
Synopsis
========
.. c:function:: int ioctl( int fd, VIDIOC_ENUMAUDIO, struct v4l2_audio *argp )
:name: VIDIOC_ENUMAUDIO
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <func-open>`.
``argp``
Pointer to struct :c:type:`v4l2_audio`.
Description
===========
To query the attributes of an audio input applications initialize the
``index`` field and zero out the ``reserved`` array of a struct
:c:type:`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
:c:type:`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.
|
