1 .. SPDX-License-Identifier: GFDL-1.1-no-invari 1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2 .. c:namespace:: V4L 2 .. c:namespace:: V4L
3 3
4 .. _VIDIOC_ENUMAUDIO: 4 .. _VIDIOC_ENUMAUDIO:
5 5
6 ********************** 6 **********************
7 ioctl VIDIOC_ENUMAUDIO 7 ioctl VIDIOC_ENUMAUDIO
8 ********************** 8 **********************
9 9
10 Name 10 Name
11 ==== 11 ====
12 12
13 VIDIOC_ENUMAUDIO - Enumerate audio inputs 13 VIDIOC_ENUMAUDIO - Enumerate audio inputs
14 14
15 Synopsis 15 Synopsis
16 ======== 16 ========
17 17
18 .. c:macro:: VIDIOC_ENUMAUDIO 18 .. c:macro:: VIDIOC_ENUMAUDIO
19 19
20 ``int ioctl(int fd, VIDIOC_ENUMAUDIO, struct v 20 ``int ioctl(int fd, VIDIOC_ENUMAUDIO, struct v4l2_audio *argp)``
21 21
22 Arguments 22 Arguments
23 ========= 23 =========
24 24
25 ``fd`` 25 ``fd``
26 File descriptor returned by :c:func:`open( 26 File descriptor returned by :c:func:`open()`.
27 27
28 ``argp`` 28 ``argp``
29 Pointer to struct :c:type:`v4l2_audio`. 29 Pointer to struct :c:type:`v4l2_audio`.
30 30
31 Description 31 Description
32 =========== 32 ===========
33 33
34 To query the attributes of an audio input appl 34 To query the attributes of an audio input applications initialize the
35 ``index`` field and zero out the ``reserved`` 35 ``index`` field and zero out the ``reserved`` array of a struct
36 :c:type:`v4l2_audio` and call the :ref:`VIDIOC 36 :c:type:`v4l2_audio` and call the :ref:`VIDIOC_ENUMAUDIO`
37 ioctl with a pointer to this structure. Driver 37 ioctl with a pointer to this structure. Drivers fill the rest of the
38 structure or return an ``EINVAL`` error code w 38 structure or return an ``EINVAL`` error code when the index is out of
39 bounds. To enumerate all audio inputs applicat 39 bounds. To enumerate all audio inputs applications shall begin at index
40 zero, incrementing by one until the driver ret 40 zero, incrementing by one until the driver returns ``EINVAL``.
41 41
42 See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for 42 See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for a description of struct
43 :c:type:`v4l2_audio`. 43 :c:type:`v4l2_audio`.
44 44
45 Return Value 45 Return Value
46 ============ 46 ============
47 47
48 On success 0 is returned, on error -1 and the 48 On success 0 is returned, on error -1 and the ``errno`` variable is set
49 appropriately. The generic error codes are des 49 appropriately. The generic error codes are described at the
50 :ref:`Generic Error Codes <gen-errors>` chapte 50 :ref:`Generic Error Codes <gen-errors>` chapter.
51 51
52 EINVAL 52 EINVAL
53 The number of the audio input is out of bo 53 The number of the audio input is out of bounds.
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