1 .. SPDX-License-Identifier: GFDL-1.1-no-invari !! 1 .. Permission is granted to copy, distribute and/or modify this
2 .. c:namespace:: V4L !! 2 .. document under the terms of the GNU Free Documentation License,
>> 3 .. Version 1.1 or any later version published by the Free Software
>> 4 .. Foundation, with no Invariant Sections, no Front-Cover Texts
>> 5 .. and no Back-Cover Texts. A copy of the license is included at
>> 6 .. Documentation/userspace-api/media/fdl-appendix.rst.
>> 7 ..
>> 8 .. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
3 9
4 .. _VIDIOC_G_AUDOUT: 10 .. _VIDIOC_G_AUDOUT:
5 11
6 ************************************** 12 **************************************
7 ioctl VIDIOC_G_AUDOUT, VIDIOC_S_AUDOUT 13 ioctl VIDIOC_G_AUDOUT, VIDIOC_S_AUDOUT
8 ************************************** 14 **************************************
9 15
10 Name 16 Name
11 ==== 17 ====
12 18
13 VIDIOC_G_AUDOUT - VIDIOC_S_AUDOUT - Query or s 19 VIDIOC_G_AUDOUT - VIDIOC_S_AUDOUT - Query or select the current audio output
14 20
>> 21
15 Synopsis 22 Synopsis
16 ======== 23 ========
17 24
18 .. c:macro:: VIDIOC_G_AUDOUT !! 25 .. c:function:: int ioctl( int fd, VIDIOC_G_AUDOUT, struct v4l2_audioout *argp )
19 !! 26 :name: VIDIOC_G_AUDOUT
20 ``int ioctl(int fd, VIDIOC_G_AUDOUT, struct v4 <<
21 27
22 .. c:macro:: VIDIOC_S_AUDOUT !! 28 .. c:function:: int ioctl( int fd, VIDIOC_S_AUDOUT, const struct v4l2_audioout *argp )
>> 29 :name: VIDIOC_S_AUDOUT
23 30
24 ``int ioctl(int fd, VIDIOC_S_AUDOUT, const str <<
25 31
26 Arguments 32 Arguments
27 ========= 33 =========
28 34
29 ``fd`` 35 ``fd``
30 File descriptor returned by :c:func:`open( !! 36 File descriptor returned by :ref:`open() <func-open>`.
31 37
32 ``argp`` 38 ``argp``
33 Pointer to struct :c:type:`v4l2_audioout`. 39 Pointer to struct :c:type:`v4l2_audioout`.
34 40
>> 41
35 Description 42 Description
36 =========== 43 ===========
37 44
38 To query the current audio output applications 45 To query the current audio output applications zero out the ``reserved``
39 array of a struct :c:type:`v4l2_audioout` and 46 array of a struct :c:type:`v4l2_audioout` and call the
40 ``VIDIOC_G_AUDOUT`` ioctl with a pointer to th 47 ``VIDIOC_G_AUDOUT`` ioctl with a pointer to this structure. Drivers fill
41 the rest of the structure or return an ``EINVA 48 the rest of the structure or return an ``EINVAL`` error code when the device
42 has no audio inputs, or none which combine wit 49 has no audio inputs, or none which combine with the current video
43 output. 50 output.
44 51
45 Audio outputs have no writable properties. Nev 52 Audio outputs have no writable properties. Nevertheless, to select the
46 current audio output applications can initiali 53 current audio output applications can initialize the ``index`` field and
47 ``reserved`` array (which in the future may co 54 ``reserved`` array (which in the future may contain writable properties)
48 of a struct :c:type:`v4l2_audioout` structure 55 of a struct :c:type:`v4l2_audioout` structure and call the
49 ``VIDIOC_S_AUDOUT`` ioctl. Drivers switch to t 56 ``VIDIOC_S_AUDOUT`` ioctl. Drivers switch to the requested output or
50 return the ``EINVAL`` error code when the inde 57 return the ``EINVAL`` error code when the index is out of bounds. This is a
51 write-only ioctl, it does not return the curre 58 write-only ioctl, it does not return the current audio output attributes
52 as ``VIDIOC_G_AUDOUT`` does. 59 as ``VIDIOC_G_AUDOUT`` does.
53 60
54 .. note:: 61 .. note::
55 62
56 Connectors on a TV card to loop back the re 63 Connectors on a TV card to loop back the received audio signal
57 to a sound card are not audio outputs in th 64 to a sound card are not audio outputs in this sense.
58 65
>> 66
59 .. c:type:: v4l2_audioout 67 .. c:type:: v4l2_audioout
60 68
61 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm !! 69 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
62 70
63 .. flat-table:: struct v4l2_audioout 71 .. flat-table:: struct v4l2_audioout
64 :header-rows: 0 72 :header-rows: 0
65 :stub-columns: 0 73 :stub-columns: 0
66 :widths: 1 1 2 74 :widths: 1 1 2
67 75
68 * - __u32 76 * - __u32
69 - ``index`` 77 - ``index``
70 - Identifies the audio output, set by th 78 - Identifies the audio output, set by the driver or application.
71 * - __u8 79 * - __u8
72 - ``name``\ [32] 80 - ``name``\ [32]
73 - Name of the audio output, a NUL-termin 81 - Name of the audio output, a NUL-terminated ASCII string, for
74 example: "Line Out". This information 82 example: "Line Out". This information is intended for the user,
75 preferably the connector label on the 83 preferably the connector label on the device itself.
76 * - __u32 84 * - __u32
77 - ``capability`` 85 - ``capability``
78 - Audio capability flags, none defined y 86 - Audio capability flags, none defined yet. Drivers must set this
79 field to zero. 87 field to zero.
80 * - __u32 88 * - __u32
81 - ``mode`` 89 - ``mode``
82 - Audio mode, none defined yet. Drivers 90 - Audio mode, none defined yet. Drivers and applications (on
83 ``VIDIOC_S_AUDOUT``) must set this fie 91 ``VIDIOC_S_AUDOUT``) must set this field to zero.
84 * - __u32 92 * - __u32
85 - ``reserved``\ [2] 93 - ``reserved``\ [2]
86 - Reserved for future extensions. Driver 94 - Reserved for future extensions. Drivers and applications must set
87 the array to zero. 95 the array to zero.
>> 96
88 97
89 Return Value 98 Return Value
90 ============ 99 ============
91 100
92 On success 0 is returned, on error -1 and the 101 On success 0 is returned, on error -1 and the ``errno`` variable is set
93 appropriately. The generic error codes are des 102 appropriately. The generic error codes are described at the
94 :ref:`Generic Error Codes <gen-errors>` chapte 103 :ref:`Generic Error Codes <gen-errors>` chapter.
95 104
96 EINVAL 105 EINVAL
97 No audio outputs combine with the current 106 No audio outputs combine with the current video output, or the
98 number of the selected audio output is out 107 number of the selected audio output is out of bounds or it does not
99 combine. 108 combine.
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