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Diffstat (limited to 'Documentation/DocBook/v4l/vidioc-g-output.xml')
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diff --git a/Documentation/DocBook/v4l/vidioc-g-output.xml b/Documentation/DocBook/v4l/vidioc-g-output.xml new file mode 100644 index 000000000000..3ea8c0ed812e --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-g-output.xml | |||
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1 | <refentry id="vidioc-g-output"> | ||
2 | <refmeta> | ||
3 | <refentrytitle>ioctl VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT</refentrytitle> | ||
4 | &manvol; | ||
5 | </refmeta> | ||
6 | |||
7 | <refnamediv> | ||
8 | <refname>VIDIOC_G_OUTPUT</refname> | ||
9 | <refname>VIDIOC_S_OUTPUT</refname> | ||
10 | <refpurpose>Query or select the current video output</refpurpose> | ||
11 | </refnamediv> | ||
12 | |||
13 | <refsynopsisdiv> | ||
14 | <funcsynopsis> | ||
15 | <funcprototype> | ||
16 | <funcdef>int <function>ioctl</function></funcdef> | ||
17 | <paramdef>int <parameter>fd</parameter></paramdef> | ||
18 | <paramdef>int <parameter>request</parameter></paramdef> | ||
19 | <paramdef>int *<parameter>argp</parameter></paramdef> | ||
20 | </funcprototype> | ||
21 | </funcsynopsis> | ||
22 | </refsynopsisdiv> | ||
23 | |||
24 | <refsect1> | ||
25 | <title>Arguments</title> | ||
26 | |||
27 | <variablelist> | ||
28 | <varlistentry> | ||
29 | <term><parameter>fd</parameter></term> | ||
30 | <listitem> | ||
31 | <para>&fd;</para> | ||
32 | </listitem> | ||
33 | </varlistentry> | ||
34 | <varlistentry> | ||
35 | <term><parameter>request</parameter></term> | ||
36 | <listitem> | ||
37 | <para>VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT</para> | ||
38 | </listitem> | ||
39 | </varlistentry> | ||
40 | <varlistentry> | ||
41 | <term><parameter>argp</parameter></term> | ||
42 | <listitem> | ||
43 | <para></para> | ||
44 | </listitem> | ||
45 | </varlistentry> | ||
46 | </variablelist> | ||
47 | </refsect1> | ||
48 | |||
49 | <refsect1> | ||
50 | <title>Description</title> | ||
51 | |||
52 | <para>To query the current video output applications call the | ||
53 | <constant>VIDIOC_G_OUTPUT</constant> ioctl with a pointer to an integer | ||
54 | where the driver stores the number of the output, as in the | ||
55 | &v4l2-output; <structfield>index</structfield> field. This ioctl | ||
56 | will fail only when there are no video outputs, returning the | ||
57 | &EINVAL;.</para> | ||
58 | |||
59 | <para>To select a video output applications store the number of the | ||
60 | desired output in an integer and call the | ||
61 | <constant>VIDIOC_S_OUTPUT</constant> ioctl with a pointer to this integer. | ||
62 | Side effects are possible. For example outputs may support different | ||
63 | video standards, so the driver may implicitly switch the current | ||
64 | standard. It is good practice to select an output before querying or | ||
65 | negotiating any other parameters.</para> | ||
66 | |||
67 | <para>Information about video outputs is available using the | ||
68 | &VIDIOC-ENUMOUTPUT; ioctl.</para> | ||
69 | </refsect1> | ||
70 | |||
71 | <refsect1> | ||
72 | &return-value; | ||
73 | |||
74 | <variablelist> | ||
75 | <varlistentry> | ||
76 | <term><errorcode>EINVAL</errorcode></term> | ||
77 | <listitem> | ||
78 | <para>The number of the video output is out of bounds, or | ||
79 | there are no video outputs at all and this ioctl is not | ||
80 | supported.</para> | ||
81 | </listitem> | ||
82 | </varlistentry> | ||
83 | <varlistentry> | ||
84 | <term><errorcode>EBUSY</errorcode></term> | ||
85 | <listitem> | ||
86 | <para>I/O is in progress, the output cannot be | ||
87 | switched.</para> | ||
88 | </listitem> | ||
89 | </varlistentry> | ||
90 | </variablelist> | ||
91 | </refsect1> | ||
92 | </refentry> | ||
93 | |||
94 | <!-- | ||
95 | Local Variables: | ||
96 | mode: sgml | ||
97 | sgml-parent-document: "v4l2.sgml" | ||
98 | indent-tabs-mode: nil | ||
99 | End: | ||
100 | --> | ||