aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/DocBook/v4l/vidioc-g-output.xml
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/DocBook/v4l/vidioc-g-output.xml')
-rw-r--r--Documentation/DocBook/v4l/vidioc-g-output.xml100
1 files changed, 100 insertions, 0 deletions
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
@@ -0,0 +1,100 @@
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
54where the driver stores the number of the output, as in the
55&v4l2-output; <structfield>index</structfield> field. This ioctl
56will 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
60desired output in an integer and call the
61<constant>VIDIOC_S_OUTPUT</constant> ioctl with a pointer to this integer.
62Side effects are possible. For example outputs may support different
63video standards, so the driver may implicitly switch the current
64standard. It is good practice to select an output before querying or
65negotiating 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
79there are no video outputs at all and this ioctl is not
80supported.</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
87switched.</para>
88 </listitem>
89 </varlistentry>
90 </variablelist>
91 </refsect1>
92</refentry>
93
94<!--
95Local Variables:
96mode: sgml
97sgml-parent-document: "v4l2.sgml"
98indent-tabs-mode: nil
99End:
100-->