blob: b6f5d267e85612ed0d7e0aa575b2f1390eb795d1 (
plain) (
blame)
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
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
<refentry id="vidioc-g-std">
<refmeta>
<refentrytitle>ioctl VIDIOC_G_STD, VIDIOC_S_STD</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_G_STD</refname>
<refname>VIDIOC_S_STD</refname>
<refpurpose>Query or select the video standard of the current input</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>v4l2_std_id
*<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>const v4l2_std_id
*<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>&fd;</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>VIDIOC_G_STD, VIDIOC_S_STD</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>To query and select the current video standard applications
use the <constant>VIDIOC_G_STD</constant> and <constant>VIDIOC_S_STD</constant> ioctls which take a pointer to a
&v4l2-std-id; type as argument. <constant>VIDIOC_G_STD</constant> can
return a single flag or a set of flags as in &v4l2-standard; field
<structfield>id</structfield>. The flags must be unambiguous such
that they appear in only one enumerated <structname>v4l2_standard</structname> structure.</para>
<para><constant>VIDIOC_S_STD</constant> accepts one or more
flags, being a write-only ioctl it does not return the actual new standard as
<constant>VIDIOC_G_STD</constant> does. When no flags are given or
the current input does not support the requested standard the driver
returns an &EINVAL;. When the standard set is ambiguous drivers may
return <errorcode>EINVAL</errorcode> or choose any of the requested
standards.</para>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>EINVAL</errorcode></term>
<listitem>
<para>This ioctl is not supported, or the
<constant>VIDIOC_S_STD</constant> parameter was unsuitable.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
<!--
Local Variables:
mode: sgml
sgml-parent-document: "v4l2.sgml"
indent-tabs-mode: nil
End:
-->
|
