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8e080c2e MCC |
1 | <refentry id="vidioc-querystd"> |
2 | <refmeta> | |
3 | <refentrytitle>ioctl VIDIOC_QUERYSTD</refentrytitle> | |
4 | &manvol; | |
5 | </refmeta> | |
6 | ||
7 | <refnamediv> | |
8 | <refname>VIDIOC_QUERYSTD</refname> | |
9 | <refpurpose>Sense the video standard received by the current | |
10 | input</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>v4l2_std_id *<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_QUERYSTD</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>The hardware may be able to detect the current video | |
53 | standard automatically. To do so, applications call <constant> | |
54 | VIDIOC_QUERYSTD</constant> with a pointer to a &v4l2-std-id; type. The | |
55 | driver stores here a set of candidates, this can be a single flag or a | |
56 | set of supported standards if for example the hardware can only | |
57 | distinguish between 50 and 60 Hz systems. When detection is not | |
58 | possible or fails, the set must contain all standards supported by the | |
59 | current video input or output.</para> | |
60 | ||
61 | </refsect1> | |
62 | ||
63 | <refsect1> | |
64 | &return-value; | |
65 | ||
66 | <variablelist> | |
67 | <varlistentry> | |
68 | <term><errorcode>EINVAL</errorcode></term> | |
69 | <listitem> | |
70 | <para>This ioctl is not supported.</para> | |
71 | </listitem> | |
72 | </varlistentry> | |
422eaac5 MK |
73 | <varlistentry> |
74 | <term><errorcode>EBUSY</errorcode></term> | |
75 | <listitem> | |
76 | <para>The device is busy and therefore can not detect the standard</para> | |
77 | </listitem> | |
78 | </varlistentry> | |
8e080c2e MCC |
79 | </variablelist> |
80 | </refsect1> | |
81 | </refentry> | |
82 | ||
83 | <!-- | |
84 | Local Variables: | |
85 | mode: sgml | |
86 | sgml-parent-document: "v4l2.sgml" | |
87 | indent-tabs-mode: nil | |
88 | End: | |
89 | --> |