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1<refentry id="vidioc-enum-dv-timings">
2 <refmeta>
3 <refentrytitle>ioctl VIDIOC_ENUM_DV_TIMINGS</refentrytitle>
4 &manvol;
5 </refmeta>
6
7 <refnamediv>
8 <refname>VIDIOC_ENUM_DV_TIMINGS</refname>
9 <refpurpose>Enumerate supported Digital Video timings</refpurpose>
10 </refnamediv>
11
12 <refsynopsisdiv>
13 <funcsynopsis>
14 <funcprototype>
15 <funcdef>int <function>ioctl</function></funcdef>
16 <paramdef>int <parameter>fd</parameter></paramdef>
17 <paramdef>int <parameter>request</parameter></paramdef>
18 <paramdef>struct v4l2_enum_dv_timings *<parameter>argp</parameter></paramdef>
19 </funcprototype>
20 </funcsynopsis>
21 </refsynopsisdiv>
22
23 <refsect1>
24 <title>Arguments</title>
25
26 <variablelist>
27 <varlistentry>
28 <term><parameter>fd</parameter></term>
29 <listitem>
30 <para>&fd;</para>
31 </listitem>
32 </varlistentry>
33 <varlistentry>
34 <term><parameter>request</parameter></term>
35 <listitem>
36 <para>VIDIOC_ENUM_DV_TIMINGS</para>
37 </listitem>
38 </varlistentry>
39 <varlistentry>
40 <term><parameter>argp</parameter></term>
41 <listitem>
42 <para></para>
43 </listitem>
44 </varlistentry>
45 </variablelist>
46 </refsect1>
47
48 <refsect1>
49 <title>Description</title>
50
51 <note>
52 <title>Experimental</title>
53 <para>This is an <link linkend="experimental"> experimental </link>
54 interface and may change in the future.</para>
55 </note>
56
57 <para>While some DV receivers or transmitters support a wide range of timings, others
58support only a limited number of timings. With this ioctl applications can enumerate a list
59of known supported timings. Call &VIDIOC-DV-TIMINGS-CAP; to check if it also supports other
60standards or even custom timings that are not in this list.</para>
61
62 <para>To query the available timings, applications initialize the
63<structfield>index</structfield> field and zero the reserved array of &v4l2-enum-dv-timings;
64and call the <constant>VIDIOC_ENUM_DV_TIMINGS</constant> ioctl with a pointer to this
65structure. Drivers fill the rest of the structure or return an
66&EINVAL; when the index is out of bounds. To enumerate all supported DV timings,
67applications shall begin at index zero, incrementing by one until the
68driver returns <errorcode>EINVAL</errorcode>. Note that drivers may enumerate a
69different set of DV timings after switching the video input or
70output.</para>
71
72 <table pgwide="1" frame="none" id="v4l2-enum-dv-timings">
73 <title>struct <structname>v4l2_enum_dv_timings</structname></title>
74 <tgroup cols="3">
75 &cs-str;
76 <tbody valign="top">
77 <row>
78 <entry>__u32</entry>
79 <entry><structfield>index</structfield></entry>
80 <entry>Number of the DV timings, set by the
81application.</entry>
82 </row>
83 <row>
84 <entry>__u32</entry>
85 <entry><structfield>reserved</structfield>[3]</entry>
86 <entry>Reserved for future extensions. Drivers must set the array to zero.</entry>
87 </row>
88 <row>
89 <entry>&v4l2-dv-timings;</entry>
90 <entry><structfield>timings</structfield></entry>
91 <entry>The timings.</entry>
92 </row>
93 </tbody>
94 </tgroup>
95 </table>
96 </refsect1>
97
98 <refsect1>
99 &return-value;
100
101 <variablelist>
102 <varlistentry>
103 <term><errorcode>EINVAL</errorcode></term>
104 <listitem>
105 <para>The &v4l2-enum-dv-timings; <structfield>index</structfield>
106is out of bounds.</para>
107 </listitem>
108 </varlistentry>
109 </variablelist>
110 </refsect1>
111</refentry>
112
113<!--
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