blob: eb45c1695d8cca30719aeb587d1633200c4bb476 (
plain)
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
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
<refentry id="vidioc-dqevent">
<refmeta>
<refentrytitle>ioctl VIDIOC_DQEVENT</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_DQEVENT</refname>
<refpurpose>Dequeue event</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>struct v4l2_event
*<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_DQEVENT</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>Dequeue an event from a video device. No input is required
for this ioctl. All the fields of the &v4l2-event; structure are
filled by the driver. The file handle will also receive exceptions
which the application may get by e.g. using the select system
call.</para>
<table frame="none" pgwide="1" id="v4l2-event">
<title>struct <structname>v4l2_event</structname></title>
<tgroup cols="4">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>type</structfield></entry>
<entry></entry>
<entry>Type of the event.</entry>
</row>
<row>
<entry>union</entry>
<entry><structfield>u</structfield></entry>
<entry></entry>
<entry></entry>
</row>
<row>
<entry></entry>
<entry>__u8</entry>
<entry><structfield>data</structfield>[64]</entry>
<entry>Event data. Defined by the event type. The union
should be used to define easily accessible type for
events.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>pending</structfield></entry>
<entry></entry>
<entry>Number of pending events excluding this one.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>sequence</structfield></entry>
<entry></entry>
<entry>Event sequence number. The sequence number is
incremented for every subscribed event that takes place.
If sequence numbers are not contiguous it means that
events have been lost.
</entry>
</row>
<row>
<entry>struct timeval</entry>
<entry><structfield>timestamp</structfield></entry>
<entry></entry>
<entry>Event timestamp.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[9]</entry>
<entry></entry>
<entry>Reserved for future extensions. Drivers must set
the array to zero.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
</refentry>
<!--
Local Variables:
mode: sgml
sgml-parent-document: "v4l2.sgml"
indent-tabs-mode: nil
End:
-->
|
