Based on kernel version 3.0.4. Page generated on 2011-10-03 22:07 EST.
1 <refentry id="vidioc-dqevent"> 2 <refmeta> 3 <refentrytitle>ioctl VIDIOC_DQEVENT</refentrytitle> 4 &manvol; 5 </refmeta> 6 7 <refnamediv> 8 <refname>VIDIOC_DQEVENT</refname> 9 <refpurpose>Dequeue event</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_event 19 *<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_DQEVENT</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>Dequeue an event from a video device. No input is required 53 for this ioctl. All the fields of the &v4l2-event; structure are 54 filled by the driver. The file handle will also receive exceptions 55 which the application may get by e.g. using the select system 56 call.</para> 57 58 <table frame="none" pgwide="1" id="v4l2-event"> 59 <title>struct <structname>v4l2_event</structname></title> 60 <tgroup cols="4"> 61 &cs-str; 62 <tbody valign="top"> 63 <row> 64 <entry>__u32</entry> 65 <entry><structfield>type</structfield></entry> 66 <entry></entry> 67 <entry>Type of the event.</entry> 68 </row> 69 <row> 70 <entry>union</entry> 71 <entry><structfield>u</structfield></entry> 72 <entry></entry> 73 <entry></entry> 74 </row> 75 <row> 76 <entry></entry> 77 <entry>&v4l2-event-vsync;</entry> 78 <entry><structfield>vsync</structfield></entry> 79 <entry>Event data for event V4L2_EVENT_VSYNC. 80 </entry> 81 </row> 82 <row> 83 <entry></entry> 84 <entry>__u8</entry> 85 <entry><structfield>data</structfield>[64]</entry> 86 <entry>Event data. Defined by the event type. The union 87 should be used to define easily accessible type for 88 events.</entry> 89 </row> 90 <row> 91 <entry>__u32</entry> 92 <entry><structfield>pending</structfield></entry> 93 <entry></entry> 94 <entry>Number of pending events excluding this one.</entry> 95 </row> 96 <row> 97 <entry>__u32</entry> 98 <entry><structfield>sequence</structfield></entry> 99 <entry></entry> 100 <entry>Event sequence number. The sequence number is 101 incremented for every subscribed event that takes place. 102 If sequence numbers are not contiguous it means that 103 events have been lost. 104 </entry> 105 </row> 106 <row> 107 <entry>struct timespec</entry> 108 <entry><structfield>timestamp</structfield></entry> 109 <entry></entry> 110 <entry>Event timestamp.</entry> 111 </row> 112 <row> 113 <entry>__u32</entry> 114 <entry><structfield>reserved</structfield>[9]</entry> 115 <entry></entry> 116 <entry>Reserved for future extensions. Drivers must set 117 the array to zero.</entry> 118 </row> 119 </tbody> 120 </tgroup> 121 </table> 122 123 </refsect1> 124 </refentry> 125 <!-- 126 Local Variables: 127 mode: sgml 128 sgml-parent-document: "v4l2.sgml" 129 indent-tabs-mode: nil 130 End: 131 -->
