1 <refentry id=
"vidioc-overlay">
3 <refentrytitle>ioctl VIDIOC_OVERLAY
</refentrytitle>
8 <refname>VIDIOC_OVERLAY
</refname>
9 <refpurpose>Start or stop video overlay
</refpurpose>
15 <funcdef>int
<function>ioctl
</function></funcdef>
16 <paramdef>int
<parameter>fd
</parameter></paramdef>
17 <paramdef>int
<parameter>request
</parameter></paramdef>
18 <paramdef>const int *
<parameter>argp
</parameter></paramdef>
24 <title>Arguments
</title>
28 <term><parameter>fd
</parameter></term>
34 <term><parameter>request
</parameter></term>
36 <para>VIDIOC_OVERLAY
</para>
40 <term><parameter>argp
</parameter></term>
49 <title>Description
</title>
51 <para>This ioctl is part of the
<link linkend=
"overlay">video
52 overlay
</link> I/O method. Applications call
53 <constant>VIDIOC_OVERLAY
</constant> to start or stop the
54 overlay. It takes a pointer to an integer which must be set to
55 zero by the application to stop overlay, to one to start.
</para>
57 <para>Drivers do not support &VIDIOC-STREAMON; or
58 &VIDIOC-STREAMOFF; with
<constant>V4L2_BUF_TYPE_VIDEO_OVERLAY
</constant>.
</para>
66 <term><errorcode>EINVAL
</errorcode></term>
68 <para>Video overlay is not supported, or the
69 parameters have not been set up. See
<xref
70 linkend=
"overlay" /> for the necessary steps.
</para>
80 sgml-parent-document: "v4l2.sgml"