84 lines
2.3 KiB
XML
84 lines
2.3 KiB
XML
<refentry id="vidioc-g-input">
|
|
<refmeta>
|
|
<refentrytitle>ioctl VIDIOC_G_INPUT, VIDIOC_S_INPUT</refentrytitle>
|
|
&manvol;
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>VIDIOC_G_INPUT</refname>
|
|
<refname>VIDIOC_S_INPUT</refname>
|
|
<refpurpose>Query or select the current video input</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcprototype>
|
|
<funcdef>int <function>ioctl</function></funcdef>
|
|
<paramdef>int <parameter>fd</parameter></paramdef>
|
|
<paramdef>int <parameter>request</parameter></paramdef>
|
|
<paramdef>int *<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_G_INPUT, VIDIOC_S_INPUT</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>argp</parameter></term>
|
|
<listitem>
|
|
<para></para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para>To query the current video input applications call the
|
|
<constant>VIDIOC_G_INPUT</constant> ioctl with a pointer to an integer
|
|
where the driver stores the number of the input, as in the
|
|
&v4l2-input; <structfield>index</structfield> field. This ioctl will
|
|
fail only when there are no video inputs, returning
|
|
<errorcode>EINVAL</errorcode>.</para>
|
|
|
|
<para>To select a video input applications store the number of the
|
|
desired input in an integer and call the
|
|
<constant>VIDIOC_S_INPUT</constant> ioctl with a pointer to this
|
|
integer. Side effects are possible. For example inputs may support
|
|
different video standards, so the driver may implicitly switch the
|
|
current standard. It is good practice to select an input before
|
|
querying or negotiating any other parameters.</para>
|
|
|
|
<para>Information about video inputs is available using the
|
|
&VIDIOC-ENUMINPUT; ioctl.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
&return-value;
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><errorcode>EINVAL</errorcode></term>
|
|
<listitem>
|
|
<para>The number of the video input is out of bounds.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
</refentry>
|