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<refentry id="vidioc-g-std">
<refmeta>
<refentrytitle>ioctl VIDIOC_G_STD, VIDIOC_S_STD</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_G_STD</refname>
<refname>VIDIOC_S_STD</refname>
<refpurpose>Query or select the video standard of the current 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>v4l2_std_id
*<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>const v4l2_std_id
*<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_STD, VIDIOC_S_STD</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>To query and select the current video standard applications
use the <constant>VIDIOC_G_STD</constant> and <constant>VIDIOC_S_STD</constant> ioctls which take a pointer to a
&v4l2-std-id; type as argument. <constant>VIDIOC_G_STD</constant> can
return a single flag or a set of flags as in &v4l2-standard; field
<structfield>id</structfield>. The flags must be unambiguous such
that they appear in only one enumerated <structname>v4l2_standard</structname> structure.</para>
<para><constant>VIDIOC_S_STD</constant> accepts one or more
flags, being a write-only ioctl it does not return the actual new standard as
<constant>VIDIOC_G_STD</constant> does. When no flags are given or
the current input does not support the requested standard the driver
returns an &EINVAL;. When the standard set is ambiguous drivers may
return <errorcode>EINVAL</errorcode> or choose any of the requested
standards. If the current input or output does not support standard video timings (e.g. if
&VIDIOC-ENUMINPUT; does not set the <constant>V4L2_IN_CAP_STD</constant> flag), then
&ENODATA; is returned.</para>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>EINVAL</errorcode></term>
<listitem>
<para>The <constant>VIDIOC_S_STD</constant> parameter was unsuitable.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>ENODATA</errorcode></term>
<listitem>
<para>Standard video timings are not supported for this input or output.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
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