![Muralidharan Karicheri](/assets/img/avatar_default.png)
During review of Video Timing API documentation, Hans Verkuil had a comment on adding EBUSY error code for VIDIOC_S_STD and VIDIOC_QUERYSTD ioctls. This patch updates the document for this. Signed-off-by: Muralidharan Karicheri <m-karicheri2@ti.com> Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
90 lines
2.2 KiB
XML
90 lines
2.2 KiB
XML
<refentry id="vidioc-querystd">
|
|
<refmeta>
|
|
<refentrytitle>ioctl VIDIOC_QUERYSTD</refentrytitle>
|
|
&manvol;
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>VIDIOC_QUERYSTD</refname>
|
|
<refpurpose>Sense the video standard received by 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>
|
|
</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_QUERYSTD</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>argp</parameter></term>
|
|
<listitem>
|
|
<para></para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para>The hardware may be able to detect the current video
|
|
standard automatically. To do so, applications call <constant>
|
|
VIDIOC_QUERYSTD</constant> with a pointer to a &v4l2-std-id; type. The
|
|
driver stores here a set of candidates, this can be a single flag or a
|
|
set of supported standards if for example the hardware can only
|
|
distinguish between 50 and 60 Hz systems. When detection is not
|
|
possible or fails, the set must contain all standards supported by the
|
|
current video input or output.</para>
|
|
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
&return-value;
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><errorcode>EINVAL</errorcode></term>
|
|
<listitem>
|
|
<para>This ioctl is not supported.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorcode>EBUSY</errorcode></term>
|
|
<listitem>
|
|
<para>The device is busy and therefore can not detect the standard</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
<!--
|
|
Local Variables:
|
|
mode: sgml
|
|
sgml-parent-document: "v4l2.sgml"
|
|
indent-tabs-mode: nil
|
|
End:
|
|
-->
|