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linux/Documentation/DocBook/v4l/vidioc-querystd.xml
Mauro Carvalho Chehab 8e080c2e6c V4L/DVB (12761): DocBook: add media API specs
The V4L and DVB API's are there for a long time. however, up to now,
no efforts were done to merge them to kernel DocBook.

This patch adds the current versions of the specs as an unique compendium.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-09-18 23:47:55 -03:00

84 lines
2.0 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>
</variablelist>
</refsect1>
</refentry>
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