linux/Documentation/DocBook/media/v4l/vidioc-g-std.xml
Mauro Carvalho Chehab 4266129964 [media] DocBook: Move all media docbook stuff into its own directory
This patch addresses several issues pointed by Randy Dunlap
<rdunlap@xenotime.net> at changeset ece722c:

- In the generated index.html file, "media" is listed first, but it
  should be listed in alphabetical order, not first.

- The generated files are (hidden) in .tmpmedia/

- The link from the top-level index.html file to "media" is to
  media/index.html, but the file is actually in .tmpmedia/media/index.html

- Please build docs with and without using "O=builddir" and test that.

- Would it be possible for media to have its own Makefile instead of
  merging into this one?

Due to the way cleandocs target works, I had to rename the media DocBook
to media_api, otherwise cleandocs would remove the /media directory.

Thanks-to: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-07-27 17:52:05 -03:00

106 lines
3.0 KiB
XML

<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.</para>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>EINVAL</errorcode></term>
<listitem>
<para>This ioctl is not supported, or the
<constant>VIDIOC_S_STD</constant> parameter was unsuitable.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EBUSY</errorcode></term>
<listitem>
<para>The device is busy and therefore can not change the standard</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
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