kernel-fxtec-pro1x/Documentation/DocBook/media/v4l/vidioc-g-input.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

100 lines
2.7 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, or
there are no video inputs at all and this ioctl is not
supported.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EBUSY</errorcode></term>
<listitem>
<para>I/O is in progress, the input cannot be
switched.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
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