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Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-g-input.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-g-input.xml | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-g-input.xml b/Documentation/DocBook/media/v4l/vidioc-g-input.xml new file mode 100644 index 00000000000..08ae82f131f --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-g-input.xml @@ -0,0 +1,83 @@ +<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.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> |