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+<refentry id="vidioc-enumaudioout">
+ <refmeta>
+ <refentrytitle>ioctl VIDIOC_ENUMAUDOUT</refentrytitle>
+ &manvol;
+ </refmeta>
+
+ <refnamediv>
+ <refname>VIDIOC_ENUMAUDOUT</refname>
+ <refpurpose>Enumerate audio outputs</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>int <function>ioctl</function></funcdef>
+ <paramdef>int <parameter>fd</parameter></paramdef>
+ <paramdef>int <parameter>request</parameter></paramdef>
+ <paramdef>struct v4l2_audioout *<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_ENUMAUDOUT</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>argp</parameter></term>
+ <listitem>
+ <para></para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>To query the attributes of an audio output applications
+initialize the <structfield>index</structfield> field and zero out the
+<structfield>reserved</structfield> array of a &v4l2-audioout; and
+call the <constant>VIDIOC_G_AUDOUT</constant> ioctl with a pointer
+to this structure. Drivers fill the rest of the structure or return an
+&EINVAL; when the index is out of bounds. To enumerate all audio
+outputs applications shall begin at index zero, incrementing by one
+until the driver returns <errorcode>EINVAL</errorcode>.</para>
+
+ <para>Note connectors on a TV card to loop back the received audio
+signal to a sound card are not audio outputs in this sense.</para>
+
+ <para>See <xref linkend="vidioc-g-audioout" /> for a description of
+&v4l2-audioout;.</para>
+ </refsect1>
+
+ <refsect1>
+ &return-value;
+
+ <variablelist>
+ <varlistentry>
+ <term><errorcode>EINVAL</errorcode></term>
+ <listitem>
+ <para>The number of the audio output is out of bounds, or
+there are no audio outputs at all and this ioctl is not
+supported.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+</refentry>
+
+<!--
+Local Variables:
+mode: sgml
+sgml-parent-document: "v4l2.sgml"
+indent-tabs-mode: nil
+End:
+-->