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+<refentry id="vidioc-enumoutput">
+ <refmeta>
+ <refentrytitle>ioctl VIDIOC_ENUMOUTPUT</refentrytitle>
+ &manvol;
+ </refmeta>
+
+ <refnamediv>
+ <refname>VIDIOC_ENUMOUTPUT</refname>
+ <refpurpose>Enumerate video 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_output *<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_ENUMOUTPUT</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 a video outputs applications
+initialize the <structfield>index</structfield> field of &v4l2-output;
+and call the <constant>VIDIOC_ENUMOUTPUT</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
+outputs applications shall begin at index zero, incrementing by one
+until the driver returns <errorcode>EINVAL</errorcode>.</para>
+
+ <table frame="none" pgwide="1" id="v4l2-output">
+ <title>struct <structname>v4l2_output</structname></title>
+ <tgroup cols="3">
+ &cs-str;
+ <tbody valign="top">
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>index</structfield></entry>
+ <entry>Identifies the output, set by the
+application.</entry>
+ </row>
+ <row>
+ <entry>__u8</entry>
+ <entry><structfield>name</structfield>[32]</entry>
+ <entry>Name of the video output, a NUL-terminated ASCII
+string, for example: "Vout". This information is intended for the
+user, preferably the connector label on the device itself.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>type</structfield></entry>
+ <entry>Type of the output, see <xref
+ linkend="output-type" />.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>audioset</structfield></entry>
+ <entry><para>Drivers can enumerate up to 32 video and
+audio outputs. This field shows which audio outputs were
+selectable as the current output if this was the currently selected
+video output. It is a bit mask. The LSB corresponds to audio output 0,
+the MSB to output 31. Any number of bits can be set, or
+none.</para><para>When the driver does not enumerate audio outputs no
+bits must be set. Applications shall not interpret this as lack of
+audio support. Drivers may automatically select audio outputs without
+enumerating them.</para><para>For details on audio outputs and how to
+select the current output see <xref linkend="audio" />.</para></entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>modulator</structfield></entry>
+ <entry>Output devices can have zero or more RF modulators.
+When the <structfield>type</structfield> is
+<constant>V4L2_OUTPUT_TYPE_MODULATOR</constant> this is an RF
+connector and this field identifies the modulator. It corresponds to
+&v4l2-modulator; field <structfield>index</structfield>. For details
+on modulators see <xref linkend="tuner" />.</entry>
+ </row>
+ <row>
+ <entry>&v4l2-std-id;</entry>
+ <entry><structfield>std</structfield></entry>
+ <entry>Every video output supports one or more different
+video standards. This field is a set of all supported standards. For
+details on video standards and how to switch see <xref
+ linkend="standard" />.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>reserved</structfield>[4]</entry>
+ <entry>Reserved for future extensions. Drivers must set
+the array to zero.</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <table frame="none" pgwide="1" id="output-type">
+ <title>Output Type</title>
+ <tgroup cols="3">
+ &cs-def;
+ <tbody valign="top">
+ <row>
+ <entry><constant>V4L2_OUTPUT_TYPE_MODULATOR</constant></entry>
+ <entry>1</entry>
+ <entry>This output is an analog TV modulator.</entry>
+ </row>
+ <row>
+ <entry><constant>V4L2_OUTPUT_TYPE_ANALOG</constant></entry>
+ <entry>2</entry>
+ <entry>Analog baseband output, for example Composite /
+CVBS, S-Video, RGB.</entry>
+ </row>
+ <row>
+ <entry><constant>V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY</constant></entry>
+ <entry>3</entry>
+ <entry>[?]</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ </refsect1>
+ <refsect1>
+ &return-value;
+
+ <variablelist>
+ <varlistentry>
+ <term><errorcode>EINVAL</errorcode></term>
+ <listitem>
+ <para>The &v4l2-output; <structfield>index</structfield>
+is out of bounds.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+</refentry>
+
+<!--
+Local Variables:
+mode: sgml
+sgml-parent-document: "v4l2.sgml"
+indent-tabs-mode: nil
+End:
+-->