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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:02 EST.

1	<refentry id="vidioc-enumaudioout">
2	  <refmeta>
3	    <refentrytitle>ioctl VIDIOC_ENUMAUDOUT</refentrytitle>
4	    &manvol;
5	  </refmeta>
6	
7	  <refnamediv>
8	    <refname>VIDIOC_ENUMAUDOUT</refname>
9	    <refpurpose>Enumerate audio outputs</refpurpose>
10	  </refnamediv>
11	
12	  <refsynopsisdiv>
13	    <funcsynopsis>
14	      <funcprototype>
15		<funcdef>int <function>ioctl</function></funcdef>
16		<paramdef>int <parameter>fd</parameter></paramdef>
17		<paramdef>int <parameter>request</parameter></paramdef>
18		<paramdef>struct v4l2_audioout *<parameter>argp</parameter></paramdef>
19	      </funcprototype>
20	    </funcsynopsis>
21	  </refsynopsisdiv>
22	
23	  <refsect1>
24	    <title>Arguments</title>
25	
26	    <variablelist>
27	      <varlistentry>
28		<term><parameter>fd</parameter></term>
29		<listitem>
30		  <para>&fd;</para>
31		</listitem>
32	      </varlistentry>
33	      <varlistentry>
34		<term><parameter>request</parameter></term>
35		<listitem>
36		  <para>VIDIOC_ENUMAUDOUT</para>
37		</listitem>
38	      </varlistentry>
39	      <varlistentry>
40		<term><parameter>argp</parameter></term>
41		<listitem>
42		  <para></para>
43		</listitem>
44	      </varlistentry>
45	    </variablelist>
46	  </refsect1>
47	
48	  <refsect1>
49	    <title>Description</title>
50	
51	    <para>To query the attributes of an audio output applications
52	initialize the <structfield>index</structfield> field and zero out the
53	<structfield>reserved</structfield> array of a &v4l2-audioout; and
54	call the <constant>VIDIOC_G_AUDOUT</constant> ioctl with a pointer
55	to this structure. Drivers fill the rest of the structure or return an
56	&EINVAL; when the index is out of bounds. To enumerate all audio
57	outputs applications shall begin at index zero, incrementing by one
58	until the driver returns <errorcode>EINVAL</errorcode>.</para>
59	
60	    <para>Note connectors on a TV card to loop back the received audio
61	signal to a sound card are not audio outputs in this sense.</para>
62	
63	    <para>See <xref linkend="vidioc-g-audioout" /> for a description of
64	&v4l2-audioout;.</para>
65	  </refsect1>
66	
67	  <refsect1>
68	    &return-value;
69	
70	    <variablelist>
71	      <varlistentry>
72		<term><errorcode>EINVAL</errorcode></term>
73		<listitem>
74		  <para>The number of the audio output is out of bounds.</para>
75		</listitem>
76	      </varlistentry>
77	    </variablelist>
78	  </refsect1>
79	</refentry>
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