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Based on kernel version 3.13. Page generated on 2014-01-20 22:02 EST.

1	<refentry id="vidioc-enumoutput">
2	  <refmeta>
3	    <refentrytitle>ioctl VIDIOC_ENUMOUTPUT</refentrytitle>
4	    &manvol;
5	  </refmeta>
6	
7	  <refnamediv>
8	    <refname>VIDIOC_ENUMOUTPUT</refname>
9	    <refpurpose>Enumerate video 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_output *<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_ENUMOUTPUT</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 a video outputs applications
52	initialize the <structfield>index</structfield> field of &v4l2-output;
53	and call the <constant>VIDIOC_ENUMOUTPUT</constant> ioctl with a
54	pointer to this structure. Drivers fill the rest of the structure or
55	return an &EINVAL; when the index is out of bounds. To enumerate all
56	outputs applications shall begin at index zero, incrementing by one
57	until the driver returns <errorcode>EINVAL</errorcode>.</para>
58	
59	    <table frame="none" pgwide="1" id="v4l2-output">
60	      <title>struct <structname>v4l2_output</structname></title>
61	      <tgroup cols="3">
62		&cs-str;
63		<tbody valign="top">
64		  <row>
65		    <entry>__u32</entry>
66		    <entry><structfield>index</structfield></entry>
67		    <entry>Identifies the output, set by the
68	application.</entry>
69		  </row>
70		  <row>
71		    <entry>__u8</entry>
72		    <entry><structfield>name</structfield>[32]</entry>
73		    <entry>Name of the video output, a NUL-terminated ASCII
74	string, for example: "Vout". This information is intended for the
75	user, preferably the connector label on the device itself.</entry>
76		  </row>
77		  <row>
78		    <entry>__u32</entry>
79		    <entry><structfield>type</structfield></entry>
80		    <entry>Type of the output, see <xref
81			linkend="output-type" />.</entry>
82		  </row>
83		  <row>
84		    <entry>__u32</entry>
85		    <entry><structfield>audioset</structfield></entry>
86		    <entry><para>Drivers can enumerate up to 32 video and
87	audio outputs. This field shows which audio outputs were
88	selectable as the current output if this was the currently selected
89	video output. It is a bit mask. The LSB corresponds to audio output 0,
90	the MSB to output 31. Any number of bits can be set, or
91	none.</para><para>When the driver does not enumerate audio outputs no
92	bits must be set. Applications shall not interpret this as lack of
93	audio support. Drivers may automatically select audio outputs without
94	enumerating them.</para><para>For details on audio outputs and how to
95	select the current output see <xref linkend="audio" />.</para></entry>
96		  </row>
97		  <row>
98		    <entry>__u32</entry>
99		    <entry><structfield>modulator</structfield></entry>
100		    <entry>Output devices can have zero or more RF modulators.
101	When the <structfield>type</structfield> is
102	<constant>V4L2_OUTPUT_TYPE_MODULATOR</constant> this is an RF
103	connector and this field identifies the modulator. It corresponds to
104	&v4l2-modulator; field <structfield>index</structfield>. For details
105	on modulators see <xref linkend="tuner" />.</entry>
106		  </row>
107		  <row>
108		    <entry>&v4l2-std-id;</entry>
109		    <entry><structfield>std</structfield></entry>
110		    <entry>Every video output supports one or more different
111	video standards. This field is a set of all supported standards. For
112	details on video standards and how to switch see <xref
113			linkend="standard" />.</entry>
114		  </row>
115		  <row>
116		    <entry>__u32</entry>
117		    <entry><structfield>capabilities</structfield></entry>
118		    <entry>This field provides capabilities for the
119	output. See <xref linkend="output-capabilities" /> for flags.</entry>
120		  </row>
121		  <row>
122		    <entry>__u32</entry>
123		    <entry><structfield>reserved</structfield>[3]</entry>
124		    <entry>Reserved for future extensions. Drivers must set
125	the array to zero.</entry>
126		  </row>
127		</tbody>
128	      </tgroup>
129	    </table>
130	
131	    <table frame="none" pgwide="1" id="output-type">
132	      <title>Output Type</title>
133	      <tgroup cols="3">
134		&cs-def;
135		<tbody valign="top">
136		  <row>
137		    <entry><constant>V4L2_OUTPUT_TYPE_MODULATOR</constant></entry>
138		    <entry>1</entry>
139		    <entry>This output is an analog TV modulator.</entry>
140		  </row>
141		  <row>
142		    <entry><constant>V4L2_OUTPUT_TYPE_ANALOG</constant></entry>
143		    <entry>2</entry>
144		    <entry>Analog baseband output, for example Composite /
145	CVBS, S-Video, RGB.</entry>
146		  </row>
147		  <row>
148		    <entry><constant>V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY</constant></entry>
149		    <entry>3</entry>
150		    <entry>[?]</entry>
151		  </row>
152		</tbody>
153	      </tgroup>
154	    </table>
155	
156	    <!-- Capabilities flags based on video timings RFC by Muralidharan
157	Karicheri, titled RFC (v1.2): V4L - Support for video timings at the
158	input/output interface to linux-media@vger.kernel.org on 19 Oct 2009.
159		-->
160	    <table frame="none" pgwide="1" id="output-capabilities">
161	      <title>Output capabilities</title>
162	      <tgroup cols="3">
163		&cs-def;
164		<tbody valign="top">
165		  <row>
166		    <entry><constant>V4L2_OUT_CAP_DV_TIMINGS</constant></entry>
167		    <entry>0x00000002</entry>
168		    <entry>This output supports setting video timings by using VIDIOC_S_DV_TIMINGS.</entry>
169		  </row>
170		  <row>
171		    <entry><constant>V4L2_OUT_CAP_STD</constant></entry>
172		    <entry>0x00000004</entry>
173		    <entry>This output supports setting the TV standard by using VIDIOC_S_STD.</entry>
174		  </row>
175		</tbody>
176	      </tgroup>
177	    </table>
178	
179	  </refsect1>
180	  <refsect1>
181	    &return-value;
182	
183	    <variablelist>
184	      <varlistentry>
185		<term><errorcode>EINVAL</errorcode></term>
186		<listitem>
187		  <para>The &v4l2-output; <structfield>index</structfield>
188	is out of bounds.</para>
189		</listitem>
190	      </varlistentry>
191	    </variablelist>
192	  </refsect1>
193	</refentry>
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