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

1	<refentry id="vidioc-enuminput">
2	  <refmeta>
3	    <refentrytitle>ioctl VIDIOC_ENUMINPUT</refentrytitle>
4	    &manvol;
5	  </refmeta>
6	
7	  <refnamediv>
8	    <refname>VIDIOC_ENUMINPUT</refname>
9	    <refpurpose>Enumerate video inputs</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_input
19	*<parameter>argp</parameter></paramdef>
20	      </funcprototype>
21	    </funcsynopsis>
22	  </refsynopsisdiv>
23	
24	  <refsect1>
25	    <title>Arguments</title>
26	
27	    <variablelist>
28	      <varlistentry>
29		<term><parameter>fd</parameter></term>
30		<listitem>
31		  <para>&fd;</para>
32		</listitem>
33	      </varlistentry>
34	      <varlistentry>
35		<term><parameter>request</parameter></term>
36		<listitem>
37		  <para>VIDIOC_ENUMINPUT</para>
38		</listitem>
39	      </varlistentry>
40	      <varlistentry>
41		<term><parameter>argp</parameter></term>
42		<listitem>
43		  <para></para>
44		</listitem>
45	      </varlistentry>
46	    </variablelist>
47	  </refsect1>
48	
49	  <refsect1>
50	    <title>Description</title>
51	
52	    <para>To query the attributes of a video input applications
53	initialize the <structfield>index</structfield> field of &v4l2-input;
54	and call the <constant>VIDIOC_ENUMINPUT</constant> ioctl with a
55	pointer to this structure. Drivers fill the rest of the structure or
56	return an &EINVAL; when the index is out of bounds. To enumerate all
57	inputs applications shall begin at index zero, incrementing by one
58	until the driver returns <errorcode>EINVAL</errorcode>.</para>
59	
60	    <table frame="none" pgwide="1" id="v4l2-input">
61	      <title>struct <structname>v4l2_input</structname></title>
62	      <tgroup cols="3">
63		&cs-str;
64		<tbody valign="top">
65		  <row>
66		    <entry>__u32</entry>
67		    <entry><structfield>index</structfield></entry>
68		    <entry>Identifies the input, set by the
69	application.</entry>
70		  </row>
71		  <row>
72		    <entry>__u8</entry>
73		    <entry><structfield>name</structfield>[32]</entry>
74		    <entry>Name of the video input, a NUL-terminated ASCII
75	string, for example: "Vin (Composite 2)". This information is intended
76	for the user, preferably the connector label on the device itself.</entry>
77		  </row>
78		  <row>
79		    <entry>__u32</entry>
80		    <entry><structfield>type</structfield></entry>
81		    <entry>Type of the input, see <xref
82			linkend="input-type" />.</entry>
83		  </row>
84		  <row>
85		    <entry>__u32</entry>
86		    <entry><structfield>audioset</structfield></entry>
87		    <entry><para>Drivers can enumerate up to 32 video and
88	audio inputs. This field shows which audio inputs were selectable as
89	audio source if this was the currently selected video input. It is a
90	bit mask. The LSB corresponds to audio input 0, the MSB to input 31.
91	Any number of bits can be set, or none.</para><para>When the driver
92	does not enumerate audio inputs no bits must be set. Applications
93	shall not interpret this as lack of audio support. Some drivers
94	automatically select audio sources and do not enumerate them since
95	there is no choice anyway.</para><para>For details on audio inputs and
96	how to select the current input see <xref
97			  linkend="audio" />.</para></entry>
98		  </row>
99		  <row>
100		    <entry>__u32</entry>
101		    <entry><structfield>tuner</structfield></entry>
102		    <entry>Capture devices can have zero or more tuners (RF
103	demodulators). When the <structfield>type</structfield> is set to
104	<constant>V4L2_INPUT_TYPE_TUNER</constant> this is an RF connector and
105	this field identifies the tuner. It corresponds to
106	&v4l2-tuner; field <structfield>index</structfield>. For details on
107	tuners see <xref linkend="tuner" />.</entry>
108		  </row>
109		  <row>
110		    <entry>&v4l2-std-id;</entry>
111		    <entry><structfield>std</structfield></entry>
112		    <entry>Every video input supports one or more different
113	video standards. This field is a set of all supported standards. For
114	details on video standards and how to switch see <xref
115	linkend="standard" />.</entry>
116		  </row>
117		  <row>
118		    <entry>__u32</entry>
119		    <entry><structfield>status</structfield></entry>
120		    <entry>This field provides status information about the
121	input. See <xref linkend="input-status" /> for flags.
122	With the exception of the sensor orientation bits <structfield>status</structfield> is only valid when this is the
123	current input.</entry>
124		  </row>
125		  <row>
126		    <entry>__u32</entry>
127		    <entry><structfield>capabilities</structfield></entry>
128		    <entry>This field provides capabilities for the
129	input. See <xref linkend="input-capabilities" /> for flags.</entry>
130		  </row>
131		  <row>
132		    <entry>__u32</entry>
133		    <entry><structfield>reserved</structfield>[3]</entry>
134		    <entry>Reserved for future extensions. Drivers must set
135	the array to zero.</entry>
136		  </row>
137		</tbody>
138	      </tgroup>
139	    </table>
140	
141	    <table frame="none" pgwide="1" id="input-type">
142	      <title>Input Types</title>
143	      <tgroup cols="3">
144		&cs-def;
145		<tbody valign="top">
146		  <row>
147		    <entry><constant>V4L2_INPUT_TYPE_TUNER</constant></entry>
148		    <entry>1</entry>
149		    <entry>This input uses a tuner (RF demodulator).</entry>
150		  </row>
151		  <row>
152		    <entry><constant>V4L2_INPUT_TYPE_CAMERA</constant></entry>
153		    <entry>2</entry>
154		    <entry>Analog baseband input, for example CVBS /
155	Composite Video, S-Video, RGB.</entry>
156		  </row>
157		</tbody>
158	      </tgroup>
159	    </table>
160	
161	    <!-- Status flags based on proposal by Mark McClelland,
162	video4linux-list@redhat.com on 18 Oct 2002, subject "Re: [V4L] Re:
163	v4l2 api". "Why are some of them inverted? So that the driver doesn't
164	have to lie about the status in cases where it can't tell one way or
165	the other. Plus, a status of zero would generally mean that everything
166	is OK." -->
167	
168	    <table frame="none" pgwide="1" id="input-status">
169	      <title>Input Status Flags</title>
170	      <tgroup cols="3">
171		<colspec colname="c1" />
172		<colspec colname="c2" align="center" />
173		<colspec colname="c3" />
174		<spanspec namest="c1" nameend="c3" spanname="hspan"
175		  align="left" />
176		<tbody valign="top">
177		  <row>
178		    <entry spanname="hspan">General</entry>
179		  </row>
180		  <row>
181		    <entry><constant>V4L2_IN_ST_NO_POWER</constant></entry>
182		    <entry>0x00000001</entry>
183		    <entry>Attached device is off.</entry>
184		  </row>
185		  <row>
186		    <entry><constant>V4L2_IN_ST_NO_SIGNAL</constant></entry>
187		    <entry>0x00000002</entry>
188		    <entry></entry>
189		  </row>
190		  <row>
191		    <entry><constant>V4L2_IN_ST_NO_COLOR</constant></entry>
192		    <entry>0x00000004</entry>
193		    <entry>The hardware supports color decoding, but does not
194	detect color modulation in the signal.</entry>
195		  </row>
196		  <row>
197		    <entry spanname="hspan">Sensor Orientation</entry>
198		  </row>
199		  <row>
200		    <entry><constant>V4L2_IN_ST_HFLIP</constant></entry>
201		    <entry>0x00000010</entry>
202		    <entry>The input is connected to a device that produces a signal
203	that is flipped horizontally and does not correct this before passing the
204	signal to userspace.</entry>
205		  </row>
206		  <row>
207		    <entry><constant>V4L2_IN_ST_VFLIP</constant></entry>
208		    <entry>0x00000020</entry>
209		    <entry>The input is connected to a device that produces a signal
210	that is flipped vertically and does not correct this before passing the
211	signal to userspace. Note that a 180 degree rotation is the same as HFLIP | VFLIP</entry>
212		  </row>
213		  <row>
214		    <entry spanname="hspan">Analog Video</entry>
215		  </row>
216		  <row>
217		    <entry><constant>V4L2_IN_ST_NO_H_LOCK</constant></entry>
218		    <entry>0x00000100</entry>
219		    <entry>No horizontal sync lock.</entry>
220		  </row>
221		  <row>
222		    <entry><constant>V4L2_IN_ST_COLOR_KILL</constant></entry>
223		    <entry>0x00000200</entry>
224		    <entry>A color killer circuit automatically disables color
225	decoding when it detects no color modulation. When this flag is set
226	the color killer is enabled <emphasis>and</emphasis> has shut off
227	color decoding.</entry>
228		  </row>
229		  <row>
230		    <entry spanname="hspan">Digital Video</entry>
231		  </row>
232		  <row>
233		    <entry><constant>V4L2_IN_ST_NO_SYNC</constant></entry>
234		    <entry>0x00010000</entry>
235		    <entry>No synchronization lock.</entry>
236		  </row>
237		  <row>
238		    <entry><constant>V4L2_IN_ST_NO_EQU</constant></entry>
239		    <entry>0x00020000</entry>
240		    <entry>No equalizer lock.</entry>
241		  </row>
242		  <row>
243		    <entry><constant>V4L2_IN_ST_NO_CARRIER</constant></entry>
244		    <entry>0x00040000</entry>
245		    <entry>Carrier recovery failed.</entry>
246		  </row>
247		  <row>
248		    <entry spanname="hspan">VCR and Set-Top Box</entry>
249		  </row>
250		  <row>
251		    <entry><constant>V4L2_IN_ST_MACROVISION</constant></entry>
252		    <entry>0x01000000</entry>
253		    <entry>Macrovision is an analog copy prevention system
254	mangling the video signal to confuse video recorders. When this
255	flag is set Macrovision has been detected.</entry>
256		  </row>
257		  <row>
258		    <entry><constant>V4L2_IN_ST_NO_ACCESS</constant></entry>
259		    <entry>0x02000000</entry>
260		    <entry>Conditional access denied.</entry>
261		  </row>
262		  <row>
263		    <entry><constant>V4L2_IN_ST_VTR</constant></entry>
264		    <entry>0x04000000</entry>
265		    <entry>VTR time constant. [?]</entry>
266		  </row>
267		</tbody>
268	      </tgroup>
269	    </table>
270	
271	    <!-- Capability flags based on video timings RFC by Muralidharan
272	Karicheri, titled RFC (v1.2): V4L - Support for video timings at the
273	input/output interface to linux-media@vger.kernel.org on 19 Oct 2009.
274		-->
275	    <table frame="none" pgwide="1" id="input-capabilities">
276	      <title>Input capabilities</title>
277	      <tgroup cols="3">
278		&cs-def;
279		<tbody valign="top">
280		  <row>
281		    <entry><constant>V4L2_IN_CAP_DV_TIMINGS</constant></entry>
282		    <entry>0x00000002</entry>
283		    <entry>This input supports setting video timings by using VIDIOC_S_DV_TIMINGS.</entry>
284		  </row>
285		  <row>
286		    <entry><constant>V4L2_IN_CAP_STD</constant></entry>
287		    <entry>0x00000004</entry>
288		    <entry>This input supports setting the TV standard by using VIDIOC_S_STD.</entry>
289		  </row>
290		</tbody>
291	      </tgroup>
292	    </table>
293	  </refsect1>
294	
295	  <refsect1>
296	    &return-value;
297	
298	    <variablelist>
299	      <varlistentry>
300		<term><errorcode>EINVAL</errorcode></term>
301		<listitem>
302		  <para>The &v4l2-input; <structfield>index</structfield> is
303	out of bounds.</para>
304		</listitem>
305	      </varlistentry>
306	    </variablelist>
307	  </refsect1>
308	</refentry>
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