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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> | |
007701e2 MK |
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> | |
8e080c2e MCC |
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> | |
007701e2 MK |
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_PRESETS</constant></entry> | |
282 | <entry>0x00000001</entry> | |
283 | <entry>This input supports setting DV presets by using VIDIOC_S_DV_PRESET.</entry> | |
284 | </row> | |
285 | <row> | |
b4162f4a | 286 | <entry><constant>V4L2_IN_CAP_CUSTOM_TIMINGS</constant></entry> |
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287 | <entry>0x00000002</entry> |
288 | <entry>This input supports setting custom video timings by using VIDIOC_S_DV_TIMINGS.</entry> | |
289 | </row> | |
290 | <row> | |
291 | <entry><constant>V4L2_IN_CAP_STD</constant></entry> | |
292 | <entry>0x00000004</entry> | |
293 | <entry>This input supports setting the TV standard by using VIDIOC_S_STD.</entry> | |
294 | </row> | |
295 | </tbody> | |
296 | </tgroup> | |
297 | </table> | |
8e080c2e MCC |
298 | </refsect1> |
299 | ||
300 | <refsect1> | |
301 | &return-value; | |
302 | ||
303 | <variablelist> | |
304 | <varlistentry> | |
305 | <term><errorcode>EINVAL</errorcode></term> | |
306 | <listitem> | |
307 | <para>The &v4l2-input; <structfield>index</structfield> is | |
308 | out of bounds.</para> | |
309 | </listitem> | |
310 | </varlistentry> | |
311 | </variablelist> | |
312 | </refsect1> | |
313 | </refentry> |