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Based on kernel version 4.7.2. Page generated on 2016-08-22 22:45 EST.

1	<refentry id="vidioc-enum-dv-timings">
2	  <refmeta>
3	    <refentrytitle>ioctl VIDIOC_ENUM_DV_TIMINGS, VIDIOC_SUBDEV_ENUM_DV_TIMINGS</refentrytitle>
4	    &manvol;
5	  </refmeta>
6	
7	  <refnamediv>
8	    <refname>VIDIOC_ENUM_DV_TIMINGS</refname>
9	    <refname>VIDIOC_SUBDEV_ENUM_DV_TIMINGS</refname>
10	    <refpurpose>Enumerate supported Digital Video timings</refpurpose>
11	  </refnamediv>
12	
13	  <refsynopsisdiv>
14	    <funcsynopsis>
15	      <funcprototype>
16		<funcdef>int <function>ioctl</function></funcdef>
17		<paramdef>int <parameter>fd</parameter></paramdef>
18		<paramdef>int <parameter>request</parameter></paramdef>
19		<paramdef>struct v4l2_enum_dv_timings *<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_ENUM_DV_TIMINGS, VIDIOC_SUBDEV_ENUM_DV_TIMINGS</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>While some DV receivers or transmitters support a wide range of timings, others
53	support only a limited number of timings. With this ioctl applications can enumerate a list
54	of known supported timings. Call &VIDIOC-DV-TIMINGS-CAP; to check if it also supports other
55	standards or even custom timings that are not in this list.</para>
56	
57	    <para>To query the available timings, applications initialize the
58	<structfield>index</structfield> field, set the <structfield>pad</structfield> field to 0,
59	zero the reserved array of &v4l2-enum-dv-timings; and call the
60	<constant>VIDIOC_ENUM_DV_TIMINGS</constant> ioctl on a video node with a
61	pointer to this structure. Drivers fill the rest of the structure or return an
62	&EINVAL; when the index is out of bounds. To enumerate all supported DV timings,
63	applications shall begin at index zero, incrementing by one until the
64	driver returns <errorcode>EINVAL</errorcode>. Note that drivers may enumerate a
65	different set of DV timings after switching the video input or
66	output.</para>
67	
68	    <para>When implemented by the driver DV timings of subdevices can be queried
69	by calling the <constant>VIDIOC_SUBDEV_ENUM_DV_TIMINGS</constant> ioctl directly
70	on a subdevice node. The DV timings are specific to inputs (for DV receivers) or
71	outputs (for DV transmitters), applications must specify the desired pad number
72	in the &v4l2-enum-dv-timings; <structfield>pad</structfield> field. Attempts to
73	enumerate timings on a pad that doesn't support them will return an &EINVAL;.</para>
74	
75	    <table pgwide="1" frame="none" id="v4l2-enum-dv-timings">
76	      <title>struct <structname>v4l2_enum_dv_timings</structname></title>
77	      <tgroup cols="3">
78		&cs-str;
79		<tbody valign="top">
80		  <row>
81		    <entry>__u32</entry>
82		    <entry><structfield>index</structfield></entry>
83		    <entry>Number of the DV timings, set by the
84	application.</entry>
85		  </row>
86		  <row>
87		    <entry>__u32</entry>
88		    <entry><structfield>pad</structfield></entry>
89		    <entry>Pad number as reported by the media controller API. This field
90		    is only used when operating on a subdevice node. When operating on a
91		    video node applications must set this field to zero.</entry>
92		  </row>
93		  <row>
94		    <entry>__u32</entry>
95		    <entry><structfield>reserved</structfield>[2]</entry>
96		    <entry>Reserved for future extensions. Drivers and applications must
97		    set the array to zero.</entry>
98		  </row>
99		  <row>
100		    <entry>&v4l2-dv-timings;</entry>
101		    <entry><structfield>timings</structfield></entry>
102		    <entry>The timings.</entry>
103		  </row>
104		</tbody>
105	      </tgroup>
106	    </table>
107	  </refsect1>
108	
109	  <refsect1>
110	    &return-value;
111	
112	    <variablelist>
113	      <varlistentry>
114		<term><errorcode>EINVAL</errorcode></term>
115		<listitem>
116		  <para>The &v4l2-enum-dv-timings; <structfield>index</structfield>
117	is out of bounds or the <structfield>pad</structfield> number is invalid.</para>
118		</listitem>
119	      </varlistentry>
120	      <varlistentry>
121		<term><errorcode>ENODATA</errorcode></term>
122		<listitem>
123		  <para>Digital video presets are not supported for this input or output.</para>
124		</listitem>
125	      </varlistentry>
126	    </variablelist>
127	  </refsect1>
128	</refentry>
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