About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / DocBook / media / v4l / vidioc-enum-dv-timings.xml




Custom Search

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

1	<refentry id="vidioc-enum-dv-timings">
2	  <refmeta>
3	    <refentrytitle>ioctl VIDIOC_ENUM_DV_TIMINGS</refentrytitle>
4	    &manvol;
5	  </refmeta>
6	
7	  <refnamediv>
8	    <refname>VIDIOC_ENUM_DV_TIMINGS</refname>
9	    <refpurpose>Enumerate supported Digital Video timings</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_enum_dv_timings *<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_ENUM_DV_TIMINGS</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	    <note>
52	      <title>Experimental</title>
53	      <para>This is an <link linkend="experimental"> experimental </link>
54	      interface and may change in the future.</para>
55	    </note>
56	
57	    <para>While some DV receivers or transmitters support a wide range of timings, others
58	support only a limited number of timings. With this ioctl applications can enumerate a list
59	of known supported timings. Call &VIDIOC-DV-TIMINGS-CAP; to check if it also supports other
60	standards or even custom timings that are not in this list.</para>
61	
62	    <para>To query the available timings, applications initialize the
63	<structfield>index</structfield> field and zero the reserved array of &v4l2-enum-dv-timings;
64	and call the <constant>VIDIOC_ENUM_DV_TIMINGS</constant> ioctl with a pointer to this
65	structure. Drivers fill the rest of the structure or return an
66	&EINVAL; when the index is out of bounds. To enumerate all supported DV timings,
67	applications shall begin at index zero, incrementing by one until the
68	driver returns <errorcode>EINVAL</errorcode>. Note that drivers may enumerate a
69	different set of DV timings after switching the video input or
70	output.</para>
71	
72	    <table pgwide="1" frame="none" id="v4l2-enum-dv-timings">
73	      <title>struct <structname>v4l2_enum_dv_timings</structname></title>
74	      <tgroup cols="3">
75		&cs-str;
76		<tbody valign="top">
77		  <row>
78		    <entry>__u32</entry>
79		    <entry><structfield>index</structfield></entry>
80		    <entry>Number of the DV timings, set by the
81	application.</entry>
82		  </row>
83		  <row>
84		    <entry>__u32</entry>
85		    <entry><structfield>reserved</structfield>[3]</entry>
86		    <entry>Reserved for future extensions. Drivers must set the array to zero.</entry>
87		  </row>
88		  <row>
89		    <entry>&v4l2-dv-timings;</entry>
90		    <entry><structfield>timings</structfield></entry>
91		    <entry>The timings.</entry>
92		  </row>
93		</tbody>
94	      </tgroup>
95	    </table>
96	  </refsect1>
97	
98	  <refsect1>
99	    &return-value;
100	
101	    <variablelist>
102	      <varlistentry>
103		<term><errorcode>EINVAL</errorcode></term>
104		<listitem>
105		  <para>The &v4l2-enum-dv-timings; <structfield>index</structfield>
106	is out of bounds.</para>
107		</listitem>
108	      </varlistentry>
109	      <varlistentry>
110		<term><errorcode>ENODATA</errorcode></term>
111		<listitem>
112		  <para>Digital video presets are not supported for this input or output.</para>
113		</listitem>
114	      </varlistentry>
115	    </variablelist>
116	  </refsect1>
117	</refentry>
118	
119	<!--
120	Local Variables:
121	mode: sgml
122	sgml-parent-document: "v4l2.sgml"
123	indent-tabs-mode: nil
124	End:
125	-->
Hide Line Numbers
About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Information is copyright its respective author. All material is available from the Linux Kernel Source distributed under a GPL License. This page is provided as a free service by mjmwired.net.