Commit | Line | Data |
---|---|---|
7dcc606b HV |
1 | <refentry id="vidioc-enum-dv-timings"> |
2 | <refmeta> | |
9cfd65e8 | 3 | <refentrytitle>ioctl VIDIOC_ENUM_DV_TIMINGS, VIDIOC_SUBDEV_ENUM_DV_TIMINGS</refentrytitle> |
7dcc606b HV |
4 | &manvol; |
5 | </refmeta> | |
6 | ||
7 | <refnamediv> | |
8 | <refname>VIDIOC_ENUM_DV_TIMINGS</refname> | |
9cfd65e8 | 9 | <refname>VIDIOC_SUBDEV_ENUM_DV_TIMINGS</refname> |
7dcc606b HV |
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> | |
9cfd65e8 | 37 | <para>VIDIOC_ENUM_DV_TIMINGS, VIDIOC_SUBDEV_ENUM_DV_TIMINGS</para> |
7dcc606b HV |
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 | ||
7dcc606b HV |
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 | |
0c53fee9 HV |
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 | |
9cfd65e8 | 61 | pointer to this structure. Drivers fill the rest of the structure or return an |
7dcc606b HV |
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 | ||
9cfd65e8 LP |
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 | ||
7dcc606b HV |
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> | |
9cfd65e8 LP |
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> | |
7dcc606b HV |
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> | |
9cfd65e8 | 117 | is out of bounds or the <structfield>pad</structfield> number is invalid.</para> |
7dcc606b HV |
118 | </listitem> |
119 | </varlistentry> | |
663dc7f3 HV |
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> | |
7dcc606b HV |
126 | </variablelist> |
127 | </refsect1> | |
128 | </refentry> |