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Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-query-dv-timings.xml')
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1 files changed, 104 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-query-dv-timings.xml b/Documentation/DocBook/media/v4l/vidioc-query-dv-timings.xml new file mode 100644 index 000000000000..44935a0ffcf0 --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-query-dv-timings.xml | |||
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1 | <refentry id="vidioc-query-dv-timings"> | ||
2 | <refmeta> | ||
3 | <refentrytitle>ioctl VIDIOC_QUERY_DV_TIMINGS</refentrytitle> | ||
4 | &manvol; | ||
5 | </refmeta> | ||
6 | |||
7 | <refnamediv> | ||
8 | <refname>VIDIOC_QUERY_DV_TIMINGS</refname> | ||
9 | <refpurpose>Sense the DV preset received by the current | ||
10 | input</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_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_QUERY_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 | <note> | ||
53 | <title>Experimental</title> | ||
54 | <para>This is an <link linkend="experimental"> experimental </link> | ||
55 | interface and may change in the future.</para> | ||
56 | </note> | ||
57 | |||
58 | <para>The hardware may be able to detect the current DV timings | ||
59 | automatically, similar to sensing the video standard. To do so, applications | ||
60 | call <constant>VIDIOC_QUERY_DV_TIMINGS</constant> with a pointer to a | ||
61 | &v4l2-dv-timings;. Once the hardware detects the timings, it will fill in the | ||
62 | timings structure. | ||
63 | |||
64 | If the timings could not be detected because there was no signal, then | ||
65 | <errorcode>ENOLINK</errorcode> is returned. If a signal was detected, but | ||
66 | it was unstable and the receiver could not lock to the signal, then | ||
67 | <errorcode>ENOLCK</errorcode> is returned. If the receiver could lock to the signal, | ||
68 | but the format is unsupported (e.g. because the pixelclock is out of range | ||
69 | of the hardware capabilities), then the driver fills in whatever timings it | ||
70 | could find and returns <errorcode>ERANGE</errorcode>. In that case the application | ||
71 | can call &VIDIOC-DV-TIMINGS-CAP; to compare the found timings with the hardware's | ||
72 | capabilities in order to give more precise feedback to the user. | ||
73 | </para> | ||
74 | </refsect1> | ||
75 | |||
76 | <refsect1> | ||
77 | &return-value; | ||
78 | |||
79 | <variablelist> | ||
80 | <varlistentry> | ||
81 | <term><errorcode>ENOLINK</errorcode></term> | ||
82 | <listitem> | ||
83 | <para>No timings could be detected because no signal was found. | ||
84 | </para> | ||
85 | </listitem> | ||
86 | </varlistentry> | ||
87 | <varlistentry> | ||
88 | <term><errorcode>ENOLCK</errorcode></term> | ||
89 | <listitem> | ||
90 | <para>The signal was unstable and the hardware could not lock on to it. | ||
91 | </para> | ||
92 | </listitem> | ||
93 | </varlistentry> | ||
94 | <varlistentry> | ||
95 | <term><errorcode>ERANGE</errorcode></term> | ||
96 | <listitem> | ||
97 | <para>Timings were found, but they are out of range of the hardware | ||
98 | capabilities. | ||
99 | </para> | ||
100 | </listitem> | ||
101 | </varlistentry> | ||
102 | </variablelist> | ||
103 | </refsect1> | ||
104 | </refentry> | ||