Commit | Line | Data |
---|---|---|
333c8b97 LP |
1 | <refentry id="vidioc-subdev-enum-frame-size"> |
2 | <refmeta> | |
3 | <refentrytitle>ioctl VIDIOC_SUBDEV_ENUM_FRAME_SIZE</refentrytitle> | |
4 | &manvol; | |
5 | </refmeta> | |
6 | ||
7 | <refnamediv> | |
8 | <refname>VIDIOC_SUBDEV_ENUM_FRAME_SIZE</refname> | |
9 | <refpurpose>Enumerate media bus frame sizes</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_subdev_frame_size_enum * | |
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_SUBDEV_ENUM_FRAME_SIZE</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>This ioctl allows applications to enumerate all frame sizes | |
59 | supported by a sub-device on the given pad for the given media bus format. | |
60 | Supported formats can be retrieved with the &VIDIOC-SUBDEV-ENUM-MBUS-CODE; | |
61 | ioctl.</para> | |
62 | ||
63 | <para>To enumerate frame sizes applications initialize the | |
64 | <structfield>pad</structfield>, <structfield>code</structfield> and | |
65 | <structfield>index</structfield> fields of the | |
66 | &v4l2-subdev-mbus-code-enum; and call the | |
67 | <constant>VIDIOC_SUBDEV_ENUM_FRAME_SIZE</constant> ioctl with a pointer to | |
68 | the structure. Drivers fill the minimum and maximum frame sizes or return | |
69 | an &EINVAL; if one of the input parameters is invalid.</para> | |
70 | ||
71 | <para>Sub-devices that only support discrete frame sizes (such as most | |
72 | sensors) will return one or more frame sizes with identical minimum and | |
73 | maximum values.</para> | |
74 | ||
75 | <para>Not all possible sizes in given [minimum, maximum] ranges need to be | |
76 | supported. For instance, a scaler that uses a fixed-point scaling ratio | |
77 | might not be able to produce every frame size between the minimum and | |
78 | maximum values. Applications must use the &VIDIOC-SUBDEV-S-FMT; ioctl to | |
79 | try the sub-device for an exact supported frame size.</para> | |
80 | ||
81 | <para>Available frame sizes may depend on the current 'try' formats at other | |
82 | pads of the sub-device, as well as on the current active links and the | |
83 | current values of V4L2 controls. See &VIDIOC-SUBDEV-G-FMT; for more | |
84 | information about try formats.</para> | |
85 | ||
86 | <table pgwide="1" frame="none" id="v4l2-subdev-frame-size-enum"> | |
87 | <title>struct <structname>v4l2_subdev_frame_size_enum</structname></title> | |
88 | <tgroup cols="3"> | |
89 | &cs-str; | |
90 | <tbody valign="top"> | |
91 | <row> | |
92 | <entry>__u32</entry> | |
93 | <entry><structfield>index</structfield></entry> | |
94 | <entry>Number of the format in the enumeration, set by the | |
95 | application.</entry> | |
96 | </row> | |
97 | <row> | |
98 | <entry>__u32</entry> | |
99 | <entry><structfield>pad</structfield></entry> | |
100 | <entry>Pad number as reported by the media controller API.</entry> | |
101 | </row> | |
102 | <row> | |
103 | <entry>__u32</entry> | |
104 | <entry><structfield>code</structfield></entry> | |
105 | <entry>The media bus format code, as defined in | |
106 | <xref linkend="v4l2-mbus-format" />.</entry> | |
107 | </row> | |
108 | <row> | |
109 | <entry>__u32</entry> | |
110 | <entry><structfield>min_width</structfield></entry> | |
111 | <entry>Minimum frame width, in pixels.</entry> | |
112 | </row> | |
113 | <row> | |
114 | <entry>__u32</entry> | |
115 | <entry><structfield>max_width</structfield></entry> | |
116 | <entry>Maximum frame width, in pixels.</entry> | |
117 | </row> | |
118 | <row> | |
119 | <entry>__u32</entry> | |
120 | <entry><structfield>min_height</structfield></entry> | |
121 | <entry>Minimum frame height, in pixels.</entry> | |
122 | </row> | |
123 | <row> | |
124 | <entry>__u32</entry> | |
125 | <entry><structfield>max_height</structfield></entry> | |
126 | <entry>Maximum frame height, in pixels.</entry> | |
127 | </row> | |
128 | <row> | |
129 | <entry>__u32</entry> | |
130 | <entry><structfield>reserved</structfield>[9]</entry> | |
131 | <entry>Reserved for future extensions. Applications and drivers must | |
132 | set the array to zero.</entry> | |
133 | </row> | |
134 | </tbody> | |
135 | </tgroup> | |
136 | </table> | |
137 | </refsect1> | |
138 | ||
139 | <refsect1> | |
140 | &return-value; | |
141 | ||
142 | <variablelist> | |
143 | <varlistentry> | |
144 | <term><errorcode>EINVAL</errorcode></term> | |
145 | <listitem> | |
146 | <para>The &v4l2-subdev-frame-size-enum; <structfield>pad</structfield> | |
147 | references a non-existing pad, the <structfield>code</structfield> is | |
148 | invalid for the given pad or the <structfield>index</structfield> | |
149 | field is out of bounds.</para> | |
150 | </listitem> | |
151 | </varlistentry> | |
152 | </variablelist> | |
153 | </refsect1> | |
154 | </refentry> |