projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 8e080c2e MCC |
1 | <refentry id="vidioc-g-input"> |
| 2 | <refmeta> | |
| 3 | <refentrytitle>ioctl VIDIOC_G_INPUT, VIDIOC_S_INPUT</refentrytitle> | |
| 4 | &manvol; | |
| 5 | </refmeta> | |
| 6 | ||
| 7 | <refnamediv> | |
| 8 | <refname>VIDIOC_G_INPUT</refname> | |
| 9 | <refname>VIDIOC_S_INPUT</refname> | |
| 10 | <refpurpose>Query or select the current video 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>int *<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_G_INPUT, VIDIOC_S_INPUT</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>To query the current video input applications call the | |
| 53 | <constant>VIDIOC_G_INPUT</constant> ioctl with a pointer to an integer | |
| 54 | where the driver stores the number of the input, as in the | |
| 55 | &v4l2-input; <structfield>index</structfield> field. This ioctl will | |
| 56 | fail only when there are no video inputs, returning | |
| 57 | <errorcode>EINVAL</errorcode>.</para> | |
| 58 | ||
| 59 | <para>To select a video input applications store the number of the | |
| 60 | desired input in an integer and call the | |
| 61 | <constant>VIDIOC_S_INPUT</constant> ioctl with a pointer to this | |
| 62 | integer. Side effects are possible. For example inputs may support | |
| 63 | different video standards, so the driver may implicitly switch the | |
| 64 | current standard. It is good practice to select an input before | |
| 65 | querying or negotiating any other parameters.</para> | |
| 66 | ||
| 67 | <para>Information about video inputs is available using the | |
| 68 | &VIDIOC-ENUMINPUT; ioctl.</para> | |
| 69 | </refsect1> | |
| 70 | ||
| 71 | <refsect1> | |
| 72 | &return-value; | |
| 73 | ||
| 74 | <variablelist> | |
| 75 | <varlistentry> | |
| 76 | <term><errorcode>EINVAL</errorcode></term> | |
| 77 | <listitem> | |
| 78 | <para>The number of the video input is out of bounds, or | |
| 79 | there are no video inputs at all and this ioctl is not | |
| 80 | supported.</para> | |
| 81 | </listitem> | |
| 82 | </varlistentry> | |
| 83 | <varlistentry> | |
| 84 | <term><errorcode>EBUSY</errorcode></term> | |
| 85 | <listitem> | |
| 86 | <para>I/O is in progress, the input cannot be | |
| 87 | switched.</para> | |
| 88 | </listitem> | |
| 89 | </varlistentry> | |
| 90 | </variablelist> | |
| 91 | </refsect1> | |
| 92 | </refentry> | |
| 93 | ||
| 94 | <!-- | |
| 95 | Local Variables: | |
| 96 | mode: sgml | |
| 97 | sgml-parent-document: "v4l2.sgml" | |
| 98 | indent-tabs-mode: nil | |
| 99 | End: | |
| 100 | --> |