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 54where the driver stores the number of the input, as in the 55&v4l2-input; <structfield>index</structfield> field. This ioctl will 56fail 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 60desired input in an integer and call the 61<constant>VIDIOC_S_INPUT</constant> ioctl with a pointer to this 62integer. Side effects are possible. For example inputs may support 63different video standards, so the driver may implicitly switch the 64current standard. It is good practice to select an input before 65querying 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 79there are no video inputs at all and this ioctl is not 80supported.</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 87switched.</para> 88 </listitem> 89 </varlistentry> 90 </variablelist> 91 </refsect1> 92</refentry> 93 94<!-- 95Local Variables: 96mode: sgml 97sgml-parent-document: "v4l2.sgml" 98indent-tabs-mode: nil 99End: 100--> 101