1<refentry id="vidioc-g-std"> 2 <refmeta> 3 <refentrytitle>ioctl VIDIOC_G_STD, VIDIOC_S_STD</refentrytitle> 4 &manvol; 5 </refmeta> 6 7 <refnamediv> 8 <refname>VIDIOC_G_STD</refname> 9 <refname>VIDIOC_S_STD</refname> 10 <refpurpose>Query or select the video standard of the current 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>v4l2_std_id 20*<parameter>argp</parameter></paramdef> 21 </funcprototype> 22 </funcsynopsis> 23 <funcsynopsis> 24 <funcprototype> 25 <funcdef>int <function>ioctl</function></funcdef> 26 <paramdef>int <parameter>fd</parameter></paramdef> 27 <paramdef>int <parameter>request</parameter></paramdef> 28 <paramdef>const v4l2_std_id 29*<parameter>argp</parameter></paramdef> 30 </funcprototype> 31 </funcsynopsis> 32 </refsynopsisdiv> 33 34 <refsect1> 35 <title>Arguments</title> 36 37 <variablelist> 38 <varlistentry> 39 <term><parameter>fd</parameter></term> 40 <listitem> 41 <para>&fd;</para> 42 </listitem> 43 </varlistentry> 44 <varlistentry> 45 <term><parameter>request</parameter></term> 46 <listitem> 47 <para>VIDIOC_G_STD, VIDIOC_S_STD</para> 48 </listitem> 49 </varlistentry> 50 <varlistentry> 51 <term><parameter>argp</parameter></term> 52 <listitem> 53 <para></para> 54 </listitem> 55 </varlistentry> 56 </variablelist> 57 </refsect1> 58 59 <refsect1> 60 <title>Description</title> 61 62 <para>To query and select the current video standard applications 63use the <constant>VIDIOC_G_STD</constant> and <constant>VIDIOC_S_STD</constant> ioctls which take a pointer to a 64&v4l2-std-id; type as argument. <constant>VIDIOC_G_STD</constant> can 65return a single flag or a set of flags as in &v4l2-standard; field 66<structfield>id</structfield>. The flags must be unambiguous such 67that they appear in only one enumerated <structname>v4l2_standard</structname> structure.</para> 68 69 <para><constant>VIDIOC_S_STD</constant> accepts one or more 70flags, being a write-only ioctl it does not return the actual new standard as 71<constant>VIDIOC_G_STD</constant> does. When no flags are given or 72the current input does not support the requested standard the driver 73returns an &EINVAL;. When the standard set is ambiguous drivers may 74return <errorcode>EINVAL</errorcode> or choose any of the requested 75standards.</para> 76 </refsect1> 77 78 <refsect1> 79 &return-value; 80 81 <variablelist> 82 <varlistentry> 83 <term><errorcode>EINVAL</errorcode></term> 84 <listitem> 85 <para>This ioctl is not supported, or the 86<constant>VIDIOC_S_STD</constant> parameter was unsuitable.</para> 87 </listitem> 88 </varlistentry> 89 <varlistentry> 90 <term><errorcode>EBUSY</errorcode></term> 91 <listitem> 92 <para>The device is busy and therefore can not change the standard</para> 93 </listitem> 94 </varlistentry> 95 </variablelist> 96 </refsect1> 97</refentry> 98 99<!-- 100Local Variables: 101mode: sgml 102sgml-parent-document: "v4l2.sgml" 103indent-tabs-mode: nil 104End: 105--> 106