Based on kernel version 3.0.4. Page generated on 2011-10-03 22:07 EST.
1 <refentry id="vidioc-querystd"> 2 <refmeta> 3 <refentrytitle>ioctl VIDIOC_QUERYSTD</refentrytitle> 4 &manvol; 5 </refmeta> 6 7 <refnamediv> 8 <refname>VIDIOC_QUERYSTD</refname> 9 <refpurpose>Sense the video standard 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>v4l2_std_id *<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_QUERYSTD</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>The hardware may be able to detect the current video 53 standard automatically. To do so, applications call <constant> 54 VIDIOC_QUERYSTD</constant> with a pointer to a &v4l2-std-id; type. The 55 driver stores here a set of candidates, this can be a single flag or a 56 set of supported standards if for example the hardware can only 57 distinguish between 50 and 60 Hz systems. When detection is not 58 possible or fails, the set must contain all standards supported by the 59 current video input or output.</para> 60 61 </refsect1> 62 63 <refsect1> 64 &return-value; 65 66 <variablelist> 67 <varlistentry> 68 <term><errorcode>EINVAL</errorcode></term> 69 <listitem> 70 <para>This ioctl is not supported.</para> 71 </listitem> 72 </varlistentry> 73 <varlistentry> 74 <term><errorcode>EBUSY</errorcode></term> 75 <listitem> 76 <para>The device is busy and therefore can not detect the standard</para> 77 </listitem> 78 </varlistentry> 79 </variablelist> 80 </refsect1> 81 </refentry> 82 83 <!-- 84 Local Variables: 85 mode: sgml 86 sgml-parent-document: "v4l2.sgml" 87 indent-tabs-mode: nil 88 End: 89 -->
