Mauro Carvalho Chehab | 8e080c2 | 2009-09-13 22:16:04 -0300 | [diff] [blame] | 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> |
Muralidharan Karicheri | 422eaac | 2009-12-10 10:31:44 -0300 | [diff] [blame] | 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> |
Mauro Carvalho Chehab | 8e080c2 | 2009-09-13 22:16:04 -0300 | [diff] [blame] | 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 | --> |