Documentation/DocBook/v4l/vidioc-g-dv-preset.xml

   1 <refentry id="vidioc-g-dv-preset">
   2   <refmeta>
   3     <refentrytitle>ioctl VIDIOC_G_DV_PRESET, VIDIOC_S_DV_PRESET</refentrytitle>
   4     &manvol;
   5   </refmeta>
   6
   7   <refnamediv>
   8     <refname>VIDIOC_G_DV_PRESET</refname>
   9     <refname>VIDIOC_S_DV_PRESET</refname>
  10     <refpurpose>Query or select the DV preset of the current input or output</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-dv-preset;
  20 *<parameter>argp</parameter></paramdef>
  21       </funcprototype>
  22     </funcsynopsis>
  23   </refsynopsisdiv>
  24
  25   <refsect1>
  26     <title>Arguments</title>
  27
  28     <variablelist>
  29       <varlistentry>
  30         <term><parameter>fd</parameter></term>
  31         <listitem>
  32           <para>&fd;</para>
  33         </listitem>
  34       </varlistentry>
  35       <varlistentry>
  36         <term><parameter>request</parameter></term>
  37         <listitem>
  38           <para>VIDIOC_G_DV_PRESET, VIDIOC_S_DV_PRESET</para>
  39         </listitem>
  40       </varlistentry>
  41       <varlistentry>
  42         <term><parameter>argp</parameter></term>
  43         <listitem>
  44           <para></para>
  45         </listitem>
  46       </varlistentry>
  47     </variablelist>
  48   </refsect1>
  49
  50   <refsect1>
  51     <title>Description</title>
  52     <para>To query and select the current DV preset, applications
  53 use the <constant>VIDIOC_G_DV_PRESET</constant> and <constant>VIDIOC_S_DV_PRESET</constant>
  54 ioctls which take a pointer to a &v4l2-dv-preset; type as argument.
  55 Applications must zero the reserved array in &v4l2-dv-preset;.
  56 <constant>VIDIOC_G_DV_PRESET</constant> returns a dv preset in the field
  57 <structfield>preset</structfield> of &v4l2-dv-preset;.</para>
  58
  59     <para><constant>VIDIOC_S_DV_PRESET</constant> accepts a pointer to a &v4l2-dv-preset;
  60 that has the preset value to be set. Applications must zero the reserved array in &v4l2-dv-preset;.
  61 If the preset is not supported, it returns an &EINVAL; </para>
  62   </refsect1>
  63
  64   <refsect1>
  65     &return-value;
  66
  67     <variablelist>
  68       <varlistentry>
  69         <term><errorcode>EINVAL</errorcode></term>
  70         <listitem>
  71           <para>This ioctl is not supported, or the
  72 <constant>VIDIOC_S_DV_PRESET</constant>,<constant>VIDIOC_S_DV_PRESET</constant> parameter was unsuitable.</para>
  73         </listitem>
  74       </varlistentry>
  75       <varlistentry>
  76         <term><errorcode>EBUSY</errorcode></term>
  77         <listitem>
  78           <para>The device is busy and therefore can not change the preset.</para>
  79         </listitem>
  80       </varlistentry>
  81     </variablelist>
  82
  83     <table pgwide="1" frame="none" id="v4l2-dv-preset">
  84       <title>struct <structname>v4l2_dv_preset</structname></title>
  85       <tgroup cols="3">
  86         &cs-str;
  87         <tbody valign="top">
  88           <row>
  89             <entry>__u32</entry>
  90             <entry><structfield>preset</structfield></entry>
  91             <entry>Preset value to represent the digital video timings</entry>
  92           </row>
  93           <row>
  94             <entry>__u32</entry>
  95             <entry><structfield>reserved[4]</structfield></entry>
  96             <entry>Reserved fields for future use</entry>
  97           </row>
  98         </tbody>
  99       </tgroup>
 100     </table>
 101
 102   </refsect1>
 103 </refentry>
 104
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