Documentation/DocBook/media/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>struct v4l2_dv_preset *<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_DV_PRESET, VIDIOC_S_DV_PRESET</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     <para>To query and select the current DV preset, applications
  52 use the <constant>VIDIOC_G_DV_PRESET</constant> and <constant>VIDIOC_S_DV_PRESET</constant>
  53 ioctls which take a pointer to a &v4l2-dv-preset; type as argument.
  54 Applications must zero the reserved array in &v4l2-dv-preset;.
  55 <constant>VIDIOC_G_DV_PRESET</constant> returns a dv preset in the field
  56 <structfield>preset</structfield> of &v4l2-dv-preset;.</para>
  57
  58     <para><constant>VIDIOC_S_DV_PRESET</constant> accepts a pointer to a &v4l2-dv-preset;
  59 that has the preset value to be set. Applications must zero the reserved array in &v4l2-dv-preset;.
  60 If the preset is not supported, it returns an &EINVAL; </para>
  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, or the
  71 <constant>VIDIOC_S_DV_PRESET</constant>,<constant>VIDIOC_S_DV_PRESET</constant> parameter was unsuitable.</para>
  72         </listitem>
  73       </varlistentry>
  74       <varlistentry>
  75         <term><errorcode>EBUSY</errorcode></term>
  76         <listitem>
  77           <para>The device is busy and therefore can not change the preset.</para>
  78         </listitem>
  79       </varlistentry>
  80     </variablelist>
  81
  82     <table pgwide="1" frame="none" id="v4l2-dv-preset">
  83       <title>struct <structname>v4l2_dv_preset</structname></title>
  84       <tgroup cols="3">
  85         &cs-str;
  86         <tbody valign="top">
  87           <row>
  88             <entry>__u32</entry>
  89             <entry><structfield>preset</structfield></entry>
  90             <entry>Preset value to represent the digital video timings</entry>
  91           </row>
  92           <row>
  93             <entry>__u32</entry>
  94             <entry><structfield>reserved[4]</structfield></entry>
  95             <entry>Reserved fields for future use</entry>
  96           </row>
  97         </tbody>
  98       </tgroup>
  99     </table>
 100   </refsect1>
 101   <refsect1>
 102     &return-value;
 103   </refsect1>
 104 </refentry>