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

<refentry id="vidioc-g-dv-preset">
  <refmeta>
    <refentrytitle>ioctl VIDIOC_G_DV_PRESET, VIDIOC_S_DV_PRESET</refentrytitle>
    &manvol;
  </refmeta>

  <refnamediv>
    <refname>VIDIOC_G_DV_PRESET</refname>
    <refname>VIDIOC_S_DV_PRESET</refname>
    <refpurpose>Query or select the DV preset of the current input or output</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <funcsynopsis>
      <funcprototype>
	<funcdef>int <function>ioctl</function></funcdef>
	<paramdef>int <parameter>fd</parameter></paramdef>
	<paramdef>int <parameter>request</parameter></paramdef>
	<paramdef>struct v4l2_dv_preset *<parameter>argp</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Arguments</title>

    <variablelist>
      <varlistentry>
	<term><parameter>fd</parameter></term>
	<listitem>
	  <para>&fd;</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><parameter>request</parameter></term>
	<listitem>
	  <para>VIDIOC_G_DV_PRESET, VIDIOC_S_DV_PRESET</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><parameter>argp</parameter></term>
	<listitem>
	  <para></para>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Description</title>
    <para>To query and select the current DV preset, applications
use the <constant>VIDIOC_G_DV_PRESET</constant> and <constant>VIDIOC_S_DV_PRESET</constant>
ioctls which take a pointer to a &v4l2-dv-preset; type as argument.
Applications must zero the reserved array in &v4l2-dv-preset;.
<constant>VIDIOC_G_DV_PRESET</constant> returns a dv preset in the field
<structfield>preset</structfield> of &v4l2-dv-preset;.</para>

    <para><constant>VIDIOC_S_DV_PRESET</constant> accepts a pointer to a &v4l2-dv-preset;
that has the preset value to be set. Applications must zero the reserved array in &v4l2-dv-preset;.
If the preset is not supported, it returns an &EINVAL; </para>
  </refsect1>

  <refsect1>
    &return-value;

    <variablelist>
      <varlistentry>
	<term><errorcode>EINVAL</errorcode></term>
	<listitem>
	  <para>This ioctl is not supported, or the
<constant>VIDIOC_S_DV_PRESET</constant>,<constant>VIDIOC_S_DV_PRESET</constant> parameter was unsuitable.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><errorcode>EBUSY</errorcode></term>
	<listitem>
	  <para>The device is busy and therefore can not change the preset.</para>
	</listitem>
      </varlistentry>
    </variablelist>

    <table pgwide="1" frame="none" id="v4l2-dv-preset">
      <title>struct <structname>v4l2_dv_preset</structname></title>
      <tgroup cols="3">
	&cs-str;
	<tbody valign="top">
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>preset</structfield></entry>
	    <entry>Preset value to represent the digital video timings</entry>
	  </row>
	  <row>
	    <entry>__u32</entry>
	    <entry><structfield>reserved[4]</structfield></entry>
	    <entry>Reserved fields for future use</entry>
	  </row>
	</tbody>
      </tgroup>
    </table>

  </refsect1>
</refentry>

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