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

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<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>&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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