kernel-fxtec-pro1x/Documentation/DocBook/media/v4l/vidioc-query-dv-preset.xml
Hans Verkuil 663dc7f3a0 [media] DocBook: document when to return ENODATA
ENODATA should be returned if the API used for getting, changing, querying
or enumerating the current video timings is not supported by the current input
or output.
This was decided during the 2012 Media Workshop.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-09-26 09:46:39 -03:00

78 lines
2.2 KiB
XML

<refentry id="vidioc-query-dv-preset">
<refmeta>
<refentrytitle>ioctl VIDIOC_QUERY_DV_PRESET</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_QUERY_DV_PRESET</refname>
<refpurpose>Sense the DV preset received by the current
input</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_QUERY_DV_PRESET</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>This ioctl is <emphasis role="bold">deprecated</emphasis>.
New drivers and applications should use &VIDIOC-QUERY-DV-TIMINGS; instead.
</para>
<para>The hardware may be able to detect the current DV preset
automatically, similar to sensing the video standard. To do so, applications
call <constant> VIDIOC_QUERY_DV_PRESET</constant> with a pointer to a
&v4l2-dv-preset; type. Once the hardware detects a preset, that preset is
returned in the preset field of &v4l2-dv-preset;. If the preset could not be
detected because there was no signal, or the signal was unreliable, or the
signal did not map to a supported preset, then the value V4L2_DV_INVALID is
returned.</para>
</refsect1>
<refsect1>
&return-value;
<variablelist>
<varlistentry>
<term><errorcode>ENODATA</errorcode></term>
<listitem>
<para>Digital video presets are not supported for this input or output.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>