mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 22:02:28 +00:00
7dcc606b2a
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
105 lines
3.0 KiB
XML
105 lines
3.0 KiB
XML
<refentry id="vidioc-query-dv-timings">
|
|
<refmeta>
|
|
<refentrytitle>ioctl VIDIOC_QUERY_DV_TIMINGS</refentrytitle>
|
|
&manvol;
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>VIDIOC_QUERY_DV_TIMINGS</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_timings *<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_TIMINGS</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>argp</parameter></term>
|
|
<listitem>
|
|
<para></para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<note>
|
|
<title>Experimental</title>
|
|
<para>This is an <link linkend="experimental"> experimental </link>
|
|
interface and may change in the future.</para>
|
|
</note>
|
|
|
|
<para>The hardware may be able to detect the current DV timings
|
|
automatically, similar to sensing the video standard. To do so, applications
|
|
call <constant>VIDIOC_QUERY_DV_TIMINGS</constant> with a pointer to a
|
|
&v4l2-dv-timings;. Once the hardware detects the timings, it will fill in the
|
|
timings structure.
|
|
|
|
If the timings could not be detected because there was no signal, then
|
|
<errorcode>ENOLINK</errorcode> is returned. If a signal was detected, but
|
|
it was unstable and the receiver could not lock to the signal, then
|
|
<errorcode>ENOLCK</errorcode> is returned. If the receiver could lock to the signal,
|
|
but the format is unsupported (e.g. because the pixelclock is out of range
|
|
of the hardware capabilities), then the driver fills in whatever timings it
|
|
could find and returns <errorcode>ERANGE</errorcode>. In that case the application
|
|
can call &VIDIOC-DV-TIMINGS-CAP; to compare the found timings with the hardware's
|
|
capabilities in order to give more precise feedback to the user.
|
|
</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
&return-value;
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><errorcode>ENOLINK</errorcode></term>
|
|
<listitem>
|
|
<para>No timings could be detected because no signal was found.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorcode>ENOLCK</errorcode></term>
|
|
<listitem>
|
|
<para>The signal was unstable and the hardware could not lock on to it.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorcode>ERANGE</errorcode></term>
|
|
<listitem>
|
|
<para>Timings were found, but they are out of range of the hardware
|
|
capabilities.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
</refentry>
|