mirror of
https://github.com/torvalds/linux.git
synced 2024-12-16 16:12:52 +00:00
663dc7f3a0
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>
111 lines
3.2 KiB
XML
111 lines
3.2 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>ENODATA</errorcode></term>
|
|
<listitem>
|
|
<para>Digital video timings are not supported for this input or output.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<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>
|