OpenCloudOS-Kernel/Documentation/DocBook/media/v4l/vidioc-dv-timings-cap.xml

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<refentry id="vidioc-dv-timings-cap">
<refmeta>
<refentrytitle>ioctl VIDIOC_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_DV_TIMINGS_CAP</refname>
<refname>VIDIOC_SUBDEV_DV_TIMINGS_CAP</refname>
<refpurpose>The capabilities of the Digital Video receiver/transmitter</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_cap *<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_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP</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>To query the capabilities of the DV receiver/transmitter applications
can call the <constant>VIDIOC_DV_TIMINGS_CAP</constant> ioctl on a video node
and the driver will fill in the structure. Note that drivers may return
different values after switching the video input or output.</para>
<para>When implemented by the driver DV capabilities of subdevices can be
queried by calling the <constant>VIDIOC_SUBDEV_DV_TIMINGS_CAP</constant> ioctl
directly on a subdevice node. The capabilities are specific to inputs (for DV
receivers) or outputs (for DV transmitters), applications must specify the
desired pad number in the &v4l2-dv-timings-cap; <structfield>pad</structfield>
field. Attempts to query capabilities on a pad that doesn't support them will
return an &EINVAL;.</para>
<table pgwide="1" frame="none" id="v4l2-bt-timings-cap">
<title>struct <structname>v4l2_bt_timings_cap</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>min_width</structfield></entry>
<entry>Minimum width of the active video in pixels.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>max_width</structfield></entry>
<entry>Maximum width of the active video in pixels.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>min_height</structfield></entry>
<entry>Minimum height of the active video in lines.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>max_height</structfield></entry>
<entry>Maximum height of the active video in lines.</entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>min_pixelclock</structfield></entry>
<entry>Minimum pixelclock frequency in Hz.</entry>
</row>
<row>
<entry>__u64</entry>
<entry><structfield>max_pixelclock</structfield></entry>
<entry>Maximum pixelclock frequency in Hz.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>standards</structfield></entry>
<entry>The video standard(s) supported by the hardware.
See <xref linkend="dv-bt-standards"/> for a list of standards.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>capabilities</structfield></entry>
<entry>Several flags giving more information about the capabilities.
See <xref linkend="dv-bt-cap-capabilities"/> for a description of the flags.
</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[16]</entry>
<entry>Reserved for future extensions. Drivers must set the array to zero.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="v4l2-dv-timings-cap">
<title>struct <structname>v4l2_dv_timings_cap</structname></title>
<tgroup cols="4">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>type</structfield></entry>
<entry>Type of DV timings as listed in <xref linkend="dv-timing-types"/>.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>pad</structfield></entry>
<entry>Pad number as reported by the media controller API. This field
is only used when operating on a subdevice node. When operating on a
video node applications must set this field to zero.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[2]</entry>
<entry>Reserved for future extensions. Drivers must set the array to zero.</entry>
</row>
<row>
<entry>union</entry>
<entry><structfield></structfield></entry>
<entry></entry>
</row>
<row>
<entry></entry>
<entry>&v4l2-bt-timings-cap;</entry>
<entry><structfield>bt</structfield></entry>
<entry>BT.656/1120 timings capabilities of the hardware.</entry>
</row>
<row>
<entry></entry>
<entry>__u32</entry>
<entry><structfield>raw_data</structfield>[32]</entry>
<entry></entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="dv-bt-cap-capabilities">
<title>DV BT Timing capabilities</title>
<tgroup cols="2">
&cs-str;
<tbody valign="top">
<row>
<entry>Flag</entry>
<entry>Description</entry>
</row>
<row>
<entry></entry>
<entry></entry>
</row>
<row>
<entry>V4L2_DV_BT_CAP_INTERLACED</entry>
<entry>Interlaced formats are supported.
</entry>
</row>
<row>
<entry>V4L2_DV_BT_CAP_PROGRESSIVE</entry>
<entry>Progressive formats are supported.
</entry>
</row>
<row>
<entry>V4L2_DV_BT_CAP_REDUCED_BLANKING</entry>
<entry>CVT/GTF specific: the timings can make use of reduced blanking (CVT)
or the 'Secondary GTF' curve (GTF).
</entry>
</row>
<row>
<entry>V4L2_DV_BT_CAP_CUSTOM</entry>
<entry>Can support non-standard timings, i.e. timings not belonging to the
standards set in the <structfield>standards</structfield> field.
</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;
</refsect1>
</refentry>
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