mirror of
https://github.com/torvalds/linux
synced 2024-10-26 21:29:56 +00:00
4266129964
This patch addresses several issues pointed by Randy Dunlap <rdunlap@xenotime.net> at changeset ece722c: - In the generated index.html file, "media" is listed first, but it should be listed in alphabetical order, not first. - The generated files are (hidden) in .tmpmedia/ - The link from the top-level index.html file to "media" is to media/index.html, but the file is actually in .tmpmedia/media/index.html - Please build docs with and without using "O=builddir" and test that. - Would it be possible for media to have its own Makefile instead of merging into this one? Due to the way cleandocs target works, I had to rename the media DocBook to media_api, otherwise cleandocs would remove the /media directory. Thanks-to: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
156 lines
5.5 KiB
XML
156 lines
5.5 KiB
XML
<refentry id="vidioc-subdev-g-crop">
|
|
<refmeta>
|
|
<refentrytitle>ioctl VIDIOC_SUBDEV_G_CROP, VIDIOC_SUBDEV_S_CROP</refentrytitle>
|
|
&manvol;
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>VIDIOC_SUBDEV_G_CROP</refname>
|
|
<refname>VIDIOC_SUBDEV_S_CROP</refname>
|
|
<refpurpose>Get or set the crop rectangle on a subdev pad</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_subdev_crop *<parameter>argp</parameter></paramdef>
|
|
</funcprototype>
|
|
</funcsynopsis>
|
|
<funcsynopsis>
|
|
<funcprototype>
|
|
<funcdef>int <function>ioctl</function></funcdef>
|
|
<paramdef>int <parameter>fd</parameter></paramdef>
|
|
<paramdef>int <parameter>request</parameter></paramdef>
|
|
<paramdef>const struct v4l2_subdev_crop *<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_SUBDEV_G_CROP, VIDIOC_SUBDEV_S_CROP</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 retrieve the current crop rectangle applications set the
|
|
<structfield>pad</structfield> field of a &v4l2-subdev-crop; to the
|
|
desired pad number as reported by the media API and the
|
|
<structfield>which</structfield> field to
|
|
<constant>V4L2_SUBDEV_FORMAT_ACTIVE</constant>. They then call the
|
|
<constant>VIDIOC_SUBDEV_G_CROP</constant> ioctl with a pointer to this
|
|
structure. The driver fills the members of the <structfield>rect</structfield>
|
|
field or returns &EINVAL; if the input arguments are invalid, or if cropping
|
|
is not supported on the given pad.</para>
|
|
|
|
<para>To change the current crop rectangle applications set both the
|
|
<structfield>pad</structfield> and <structfield>which</structfield> fields
|
|
and all members of the <structfield>rect</structfield> field. They then call
|
|
the <constant>VIDIOC_SUBDEV_S_CROP</constant> ioctl with a pointer to this
|
|
structure. The driver verifies the requested crop rectangle, adjusts it
|
|
based on the hardware capabilities and configures the device. Upon return
|
|
the &v4l2-subdev-crop; contains the current format as would be returned
|
|
by a <constant>VIDIOC_SUBDEV_G_CROP</constant> call.</para>
|
|
|
|
<para>Applications can query the device capabilities by setting the
|
|
<structfield>which</structfield> to
|
|
<constant>V4L2_SUBDEV_FORMAT_TRY</constant>. When set, 'try' crop
|
|
rectangles are not applied to the device by the driver, but are mangled
|
|
exactly as active crop rectangles and stored in the sub-device file handle.
|
|
Two applications querying the same sub-device would thus not interact with
|
|
each other.</para>
|
|
|
|
<para>Drivers must not return an error solely because the requested crop
|
|
rectangle doesn't match the device capabilities. They must instead modify
|
|
the rectangle to match what the hardware can provide. The modified format
|
|
should be as close as possible to the original request.</para>
|
|
|
|
<table pgwide="1" frame="none" id="v4l2-subdev-crop">
|
|
<title>struct <structname>v4l2_subdev_crop</structname></title>
|
|
<tgroup cols="3">
|
|
&cs-str;
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>pad</structfield></entry>
|
|
<entry>Pad number as reported by the media framework.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>which</structfield></entry>
|
|
<entry>Crop rectangle to get or set, from
|
|
&v4l2-subdev-format-whence;.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>&v4l2-rect;</entry>
|
|
<entry><structfield>rect</structfield></entry>
|
|
<entry>Crop rectangle boundaries, in pixels.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>reserved</structfield>[8]</entry>
|
|
<entry>Reserved for future extensions. Applications and drivers must
|
|
set the array to zero.</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
&return-value;
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><errorcode>EBUSY</errorcode></term>
|
|
<listitem>
|
|
<para>The crop rectangle can't be changed because the pad is currently
|
|
busy. This can be caused, for instance, by an active video stream on
|
|
the pad. The ioctl must not be retried without performing another
|
|
action to fix the problem first. Only returned by
|
|
<constant>VIDIOC_SUBDEV_S_CROP</constant></para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><errorcode>EINVAL</errorcode></term>
|
|
<listitem>
|
|
<para>The &v4l2-subdev-crop; <structfield>pad</structfield>
|
|
references a non-existing pad, the <structfield>which</structfield>
|
|
field references a non-existing format, or cropping is not supported
|
|
on the given subdev pad.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
</refentry>
|