The patch number 10480 was added via Hans Verkuil <hverk...@xs4all.nl>
to http://linuxtv.org/hg/v4l-dvb master development tree.
Kernel patches in this development tree may be modified to be backward
compatible with older kernels. Compatibility modifications will be
removed before inclusion into the mainstream Kernel
If anyone has any objections, please let us know by sending a message to:
Linux Media Mailing List <linux-me...@vger.kernel.org>
------
From: Hans Verkuil <hverk...@xs4all.nl>
v4l2-spec: added missing vidioc-cropcap.sgml
Priority: normal
Signed-off-by: Hans Verkuil <hverk...@xs4all.nl>
---
v4l2-spec/vidioc-cropcap.sgml | 174 ++++++++++++++++++++++++++++++++++
1 file changed, 174 insertions(+)
diff -r 3f4f4326acba -r 68de51ae08c3 v4l2-spec/vidioc-cropcap.sgml
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/v4l2-spec/vidioc-cropcap.sgml Thu Jan 22 08:10:36 2009 +0100
@@ -0,0 +1,174 @@
+<refentry id="vidioc-cropcap">
+ <refmeta>
+ <refentrytitle>ioctl VIDIOC_CROPCAP</refentrytitle>
+ &manvol;
+ </refmeta>
+
+ <refnamediv>
+ <refname>VIDIOC_CROPCAP</refname>
+ <refpurpose>Information about the video cropping and scaling
abilities</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_cropcap
+*<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_CROPCAP</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>argp</parameter></term>
+ <listitem>
+ <para></para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>Applications use this function to query the cropping
+limits, the pixel aspect of images and to calculate scale factors.
+They set the <structfield>type</structfield> field of a v4l2_cropcap
+structure to the respective buffer (stream) type and call the
+<constant>VIDIOC_CROPCAP</constant> ioctl with a pointer to this
+structure. Drivers fill the rest of the structure. The results are
+constant except when switching the video standard. Remember this
+switch can occur implicit when switching the video input or
+output.</para>
+
+ <table pgwide="1" frame="none" id="v4l2-cropcap">
+ <title>struct <structname>v4l2_cropcap</structname></title>
+ <tgroup cols="3">
+ &cs-str;
+ <tbody valign="top">
+ <row>
+ <entry>&v4l2-buf-type;</entry>
+ <entry><structfield>type</structfield></entry>
+ <entry>Type of the data stream, set by the application.
+Only these types are valid here:
+<constant>V4L2_BUF_TYPE_VIDEO_CAPTURE</constant>,
+<constant>V4L2_BUF_TYPE_VIDEO_OUTPUT</constant>,
+<constant>V4L2_BUF_TYPE_VIDEO_OVERLAY</constant>, and custom (driver
+defined) types with code <constant>V4L2_BUF_TYPE_PRIVATE</constant>
+and higher.</entry>
+ </row>
+ <row>
+ <entry>struct <link
linkend="v4l2-rect-crop">v4l2_rect</link></entry>
+ <entry><structfield>bounds</structfield></entry>
+ <entry>Defines the window within capturing or output is
+possible, this may exclude for example the horizontal and vertical
+blanking areas. The cropping rectangle cannot exceed these limits.
+Width and height are defined in pixels, the driver writer is free to
+choose origin and units of the coordinate system in the analog
+domain.</entry>
+ </row>
+ <row>
+ <entry>struct <link
linkend="v4l2-rect-crop">v4l2_rect</link></entry>
+ <entry><structfield>defrect</structfield></entry>
+ <entry>Default cropping rectangle, it shall cover the
+"whole picture". Assuming pixel aspect 1/1 this could be for example a
+640 × 480 rectangle for NTSC, a
+768 × 576 rectangle for PAL and SECAM centered over
+the active picture area. The same co-ordinate system as for
+ <structfield>bounds</structfield> is used.</entry>
+ </row>
+ <row>
+ <entry>&v4l2-fract;</entry>
+ <entry><structfield>pixelaspect</structfield></entry>
+ <entry><para>This is the pixel aspect (y / x) when no
+scaling is applied, the ratio of the actual sampling
+frequency and the frequency required to get square
+pixels.</para><para>When cropping coordinates refer to square pixels,
+the driver sets <structfield>pixelaspect</structfield> to 1/1. Other
+common values are 54/59 for PAL and SECAM, 11/10 for NTSC sampled
+according to [<xref linkend="itu601">].</para></entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <!-- NB this table is duplicated in the overlay chapter. -->
+
+ <table pgwide="1" frame="none" id="v4l2-rect-crop">
+ <title>struct <structname>v4l2_rect</structname></title>
+ <tgroup cols="3">
+ &cs-str;
+ <tbody valign="top">
+ <row>
+ <entry>__s32</entry>
+ <entry><structfield>left</structfield></entry>
+ <entry>Horizontal offset of the top, left corner of the
+rectangle, in pixels.</entry>
+ </row>
+ <row>
+ <entry>__s32</entry>
+ <entry><structfield>top</structfield></entry>
+ <entry>Vertical offset of the top, left corner of the
+rectangle, in pixels.</entry>
+ </row>
+ <row>
+ <entry>__s32</entry>
+ <entry><structfield>width</structfield></entry>
+ <entry>Width of the rectangle, in pixels.</entry>
+ </row>
+ <row>
+ <entry>__s32</entry>
+ <entry><structfield>height</structfield></entry>
+ <entry>Height of the rectangle, in pixels. Width
+and height cannot be negative, the fields are signed for
+hysterical reasons. <!-- video4linux-l...@redhat.com
+on 22 Oct 2002 subject "Re:[V4L][patches!] Re:v4l2/kernel-2.5" -->
+</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </refsect1>
+
+ <refsect1>
+ &return-value;
+
+ <variablelist>
+ <varlistentry>
+ <term><errorcode>EINVAL</errorcode></term>
+ <listitem>
+ <para>The &v4l2-cropcap; <structfield>type</structfield> is
+invalid or the ioctl is not supported. This is not permitted for
+video capture, output and overlay devices, which must support
+<constant>VIDIOC_CROPCAP</constant>.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+</refentry>
+
+<!--
+Local Variables:
+mode: sgml
+sgml-parent-document: "v4l2.sgml"
+indent-tabs-mode: nil
+End:
+-->
---
Patch is available at:
http://linuxtv.org/hg/v4l-dvb/rev/68de51ae08c33e4bebec58c944b288897149efc6
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