summaryrefslogtreecommitdiffstats
path: root/Documentation/DocBook/media/v4l/vidioc-querybuf.xml
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-querybuf.xml')
-rw-r--r--Documentation/DocBook/media/v4l/vidioc-querybuf.xml102
1 files changed, 0 insertions, 102 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-querybuf.xml b/Documentation/DocBook/media/v4l/vidioc-querybuf.xml
deleted file mode 100644
index 6e414d7..0000000
--- a/Documentation/DocBook/media/v4l/vidioc-querybuf.xml
+++ /dev/null
@@ -1,102 +0,0 @@
-<refentry id="vidioc-querybuf">
- <refmeta>
- <refentrytitle>ioctl VIDIOC_QUERYBUF</refentrytitle>
- &manvol;
- </refmeta>
-
- <refnamediv>
- <refname>VIDIOC_QUERYBUF</refname>
- <refpurpose>Query the status of a buffer</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_buffer *<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_QUERYBUF</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><parameter>argp</parameter></term>
- <listitem>
- <para></para>
- </listitem>
- </varlistentry>
- </variablelist>
- </refsect1>
-
- <refsect1>
- <title>Description</title>
-
- <para>This ioctl is part of the <link linkend="mmap">memory
-mapping</link> I/O method. It can be used to query the status of a
-buffer at any time after buffers have been allocated with the
-&VIDIOC-REQBUFS; ioctl.</para>
-
- <para>Applications set the <structfield>type</structfield> field
- of a &v4l2-buffer; to the same buffer type as was previously used with
-&v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers;
-<structfield>type</structfield>, and the <structfield>index</structfield>
- field. Valid index numbers range from zero
-to the number of buffers allocated with &VIDIOC-REQBUFS;
- (&v4l2-requestbuffers; <structfield>count</structfield>) minus one.
-The <structfield>reserved</structfield> field should to set to 0.
-When using the <link linkend="planar-apis">multi-planar API</link>, the
-<structfield>m.planes</structfield> field must contain a userspace pointer to an
-array of &v4l2-plane; and the <structfield>length</structfield> field has
-to be set to the number of elements in that array.
-After calling <constant>VIDIOC_QUERYBUF</constant> with a pointer to
- this structure drivers return an error code or fill the rest of
-the structure.</para>
-
- <para>In the <structfield>flags</structfield> field the
-<constant>V4L2_BUF_FLAG_MAPPED</constant>,
-<constant>V4L2_BUF_FLAG_QUEUED</constant> and
-<constant>V4L2_BUF_FLAG_DONE</constant> flags will be valid. The
-<structfield>memory</structfield> field will be set to the current
-I/O method. For the single-planar API, the <structfield>m.offset</structfield>
-contains the offset of the buffer from the start of the device memory,
-the <structfield>length</structfield> field its size. For the multi-planar API,
-fields <structfield>m.mem_offset</structfield> and
-<structfield>length</structfield> in the <structfield>m.planes</structfield>
-array elements will be used instead. The driver may or may not set the remaining
-fields and flags, they are meaningless in this context.</para>
-
- <para>The <structname>v4l2_buffer</structname> structure is
- specified in <xref linkend="buffer" />.</para>
- </refsect1>
-
- <refsect1>
- &return-value;
-
- <variablelist>
- <varlistentry>
- <term><errorcode>EINVAL</errorcode></term>
- <listitem>
- <para>The buffer <structfield>type</structfield> is not
-supported, or the <structfield>index</structfield> is out of bounds.</para>
- </listitem>
- </varlistentry>
- </variablelist>
- </refsect1>
-</refentry>