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+<refentry id="vidioc-create-bufs">
+  <refmeta>
+    <refentrytitle>ioctl VIDIOC_CREATE_BUFS</refentrytitle>
+    &manvol;
+  </refmeta>
+
+  <refnamediv>
+    <refname>VIDIOC_CREATE_BUFS</refname>
+    <refpurpose>Create buffers for Memory Mapped or User Pointer or DMA Buffer
+    I/O</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_create_buffers *<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_CREATE_BUFS</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>This ioctl is used to create buffers for <link linkend="mmap">memory
+mapped</link> or <link linkend="userp">user pointer</link> or <link
+linkend="dmabuf">DMA buffer</link> I/O. It can be used as an alternative or in
+addition to the <constant>VIDIOC_REQBUFS</constant> ioctl, when a tighter
+control over buffers is required. This ioctl can be called multiple times to
+create buffers of different sizes.</para>
+
+    <para>To allocate the device buffers applications must initialize the
+relevant fields of the <structname>v4l2_create_buffers</structname> structure.
+The <structfield>count</structfield> field must be set to the number of
+requested buffers, the <structfield>memory</structfield> field specifies the
+requested I/O method and the <structfield>reserved</structfield> array must be
+zeroed.</para>
+
+    <para>The <structfield>format</structfield> field specifies the image format
+that the buffers must be able to handle. The application has to fill in this
+&v4l2-format;. Usually this will be done using the
+<constant>VIDIOC_TRY_FMT</constant> or <constant>VIDIOC_G_FMT</constant> ioctl()
+to ensure that the requested format is supported by the driver. Unsupported
+formats will result in an error.</para>
+
+    <para>The buffers created by this ioctl will have as minimum size the size
+defined by the <structfield>format.pix.sizeimage</structfield> field. If the
+<structfield>format.pix.sizeimage</structfield> field is less than the minimum
+required for the given format, then <structfield>sizeimage</structfield> will be
+increased by the driver to that minimum to allocate the buffers. If it is
+larger, then the value will be used as-is. The same applies to the
+<structfield>sizeimage</structfield> field of the
+<structname>v4l2_plane_pix_format</structname> structure in the case of
+multiplanar formats.</para>
+
+    <para>When the ioctl is called with a pointer to this structure the driver
+will attempt to allocate up to the requested number of buffers and store the
+actual number allocated and the starting index in the
+<structfield>count</structfield> and the <structfield>index</structfield> fields
+respectively. On return <structfield>count</structfield> can be smaller than
+the number requested. The driver may also increase buffer sizes if required,
+however, it will not update <structfield>sizeimage</structfield> field values.
+The user has to use <constant>VIDIOC_QUERYBUF</constant> to retrieve that
+information.</para>
+
+    <table pgwide="1" frame="none" id="v4l2-create-buffers">
+      <title>struct <structname>v4l2_create_buffers</structname></title>
+      <tgroup cols="3">
+	&cs-str;
+	<tbody valign="top">
+	  <row>
+	    <entry>__u32</entry>
+	    <entry><structfield>index</structfield></entry>
+	    <entry>The starting buffer index, returned by the driver.</entry>
+	  </row>
+	  <row>
+	    <entry>__u32</entry>
+	    <entry><structfield>count</structfield></entry>
+	    <entry>The number of buffers requested or granted. If count == 0, then
+	    <constant>VIDIOC_CREATE_BUFS</constant> will set <structfield>index</structfield>
+	    to the current number of created buffers, and it will check the validity of
+	    <structfield>memory</structfield> and <structfield>format.type</structfield>.
+	    If those are invalid -1 is returned and errno is set to &EINVAL;,
+	    otherwise <constant>VIDIOC_CREATE_BUFS</constant> returns 0. It will
+	    never set errno to &EBUSY; in this particular case.</entry>
+	  </row>
+	  <row>
+	    <entry>__u32</entry>
+	    <entry><structfield>memory</structfield></entry>
+	    <entry>Applications set this field to
+<constant>V4L2_MEMORY_MMAP</constant>,
+<constant>V4L2_MEMORY_DMABUF</constant> or
+<constant>V4L2_MEMORY_USERPTR</constant>. See <xref linkend="v4l2-memory"
+/></entry>
+	  </row>
+	  <row>
+	    <entry>&v4l2-format;</entry>
+	    <entry><structfield>format</structfield></entry>
+	    <entry>Filled in by the application, preserved by the driver.</entry>
+	  </row>
+	  <row>
+	    <entry>__u32</entry>
+	    <entry><structfield>reserved</structfield>[8]</entry>
+	    <entry>A place holder for future extensions.</entry>
+	  </row>
+	</tbody>
+      </tgroup>
+    </table>
+  </refsect1>
+
+  <refsect1>
+    &return-value;
+
+    <variablelist>
+      <varlistentry>
+	<term><errorcode>ENOMEM</errorcode></term>
+	<listitem>
+	  <para>No memory to allocate buffers for <link linkend="mmap">memory
+mapped</link> I/O.</para>
+	</listitem>
+      </varlistentry>
+      <varlistentry>
+	<term><errorcode>EINVAL</errorcode></term>
+	<listitem>
+	  <para>The buffer type (<structfield>format.type</structfield> field),
+requested I/O method (<structfield>memory</structfield>) or format
+(<structfield>format</structfield> field) is not valid.</para>
+	</listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+</refentry>