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+.. -*- coding: utf-8; mode: rst -*-
+
+.. _VIDIOC_OVERLAY:
+
+********************
+ioctl VIDIOC_OVERLAY
+********************
+
+Name
+====
+
+VIDIOC_OVERLAY - Start or stop video overlay
+
+
+Synopsis
+========
+
+.. cpp:function:: int ioctl( int fd, int request, const int *argp )
+
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :ref:`open() <func-open>`.
+
+``request``
+    VIDIOC_OVERLAY
+
+``argp``
+
+
+Description
+===========
+
+This ioctl is part of the :ref:`video overlay <overlay>` I/O method.
+Applications call :ref:`VIDIOC_OVERLAY` to start or stop the overlay. It
+takes a pointer to an integer which must be set to zero by the
+application to stop overlay, to one to start.
+
+Drivers do not support :ref:`VIDIOC_STREAMON` or
+:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` with
+``V4L2_BUF_TYPE_VIDEO_OVERLAY``.
+
+
+Return Value
+============
+
+On success 0 is returned, on error -1 and the ``errno`` variable is set
+appropriately. The generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.
+
+EINVAL
+    The overlay parameters have not been set up. See :ref:`overlay`
+    for the necessary steps.