.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later .. c:namespace:: V4L

.. _VIDIOC_OVERLAY:

---

ioctl VIDIOC_OVERLAY

---

Name

VIDIOC_OVERLAY - Start or stop video overlay

Synopsis

.. c:macro:: VIDIOC_OVERLAY

int ioctl(int fd, VIDIOC_OVERLAY, const int *argp)

Arguments

fd File descriptor returned by :c:func:open().

argp Pointer to an integer.

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.