1059b1c5bSMauro Carvalho Chehab.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2407e84cdSMauro Carvalho Chehab.. c:namespace:: V4L 354f38fcaSMauro Carvalho Chehab 454f38fcaSMauro Carvalho Chehab.. _VIDIOC_OVERLAY: 554f38fcaSMauro Carvalho Chehab 654f38fcaSMauro Carvalho Chehab******************** 754f38fcaSMauro Carvalho Chehabioctl VIDIOC_OVERLAY 854f38fcaSMauro Carvalho Chehab******************** 954f38fcaSMauro Carvalho Chehab 1054f38fcaSMauro Carvalho ChehabName 1154f38fcaSMauro Carvalho Chehab==== 1254f38fcaSMauro Carvalho Chehab 1354f38fcaSMauro Carvalho ChehabVIDIOC_OVERLAY - Start or stop video overlay 1454f38fcaSMauro Carvalho Chehab 1554f38fcaSMauro Carvalho ChehabSynopsis 1654f38fcaSMauro Carvalho Chehab======== 1754f38fcaSMauro Carvalho Chehab 18407e84cdSMauro Carvalho Chehab.. c:macro:: VIDIOC_OVERLAY 1954f38fcaSMauro Carvalho Chehab 20407e84cdSMauro Carvalho Chehab``int ioctl(int fd, VIDIOC_OVERLAY, const int *argp)`` 2154f38fcaSMauro Carvalho Chehab 2254f38fcaSMauro Carvalho ChehabArguments 2354f38fcaSMauro Carvalho Chehab========= 2454f38fcaSMauro Carvalho Chehab 2554f38fcaSMauro Carvalho Chehab``fd`` 26407e84cdSMauro Carvalho Chehab File descriptor returned by :c:func:`open()`. 2754f38fcaSMauro Carvalho Chehab 2854f38fcaSMauro Carvalho Chehab``argp`` 2954f38fcaSMauro Carvalho Chehab Pointer to an integer. 3054f38fcaSMauro Carvalho Chehab 3154f38fcaSMauro Carvalho ChehabDescription 3254f38fcaSMauro Carvalho Chehab=========== 3354f38fcaSMauro Carvalho Chehab 3454f38fcaSMauro Carvalho ChehabThis ioctl is part of the :ref:`video overlay <overlay>` I/O method. 3554f38fcaSMauro Carvalho ChehabApplications call :ref:`VIDIOC_OVERLAY` to start or stop the overlay. It 3654f38fcaSMauro Carvalho Chehabtakes a pointer to an integer which must be set to zero by the 3754f38fcaSMauro Carvalho Chehabapplication to stop overlay, to one to start. 3854f38fcaSMauro Carvalho Chehab 3954f38fcaSMauro Carvalho ChehabDrivers do not support :ref:`VIDIOC_STREAMON` or 4054f38fcaSMauro Carvalho Chehab:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` with 4154f38fcaSMauro Carvalho Chehab``V4L2_BUF_TYPE_VIDEO_OVERLAY``. 4254f38fcaSMauro Carvalho Chehab 4354f38fcaSMauro Carvalho ChehabReturn Value 4454f38fcaSMauro Carvalho Chehab============ 4554f38fcaSMauro Carvalho Chehab 4654f38fcaSMauro Carvalho ChehabOn success 0 is returned, on error -1 and the ``errno`` variable is set 4754f38fcaSMauro Carvalho Chehabappropriately. The generic error codes are described at the 4854f38fcaSMauro Carvalho Chehab:ref:`Generic Error Codes <gen-errors>` chapter. 4954f38fcaSMauro Carvalho Chehab 5054f38fcaSMauro Carvalho ChehabEINVAL 5154f38fcaSMauro Carvalho Chehab The overlay parameters have not been set up. See :ref:`overlay` 5254f38fcaSMauro Carvalho Chehab for the necessary steps. 53