1059b1c5bSMauro Carvalho Chehab.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 254f38fcaSMauro Carvalho Chehab 354f38fcaSMauro Carvalho Chehab.. _VIDIOC_OVERLAY: 454f38fcaSMauro Carvalho Chehab 554f38fcaSMauro Carvalho Chehab******************** 654f38fcaSMauro Carvalho Chehabioctl VIDIOC_OVERLAY 754f38fcaSMauro Carvalho Chehab******************** 854f38fcaSMauro Carvalho Chehab 954f38fcaSMauro Carvalho ChehabName 1054f38fcaSMauro Carvalho Chehab==== 1154f38fcaSMauro Carvalho Chehab 1254f38fcaSMauro Carvalho ChehabVIDIOC_OVERLAY - Start or stop video overlay 1354f38fcaSMauro Carvalho Chehab 1454f38fcaSMauro Carvalho Chehab 1554f38fcaSMauro Carvalho ChehabSynopsis 1654f38fcaSMauro Carvalho Chehab======== 1754f38fcaSMauro Carvalho Chehab 1854f38fcaSMauro Carvalho Chehab.. c:function:: int ioctl( int fd, VIDIOC_OVERLAY, const int *argp ) 1954f38fcaSMauro Carvalho Chehab :name: VIDIOC_OVERLAY 2054f38fcaSMauro Carvalho Chehab 2154f38fcaSMauro Carvalho Chehab 2254f38fcaSMauro Carvalho ChehabArguments 2354f38fcaSMauro Carvalho Chehab========= 2454f38fcaSMauro Carvalho Chehab 2554f38fcaSMauro Carvalho Chehab``fd`` 2654f38fcaSMauro Carvalho Chehab File descriptor returned by :ref:`open() <func-open>`. 2754f38fcaSMauro Carvalho Chehab 2854f38fcaSMauro Carvalho Chehab``argp`` 2954f38fcaSMauro Carvalho Chehab Pointer to an integer. 3054f38fcaSMauro Carvalho Chehab 3154f38fcaSMauro Carvalho Chehab 3254f38fcaSMauro Carvalho ChehabDescription 3354f38fcaSMauro Carvalho Chehab=========== 3454f38fcaSMauro Carvalho Chehab 3554f38fcaSMauro Carvalho ChehabThis ioctl is part of the :ref:`video overlay <overlay>` I/O method. 3654f38fcaSMauro Carvalho ChehabApplications call :ref:`VIDIOC_OVERLAY` to start or stop the overlay. It 3754f38fcaSMauro Carvalho Chehabtakes a pointer to an integer which must be set to zero by the 3854f38fcaSMauro Carvalho Chehabapplication to stop overlay, to one to start. 3954f38fcaSMauro Carvalho Chehab 4054f38fcaSMauro Carvalho ChehabDrivers do not support :ref:`VIDIOC_STREAMON` or 4154f38fcaSMauro Carvalho Chehab:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` with 4254f38fcaSMauro Carvalho Chehab``V4L2_BUF_TYPE_VIDEO_OVERLAY``. 4354f38fcaSMauro Carvalho Chehab 4454f38fcaSMauro Carvalho Chehab 4554f38fcaSMauro Carvalho ChehabReturn Value 4654f38fcaSMauro Carvalho Chehab============ 4754f38fcaSMauro Carvalho Chehab 4854f38fcaSMauro Carvalho ChehabOn success 0 is returned, on error -1 and the ``errno`` variable is set 4954f38fcaSMauro Carvalho Chehabappropriately. The generic error codes are described at the 5054f38fcaSMauro Carvalho Chehab:ref:`Generic Error Codes <gen-errors>` chapter. 5154f38fcaSMauro Carvalho Chehab 5254f38fcaSMauro Carvalho ChehabEINVAL 5354f38fcaSMauro Carvalho Chehab The overlay parameters have not been set up. See :ref:`overlay` 5454f38fcaSMauro Carvalho Chehab for the necessary steps. 55