154f38fcaSMauro Carvalho Chehab.. Permission is granted to copy, distribute and/or modify this 254f38fcaSMauro Carvalho Chehab.. document under the terms of the GNU Free Documentation License, 354f38fcaSMauro Carvalho Chehab.. Version 1.1 or any later version published by the Free Software 454f38fcaSMauro Carvalho Chehab.. Foundation, with no Invariant Sections, no Front-Cover Texts 554f38fcaSMauro Carvalho Chehab.. and no Back-Cover Texts. A copy of the license is included at 654f38fcaSMauro Carvalho Chehab.. Documentation/userspace-api/media/fdl-appendix.rst. 754f38fcaSMauro Carvalho Chehab.. 854f38fcaSMauro Carvalho Chehab.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections 954f38fcaSMauro Carvalho Chehab 1054f38fcaSMauro Carvalho Chehab.. _VIDIOC_OVERLAY: 1154f38fcaSMauro Carvalho Chehab 1254f38fcaSMauro Carvalho Chehab******************** 1354f38fcaSMauro Carvalho Chehabioctl VIDIOC_OVERLAY 1454f38fcaSMauro Carvalho Chehab******************** 1554f38fcaSMauro Carvalho Chehab 1654f38fcaSMauro Carvalho ChehabName 1754f38fcaSMauro Carvalho Chehab==== 1854f38fcaSMauro Carvalho Chehab 1954f38fcaSMauro Carvalho ChehabVIDIOC_OVERLAY - Start or stop video overlay 2054f38fcaSMauro Carvalho Chehab 2154f38fcaSMauro Carvalho Chehab 2254f38fcaSMauro Carvalho ChehabSynopsis 2354f38fcaSMauro Carvalho Chehab======== 2454f38fcaSMauro Carvalho Chehab 2554f38fcaSMauro Carvalho Chehab.. c:function:: int ioctl( int fd, VIDIOC_OVERLAY, const int *argp ) 2654f38fcaSMauro Carvalho Chehab :name: VIDIOC_OVERLAY 2754f38fcaSMauro Carvalho Chehab 2854f38fcaSMauro Carvalho Chehab 2954f38fcaSMauro Carvalho ChehabArguments 3054f38fcaSMauro Carvalho Chehab========= 3154f38fcaSMauro Carvalho Chehab 3254f38fcaSMauro Carvalho Chehab``fd`` 3354f38fcaSMauro Carvalho Chehab File descriptor returned by :ref:`open() <func-open>`. 3454f38fcaSMauro Carvalho Chehab 3554f38fcaSMauro Carvalho Chehab``argp`` 3654f38fcaSMauro Carvalho Chehab Pointer to an integer. 3754f38fcaSMauro Carvalho Chehab 3854f38fcaSMauro Carvalho Chehab 3954f38fcaSMauro Carvalho ChehabDescription 4054f38fcaSMauro Carvalho Chehab=========== 4154f38fcaSMauro Carvalho Chehab 4254f38fcaSMauro Carvalho ChehabThis ioctl is part of the :ref:`video overlay <overlay>` I/O method. 4354f38fcaSMauro Carvalho ChehabApplications call :ref:`VIDIOC_OVERLAY` to start or stop the overlay. It 4454f38fcaSMauro Carvalho Chehabtakes a pointer to an integer which must be set to zero by the 4554f38fcaSMauro Carvalho Chehabapplication to stop overlay, to one to start. 4654f38fcaSMauro Carvalho Chehab 4754f38fcaSMauro Carvalho ChehabDrivers do not support :ref:`VIDIOC_STREAMON` or 4854f38fcaSMauro Carvalho Chehab:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` with 4954f38fcaSMauro Carvalho Chehab``V4L2_BUF_TYPE_VIDEO_OVERLAY``. 5054f38fcaSMauro Carvalho Chehab 5154f38fcaSMauro Carvalho Chehab 5254f38fcaSMauro Carvalho ChehabReturn Value 5354f38fcaSMauro Carvalho Chehab============ 5454f38fcaSMauro Carvalho Chehab 5554f38fcaSMauro Carvalho ChehabOn success 0 is returned, on error -1 and the ``errno`` variable is set 5654f38fcaSMauro Carvalho Chehabappropriately. The generic error codes are described at the 5754f38fcaSMauro Carvalho Chehab:ref:`Generic Error Codes <gen-errors>` chapter. 5854f38fcaSMauro Carvalho Chehab 5954f38fcaSMauro Carvalho ChehabEINVAL 6054f38fcaSMauro Carvalho Chehab The overlay parameters have not been set up. See :ref:`overlay` 6154f38fcaSMauro Carvalho Chehab for the necessary steps. 62