| .. -*- coding: utf-8; mode: rst -*- |
| |
| .. _vidioc-overlay: |
| |
| ******************** |
| ioctl VIDIOC_OVERLAY |
| ******************** |
| |
| *man VIDIOC_OVERLAY(2)* |
| |
| Start or stop video overlay |
| |
| |
| Synopsis |
| ======== |
| |
| .. c: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 ``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 <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. |
| |
| |
| .. ------------------------------------------------------------------------------ |
| .. This file was automatically converted from DocBook-XML with the dbxml |
| .. library (https://github.com/return42/sphkerneldoc). The origin XML comes |
| .. from the linux kernel, refer to: |
| .. |
| .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook |
| .. ------------------------------------------------------------------------------ |