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1 | .. -*- coding: utf-8; mode: rst -*- |
2 | ||
af4a4d0d | 3 | .. _VIDIOC_OVERLAY: |
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4 | |
5 | ******************** | |
6 | ioctl VIDIOC_OVERLAY | |
7 | ******************** | |
8 | ||
15e7d615 | 9 | Name |
586027ce | 10 | ==== |
5377d91f | 11 | |
586027ce | 12 | VIDIOC_OVERLAY - Start or stop video overlay |
5377d91f | 13 | |
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14 | |
15 | Synopsis | |
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16 | ======== |
17 | ||
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18 | .. c:function:: int ioctl( int fd, VIDIOC_OVERLAY, const int *argp ) |
19 | :name: VIDIOC_OVERLAY | |
5377d91f | 20 | |
586027ce | 21 | |
15e7d615 | 22 | Arguments |
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23 | ========= |
24 | ||
25 | ``fd`` | |
26 | File descriptor returned by :ref:`open() <func-open>`. | |
27 | ||
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28 | ``argp`` |
29 | ||
30 | ||
15e7d615 | 31 | Description |
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32 | =========== |
33 | ||
34 | This ioctl is part of the :ref:`video overlay <overlay>` I/O method. | |
2212ff25 | 35 | Applications call :ref:`VIDIOC_OVERLAY` to start or stop the overlay. It |
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36 | takes a pointer to an integer which must be set to zero by the |
37 | application to stop overlay, to one to start. | |
38 | ||
7347081e | 39 | Drivers do not support :ref:`VIDIOC_STREAMON` or |
af4a4d0d | 40 | :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` with |
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41 | ``V4L2_BUF_TYPE_VIDEO_OVERLAY``. |
42 | ||
43 | ||
15e7d615 | 44 | Return Value |
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45 | ============ |
46 | ||
47 | On success 0 is returned, on error -1 and the ``errno`` variable is set | |
48 | appropriately. The generic error codes are described at the | |
49 | :ref:`Generic Error Codes <gen-errors>` chapter. | |
50 | ||
51 | EINVAL | |
52 | The overlay parameters have not been set up. See :ref:`overlay` | |
53 | for the necessary steps. |