projects / deliverable / linux.git / blame
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|---|---|---|
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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. |