projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
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1 | .. -*- coding: utf-8; mode: rst -*- |
| 2 | ||
| 3 | .. _VIDEO_GET_EVENT: | |
| 4 | ||
| 586027ce | 5 | =============== |
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6 | VIDEO_GET_EVENT |
| 7 | =============== | |
| 8 | ||
| 15e7d615 | 9 | Name |
| 586027ce | 10 | ---- |
| 47d23e36 | 11 | |
| 586027ce | 12 | VIDEO_GET_EVENT |
| 47d23e36 | 13 | |
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14 | |
| 15 | Synopsis | |
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16 | -------- |
| 17 | ||
| 18 | .. c:function:: int ioctl(fd, int request = VIDEO_GET_EVENT, struct video_event *ev) | |
| 19 | ||
| 47d23e36 | 20 | |
| 15e7d615 | 21 | Arguments |
| 586027ce | 22 | --------- |
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23 | |
| 24 | .. flat-table:: | |
| 25 | :header-rows: 0 | |
| 26 | :stub-columns: 0 | |
| 27 | ||
| 28 | ||
| 29 | - .. row 1 | |
| 30 | ||
| 31 | - int fd | |
| 32 | ||
| 33 | - File descriptor returned by a previous call to open(). | |
| 34 | ||
| 35 | - .. row 2 | |
| 36 | ||
| 37 | - int request | |
| 38 | ||
| 39 | - Equals VIDEO_GET_EVENT for this command. | |
| 40 | ||
| 41 | - .. row 3 | |
| 42 | ||
| 43 | - struct video_event \*ev | |
| 44 | ||
| 45 | - Points to the location where the event, if any, is to be stored. | |
| 46 | ||
| 47 | ||
| 15e7d615 | 48 | Description |
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49 | ----------- |
| 50 | ||
| 51 | This ioctl is for DVB devices only. To get events from a V4L2 decoder | |
| 52 | use the V4L2 :ref:`VIDIOC_DQEVENT` ioctl instead. | |
| 53 | ||
| 54 | This ioctl call returns an event of type video_event if available. If | |
| 55 | an event is not available, the behavior depends on whether the device is | |
| 56 | in blocking or non-blocking mode. In the latter case, the call fails | |
| 57 | immediately with errno set to ``EWOULDBLOCK``. In the former case, the call | |
| 58 | blocks until an event becomes available. The standard Linux poll() | |
| 59 | and/or select() system calls can be used with the device file descriptor | |
| 60 | to watch for new events. For select(), the file descriptor should be | |
| 61 | included in the exceptfds argument, and for poll(), POLLPRI should be | |
| 62 | specified as the wake-up condition. Read-only permissions are sufficient | |
| 63 | for this ioctl call. | |
| 64 | ||
| 65 | ||
| 15e7d615 | 66 | Return Value |
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67 | ------------ |
| 68 | ||
| 69 | On success 0 is returned, on error -1 and the ``errno`` variable is set | |
| 70 | appropriately. The generic error codes are described at the | |
| 71 | :ref:`Generic Error Codes <gen-errors>` chapter. | |
| 72 | ||
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73 | .. flat-table:: |
| 74 | :header-rows: 0 | |
| 75 | :stub-columns: 0 | |
| 76 | ||
| 77 | ||
| 78 | - .. row 1 | |
| 79 | ||
| 80 | - ``EWOULDBLOCK`` | |
| 81 | ||
| 82 | - There is no event pending, and the device is in non-blocking mode. | |
| 83 | ||
| 84 | - .. row 2 | |
| 85 | ||
| 86 | - ``EOVERFLOW`` | |
| 87 | ||
| 88 | - Overflow in event queue - one or more events were lost. |