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1 | .. -*- coding: utf-8; mode: rst -*- |
2 | ||
af4a4d0d | 3 | .. _VIDIOC_ENUMAUDIO: |
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4 | |
5 | ********************** | |
6 | ioctl VIDIOC_ENUMAUDIO | |
7 | ********************** | |
8 | ||
15e7d615 | 9 | Name |
586027ce | 10 | ==== |
5377d91f | 11 | |
586027ce | 12 | VIDIOC_ENUMAUDIO - Enumerate audio inputs |
5377d91f | 13 | |
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14 | |
15 | Synopsis | |
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16 | ======== |
17 | ||
b7e67f6c | 18 | .. cpp:function:: int ioctl( int fd, int request, struct v4l2_audio *argp ) |
5377d91f | 19 | |
586027ce | 20 | |
15e7d615 | 21 | Arguments |
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22 | ========= |
23 | ||
24 | ``fd`` | |
25 | File descriptor returned by :ref:`open() <func-open>`. | |
26 | ||
27 | ``request`` | |
28 | VIDIOC_ENUMAUDIO | |
29 | ||
30 | ``argp`` | |
31 | ||
32 | ||
15e7d615 | 33 | Description |
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34 | =========== |
35 | ||
36 | To query the attributes of an audio input applications initialize the | |
37 | ``index`` field and zero out the ``reserved`` array of a struct | |
2212ff25 | 38 | :ref:`v4l2_audio <v4l2-audio>` and call the :ref:`VIDIOC_ENUMAUDIO` |
5377d91f | 39 | ioctl with a pointer to this structure. Drivers fill the rest of the |
cdb4af0f | 40 | structure or return an ``EINVAL`` error code when the index is out of |
5377d91f | 41 | bounds. To enumerate all audio inputs applications shall begin at index |
cdb4af0f | 42 | zero, incrementing by one until the driver returns ``EINVAL``. |
5377d91f | 43 | |
4e03cb76 | 44 | See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for a description of struct |
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45 | :ref:`v4l2_audio <v4l2-audio>`. |
46 | ||
47 | ||
15e7d615 | 48 | Return Value |
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49 | ============ |
50 | ||
51 | On success 0 is returned, on error -1 and the ``errno`` variable is set | |
52 | appropriately. The generic error codes are described at the | |
53 | :ref:`Generic Error Codes <gen-errors>` chapter. | |
54 | ||
55 | EINVAL | |
56 | The number of the audio input is out of bounds. |