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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 | ||
9 | *man VIDIOC_ENUMAUDIO(2)* | |
10 | ||
11 | Enumerate audio inputs | |
12 | ||
13 | ||
14 | Synopsis | |
15 | ======== | |
16 | ||
b7e67f6c | 17 | .. cpp:function:: int ioctl( int fd, int request, struct v4l2_audio *argp ) |
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18 | |
19 | Arguments | |
20 | ========= | |
21 | ||
22 | ``fd`` | |
23 | File descriptor returned by :ref:`open() <func-open>`. | |
24 | ||
25 | ``request`` | |
26 | VIDIOC_ENUMAUDIO | |
27 | ||
28 | ``argp`` | |
29 | ||
30 | ||
31 | Description | |
32 | =========== | |
33 | ||
34 | To query the attributes of an audio input applications initialize the | |
35 | ``index`` field and zero out the ``reserved`` array of a struct | |
2212ff25 | 36 | :ref:`v4l2_audio <v4l2-audio>` and call the :ref:`VIDIOC_ENUMAUDIO` |
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37 | ioctl with a pointer to this structure. Drivers fill the rest of the |
38 | structure or return an EINVAL error code when the index is out of | |
39 | bounds. To enumerate all audio inputs applications shall begin at index | |
40 | zero, incrementing by one until the driver returns EINVAL. | |
41 | ||
4e03cb76 | 42 | See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for a description of struct |
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43 | :ref:`v4l2_audio <v4l2-audio>`. |
44 | ||
45 | ||
46 | Return Value | |
47 | ============ | |
48 | ||
49 | On success 0 is returned, on error -1 and the ``errno`` variable is set | |
50 | appropriately. The generic error codes are described at the | |
51 | :ref:`Generic Error Codes <gen-errors>` chapter. | |
52 | ||
53 | EINVAL | |
54 | The number of the audio input is out of bounds. | |
55 | ||
56 | ||
57 | .. ------------------------------------------------------------------------------ | |
58 | .. This file was automatically converted from DocBook-XML with the dbxml | |
59 | .. library (https://github.com/return42/sphkerneldoc). The origin XML comes | |
60 | .. from the linux kernel, refer to: | |
61 | .. | |
62 | .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook | |
63 | .. ------------------------------------------------------------------------------ |