1 .. SPDX-License-Identifier: GFDL-1.1-no-invari
2
3 .. _video:
4
5 ************************
6 Video Inputs and Outputs
7 ************************
8
9 Video inputs and outputs are physical connecto
10 be for example: RF connectors (antenna/cable),
11 Video, S-Video and RGB connectors. Camera sens
12 be a video input. Video and VBI capture device
13 VBI output devices have outputs, at least one
14 no video inputs or outputs.
15
16 To learn about the number and attributes of th
17 outputs applications can enumerate them with t
18 :ref:`VIDIOC_ENUMINPUT` and
19 :ref:`VIDIOC_ENUMOUTPUT` ioctl, respectively.
20 struct :c:type:`v4l2_input` returned by the
21 :ref:`VIDIOC_ENUMINPUT` ioctl also contains si
22 status information applicable when the current
23
24 The :ref:`VIDIOC_G_INPUT <VIDIOC_G_INPUT>` and
25 :ref:`VIDIOC_G_OUTPUT <VIDIOC_G_OUTPUT>` ioctl
26 the current video input or output. To select a
27 applications call the :ref:`VIDIOC_S_INPUT <VI
28 :ref:`VIDIOC_S_OUTPUT <VIDIOC_G_OUTPUT>` ioctl
29 implement all the input ioctls when the device
30 all the output ioctls when the device has one
31
32 Example: Information about the current video i
33 ==============================================
34
35 .. code-block:: c
36
37 struct v4l2_input input;
38 int index;
39
40 if (-1 == ioctl(fd, VIDIOC_G_INPUT, &index
41 perror("VIDIOC_G_INPUT");
42 exit(EXIT_FAILURE);
43 }
44
45 memset(&input, 0, sizeof(input));
46 input.index = index;
47
48 if (-1 == ioctl(fd, VIDIOC_ENUMINPUT, &inp
49 perror("VIDIOC_ENUMINPUT");
50 exit(EXIT_FAILURE);
51 }
52
53 printf("Current input: %s\\n", input.name)
54
55
56 Example: Switching to the first video input
57 ===========================================
58
59 .. code-block:: c
60
61 int index;
62
63 index = 0;
64
65 if (-1 == ioctl(fd, VIDIOC_S_INPUT, &index
66 perror("VIDIOC_S_INPUT");
67 exit(EXIT_FAILURE);
68 }
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