1 .. -*- coding: utf-8; mode: rst -*-
5 ***********************
6 ioctl VIDIOC_ENUMOUTPUT
7 ***********************
12 VIDIOC_ENUMOUTPUT - Enumerate video outputs
18 .. c:function:: int ioctl( int fd, VIDIOC_ENUMOUTPUT, struct v4l2_output *argp )
19 :name: VIDIOC_ENUMOUTPUT
26 File descriptor returned by :ref:`open() <func-open>`.
34 To query the attributes of a video outputs applications initialize the
35 ``index`` field of struct :c:type:`v4l2_output` and call
36 the :ref:`VIDIOC_ENUMOUTPUT` with a pointer to this structure.
37 Drivers fill the rest of the structure or return an ``EINVAL`` error code
38 when the index is out of bounds. To enumerate all outputs applications
39 shall begin at index zero, incrementing by one until the driver returns
43 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
45 .. c:type:: v4l2_output
47 .. flat-table:: struct v4l2_output
54 - Identifies the output, set by the application.
57 - Name of the video output, a NUL-terminated ASCII string, for
58 example: "Vout". This information is intended for the user,
59 preferably the connector label on the device itself.
62 - Type of the output, see :ref:`output-type`.
65 - Drivers can enumerate up to 32 video and audio outputs. This field
66 shows which audio outputs were selectable as the current output if
67 this was the currently selected video output. It is a bit mask.
68 The LSB corresponds to audio output 0, the MSB to output 31. Any
69 number of bits can be set, or none.
71 When the driver does not enumerate audio outputs no bits must be
72 set. Applications shall not interpret this as lack of audio
73 support. Drivers may automatically select audio outputs without
76 For details on audio outputs and how to select the current output
80 - Output devices can have zero or more RF modulators. When the
81 ``type`` is ``V4L2_OUTPUT_TYPE_MODULATOR`` this is an RF connector
82 and this field identifies the modulator. It corresponds to struct
83 :c:type:`v4l2_modulator` field ``index``. For
84 details on modulators see :ref:`tuner`.
85 * - :ref:`v4l2_std_id <v4l2-std-id>`
87 - Every video output supports one or more different video standards.
88 This field is a set of all supported standards. For details on
89 video standards and how to switch see :ref:`standard`.
92 - This field provides capabilities for the output. See
93 :ref:`output-capabilities` for flags.
96 - Reserved for future extensions. Drivers must set the array to
101 .. tabularcolumns:: |p{7.0cm}|p{1.8cm}|p{8.7cm}|
105 .. flat-table:: Output Type
110 * - ``V4L2_OUTPUT_TYPE_MODULATOR``
112 - This output is an analog TV modulator.
113 * - ``V4L2_OUTPUT_TYPE_ANALOG``
115 - Any non-modulator video output, for example Composite Video,
116 S-Video, HDMI. The naming as ``_TYPE_ANALOG`` is historical,
117 today we would have called it ``_TYPE_VIDEO``.
118 * - ``V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY``
120 - The video output will be copied to a :ref:`video overlay <overlay>`.
124 .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
126 .. _output-capabilities:
128 .. flat-table:: Output capabilities
133 * - ``V4L2_OUT_CAP_DV_TIMINGS``
135 - This output supports setting video timings by using
136 ``VIDIOC_S_DV_TIMINGS``.
137 * - ``V4L2_OUT_CAP_STD``
139 - This output supports setting the TV standard by using
141 * - ``V4L2_OUT_CAP_NATIVE_SIZE``
143 - This output supports setting the native size using the
144 ``V4L2_SEL_TGT_NATIVE_SIZE`` selection target, see
145 :ref:`v4l2-selections-common`.
151 On success 0 is returned, on error -1 and the ``errno`` variable is set
152 appropriately. The generic error codes are described at the
153 :ref:`Generic Error Codes <gen-errors>` chapter.
156 The struct :c:type:`v4l2_output` ``index`` is out of