230 lines
6.9 KiB
ReStructuredText
230 lines
6.9 KiB
ReStructuredText
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
|
|
.. c:namespace:: V4L
|
|
|
|
.. _VIDIOC_ENUMINPUT:
|
|
|
|
**********************
|
|
ioctl VIDIOC_ENUMINPUT
|
|
**********************
|
|
|
|
Name
|
|
====
|
|
|
|
VIDIOC_ENUMINPUT - Enumerate video inputs
|
|
|
|
Synopsis
|
|
========
|
|
|
|
.. c:macro:: VIDIOC_ENUMINPUT
|
|
|
|
``int ioctl(int fd, VIDIOC_ENUMINPUT, struct v4l2_input *argp)``
|
|
|
|
Arguments
|
|
=========
|
|
|
|
``fd``
|
|
File descriptor returned by :c:func:`open()`.
|
|
|
|
``argp``
|
|
Pointer to struct :c:type:`v4l2_input`.
|
|
|
|
Description
|
|
===========
|
|
|
|
To query the attributes of a video input applications initialize the
|
|
``index`` field of struct :c:type:`v4l2_input` and call the
|
|
:ref:`VIDIOC_ENUMINPUT` with a pointer to this structure. Drivers
|
|
fill the rest of the structure or return an ``EINVAL`` error code when the
|
|
index is out of bounds. To enumerate all inputs applications shall begin
|
|
at index zero, incrementing by one until the driver returns ``EINVAL``.
|
|
|
|
.. tabularcolumns:: |p{3.0cm}|p{3.5cm}|p{10.8cm}|
|
|
|
|
.. c:type:: v4l2_input
|
|
|
|
.. flat-table:: struct v4l2_input
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 1 1 2
|
|
|
|
* - __u32
|
|
- ``index``
|
|
- Identifies the input, set by the application.
|
|
* - __u8
|
|
- ``name``\ [32]
|
|
- Name of the video input, a NUL-terminated ASCII string, for
|
|
example: "Vin (Composite 2)". This information is intended for the
|
|
user, preferably the connector label on the device itself.
|
|
* - __u32
|
|
- ``type``
|
|
- Type of the input, see :ref:`input-type`.
|
|
* - __u32
|
|
- ``audioset``
|
|
- Drivers can enumerate up to 32 video and audio inputs. This field
|
|
shows which audio inputs were selectable as audio source if this
|
|
was the currently selected video input. It is a bit mask. The LSB
|
|
corresponds to audio input 0, the MSB to input 31. Any number of
|
|
bits can be set, or none.
|
|
|
|
When the driver does not enumerate audio inputs no bits must be
|
|
set. Applications shall not interpret this as lack of audio
|
|
support. Some drivers automatically select audio sources and do
|
|
not enumerate them since there is no choice anyway.
|
|
|
|
For details on audio inputs and how to select the current input
|
|
see :ref:`audio`.
|
|
* - __u32
|
|
- ``tuner``
|
|
- Capture devices can have zero or more tuners (RF demodulators).
|
|
When the ``type`` is set to ``V4L2_INPUT_TYPE_TUNER`` this is an
|
|
RF connector and this field identifies the tuner. It corresponds
|
|
to struct :c:type:`v4l2_tuner` field ``index``. For
|
|
details on tuners see :ref:`tuner`.
|
|
* - :ref:`v4l2_std_id <v4l2-std-id>`
|
|
- ``std``
|
|
- Every video input supports one or more different video standards.
|
|
This field is a set of all supported standards. For details on
|
|
video standards and how to switch see :ref:`standard`.
|
|
* - __u32
|
|
- ``status``
|
|
- This field provides status information about the input. See
|
|
:ref:`input-status` for flags. With the exception of the sensor
|
|
orientation bits ``status`` is only valid when this is the current
|
|
input.
|
|
* - __u32
|
|
- ``capabilities``
|
|
- This field provides capabilities for the input. See
|
|
:ref:`input-capabilities` for flags.
|
|
* - __u32
|
|
- ``reserved``\ [3]
|
|
- Reserved for future extensions. Drivers must set the array to
|
|
zero.
|
|
|
|
|
|
.. tabularcolumns:: |p{6.6cm}|p{1.0cm}|p{9.7cm}|
|
|
|
|
.. _input-type:
|
|
|
|
.. flat-table:: Input Types
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 3 1 4
|
|
|
|
* - ``V4L2_INPUT_TYPE_TUNER``
|
|
- 1
|
|
- This input uses a tuner (RF demodulator).
|
|
* - ``V4L2_INPUT_TYPE_CAMERA``
|
|
- 2
|
|
- Any non-tuner video input, for example Composite Video,
|
|
S-Video, HDMI, camera sensor. The naming as ``_TYPE_CAMERA`` is historical,
|
|
today we would have called it ``_TYPE_VIDEO``.
|
|
* - ``V4L2_INPUT_TYPE_TOUCH``
|
|
- 3
|
|
- This input is a touch device for capturing raw touch data.
|
|
|
|
|
|
.. tabularcolumns:: |p{5.6cm}|p{2.6cm}|p{9.1cm}|
|
|
|
|
.. _input-status:
|
|
|
|
.. flat-table:: Input Status Flags
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
|
|
* - :cspan:`2` General
|
|
* - ``V4L2_IN_ST_NO_POWER``
|
|
- 0x00000001
|
|
- Attached device is off.
|
|
* - ``V4L2_IN_ST_NO_SIGNAL``
|
|
- 0x00000002
|
|
-
|
|
* - ``V4L2_IN_ST_NO_COLOR``
|
|
- 0x00000004
|
|
- The hardware supports color decoding, but does not detect color
|
|
modulation in the signal.
|
|
* - :cspan:`2` Sensor Orientation
|
|
* - ``V4L2_IN_ST_HFLIP``
|
|
- 0x00000010
|
|
- The input is connected to a device that produces a signal that is
|
|
flipped horizontally and does not correct this before passing the
|
|
signal to userspace.
|
|
* - ``V4L2_IN_ST_VFLIP``
|
|
- 0x00000020
|
|
- The input is connected to a device that produces a signal that is
|
|
flipped vertically and does not correct this before passing the
|
|
signal to userspace.
|
|
.. note:: A 180 degree rotation is the same as HFLIP | VFLIP
|
|
* - :cspan:`2` Analog Video
|
|
* - ``V4L2_IN_ST_NO_H_LOCK``
|
|
- 0x00000100
|
|
- No horizontal sync lock.
|
|
* - ``V4L2_IN_ST_COLOR_KILL``
|
|
- 0x00000200
|
|
- A color killer circuit automatically disables color decoding when
|
|
it detects no color modulation. When this flag is set the color
|
|
killer is enabled *and* has shut off color decoding.
|
|
* - ``V4L2_IN_ST_NO_V_LOCK``
|
|
- 0x00000400
|
|
- No vertical sync lock.
|
|
* - ``V4L2_IN_ST_NO_STD_LOCK``
|
|
- 0x00000800
|
|
- No standard format lock in case of auto-detection format
|
|
by the component.
|
|
* - :cspan:`2` Digital Video
|
|
* - ``V4L2_IN_ST_NO_SYNC``
|
|
- 0x00010000
|
|
- No synchronization lock.
|
|
* - ``V4L2_IN_ST_NO_EQU``
|
|
- 0x00020000
|
|
- No equalizer lock.
|
|
* - ``V4L2_IN_ST_NO_CARRIER``
|
|
- 0x00040000
|
|
- Carrier recovery failed.
|
|
* - :cspan:`2` VCR and Set-Top Box
|
|
* - ``V4L2_IN_ST_MACROVISION``
|
|
- 0x01000000
|
|
- Macrovision is an analog copy prevention system mangling the video
|
|
signal to confuse video recorders. When this flag is set
|
|
Macrovision has been detected.
|
|
* - ``V4L2_IN_ST_NO_ACCESS``
|
|
- 0x02000000
|
|
- Conditional access denied.
|
|
* - ``V4L2_IN_ST_VTR``
|
|
- 0x04000000
|
|
- VTR time constant. [?]
|
|
|
|
|
|
.. tabularcolumns:: |p{6.6cm}|p{2.4cm}|p{8.3cm}|
|
|
|
|
.. _input-capabilities:
|
|
|
|
.. flat-table:: Input capabilities
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 3 1 4
|
|
|
|
* - ``V4L2_IN_CAP_DV_TIMINGS``
|
|
- 0x00000002
|
|
- This input supports setting video timings by using
|
|
``VIDIOC_S_DV_TIMINGS``.
|
|
* - ``V4L2_IN_CAP_STD``
|
|
- 0x00000004
|
|
- This input supports setting the TV standard by using
|
|
``VIDIOC_S_STD``.
|
|
* - ``V4L2_IN_CAP_NATIVE_SIZE``
|
|
- 0x00000008
|
|
- This input supports setting the native size using the
|
|
``V4L2_SEL_TGT_NATIVE_SIZE`` selection target, see
|
|
:ref:`v4l2-selections-common`.
|
|
|
|
Return Value
|
|
============
|
|
|
|
On success 0 is returned, on error -1 and the ``errno`` variable is set
|
|
appropriately. The generic error codes are described at the
|
|
:ref:`Generic Error Codes <gen-errors>` chapter.
|
|
|
|
EINVAL
|
|
The struct :c:type:`v4l2_input` ``index`` is out of
|
|
bounds.
|