xref: /linux/Documentation/userspace-api/media/glossary.rst (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
1.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
2
3========
4Glossary
5========
6
7.. note::
8
9   The goal of this section is to standardize the terms used within the media
10   userspace API documentation. This is Work In Progress.
11
12.. Please keep the glossary entries in alphabetical order
13
14.. glossary::
15
16    Bridge Driver
17	A :term:`Device Driver` that implements the main logic to talk with
18	media hardware.
19
20    CEC API
21	**Consumer Electronics Control API**
22
23	An API designed to receive and transmit data via an HDMI
24	CEC interface.
25
26	See :ref:`cec`.
27
28    Device Driver
29	Part of the Linux Kernel that implements support for a hardware
30	component.
31
32    Device Node
33	A character device node in the file system used to control and
34	transfer data in and out of a Kernel driver.
35
36    Digital TV API
37	**Previously known as DVB API**
38
39	An API designed to control a subset of the :term:`Media Hardware`
40	that implements	digital TV (e. g. DVB, ATSC, ISDB, etc).
41
42	See :ref:`dvbapi`.
43
44    DSP
45        **Digital Signal Processor**
46
47	A specialized :term:`Microprocessor`, with its architecture
48	optimized for the operational needs of digital signal processing.
49
50    FPGA
51	**Field-programmable Gate Array**
52
53	An :term:`IC` circuit designed to be configured by a customer or
54	a designer after manufacturing.
55
56	See https://en.wikipedia.org/wiki/Field-programmable_gate_array.
57
58    Hardware Component
59	A subset of the :term:`Media Hardware`. For example an :term:`I²C` or
60	:term:`SPI` device, or an :term:`IP Block` inside an
61	:term:`SoC` or :term:`FPGA`.
62
63    Hardware Peripheral
64	A group of :term:`hardware components <Hardware Component>` that
65	together make a larger user-facing functional peripheral. For
66	instance, the :term:`SoC` :term:`ISP` :term:`IP Block`
67	and the external camera sensors together make a camera hardware
68	peripheral.
69
70	Also known as :term:`Peripheral`.
71
72    I²C
73	**Inter-Integrated Circuit**
74
75	A  multi-master, multi-slave, packet switched, single-ended,
76	serial computer bus used to control some hardware components
77	like sub-device hardware components.
78
79	See http://www.nxp.com/docs/en/user-guide/UM10204.pdf.
80
81    IC
82	**Integrated circuit**
83
84	A set of electronic circuits on one small flat piece of
85	semiconductor material, normally silicon.
86
87	Also known as chip.
88
89    IP Block
90	**Intellectual property core**
91
92	In electronic design a semiconductor intellectual property core,
93	is a reusable unit of logic, cell, or integrated circuit layout
94	design that is the intellectual property of one party.
95	IP Blocks may be licensed to another party or can be owned
96	and used by a single party alone.
97
98	See https://en.wikipedia.org/wiki/Semiconductor_intellectual_property_core).
99
100    ISP
101	**Image Signal Processor**
102
103	A specialized processor that implements a set of algorithms for
104	processing image data. ISPs may implement algorithms for lens
105	shading correction, demosaicing, scaling and pixel format conversion
106	as well as produce statistics for the use of the control
107	algorithms (e.g. automatic exposure, white balance and focus).
108
109    Media API
110	A set of userspace APIs used to control the media hardware. It is
111	composed by:
112
113	  - :term:`CEC API`;
114	  - :term:`Digital TV API`;
115	  - :term:`MC API`;
116	  - :term:`RC API`; and
117	  - :term:`V4L2 API`.
118
119	See :doc:`index`.
120
121    MC API
122	**Media Controller API**
123
124	An API designed to expose and control the relationships between
125	multimedia devices and sub-devices.
126
127	See :ref:`media_controller`.
128
129    MC-centric
130	:term:`V4L2 Hardware` device driver that requires :term:`MC API`.
131
132	Such drivers have ``V4L2_CAP_IO_MC`` device_caps field set
133	(see :ref:`VIDIOC_QUERYCAP`).
134
135	See :ref:`v4l2_hardware_control` for more details.
136
137    Media Hardware
138	Subset of the hardware that is supported by the Linux Media API.
139
140	This includes audio and video capture and playback hardware,
141	digital and analog TV, camera sensors, ISPs, remote controllers,
142	codecs, HDMI Consumer Electronics Control, HDMI capture, etc.
143
144    Microprocessor
145	Electronic circuitry that carries out the instructions of a
146	computer program by performing the basic arithmetic, logical,
147	control and input/output (I/O) operations specified by the
148	instructions on a single integrated circuit.
149
150    Peripheral
151	The same as :term:`Hardware Peripheral`.
152
153    RC API
154	**Remote Controller API**
155
156	An API designed to receive and transmit data from remote
157	controllers.
158
159	See :ref:`remote_controllers`.
160
161    SMBus
162	A subset of I²C, which defines a stricter usage of the bus.
163
164    SPI
165	**Serial Peripheral Interface Bus**
166
167	Synchronous serial communication interface specification used for
168	short distance communication, primarily in embedded systems.
169
170    SoC
171	**System on a Chip**
172
173	An integrated circuit that integrates all components of a computer
174	or other electronic systems.
175
176    V4L2 API
177	**V4L2 userspace API**
178
179	The userspace API defined in :ref:`v4l2spec`, which is used to
180	control a V4L2 hardware.
181
182    V4L2 Device Node
183	A :term:`Device Node` that is associated to a V4L driver.
184
185	The V4L2 device node naming is specified at :ref:`v4l2_device_naming`.
186
187    V4L2 Hardware
188	Part of the media hardware which is supported by the :term:`V4L2 API`.
189
190    V4L2 Sub-device
191	V4L2 hardware components that aren't controlled by a
192	:term:`Bridge Driver`. See :ref:`subdev`.
193
194    Video-node-centric
195	V4L2 device driver that doesn't require a media controller to be used.
196
197	Such drivers have the ``V4L2_CAP_IO_MC`` device_caps field unset
198	(see :ref:`VIDIOC_QUERYCAP`).
199
200    V4L2 Sub-device API
201	Part of the :term:`V4L2 API` which control
202	:term:`V4L2 sub-devices <V4L2 Sub-device>`, like sensors,
203	HDMI receivers, scalers, deinterlacers.
204
205	See :ref:`v4l2_hardware_control` for more details.
206