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 Data Unit 29 30 Unit of data transported by a bus. On parallel buses, the data unit 31 consists of one or more related samples while on serial buses the data 32 unit is logical. If the data unit is image data, it may also be called a 33 pixel. 34 35 Device Driver 36 Part of the Linux Kernel that implements support for a hardware 37 component. 38 39 Device Node 40 A character device node in the file system used to control and 41 transfer data in and out of a Kernel driver. 42 43 Digital TV API 44 **Previously known as DVB API** 45 46 An API designed to control a subset of the :term:`Media Hardware` 47 that implements digital TV (e. g. DVB, ATSC, ISDB, etc). 48 49 See :ref:`dvbapi`. 50 51 DSP 52 **Digital Signal Processor** 53 54 A specialized :term:`Microprocessor`, with its architecture 55 optimized for the operational needs of digital signal processing. 56 57 FPGA 58 **Field-programmable Gate Array** 59 60 An :term:`IC` circuit designed to be configured by a customer or 61 a designer after manufacturing. 62 63 See https://en.wikipedia.org/wiki/Field-programmable_gate_array. 64 65 Hardware Component 66 A subset of the :term:`Media Hardware`. For example an :term:`I²C` or 67 :term:`SPI` device, or an :term:`IP Block` inside an 68 :term:`SoC` or :term:`FPGA`. 69 70 Hardware Peripheral 71 A group of :term:`hardware components <Hardware Component>` that 72 together make a larger user-facing functional peripheral. For 73 instance, the :term:`SoC` :term:`ISP` :term:`IP Block` 74 and the external camera sensors together make a camera hardware 75 peripheral. 76 77 Also known as :term:`Peripheral`. 78 79 I²C 80 **Inter-Integrated Circuit** 81 82 A multi-master, multi-slave, packet switched, single-ended, 83 serial computer bus used to control some hardware components 84 like sub-device hardware components. 85 86 See http://www.nxp.com/docs/en/user-guide/UM10204.pdf. 87 88 IC 89 **Integrated circuit** 90 91 A set of electronic circuits on one small flat piece of 92 semiconductor material, normally silicon. 93 94 Also known as chip. 95 96 IP Block 97 **Intellectual property core** 98 99 In electronic design a semiconductor intellectual property core, 100 is a reusable unit of logic, cell, or integrated circuit layout 101 design that is the intellectual property of one party. 102 IP Blocks may be licensed to another party or can be owned 103 and used by a single party alone. 104 105 See https://en.wikipedia.org/wiki/Semiconductor_intellectual_property_core). 106 107 ISP 108 **Image Signal Processor** 109 110 A specialized processor that implements a set of algorithms for 111 processing image data. ISPs may implement algorithms for lens 112 shading correction, demosaicing, scaling and pixel format conversion 113 as well as produce statistics for the use of the control 114 algorithms (e.g. automatic exposure, white balance and focus). 115 116 Media API 117 A set of userspace APIs used to control the media hardware. It is 118 composed by: 119 120 - :term:`CEC API`; 121 - :term:`Digital TV API`; 122 - :term:`MC API`; 123 - :term:`RC API`; and 124 - :term:`V4L2 API`. 125 126 See Documentation/userspace-api/media/index.rst. 127 128 MC API 129 **Media Controller API** 130 131 An API designed to expose and control the relationships between 132 multimedia devices and sub-devices. 133 134 See :ref:`media_controller`. 135 136 MC-centric 137 :term:`V4L2 Hardware` device driver that requires :term:`MC API`. 138 139 Such drivers have ``V4L2_CAP_IO_MC`` device_caps field set 140 (see :ref:`VIDIOC_QUERYCAP`). 141 142 See :ref:`v4l2_hardware_control` for more details. 143 144 Media Hardware 145 Subset of the hardware that is supported by the Linux Media API. 146 147 This includes audio and video capture and playback hardware, 148 digital and analog TV, camera sensors, ISPs, remote controllers, 149 codecs, HDMI Consumer Electronics Control, HDMI capture, etc. 150 151 Microprocessor 152 Electronic circuitry that carries out the instructions of a 153 computer program by performing the basic arithmetic, logical, 154 control and input/output (I/O) operations specified by the 155 instructions on a single integrated circuit. 156 157 Peripheral 158 The same as :term:`Hardware Peripheral`. 159 160 RC API 161 **Remote Controller API** 162 163 An API designed to receive and transmit data from remote 164 controllers. 165 166 See :ref:`remote_controllers`. 167 168 SMBus 169 A subset of I²C, which defines a stricter usage of the bus. 170 171 SPI 172 **Serial Peripheral Interface Bus** 173 174 Synchronous serial communication interface specification used for 175 short distance communication, primarily in embedded systems. 176 177 SoC 178 **System on a Chip** 179 180 An integrated circuit that integrates all components of a computer 181 or other electronic systems. 182 183 Stream 184 A distinct flow of data (image data or metadata) from an initial source 185 to a final sink. The initial source may be e.g. an image sensor and the 186 final sink e.g. a memory buffer. 187 188 V4L2 API 189 **V4L2 userspace API** 190 191 The userspace API defined in :ref:`v4l2spec`, which is used to 192 control a V4L2 hardware. 193 194 V4L2 Device Node 195 A :term:`Device Node` that is associated to a V4L driver. 196 197 The V4L2 device node naming is specified at :ref:`v4l2_device_naming`. 198 199 V4L2 Hardware 200 Part of the media hardware which is supported by the :term:`V4L2 API`. 201 202 V4L2 Sub-device 203 V4L2 hardware components that aren't controlled by a 204 :term:`Bridge Driver`. See :ref:`subdev`. 205 206 Video-node-centric 207 V4L2 device driver that doesn't require a media controller to be used. 208 209 Such drivers have the ``V4L2_CAP_IO_MC`` device_caps field unset 210 (see :ref:`VIDIOC_QUERYCAP`). 211 212 V4L2 Sub-device API 213 Part of the :term:`V4L2 API` which control 214 :term:`V4L2 sub-devices <V4L2 Sub-device>`, like sensors, 215 HDMI receivers, scalers, deinterlacers. 216 217 See :ref:`v4l2_hardware_control` for more details. 218