HDMI documentation assumes you already know the vocabulary. This glossary does not. Every entry starts with the plain meaning of the term, then says where it turns up on the HDfury Diva, which setting controls it and what people get wrong. Terms are linked to each other throughout the site, so wherever one appears in the manual you can jump straight to its explanation.

HDMI signals16

How a picture gets from a source to a display, and everything that can stop it.

18Gbps and 600MHz

HDMI bandwidth, TMDS clock and what fits in it

The data rate an HDMI link can carry, set by the pixel clock: 600MHz and 18Gbps are the HDMI 2.0b ceiling.

4K60

Resolutions and refresh rates the HDfury Diva handles

Ultra HD at 3840x2160 pixels and 60 frames per second, the format that pushed HDMI links up to 18Gbps.

AVI infoframe

Auxiliary Video Information infoframe and VIC

A small packet sent with every frame telling the display what format, colorimetry and quantisation range the picture uses.

BT.2020

ITU-R BT.2020, the wide colour gamut of UHD

The ITU recommendation that defines the wide colour gamut and the formats used for ultra high definition television.

Chroma subsampling

4:4:4, 4:2:2 and 4:2:0 explained

A way of sending less colour information than brightness information, because the eye notices the difference far less.

Colour gamut

BT.709, DCI-P3 and colour primaries

The range of colours a signal can describe, fixed by the red, green and blue primaries a standard nominates, such as BT.709, DCI-P3 or BT.2020.

Colour space

RGB and YCbCr, full and limited range

The way colour is encoded in a video signal: RGB or YCbCr, at full or limited range, measured against a defined set of primaries.

Deep Colour

8-bit, 10-bit and 12-bit HDMI colour depth

The number of bits used for each colour component of a pixel, above the eight bits that a standard HDMI signal carries.

HDCP

High-bandwidth Digital Content Protection

The encryption applied to video on an HDMI link, which both ends must negotiate successfully before any picture is allowed through.

HDCP Doctor

The HDfury HDCP conversion engine

The HDfury engine that decrypts HDCP on an input and re-encrypts it separately for each output, converting between HDCP 1.4 and 2.2 in both directions.

HDMI

High-Definition Multimedia Interface

The single-cable digital standard that carries video, audio, control and copy protection between a source and a display.

HDMI handshake

How a source and a sink agree before a picture appears

The exchange of hot plug, EDID and HDCP steps a source and a display complete before any picture can appear.

Hot plug detect

HPD, Rsense and +5V, the three wires that start a link

The HDMI line a display holds high to say it is present and its EDID is ready to be read, and dropping it restarts the whole link.

Infoframe

The data packets sent alongside the picture

A small tagged data packet sent between video frames to tell the display how to interpret the pixels that follow.

Source and sink

The two ends of every HDMI link

The device that sends an HDMI signal and the device that receives it, the two roles every HDMI connection assigns.

TMDS

Transition Minimised Differential Signalling

The line coding HDMI uses to send video over three data pairs, with bit patterns chosen to reduce transitions and keep the link electrically balanced.

EDID and capabilities8

The description a display hands to a source, and how the Diva rewrites it.

Automix

The HDfury Diva dynamic EDID mode

An EDID mode that builds one description from the combined capabilities of the connected displays, then lets you force individual capabilities on top of it.

CDS

Capability Data Structure, the eARC equivalent of EDID

The block of audio capability data an eARC device sends over the eARC link, in place of having an EDID read from it.

Custom EDID

The 100 EDID tables and the ten custom banks

An EDID chosen from a stored table or uploaded by hand and presented to a source in place of the one the connected display actually offers.

Data block

CEA extension blocks inside an EDID

One tagged section inside the CEA extension of an EDID, describing one class of capability such as audio formats, colorimetry or HDR support.

EDID

Extended Display Identification Data

The block of data a display hands to a source over the HDMI cable to describe the video and audio formats it is able to accept.

EDID flags

The Automix override flags

Overrides that force a specific capability into a generated EDID regardless of what the connected displays actually claim.

EDID overflow

When there is no room left in the EDID

The point at which a rewritten display description no longer fits the space the standard allows, so something you asked for is quietly left out.

Short audio descriptor

How an EDID declares audio formats

A three-byte entry in an EDID that names one audio format a display or amplifier accepts, with its channel count and sample rates.

HDR and Dolby Vision12

Dynamic range, metadata and the formats your display understands.

Dolby Vision

Dolby's dynamic HDR system

Dolby's HDR system, which carries dynamic metadata alongside the picture so that tone mapping can change from scene to scene.

Dolby Vision data block

The EDID block that declares DV support

The vendor specific block inside a display's EDID that tells a source the display accepts Dolby Vision, and in which form.

EOTF

Electro-Optical Transfer Function

Electro-Optical Transfer Function: the curve that maps a digital code value to the amount of light a display emits.

HDR

High Dynamic Range

Video carrying a far wider range of brightness than the older standard, described to the display by metadata sent alongside the picture.

HDR10

The open static-metadata HDR format

The open high dynamic range format that carries one fixed set of brightness and colour metadata for a whole title.

HDR10+

Dynamic metadata on top of HDR10

An HDR format that adds scene by scene dynamic metadata on top of the static mastering metadata that HDR10 carries.

HLG

Hybrid Log-Gamma

The broadcast high dynamic range transfer curve, designed so that a standard dynamic range display can show it without conversion.

LLDV

Low Latency Dolby Vision

Low Latency Dolby Vision: the mode in which the player performs the Dolby Vision processing and sends a display-ready picture with the metadata carried alongside.

MaxCLL and MaxFALL

The two light-level values in HDR metadata

The two light level figures in HDR metadata: the brightest pixel in the content, and the brightest frame average.

SDR

Standard Dynamic Range

Standard Dynamic Range: conventional gamma-based video with a reference white of around 100 nits, the way everything looked before HDR arrived.

STM profile

The HDfury Diva HDR to SDR tone mapping profiles

A fixed tone mapping curve, chosen once in advance, that fits high dynamic range content into what a standard dynamic range display can show.

Tone mapping

Fitting HDR into what a display can show

The process of fitting a picture graded for a high brightness range into the smaller range a particular display can actually reproduce.

Audio11

Formats, return channels and getting sound out of an HDMI stream.

ARC

Audio Return Channel

The HDMI feature that sends sound backwards along the cable, from a television to an amplifier or a soundbar.

Audio extraction

Splitting sound out of an HDMI stream

Taking the audio out of an HDMI stream and delivering it on a separate output, so a receiver can hear it without having to handle the video.

Bitstream

Sending compressed audio untouched

Sending compressed audio onward in its original encoded form, so the receiving device rather than the source does the decoding.

Dolby Atmos

Object-based surround sound

Object based surround sound, where the mix carries positioned audio objects that the decoder renders to whatever speakers are present.

Dolby Digital Plus

DD+, the streaming and ARC workhorse

The lossy Dolby codec used by streaming services and by ARC, capable of 7.1 channels and of carrying Atmos as an extra layer.

Dolby TrueHD

Lossless Dolby audio

Dolby's lossless audio codec, used on Blu-ray, which decodes to exactly what the studio mastered and carries Atmos as an extra substream.

DTS-HD and DTS:X

The DTS family of surround formats

The DTS family of surround formats, from the 5.1 core through lossless DTS-HD Master Audio to object-based DTS:X.

eARC

Enhanced Audio Return Channel

Enhanced Audio Return Channel: the link that sends sound backwards along an HDMI cable from a television to an amplifier, with room for lossless formats.

HBR audio

High Bit Rate audio over HDMI

High Bit Rate audio: the HDMI packet type for compressed streams too large for a single S/PDIF rate link, such as TrueHD and DTS-HD Master Audio.

LPCM

Linear Pulse Code Modulation, uncompressed audio

Uncompressed digital audio sent as raw samples, rather than as a coded bitstream the receiving device has to decode first.

S/PDIF

Optical and coaxial digital audio

A two channel digital audio interface, on optical or coaxial cable, which can also carry a compressed multichannel bitstream.

Control and integration10

Driving the Diva from a browser, a control system, a remote or a script.

CEC

Consumer Electronics Control

Consumer Electronics Control, the low speed control bus carried on an HDMI cable so connected devices can command one another.

Config export

Saving and restoring every Diva setting

A plain text file listing every setting a device is holding, together with the signal information it is seeing at the moment it was written.

Infrared control

IR, the NEC protocol and the Diva remote codes

Remote control by pulses of modulated infrared light, using a code format such as NEC that carries a device address and a command.

IP control

Telnet control over the network

Driving a device with the same plain text commands a serial port would take, sent over a TCP connection on the local network.

Macro

Automatic RS232 commands sent on a content change

A stored command or sequence of commands sent automatically when something changes, so equipment reconfigures itself without anyone pressing a button.

mDNS

Finding the Diva by name instead of IP

A way for devices on a local network to answer to a name ending in .local, without any DNS server being configured for them.

OSD

On-screen display

An on-screen display: text a device overlays onto the video it is sending, so the information appears on the picture itself.

Pronto hex

The universal IR code format

A text format for infrared commands, written as four-digit hex words that spell out the carrier frequency and every on and off burst in the signal.

RS232

Serial control in and out

A serial interface standard that carries control commands over one wire in each direction plus ground, at an agreed baud rate.

Web server

The browser interface built into the Diva

Configuration pages served by the equipment itself over HTTP, so any browser on the same network can set it up with nothing installed.

Diva features11

The functions the HDfury Diva adds to a chain, in plain terms.

ALLM

Auto Low Latency Mode

A flag a source sets to ask a display to switch into its low latency game mode, and to leave it again afterwards.

Ambient light

The video responsive LED strip

A strip of LEDs behind a display, driven from the picture, so the wall around the screen carries the colours at the edges of the image.

Autoswitching

Following the source that wakes up

Switching automatically to whichever input has just become active, instead of selecting a source by hand every time you turn something on.

AVR

Audio/video receiver

An audio/video receiver: the box that decodes surround formats, switches sources and drives the speakers in a home cinema.

Downscaling

4K to 1080p SDR on the TX1 output

Converting a signal to a lower resolution, and often a lower dynamic range, so that equipment which cannot accept the original can display it.

Firmware

The MCU and FPGA files that run the Diva

The software held inside a device that gives its fixed hardware its behaviour, and which can be replaced to add features or correct faults.

HDMI matrix

Routing several sources to several displays

A switch that routes any of several HDMI inputs to any of several outputs, with each output chosen independently.

HTPC mode

Telling a source it is talking to a monitor

A compatibility option that makes a device present itself to a computer source as a monitor rather than as a television.

Input lag

What the built-in lag tester measures

The time between a display receiving a frame and actually showing it, caused by the processing it performs on the way through.

OLED display

The screen and menu on the unit itself

A small self-lit screen built into a device, used to report its running state and reach a menu without a computer or a browser.

Scaler

Changing the output resolution

The stage that resamples a picture onto a different pixel grid, either upwards to fill a higher resolution panel or downwards to fit what a display can accept.