- Adaptive bitrate (ABR)
- Delivery technique where the platform makes several quality versions of a stream and the viewer's player switches between them as their connection changes.
- Audio split
- A copy of each microphone or a clean mix taken from the room's sound desk and delivered to the stream mixer, so the stream gets its own balance rather than the PA feed.
- Bitrate
- The amount of data per second in a stream, usually in megabits per second (Mbps). Higher means better quality and more bandwidth needed.
- Bonded cellular
- An encoder that combines several 4G/5G SIMs into one reliable connection; the standard backup (or field primary) path for live streaming.
- Breakout room
- A smaller virtual session split off from the main event for workshops or discussion, controlled by a producer or host.
- Bug
- A small persistent on-screen logo, usually in a corner of the frame.
- Captions (live/closed)
- Text of the spoken audio displayed on screen — generated live by a human captioner or automated speech recognition, and correctable afterwards for on-demand.
- CBR / VBR
- Constant vs variable bitrate. CBR is predictable for networks and preferred for live encoding; VBR saves data for recordings.
- CDN
- Content delivery network — the distributed servers that copy a stream around the world so each viewer fetches it from somewhere nearby.
- Chroma key
- Replacing a green or blue backdrop with another image in the vision mixer; 'green screen'.
- Cloud gallery
- A production gallery running on virtual machines in a data centre (we use AWS), operated remotely, with sources arriving over the internet.
- Comms / talkback
- The intercom system crew use to talk during a show, usually split into production, technical and floor channels.
- Confidence monitor
- A screen positioned for the presenter showing their slides, notes or the programme, out of the camera's view.
- Contribution
- Getting a source (a remote speaker, a second venue) into the production, as opposed to distribution which is getting the programme out to viewers.
- Cyclorama (cyc)
- A seamless curved backdrop, usually white, that can be lit any colour and gives a clean infinite background on camera.
- Dante
- A standard for carrying many channels of audio over an ordinary network cable; common for audio splits between desks.
- Dress rehearsal
- A full run of the show in real time with presenters, following the run order, typically the day before or the morning of the event.
- Encoder
- Hardware or software that compresses the programme picture and sound into a stream for the internet.
- Failover
- Automatic switching to a backup path (second connection, second encoder) when the primary fails.
- Floor manager
- The crew member in the room who cues presenters and relays between the stage and the gallery.
- Frame rate
- Frames per second in the video; 25 or 30 for presentations, 50 or 60 for fast motion.
- Gallery
- The production control room — physical or cloud — where the show is mixed, called and encoded.
- Green room
- A holding area (physical or virtual) where speakers wait, are tested and briefed before going on.
- H.264 / HEVC
- Video compression standards. H.264 is universal; HEVC (H.265) gives better quality per megabit but isn't supported everywhere.
- HLS
- HTTP Live Streaming — the most common delivery format, splitting the stream into small chunks; standard latency 15–45 seconds, low-latency variants a few seconds.
- Holding slide / loop
- A branded graphic (often with music and a countdown) shown before the show, in breaks and during technical problems so the screen is never black.
- Hybrid event
- An event with both an in-room audience and an online audience watching and taking part in the same show.
- ISO recording
- An isolated recording of a single source (one camera, one remote guest) separate from the mixed programme, used for re-editing.
- Keyframe interval
- How often the encoder sends a full frame rather than changes; platforms typically require every 2 seconds.
- Latency
- The delay between something happening live and the viewer seeing it; from under a second (WebRTC) to 45 seconds (standard HLS).
- LED wall
- A backdrop made of LED panels displaying live content behind presenters, used instead of a physical set or green screen.
- Line check
- A quick test of every source and route before the show, without performing.
- Lower third
- A graphic in the lower part of the frame giving a speaker's name and role; also called a name strap or super.
- Mix-minus
- A return audio feed for a remote contributor that contains everything except their own voice, preventing echo.
- Moiré
- Shimmering patterns on camera caused by fine stripes or checks in clothing or set, or by LED pixel pitch interacting with the sensor.
- NDI
- Network Device Interface — a standard for sending high-quality video between devices over an ordinary local network.
- PA feed
- Audio taken from the room's public-address mix; usually unsuitable for a stream because it's equalised for the room and carries reverberation.
- Playback
- Pre-recorded video or audio played into the show on cue, typically from the production system.
- Programme (PGM)
- The final mixed output of the show — the pictures and sound the audience sees.
- Redundancy
- Duplicate paths and kit (encoders, connections, power) so a single failure doesn't take the show off air.
- Restreaming
- Sending one stream to a cloud service that fans it out to several platforms at once (simulcast).
- RTMP
- An older protocol for sending streams to platforms; universally supported but handles packet loss poorly.
- Run order
- The minute-by-minute document listing every item in the show with its source, audio, graphics, presenter and timing; the crew's script.
- Safe area
- The part of the frame guaranteed to be visible on every device; graphics are kept inside it.
- Show caller
- The person (usually the producer) who reads the run order and gives the cues on comms.
- Simulcast
- Streaming the same show to several platforms simultaneously.
- SRT
- Secure Reliable Transport — a modern streaming protocol that recovers lost packets and encrypts by default; preferred for contribution links.
- Standby
- The warning call given before a cue ('standby VT'); the cue itself is executed on 'go'.
- Sting
- A short animated graphic with sound used to open a show or bridge between segments.
- Tech run
- A rehearsal of every technical path — sources, routes, stream — without presenters performing.
- Teleprompter
- A display in front of the lens showing the script, letting the presenter read while looking at the camera.
- Town hall
- An all-staff meeting or leadership broadcast, typically internal, with Q&A.
- Transcoding
- Converting a stream into other resolutions and bitrates (the ABR ladder), done by the platform.
- UPS
- Uninterruptible power supply — a battery that keeps critical kit running through a power cut.
- Vision mixer
- The person (or device) that switches between cameras and sources to make the programme.
- vMix
- Production software that combines vision mixing, playback, graphics, remote calling and encoding on one machine; our house system.
- vMix Call
- vMix's browser-based broadcast calling for remote guests, with individual audio control and a programme return.
- VT
- Short for videotape; in practice any pre-recorded video item played into the show.
- WebRTC
- A real-time video technology with sub-second latency, used for two-way interaction and some low-latency players.
- White label
- Production delivered under another company's name; a large part of the trade side of the events industry.
0%