Open-source browser vision mixer
Open Live gives you a vision mixer that you operate from a web browser. There is no switcher hardware to buy and no application to install: open Open Live Studio, pick a production and start cutting. Studio and the Open Live backend are open source under the MIT licence, and you can run them yourself or use the managed service on Open Source Cloud.
What is a browser-based vision mixer?
A vision mixer (also called a production switcher) chooses which camera or source goes to air and how the picture changes from one source to the next. In Open Live the control surface is a web page, Open Live Studio. The video itself is not mixed in your browser. The Open Live backend drives Strom, a GStreamer-based media engine that decodes the sources, composites the programme and encodes the outputs. Your browser sends the commands and shows you the pictures, so an operator only needs a laptop and a network connection.
What can the Open Live vision mixer do?
The controller follows the program and preview workflow of a hardware switcher:
- Program and preview buses. Select the next source on preview, then cut to it, run an auto transition, or take (swap program and preview). You can also hot-cut straight to program.
- Transitions. Mix transitions (fade and dip to black), slides and pushes in four directions, plus a set of wipes (iris, clock, barn doors, luma wipe and more) and effect takes. The wipe and effect groups are marked in Studio as needing a GPU. You choose which transitions appear on the controller and set the duration.
- Fade to black for the whole programme.
- Picture-in-picture. Up to four PiP slots per production, each with its own layout, which you select into preview and take like any other source.
- Downstream keyers and graphics. Image and HTML graphics are keyed onto the programme on DSK layers and taken on and off air from the controller. HTML templates built to the EBU OGraf specification work too, as a hosted URL. The graphics documentation explains how.
- Clip playback. Cue a media clip on an input, then play, pause, stop or seek it from the controller.
- Macros. Run a stored sequence of actions with one button.
Which sources can I switch between?
A production has up to 16 inputs. Each input is a source, and Open Live supports these source types:
| Source type | Typical use |
|---|---|
| SRT (MPEG-TS) | Cameras and encoders contributing over the internet or a private network. |
| EFP over SRT | Contribution feeds that use the EFP framing protocol. |
| WHIP | WebRTC contributions, for example from a web browser. |
| HTML | A web page rendered as a video source. |
| Clip | A media file played out on an input. |
| Test source | Built-in test signals for rehearsal and line-up. |
Each source can also get a video and an audio time offset, so feeds that arrive with different delays can be lined up.
How do I monitor sources without a hardware multiviewer?
Studio shows a multiview of your sources together with program and preview, delivered to the browser over WebRTC (WHEP) with glass-to-glass latency under 500 ms. Tally follows the mixer, so every tile shows whether that source is on program or preview.
Does the vision mixer handle audio too?
Yes. Each production has an audio mixer next to the vision mixer: per-channel faders and mutes, a main fader, aux sends and group buses, PFL and AFL monitoring, and EBU R128 loudness metering. Each channel has gain, a high-pass filter and a gate, and the main bus has a compressor, EQ and limiter. Audio-follows-video can be switched on per input, with ramp times you set, so the sound changes with the cut.
Can I use a Stream Deck or keyboard shortcuts?
Yes. The Open Live module for Bitfocus Companion controls sources, transitions, graphics and stream state from a Stream Deck or any other Companion surface. In Studio itself, cut, auto, fade to black, the first DSK layer and the preview and program bus buttons have keyboard shortcuts. Everything the controller does goes over a documented controller WebSocket protocol, so you can also build your own control surface.
Where does the programme go after the mixer?
A production can send its programme out over SRT (MPEG-TS), EFP over SRT, RTMP to a streaming platform, or WHEP for WebRTC viewing. It can also record the programme to a storage connection you set up, and since release 0.7.0 it can record chosen SRT, EFP or WHIP inputs to their own files beside the programme.
Is the Open Live vision mixer really free and open source?
Yes. Open Live Studio and the Open Live backend are both published on GitHub under the MIT licence. Self-hosted, Open Live is free: you run the backend and its CouchDB database, Studio and Strom yourself; the self-hosting guide covers what that involves. On Open Source Cloud you sign in, pick a monthly plan that includes production hours on shared Strom, and start producing. If you are new to Open Live, your first live show walks through a production from an empty account to on air.
Ready to try the vision mixer?
Sign in with your Open Source Cloud account, create an environment and open Studio.