Playing Videos

Video slides play in step on every screen from the controller, and their sound goes where you want it.

When the current stop is a video, playback controls appear at the bottom of the controller, beside the stop buttons: skip back 10 seconds, play/pause, skip forward 10 seconds, the elapsed/total time, and a scrub bar. Playback is synchronised — every connected viewer and channel screen plays, pauses, and seeks together, staying within a fraction of a second of each other.

• When the video has played to the end, the play button becomes Replay — one tap starts it again from the beginning.
• Drag the scrub bar to jump to a point in the video; the time readout follows your finger and the viewers seek once you let go. Dragging on the controls never swipes to another stop.
• On a keyboard, Space or K plays and pauses, and J / L skip 10 seconds back / forward.
• The controller itself stays silent and shows only the video's poster image — the viewers do the playing.
• Navigating away from the video stop ends playback on every screen; coming back starts it afresh.
• Blanking the screen hides the video; unblanking shows it again at the point it has reached.

Getting Video Audio Working

Browsers block videos from playing sound automatically unless you've interacted with the page or allowed the site to do so. When a viewer screen can't play sound, the video starts muted with a "Tap for sound" button over it — one tap enables audio for the rest of the session.

For screens you set up once and leave running (a projection PC, a stream capture machine), allow the site to autoplay with sound so you never need the tap:

• Firefox — click the permissions icon next to the address bar on the viewer page (or go to Settings → Privacy & Security → Permissions → Autoplay → Settings…), find the site, and choose Allow Audio and Video.
• Safari — with the viewer page open, choose Safari → Settings → Websites → Auto-Play, find the site in the list, and choose Allow All Auto-Play.
• Microsoft Edge — go to edge://settings/content/mediaAutoplay and add the site under Allow.
• Chrome — Chrome has no manual per-site autoplay list. It learns instead: after you've played video with sound on the site a few times (the "Tap for sound" button counts), Chrome allows sound automatically on future visits. For a dedicated, unattended presentation machine you can also launch Chrome with the --autoplay-policy=no-user-gesture-required flag to allow sound everywhere.
• OBS / streaming capture — OBS browser sources allow sound automatically; no set-up needed for your livestream.

Tip: in a venue with several screens showing the same presentation, give only one device audio (the one feeding your sound system) and keep the others muted or with their volume down — multiple devices playing audio a fraction of a second apart sounds like an echo.