Inside the player

What a screen keeps on its own disk, how it survives an outage, how several panels stay in step, and where the sound comes from.

It keeps working when the internet does not#

This is the part people do not expect, and the reason a screen that looks broken usually is not. A player holds two things locally:

Its schedule, for seven days. A screen that boots during an outage knows what it should be playing.
The files themselves, on disk. Up to about 2 GB, oldest first when it has to make room. Without this, a screen would know exactly what to show and be unable to fetch a single byte of it.

It also keeps a copy of the player page itself, so a television that loses power during an outage comes back playing rather than to a blank browser.

What is on a screen’s disk

ItemTypeCached

Menu boardImageheld1

Pastry filmVideoheld

Ad slotAdSlotlive2

Winter promoVideonot yet

1Your own files: cached, and played from the disk every time.

2Ad slots and VAST are never cached — each play is a separate auction and a separate paid impression.

Live items cannot play offline

An ad slot has nothing to cache — what appears is decided at the moment of play. During an outage those turns fall through to your own fallback content. That is correct behaviour, not a fault: replaying a stored advert would be showing one nobody bought.

Plays are never lost#

A play that happens during an outage is still a play, and still billable. The screen writes it to a durable queue and delivers it when the line returns — those arrive marked Offline so you can tell a delayed report from a live one.

A queue that is non-zero while the screen is offline is expected. A queue that is non-zero and growing while the screen is online is a report that cannot get through, and worth investigating.

Video walls start together#

On a wall of several devices, playback does not begin until every panel has checked in. They are then given a shared start moment, so panel 1 and panel 4 are on the same frame rather than a second apart. A panel that reconnects later is told the same start moment and works out for itself where it should be.

While the wall is waiting, each panel shows how many have arrived — “3 of 4 connected”. A wall stuck on that message has a panel that is off, unplugged, or on a different network.

Sound#

Three rules, in order:

A muted screen is silent, absolutely. If Audio enabled is off, the platform does not send audio content to that screen at all.
Only one panel carries the sound. On a multi-device wall, four panels playing the same track a fraction apart is an echo. One is chosen; if it drops, another takes over within seconds.
A video with sound takes priority. While one plays, background music pauses — and resumes where it left off, not further along a track nobody heard.

Updates reach screens on their own#

Screens poll for their schedule rather than being pushed to, and apply a change at the end of the current loop rather than cutting mid-item. Nobody sees a half-played video, and a screen that was offline when you made the change picks it up when it returns. The Rollout figure is how far a change has actually reached.

Example — What a nine-hour outage looks like

A café loses its line at 08:00. The screen keeps playing from disk all day. Ad slots fall through to the café's own content, so the loop looks slightly different but never stops. Every play is queued. At 17:00 the line returns; within a minute the queue is delivered and the day's report shows the plays marked Offline. Revenue for the ad slots is zero for those hours, correctly, because no auction ran.