How playback works

Everything ArenaDirector plays follows one path. A file becomes a source inside an item that you can trigger. That item sends its sound to one or more buses and its picture to one or more canvases, and each canvas shows on a physical display.

Once you know this path, the rest of the product makes sense, because every other feature is a variation on it.

The five parts

Source. The media: an audio file, a video file or a still image from your media library. A source never plays on its own. It always sits in a hot button, a sequence cue or a rotation item.

Hot button, sequence, rotation. These three items hold sources and play them. What sets them apart is who decides when they play. See Hot buttons, sequences and rotations.

Bus. An audio destination. A bus is a name you give to one or more stereo pairs on your audio devices, so "Main PA" means something in your configuration and you do not have to think in terms of "channels 1 and 2 of the second interface". Sound always goes to a bus, never straight to a speaker.

Canvas. A video destination. A canvas has a size, and it renders a picture at that size whether or not a screen is connected.

Display. A physical screen. You assign canvases to displays. Canvases, surfaces and displays explains why these are two different ideas.

The path

Audio and video split at the trigger, and you choose their destinations separately. One hot button can send its sound to the bowl PA and its picture to the scoreboard.

When nothing is triggered on a canvas, it shows its idle content: an image, a looped clip or a live stream, with optional audio on buses. Each item you trigger takes the canvas and releases it again when it stops.

So a hot button can also hold a video file with no target canvas and work purely as a sound.

Why destinations have names

Venues change. The interface you use this season may not be the one you used last season, and the concourse feed moves from channels 3 and 4 to channels 7 and 8 when someone rewires the rack.

Hot buttons find a bus by its name. To connect "Concourse" to different hardware, you make one change in one place, and every hot button that uses that bus follows it.

Canvases work the same way. You design your content for a canvas, and the display is whatever screen is connected on the day.

Shared destinations

Two items can try to use the same bus or canvas at the same time. Say a sequence is playing walk-in music through the bowl PA and you fire a goal horn that also uses the bowl PA.

ArenaDirector decides by priority. The live trigger wins until it stops, and then the background program plays again. Takeover and resume has the rules, including how they apply to a board with sections.

Why aligned output is slower

Destinations take different amounts of time to show a picture. A screen on a cable shows it almost immediately, a processor driving an LED wall needs one or two frames, and a stream that leaves the building and comes back through a receiver can take a tenth of a second.

To show the same moment on the fast screen and on the slow stream together, the app has to send the picture to the slow stream earlier, because it cannot make the receiver any faster. That means the app finishes the picture for a moment before the room shows it, and how far ahead it works is set by the slowest destination.

This has a cost. Once the app has made a picture in advance, a button push can only change the pictures it has not made yet. The room shows the right picture, in step, but a fraction of a second after the push. Aligned output trades away responsiveness, and the slowest destination in the group decides how much.

A second sync group removes that cost for one destination. With the slow stream in its own group, the room no longer waits for it: the room changes as fast as its own screens can, and the stream keeps its own timing.

You do give up what the first group gave you, though, since content on the stream is no longer in step with content in the room. A second group suits a destination that people do not watch next to a screen in the building. You set each output's group on Add an output.