One playlist. Two kinds of break.
In the first one, the publisher composed the picture.
In the second one, the publisher only offers.
Multi view: you build the picture.
What a break announces
Both are an EXT-X-DATERANGE of a custom class, both point at an
asset-list, and both are drawn over a programme that never stops. What differs
is what the block inside declares — and therefore who is left holding the
decision about where things go on the screen. Below is every break of this run,
each one drawn from what it actually announces.
And what arrives for one item of each
A catalogue is allowed to be longer than the screen, and one of the windows of this run is. The cap is of the grid and never of the offer: a playlist may announce eight cameras without anything being wrong, and what is capped is how many of them are up at once.
The shape of the grid
An offer carries no geometry, so the player works it out — it is the only one of the three parties that knows both things at once: how many boxes there are right now, and how big the screen is. The programme is the first box of every shape, because it is one of the views and not a backdrop. Nothing below was drawn in advance: each shape appears the first time the composition on screen reaches that many boxes, with the second it happened.
Unticking the last feed and pressing the one-view button are the same event and not two: one box is no composition, so both end in the same call. That is why leaving cannot restore the wrong thing — there is nothing to restore.
The signalling, as it is served
Not an illustration. The tags below are the ones in the media playlist this player is playing, and the JSON is the asset-list each one points at, fetched from the same URL the library fetched it from.
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