4f87f022da
A roll of a hundred thousand frames is read by a walk that tells the screen about every frame it lands. The column is redrawn out of that count, so the telling was a whole tree rebuilt a frame at a time — on the large library that is the reading spending its afternoon drawing itself, and to the reader it looks like a scan that has started over from the top every time the column breathes. Five tellings a second is a counter that still moves to the eye and a page that is doing the reading instead; every frame still lands in the counts, and only the copy the screen reads waits. What the counter said was wrong twice over, and both were the same mistake told two ways. The total was the frames already reached plus the frames still in the queue, so a roll whose catalogue already holds most of it announced itself as `29980/61211` — the numbers of the reading underneath, printed as if they were the numbers of the roll. The reading now measures itself against the frames the catalogue already holds of the folder it was pointed at: the roll's own size while the walk is still up in its first folders, and the frames under a subfolder alone when it was kept to one. And a row says at least what the catalogue holds of it, never less — where the reading's number alone had the head of the tree count 29980 while the line above it counted a hundred thousand, one question with two answers. Nor is a scan of nothing announced as `0/0` before its first pass has come back; the line waits until it knows what it is reading. The third thing is not a number but a weight. The tile kept for a frame is the tile the grid cell and the strip both paint, and there is one of them per frame of a roll that reaches six figures. At 512 on the long edge a tile weighed 42KB and a hundred and sixty thousand of them weighed six and a half gigabytes of the reader's disk — for a grid cell that is ~240px wide and a strip tile that is 132. A quarter of the pixels at the quality Lightroom keeps its own grid previews at puts the same picture in the same cell: the tile is now ~12KB and the roll a quarter of the disk it was. The canvas a tile is drawn onto is told it is opaque, so it no longer carries a channel of noughts through every draw and every encode. The stage loses a little softness at 2.4x, which is the trade and is known.