[Oliver Watson]

Oh, man. Dan, you are the best. Thanks.

[Oliver Watson]

Doh!! Embarrassing.

Thanks, Dan. You have no idea how much MotionScript and all your posts here on Creative Cow have helped me for so many years. Really appreciate it.

[Oliver Watson]

Thanks so much for the prompt reply, Dan!

Ok, I fixed my code up per your suggestions and there’s no error. Awesome!

However, maybe I’m misunderstanding what startTime really is, because the output I’m getting is unexpected as you can see in the image:

// SEQUENCE LAYERS
for (n = 2; <= myComp.numLayers; n++) {
myLayer = myComp.layer(n);
previousOutPoint = myComp.layer(n - 1).outPoint - crossfade; // get the previous layer's outPoint
myLayer.startTime = previousOutpoint; // and use it to set this layer's startTime
}

[Oliver Watson]

With help from Jeff Turnham I was able to fix it using functions:

var offset = 1270; // starting position
var segDur = 5;
var timeSeg = Math.ceil((time - 3) / segDur); // the current time segment (post)
var postAggregate = function(value) {
var total = 0;
var x = 1;
while ((x < value) && (x < thisComp.numLayers - 2)) {
total += comp(thisComp.layer(x+2).name).layer("compData").effect("Post Height")("Slider") + 100;
x += 1;
}
total += comp(thisComp.layer(x+2).name).layer("compData").effect("Image Centre")("Slider");
return total;
};

if (timeSeg < 1) {
var segEnd = segDur + 3;
var endPos = postAggregate(timeSeg+1) + offset;
var startPos = 0 + offset;
} else if (timeSeg < 2) {
var segEnd = timeSeg * segDur + 3;
var endPos = postAggregate(timeSeg) + offset;
var startPos = 0 + offset;
} else {
var segEnd = timeSeg * segDur + 3;
var endPos = postAggregate(timeSeg) + offset;
var startPos = postAggregate(timeSeg - 1) + offset;
}

var segStart = segEnd - segDur;

ease(time, segStart, segEnd, startPos, endPos);

[Oliver Watson]

Hey, guys.

So I get what you’re doing in post, but what are you using to live-stream the presentation?

[Oliver Watson]

Thanks, Michael. Yes, indeed. Nevertheless it makes no sense to me that AE cannot export the file with comparable compression. Adding an alpha channel should increase my overall data costs by 33%, and yet I can’t find a way to export the file without increasing its size by 10,000%. The math doesn’t make sense.

Not only that: I’m *removing* 80% of the RGB data in my frames by pulling this key. That far outweighs the cost of adding an alpha channel, and it seems strange that there is no compression scheme that takes advantage of this in the way that I imagine the ‘optimize stills’ setting takes advantage of static RGB values.

[Oliver Watson]

Todd, thanks for providing that insight. However, I am concerned about file size because inordinately large files will bog down even a tricked out Mac Pro. I’m struggling to keep a 13 minute video file with an alpha channel under 150 GB. That’s just unwieldy, even as an intermediate file. If anything it should be smaller than the video source file after pulling the colour key. The source file was only about 1 GB.