this starts getting close, but i think there are still some issues, particularly as the loop duration increases over time... but here's the expression (it's basically dan ebberts's
random jump cuts expression without the random part):
segDur = effect("Slider Control")("Slider");
n = Math.floor(time/segDur);
segStart = n*segDur;
startVal = effect("Slider Control 2")("Slider");
endVal = startVal + segDur;
linear(time, segStart, segStart + segDur, startVal, endVal);
before pasting this into the time remapping expression field, add two sliders to the footage. the first slider will control the loop duration, the second will control the point at which the loop will start from (both values are in seconds).
Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW