**EDIT**
See post #139 for newer,better version
reel1cap2 = avisource("PATH TO FILE") #this is the video that will be altered.
reel1cap1 = avisource("PATH TO FILE") #this is the video that will be the source that the other is matched to.
colw = reel1cap2.Width()
colh = reel1cap2.Height()
bww = reel1cap1.Width()
bwh = reel1cap1.Height()
borw = (bww-colw)/2
borh = (bwh-colh)/2
reel1cap2= reel1cap2.AddBorders((654-reel1cap2.Width)/2, (480-reel1cap2.Height)/2, (654-reel1cap2.Width)/2, (480-reel1cap2.Height)/2, color=$000000)
bwp = reel1cap1.AddBorders((654-reel1cap1.Width)/2, (480-reel1cap1.Height)/2, (654-reel1cap1.Width)/2, (480-reel1cap1.Height)/2, color=$000000)
int = Interleave(bwp,reel1cap2)
est = int.depanestimate(range=1,pixaspect=1,zoommax=1,improve=false,trust=0)
dep = int.depaninterleave(est,pixaspect=1,prev=0,next=1,subpixel=2,mirror=0,blur=0)
acol = dep.SelectEvery(4, 1)
avgcap1cap2=overlay(reel1cap1,acol,mode="blend",opacity=0.5)
return(avgcap1cap2)