Fritz Photo

[foxyshadis]

Add this to your script, top or bottom, or save it to an avsi file in your \avisynth 2.5\plugins folder:

function makemod(clip c,int "xmod",int "ymod",bool "crop") {
	xmod=default(xmod,16)
	ymod=default(ymod,xmod)
	crop=default(crop,false)
	c
	ox=width
	oy=height
	xm=width%xmod
	ym=height%ymod
	w=c.isrgb32() || c.isrgb24() ? 1 : 2
	right=c.crop(ox-w,0,w,0)
	right=right.stackhorizontal(right,right,right)
	right=xmod>w*4 ? right.stackhorizontal(right,right,right) : right	
	vx=ox % xmod==0 ? c : stackhorizontal(c,right.crop(0,0,xmod-(ox % xmod),0))
	bottom=vx.crop(0,oy-w,0,w)
	bottom=bottom.stackvertical(bottom,bottom,bottom)
	bottom=ymod>w*4 ? bottom.stackvertical(bottom,bottom,bottom) : bottom	
	vy=oy % ymod==0 ? vx : stackvertical(vx,bottom.crop(0,0,0,ymod-(oy % ymod)))
	cropped = c.crop(0,0,width-xm,height-ym)
	return crop == true ? cropped : vy
}

Use it as:

MakeMod(4)

It'll mirror the edge pixels so that filters don't munge a huge black border into the image. I used to use it a lot when I did a lot of upscaling & filtering of web images, and it had to be fairly memory efficient.