Avisynth stackhorizontal directly

[elbenno]

I was wondering if anyone could kindly advice me on the stackhorizontal filter in Avisynth. I love how you can set up a 'before and after' this way. Now I just export the filtered video and original to the same size and then afterwards I stack them in a second run.

I have been looking online, but cannot find it; is it also possible to directly at the end of your elaborate script to stack the filtered video and the original in one run?

Thanks for your help!

[ndjamena]

Src = MySource("MyFile.vdo")
Src

Filter()

StackHorizontal(last, Src)

???

[jagabo]

When you don't name a stream AviSynth uses the name "last". So a sequence like:

AviSource("filename.avi")
Filter1()
Filter2()

really means:

last = AviSource("filename.avi")
last = Filter1(last)
last = Filter2(last)
return(last)

So you can "remember" the unfiltered source and stack source and filtered videos with a sequence like:

AviSource("filename.avi")
unfiltered = last
Filter1() # acts on last (the source), creates a new last
Filter2() # acts on last from Filter1(), creates a new last
StackHorizontal(unfiltered, last)

Sometimes you want to use Interleave() instead of stacking. Then you can see very subtle difference by flipping back and forth between two successive frames in an editor like VirtualDub.

[elbenno]

Thanks so much Jagabo and ndjamena. That did the trick! Good to understand the 'last' principle!
Case closed