Video Compare overlay?

Copy this into a blank video processor preset and hit Ctrl-S to save it. Put it on which track you've got set up to be the top layer. I can't claim to understand the code itself. I just hacked this out of the Image Overlay preset, took out all the user controls and hard coded it to invert the one image and then add it to the other. Code:

Hold the phone here - there's something going on here where I don't know what I'm doing. This is the first time I've seen this, but at times now in my session, the BOTTOM video track takes precedence even when there is video on both the top and bottom tracks at the same time/frame. Every other time that I've messed around with multiple video tracks in the same project the top track has taken priority (or so I thought!). How do I set up a "video" track as the MAIN PRIORITY?

Project settings -> 'Video' tab -> Video item visibility

Can you post a screenshot of this can help users to reproduce the workflow and see the concept behind this ?

@Ice I see. thanks !

Thanks for this code @Ashcat. @xraym here's how it looks with same video on each track with 1 frame offset.

Nice! :-) But why it gives two different results when you exchange pic0 and pic1(edited) on Track1 vs Track2 ?? Shouldn't be difference "absolute"?

is there a lighten blending mode? and a simple way to invert color? There are a few video effects and transitions I'd like to use but can't without those.

TBH, I'm doing most of my more detailed video work in HitFilm nowadays pretty specifically because it has all the merge modes that I'm used to in photo editors. Even the free version has a lot of great filters and functions, and the add ons are pretty cheap. I really wanted to stick with Reaper, but it just doesn't do what I want to do with video anywhere near as well.

Simple Invert color code //Invert Color src=0; input_info(src,w,h) ? ( project_w=w; project_h=h; ); // preserve input dimensions gfx_blit(src); gfx_set(1,1,1,-1,0x80003); gfx_mode=19; colorspace == 'RGBA' ? colorspace='YV12'; gfx_fillrect(0,0,project_w,project_h); ----- used on a track it will invert all layers below used on a video item it will invert only that item used on an empty MIDI item above other items it will invert all layers for length of item. You can use built-in "Item fades affect video" after to transition, bit ugly though.