Replace Chroma with image

[arenyxx]

I feel like this should be simple but maybe its not even possible. I have this border that id like to replace with an image or a gif. its getting greenscreened out i just want it to be replaced instead of transperant. Any help?

 

[AaronD]

Put another source behind it in the same scene. Then the transparent parts will show that. Just like overhead transparency sheets if you remember those. :-)

That's entirely what transparency is for anyway. The final output doesn't have it: every pixel has a single color for each frame, and that's it.

 

[Suslik V]

If you need to make animated border from any media - you can use Image Mask/Blend filter with the Type: Alpha Mask (Color Channel) for it. The image used as mask should have border of desirable shape but of white color and background is black (as black hole). Black becomes transparent, while white areas remains visible.