Cockos Incorporated Forums - View Single Post - video processor: multiply with alpha, compositing

sonicowl · 11-05-2018, 07:00 AM

I'm looking for a way to crop video on one track with black/white image (or video) on a second track. Like this: https://en.wikipedia.org/wiki/Alpha_compositing

Two tracks get combined into one. Result would be partly seethrough video - transparent on black parts and fully visible on white parts. Video editors have this, but I cannot figure out how to do it in Reaper (apart from basic croping to rectangle).

Has anybody already written preset for video processor that can do this, and can share it?

Otherwise, which function in video processor would be appropriate for this task?

Thank you for help.

11-05-2018, 07:00 AM	#1
sonicowl Human being with feelings Join Date: Oct 2015 Posts: 739	video processor: multiply with alpha, compositing I'm looking for a way to crop video on one track with black/white image (or video) on a second track. Like this: https://en.wikipedia.org/wiki/Alpha_compositing Two tracks get combined into one. Result would be partly seethrough video - transparent on black parts and fully visible on white parts. Video editors have this, but I cannot figure out how to do it in Reaper (apart from basic croping to rectangle). Has anybody already written preset for video processor that can do this, and can share it? Otherwise, which function in video processor would be appropriate for this task? Thank you for help. Last edited by sonicowl; 11-05-2018 at 07:21 AM.