Why aren’t there easy to use formats of video that support an alpha channel (similar to a PNG)

Question

Why aren’t there easy to use formats of video that support an alpha channel (similar to a PNG)

In: Technology

Answer 1

For videos, color keying tend to be used instead of alpha (So you just replace a specific color like green).

[You can find a ton of videos with green screen elements you can replace on the web](https://www.shutterstock.com/video/featured/Green-Screen-Showcase-Stock-Footage-63679200/?kw=green%20screen%20videos&gclid=CjwKCAiAhJTyBRAvEiwAln2qB3WeiTxQHm8jURIKeTs3NghLLDG9_4X2oMZkDxz4sDsP4g92syIa8hoCOXAQAvD_BwE&gclsrc=aw.ds).

I think the reason why it is done this way is that you can film green screens, but you can’t film alpha. You could replace the green by alpha, but that’s just an extra step.