Stacking filters

[jellynoone]

First, thank you for this great library.

Context. I'm building a flutter application and looking to provide some basic video processing capabilities to users. Currently, I am experimenting with applying different filters simultaneously on the video, for instance, applying a blur and a negative.

On iOS, I was able to get this to work relatively easily, since you can apply a filter on the result of a previous transformation.

With litr this doesn't seem possible. If you use multiple VideoFrameRenderFilters, they override each other rather than stack. I'm fairly new to Android / video processing so I might be missing something.

@izzytwosheds Do you perhaps know if this is already possible? Or would the only way to apply such an effect require writing a compound VideoFrameRenderFilter?