This is a Nodegroup addon that allows you to convert between Filmic and Standard colour-spaces in the compositor... allowing you to render your 3D scene in Filmic and comp it onto a video without the whites in the video being greyed out.

It also allows you to bring an image or video into your 3D scene .... and filter it so it's not greyed out by the filmic colour space.  This could be very useful if used alongside my other addon Greenscreen Within Eevee Pro.