Slow motion & reverse playing

For a coming show, I've been asked to be able to do at a certain time slow motion and reverse playing on an incoming video input stream from a camera on stage.

I guess, the process needs to write the video stream on my hard drive, and when I decide, ask Millumin to switch from the live input video to the recorded media to be able to read the file slowlier (still while recording the stream), or to read it reversely.

Did anyone already had to do that, and what can be the tip for that.

(PS: sorry if this question has already been asked, I didn't find the concerning topic)

Thanks for your help !

Nico