I'm fairly sure DSD only works with audio and not video. Like I said I would actually be surprised if you could watch a video file while converting the audio to DSD and outputting it as DSD. Thinking about it there's likely multiple issues with that preventing it basically.
The main issue, I imagine, would be that as far as I know DSD in video files isn't already a thing. Another main issue is if audio and video is output via HDMI it definitely won't work as DSD over HDMI from any sort of computer (PCs, Mac's, etc.) isn't possible. You would have to use two different outputs (one for audio and one for video) which as far as I know isn't possible in MC (or any other media player app that I know of) and if it was it could create all kinds of issues. Maybe sync issues too and would likely be very resource intensive.
DSD for audio on videos honestly sounds pointless when DTS, Dolby Atmos, TrueHD, etc. exist.