Never use an MP4/m4v/h264/aac Audio/ mp3 Audio in the Nuendo video player
I’m on Mac and ProRes just works and works … I only need the ProRes proxy type video as a guide using the Nuendo player. Actually looks pretty good IMO!
On PC I think you can still install QuickTime 7.5 for Prores playback… but be careful with security although for pro users I don’t think there’s a huge issue. You are careful right?
It would be good for Steinberg to add native ProRes playback into Nuendo like they have in Premiere, Resolve and others.
Like others have said requesting a DNx-HD ( ie avid) encoded reference is also an option… though make sure the editor sending it understands that just choosing “MXF” for the export is as likely as not going to end up with an MP4 in an MXF wrapper… so hassle them to ensure it is really DNx-HD or you’ll be back where you started!
If you have MP4 guides videos already I guess you can transcode at you end. There are many Mac and pc utilities that do it … I have used one from a company called PavTube for over 10 years. I’m always reticent though… l’d prefer the Reference to come out of the video edit app with every frame as a distinct piece of data. Especially for long projects. That means ProRes or DNX … or technically DV-NTSC or DV-PAL in standard def. Now there’s a thought…