While watching a few videos on the new features in Resolve 12.5 around Youtube, I noticed there were a lot of people having trouble bringing in MP4 files into their media pool.
It's really as simple as dragging it in and so I don't know where their issues are but I kept explaining that you just drag it but I figured after getting a ton of e-mails with people asking me to tell them how, I would make a short video and discuss a couple other things so it's not a 30 second video.
So please see that you can indeed bring in MP4s and if you can't and you are doing exactly what I am, I'm happy to help you figure out what the issue might be. There are a lot of reasons for non-compatibility and interoperability but if you have a PC, you should have no problems bringing in a MP4 with most codecs. MAC users too, especially if you have things like the Creative Cloud installed. The only thing you need to be sure of is that you have installed the proper codecs.
:)