Sure, no problem! 
keep in mind that GearVR => Android, so here you’ll find all the informations you need: [][1]
I ended up putting a mp4 file with H264 encoding on a private server, then copypasting the complete url in my media player asset. The rest of it is fairly standard. The video won’t play in the standard viewport (you’ll see a black screen), but it will work on device.
[1]: