Many BR players can just play those files in their full glory without changes. This varies with each player but test the files with some USB stick first.
If they don't play, convert them to another encoding with HANDBRAKE (a free tool with way too many tutorials.)
Hi,
What software for Windows would you suggest to take video files (.MP4, .MKV, etc...) and burn them to a disc that would be playable with any blu-ray player?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic