Help with Joining OAR files

[Penguin]

I have a number of files that end in OAR, I am using my PC, and would love to join these high def files into a viewable format for my dvd player. Trouble is, everything I have tried joining these files with has left the results pixally, or reduced the resolution so much they just aren't worth watching.

Can anyone suggest an easy solution? I would prefer a freeware package, but if it's not, don't let that stop you offering ideas!

Thanks