Anyone using OBS to record their game play having the same problem while editing?

[LoudMouthZander]

I use OBS to record my game plays and the files are in FLV. The problem is when I convert it to MP4 using a method I found online and try to edit on adobe premiere. The video doesn't seem to be in the correct frame size. There are black bars on the sides and the frame size ratio seems to be off. Anyone else experience this problem?