Sometimes I screw up when transcoding video clips and end up with unwanted black letterboxes. Normally I quickly check my transcoded clips in VLC media player to make sure they're good but in this case it's harder to tell because the default background for videos in VLC is black. I could infer the presence of an unwanted border by playing with the size of the VLC window but I don't want to do that for every clip. VLC has no way of changing the black background it puts behind videos so I was wondering whether anyone else has solved this already and if so with what media player? I like VLC because it's so light and quick.