Frame captures have a black line around
 

When I take a capture from a file other than a VCD, the capture has black lines around. A solution would be adjusting in a photo programm, but strangely the image than is about 3 times it original size. :? How come?

And how can I get rid of those black lines? :?

I've changed resolution and searched on this forum but can't find the answer :? P.S. I have latest version of BSPlayer 8)