I'm editing a load of video, some of it was shot in 16:9 high-def and some in 4:3 regular-def. Id really hate to see the 4:3 footage go to waste. What can I tack on to the black sidebars on either end of this footage to fill in the gaps? I've also seen on TV where the sidebars on old 4:3 footage is blurred out by video from that particular frame. How can I do this?