A set of media items may be matched with a media arrangement that displays the media items in the set in a group of frames. The media arrangement may extend across an area larger than a viewable area of a display device. In order to determine the media items that appear within a viewable area, a list of media items may be divided into two portions, one on either side of a middle item in the list. If any part of a frame with which the middle item is associated is within an extended spatial area that extends beyond the viewable area, the middle item may be eliminated from the list, when no part of the frame with which the middle item is associated is within the extended area. The process may be repeated until it is determined that a part of a frame with which the middle item is associated is within the extended area.