Some embodiments provide a method for editing a composite presentation in a media-editing application. The method receives a media file to import into the media-editing application from an external device. The method creates a set of media clip data structures to represent the media file. At least one of the data structures references the media file on the external device. Before the media file is imported from the external device, the method uses the media clip data structure to edit a composite presentation with the media file. After the media file is imported from the external device, automatically modifying the data structure to refer to a copy of the media file on a local device.