aspect: The horizontal:vertical aspect ratio, eg '4:3' or '16:9'. quality: information on the quality, eg 'HDTV', '800x600'. stereo: Description of the stereo-ness of the sound. Legal values are currently 'mono','stereo','dolby','dolby digital','bilingual' and 'surround'. 'bilingual' in this case refers to a single audio stream where the left and right channels contain monophonic audio in different languages. Other values may be added later.
