Query: How many 5.1 surround sound options exist in LaserDiscs?
Context: Only one 5.1 surround sound option exists on a given LaserDisc (either Dolby Digital or DTS), so if surround sound is desired, the disc must be matched to the capabilities of the playback equipment (LD Player and Receiver/Decoder) by the purchaser. A fully capable LaserDisc playback system includes a newer LaserDisc player that is capable of playing digital tracks, has a digital optical output for digital PCM and DTS audio, is aware of AC-3 audio tracks, and has an AC-3 coaxial output; an external or internal AC-3 RF demodulator and AC-3 decoder; and a DTS decoder.