Complex sentence: The stereo information is then carried on stereo sources such as videotapes, laserdiscs and television broadcasts from which the surround information can be decoded by a processor to recreate the original four-channel surround sound.
Split into simpler sentences: The stereo information is then carried on stereo sources such as videotapes, laserdiscs and television broadcasts. A processor in the playback device decodes the surround information to recreate the original four-channel surround sound.