I’ve tried to find a good DTS decoder with no luck. The best I’ve been able to do is to turn it into a lossy AAC file that I can then split apart. Since I keep having to go through a lossy stage, I’m thinking I might as well just stick to the multi-track AC3 audio. And I have a lot of 5.1 versions because I figured out how to extract the surround information from the Dolby Stereo encoded tracks (i.e., the original 1977 Dolby Stereo of Star Wars) and how the LFE signal was extracted.