The SDDS soundtrack (blue strips on the outer edge of the film) had severe issues with reliability the older the print got. This is because that part of the film is the bit that touches the rollers while the film is being transported from the platter to the projector and back so unless everything is squeaky clean and perfectly aligned it’ll get scratched and SDDS would begin to drop out (and fallback to other formats, usually analogue depending on your config) resulting in a bad experience.
If you got a second-hand print from somewhere you’d just never bother to run SDDS.
Since it's digital data, I wonder if anyone ever captured the data the very first time it was played back, and then just played the captured version on subsequent runs.
It would eliminate the problem with it wearing out.
Commercially? Probably never happened. It is just easier to use more reliable formats like Dolby Digital or DTS (which is shipped with the print on CDs and synchronised using a timecode… some DTS units had HDDs in them you could load the soundtracks in to so you didn’t have to swap the discs over when you changed what movie was showing).
Maybe it was different elsewhere, but SDDS was pretty much a non-starter for us for any kind of effort.
I've captured Dolby Digital data to rip the audio from the film before. I don't (yet) have a SDDS reader, but when I get one it's something I want to try.
The SDDS soundtrack (blue strips on the outer edge of the film) had severe issues with reliability the older the print got. This is because that part of the film is the bit that touches the rollers while the film is being transported from the platter to the projector and back so unless everything is squeaky clean and perfectly aligned it’ll get scratched and SDDS would begin to drop out (and fallback to other formats, usually analogue depending on your config) resulting in a bad experience.
If you got a second-hand print from somewhere you’d just never bother to run SDDS.