There's also some clever coding at the physical level with the way pits are arranged on the disc: https://en.wikipedia.org/wiki/Eight-to-fourteen_modulation ht

There's also some clever coding at the physical level with the way pits are arranged on the disc: https://en.wikipedia.org/wiki/Eight-to-fourteen_modulation https://en.wikipedia.org/wiki/Eight-to-fourteen_modulation https://spectrum.ieee.org/kees-immink-the-man-who-put-compact-discs-on-track https://spectrum.ieee.org/kees-immink-the-man-who-put-compac...