It’s really amazing how many fallback layers there are in a CD to work around errors. There’s a first Reed-Solomon layer that can theoretically correct 2 error

It’s really amazing how many fallback layers there are in a CD to work around errors. There’s a first Reed-Solomon layer that can theoretically correct 2 errors per 28 byte frame, but they actually only fix 1 error and use the remaing error detection as an erasure code (instead of an error correction code) to make a second layer of Reed-Solomon correction much better due to interleaving. If that fails, they have the audio samples swizzled in a way so that you can do interpolation between neighboring samples, and if that fails, there was yet another mechanism (that I forgot the details about) for a final effort. I reminds me a bit of spacecraft, where there’s so much redundancy and flexibility to make things still work in case of a catastrophic failure. The Galileo spacecraft comes to mind, where they reprogrammed the whole communication mechanism (adding compression etc) after the main antenna failed. (https://en.m.wikipedia.org/wiki/Galileo_project#High_gain_antenna_problem https://en.m.wikipedia.org/wiki/Galileo_project#High_gain_an...)