How is a severely scratched CD still readable sometimes?

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I’ve noticed this on DVDs and BluRays but also with games on any console. I’ve rented a movie and the disk is riddled with scratches and I’m sure it’s not going to read, but it somehow does. However, sometimes it hitches. But playing it back on a different DVD player presents no issues at all. What’s happening here?

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Anonymous 0 Comments

Audio CD, data CD, DVD, and Blue Ray all have several layers of error correction, data scattering, and redundancy built into the specifications. They are not like a vinyl LP, which has a single track of analog data, and no error correction. (Although, there exist modern playback systems which can digitally reduce hiss, pop, and scratch noise on the fly. None of that is in the LP spec.)

Different results in different DVD players can be the result of dirt on the internal optics, mechanical misalignment, or even the movement of a few particles of dust on the disc when moved between players.

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