quality:corruption, information:highlighting
Error types

There are different types of error measurements, including so-called "C1", " C2 " and "CU" errors on CDs, and "PI/PO (parity inner/outer) errors" and the more critical "PI/PO failures" on DVDs. Finer-grain error measurements on CDs supported by very few optical drives are called E11, E21, E31, E21, E22, E32.

"CU" and "POF" represent uncorrectable errors on data CDs and DVDs respectively, thus data loss, and can be a result of too many consecutive smaller errors.

Due to the weaker error correction used on Audio CDs (Red Book standard) and Video CDs (White Book standard), C2 errors already lead to data loss. However, even with C2 errors, the damage is inaudible to some extent.

Blu-ray discs use so-called LDC (Long Distance Code s) and BIS (Burst Indication Subcode s) error parameters. According to the developer of the Opti Drive Control software, a disc can be considered healthy at an LDC error rate below 13 and BIS error rate below 15.