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Old 2006-02-01, 10:18 AM
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ssamadhi97 ssamadhi97 is offline
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Join Date: Nov 2004
Location: Old Europe
Re: Discs won't EAC secure, 2nd best option?

Well, here are the possible scenarios:
1) copy crc correct, test crc incorrect
2) copy crc incorrect, test crc correct
3) copy crc incorrect, test crc incorrect

I guess with problematic discs, 3) is the most likely. And I doubt that 1) is any more likely than 2).

Keep in mind that EAC has no way to actually verify that a track was extracted correctly. Roughly, it bases its "copy ok" tag on the assumption that if it reads a sector n times and gets the same result (let's say x) m times, the cd actually contains x (and not y). However if during the test pass it mostly reads x, and during the copy pass it mostly reads y, there's no way to know whether the cd actually contains x or y. It's even possible that the data originally stored on the cd was z. (all iirc)

...hope that made sense


Edit: note that matching crcs in burst mode don't necessarily indicate a perfect rip either, especially not on problematic discs. iirc people have been reporting (audibly) "better" results with burst mode though.
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