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Topic: Create accurate Rips with EAC without using CUETools and / or AccurateRip? (Read 3948 times) previous topic - next topic
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Create accurate Rips with EAC without using CUETools and / or AccurateRip?

Hi,
I want to rip my CD-collection (about 300 CDs).
Before starting I read about configuring EAC and feel pretty confident, that I'm able to set it up the correct way.

Now to my "problem":
I want to use an old offline Computer for that task, as it is the only one with a good DVD-drive. I also don't want to use CUETools to verify my rip afterwards on a regular basis.

Reading about EAC and AccurateRip, I came to the conclusion, that there are more or less 2 schools of thought with regards to this topic:

1. AccurateRip is absolutely necessary to be sure to have a perfect rip! Even if the CRCs match, using test & copy, you can never be sure, that your drive didn't produce the same error twice!
VS
2. AccurateRip is the best way to reach that goal, but if you use secure mode with EAC and the CRCs match after using test & copy, you're fine, as errors tend to be random and thus it's very unlikely, that 2 rips produce matching but incorrect CRCs.


This is making me crazy to be honest! :o  ;D
To reduce my uncertainty, I did a little "test" that confused me even more. I ripped several CDs with 2 different drives, each time as a single file with a cuesheet and also as individual files with a cuesheet (so 4 "versions" in total from 2 different drives).
(I set up the correct read-offsets for each drive individually!)

Results:
 - the CRCs from the images did match within the 2 passes that each drive produced, but when compared to those of the other drive they were different!
 - the CRCs from the individual tracks more or less matched across the 2 different drives (but not in all cases!!!)

I tried to verify the 4 different Versions via CUETools and each version was accurate! >:(


My questions to you guys:
1. How is it possible, that 2 different drives create different CRCs for the same CD? I was under the impression that AccurateRip compared those CRC values that EAC creates?!

2. Why are the CRC values in EAC matching (in about 90% of cases) when using single files instead of the version with one file for a CD?

3. Most important: Is there a way to be (pretty) sure, that a rip is accurate, even when not using AccurateRip to verify it? What's your opinion about 2 matching CRCs, using secure mode in EAC; would that be enough? And how would it be even possible for a drive to produce the same reading error twice?


Re: Create accurate Rips with EAC without using CUETools and / or AccurateRip?

Reply #1 –
You can simply rip your CDs on an old (offline) computer and then verify your rips against AccurateRip database on another (connected) computer.

Re: Create accurate Rips with EAC without using CUETools and / or AccurateRip?

Reply #2 –
1 and 2: Over-reading into the lead-out? It is supposed to be digital silence at the far end, but sometimes it is only near-silence.

Try the foobar2000 player and bit-compare the two images. Take note where the differences are - are they at the end? And how loud are they (-90 dB in less than a second?) If so, that answers 3 as well.

Re: Create accurate Rips with EAC without using CUETools and / or AccurateRip?

Reply #3 –
Quote from: Spoon's Audio Guide: CD Ripping
Re-Reading
CD is read twice, if a section contains an error it will likely return different errors, so can be detected. This is true mostly but not always, consistent errors exist and in our opinion present more of a problem to secure ripping than the C2 error pointer detection 'hole'.
korth
 

Re: Create accurate Rips with EAC without using CUETools and / or AccurateRip?

Reply #4 –
Yes, the last part of question 3 I overlooked.
Two different drives will increase security. Not saying it will do as much as comparing against someone else's rip, but errors are often read different.