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AccurateRip/Foobar bit-compare result mismatch
crystal-clear
post Apr 12 2013, 16:51
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i'm baffled. Here's what happened: I have this one CD that I ripped using EAC that is giving me some errors at the last track. I use "Copy image and create cuesheet" and the format is wavpack. I first ripped this on my computer and AccurateRip in EAC says all tracks were accurately ripped with confidence of 7. I then ripped the same CD on my brother's computer and again AccurateRip in EAC says all tracks were accurately ripped with the confidence of 7. Same checksums on all tracks, including the last track. However the CD image CRC was different and when I bit compare the last tracks of my computer's rip and my brother's rip using Foobar it says that differences found blink.gif

Long story short:

My computer's rip:
CODE
Peak level 98.8 %
Range quality 99.9 %
Copy CRC 46534B0A
Copy OK

No errors occurred


AccurateRip summary

Track 1 accurately ripped (confidence 7) [89850A3E]
Track 2 accurately ripped (confidence 7) [669E3367]
Track 3 accurately ripped (confidence 7) [71A47887]

All tracks accurately ripped



My brother's computer rip:
CODE
Peak level 98.8 %
Extraction speed 7.8 X
Range quality 99.9 %
Copy CRC 5F979B80
Copy OK

No errors occurred


AccurateRip summary

Track 1 accurately ripped (confidence 7) [89850A3E] (AR v1)
Track 2 accurately ripped (confidence 7) [669E3367] (AR v1)
Track 3 accurately ripped (confidence 7) [71A47887] (AR v1)

All tracks accurately ripped


Not the CRC difference between my pc's and my bro's pc's rips.

When I use "verify album with AccurateRip" in Foobar2000, my pc's rip says:
CODE
Track Status
01 Accurately ripped, confidence: 7.
02 Accurately ripped, confidence: 7.
03 Accurately ripped, confidence: 7.


My brother's rip:
CODE
Track Status
01 Accurately ripped with offset: -18(1).
02 Accurately ripped with offset: -18(1).
03 Accurately ripped with offset: -18(1).


Using bitcompare on the last tracks of both rips says:
CODE
Differences found: 54 sample(s), starting at 282.5593651 second(s), peak: 0.0000305 at 282.5593651 second(s), 1ch


Perhaps I'm missing something obvious here, how come two tracks that are both accurately ripped have differences when bit-compared against each other? The first two tracks return "No difference found" when bit-compared. Anyone can shed some light?

Thanks in advance
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pdq
post Apr 12 2013, 16:56
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AccurateRip CRCs omit the first few and last few frames on a CD. Apparently the differences are in the last few frames.
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spoon
post Apr 12 2013, 18:58
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...because drives have different offsets and not that many can overread to fetch the data which is lost to offset.


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Spoon http://www.dbpoweramp.com
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pdq
post Apr 12 2013, 20:06
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If you simply delete the frames that don't match then you will be sure of the accuracy of what remains, and I doubt that you could hear the difference because it is such a short time (1/75 second per frame).
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crystal-clear
post Apr 13 2013, 04:23
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I see. Thank you for the explanations! Make sense now, I was so confused.
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