Different CRCs in EAC with and without C2 Options

[audioadam]

Hello again.

I am going through a big (in my opinion) ripping project of about 75 cds. I only have access to one drive, so I figured that the most secure/borderline-paranoid way to do it is to rip each CD twice securely, once with C2 on and once with C2 off, then compare the CRCs and see that they match. One of the CDs that I came across consistently reports a different CRC when it is ripped with C2 than when it is ripped without, though EAC reports an error free rip each time. The other 72 all had matching CRCs when C2 was used and when it was not used.

Some information about the CD: It is pretty old, probably about ten years (probably purchased around 2000, and manufactured circa 1998) It doesn't appear to be too scratched, except for one point in the disc where there seems to be a deeper chip. It is pretty obscure, as are all the CDs in this project, and thus not available in the AccurateRip DB, though it is a pressed CD, not burnt.

So, I am wondering if anyone has come across this problem before, and if anyone can advise me how to correct the situation. I sincerely doubt that it is a copy-protection mechanism, given the age and source of the cd, but I won't rule anything out. It would be really nice to get an accurate rip, if possible.

If you have any additional questions I will attempt to provide answers to the best of my knowledge.

Thanks in advance.
Adam

[audioadam]

Hello Again.

Well, my new DVD drive finally arrived yesterday, but it tackled this CD the exact same way as the other one.
Here is the rip without C2 error pointers:

CODE

Exact Audio Copy V0.99 prebeta 3 from 28. July 2007

EAC extraction logfile from 16. January 2008, 21:22

Artist / Album

Used drive : Optiarc DVD RW AD-5540A Adapter: 2 ID: 0

Read mode : Secure
Utilize accurate stream : Yes
Defeat audio cache : No
Make use of C2 pointers : No

Read offset correction : 48
Overread into Lead-In and Lead-Out : No
Fill up missing offset samples with silence : Yes
Delete leading and trailing silent blocks : No
Null samples used in CRC calculations : Yes
Used interface : Installed external ASPI interface

Used output format : Internal WAV Routines
Sample format : 44.100 Hz; 16 Bit; Stereo


TOC of the extracted CD

Track | Start | Length | Start sector | End sector
---------------------------------------------------------
1 | 0:00.00 | 25:02.74 | 0 | 112723
2 | 25:02.74 | 24:06.70 | 112724 | 221243


Range status and errors

Selected range

Filename C:\Artist - Album.wav

Peak level 100.0 %
Range quality 100.0 %
Copy CRC 610A4BA1
Copy OK

No errors occurred

End of status report

Summary: It returned the same rip as the previous drive when not using C2.

And here is the rip with C2 error pointers:

CODE

Exact Audio Copy V0.99 prebeta 3 from 28. July 2007

EAC extraction logfile from 16. January 2008, 21:58

Artist / Album

Used drive : Optiarc DVD RW AD-5540A Adapter: 2 ID: 0

Read mode : Secure
Utilize accurate stream : Yes
Defeat audio cache : No
Make use of C2 pointers : Yes

Read offset correction : 48
Overread into Lead-In and Lead-Out : No
Fill up missing offset samples with silence : Yes
Delete leading and trailing silent blocks : No
Null samples used in CRC calculations : Yes
Used interface : Installed external ASPI interface

Used output format : Internal WAV Routines
Sample format : 44.100 Hz; 16 Bit; Stereo


TOC of the extracted CD

Track | Start | Length | Start sector | End sector
---------------------------------------------------------
1 | 0:00.00 | 25:02.74 | 0 | 112723
2 | 25:02.74 | 24:06.70 | 112724 | 221243


Range status and errors

Selected range

Filename C:\Artist - Album.wav

Peak level 100.0 %
Range quality 100.0 %
Copy CRC 5D76F412
Copy OK

No errors occurred

End of status report

Summary: It returned the same rip as the previous drive when using C2.

I have an older drive as well that isn't working very consistently these days, I imagine that the hardware is damaged. I did manage to get it up and running to do two more rips on the disc to see if I would get the same results. It did. Here are the logs without and with C2, respectively.

CODE

Exact Audio Copy V0.99 prebeta 3 from 28. July 2007

EAC extraction logfile from 16. January 2008, 21:36

Artist / Album

Used drive : HL-DT-STDVD-RW GWA-4082N Adapter: 2 ID: 0

Read mode : Secure
Utilize accurate stream : Yes
Defeat audio cache : No
Make use of C2 pointers : No

Read offset correction : 667
Overread into Lead-In and Lead-Out : No
Fill up missing offset samples with silence : Yes
Delete leading and trailing silent blocks : No
Null samples used in CRC calculations : Yes
Used interface : Installed external ASPI interface

Used output format : Internal WAV Routines
Sample format : 44.100 Hz; 16 Bit; Stereo


TOC of the extracted CD

Track | Start | Length | Start sector | End sector
---------------------------------------------------------
1 | 0:00.00 | 25:02.74 | 0 | 112723
2 | 25:02.74 | 24:06.70 | 112724 | 221243


Range status and errors

Selected range

Filename C:\Artist - Album.wav

Peak level 100.0 %
Range quality 100.0 %
Copy CRC 610A4BA1
Copy OK

No errors occurred

End of status report

CODE

Exact Audio Copy V0.99 prebeta 3 from 28. July 2007

EAC extraction logfile from 16. January 2008, 21:51

Artist / Album

Used drive : HL-DT-STDVD-RW GWA-4082N Adapter: 2 ID: 0

Read mode : Secure
Utilize accurate stream : Yes
Defeat audio cache : No
Make use of C2 pointers : Yes

Read offset correction : 667
Overread into Lead-In and Lead-Out : No
Fill up missing offset samples with silence : Yes
Delete leading and trailing silent blocks : No
Null samples used in CRC calculations : Yes
Used interface : Installed external ASPI interface

Used output format : Internal WAV Routines
Sample format : 44.100 Hz; 16 Bit; Stereo


TOC of the extracted CD

Track | Start | Length | Start sector | End sector
---------------------------------------------------------
1 | 0:00.00 | 25:02.74 | 0 | 112723
2 | 25:02.74 | 24:06.70 | 112724 | 221243


Range status and errors

Selected range

Filename C:\Artist - Album.wav

Peak level 100.0 %
Range quality 100.0 %
Copy CRC 5D76F412
Copy OK

No errors occurred

End of status report

Summaries: It returned the same CRCs as the other drives.

So I am out of ideas again. Each one of the drives has returned the same result, so it must be either an error on the disc, or a possible bug in the way EAC rips the data. I think I will just have to be satisfied with the rips I have for now - all of the actual music on the disc was preserved anyway, the only part with inconsistencies was in the very final moments, during the fadeout. I can't really be sure which, if either, of the rips was an accurate one, but they both sound fine anyway.

I was kinda hoping that with a new drive this problem would work itself out on its own, but it didn't. I still think that ripping with and without C2 is about the best way to find errors, such as in this case, and I will keep doing it. I will report if ever I come across another CD with this problem, or if I ever find a way to get a consistent rip with this one.

Thanks,
Adam