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Why can't you extract all the data on a factory-pressed CD when it
post Sep 5 2012, 21:28
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In the past when I have burned a CD with EAC (with read and write offset correction values consistent with Andre Wiethoff's reference), I have been able to rip files from it identical to the source files.

Based on what I could gather from this forum, I used to be of the conviction that with a drive capable of overreading and overwriting, the exact same files that were burned to a CD can be extracted from it again, and that the only disadvantage of using a drive not capable of overreading was that a few samples at the beginning or end of the first or last audio file would be replaced with silence, regardless of what the samples originally contained.

Recently, however, it has come to my understanding that it is very hard (or even impossible) to extract the original files that were burned to it from a mass-produced CD.

My question is simple: How is it that I can rip files identical to the source files from a CD I have burned myself, but not from one that is factory-pressed? And, perhaps more importantly, how is it that I managed to achieve this using 'incorrect' offset values?

I apologise in advance for any difficulty I might have understanding any mathematical arguments you put forth. I fear I am slightly dyscalculic.

(I have decided, henceforth, to rip using the 'ideal scenario' reference which is 30 samples before that established by Mr Wiethoff, but I am not sure if it is relevant.)
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post Sep 6 2012, 18:30
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QUOTE (Rollin @ Sep 6 2012, 15:09) *
If your drive has positive offset correction value and quantity of "zero" samples in end of CD is less than offset value, then you need overread in lead-out to exactly rip CD and overwrite in lead-out to exactly write it to CD-R.
If quantity of "zero" samples in beginning/end of CD is more than drive offset value, then audio data will not be affected.

I am not sure if I understood this correctly.

I use one of the old famous Plextor PX-716A. It's one of these units which has an offset of +30 (and therefore a offset of 0 according to the theory referred by the OP).

Till now I have thought that despite of having overread in & out I would lose a few samples if I used a +30 offset. So I had to chose between losing a few samples (that would be silence most of the time) and being abble to use AR or rip with a offset of 0, maintaining all "theoric samples", having the supposed absolute offset but not being able to use AR.

According to Rollin, there wouldn't be that difference in the number of kept samples due to the overreading capability. Is that assumption right?
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Posts in this topic
- guest0190   Why can't you extract all the data on a factory-pressed CD when it   Sep 5 2012, 21:28
- - AndyH-ha   Do the offsets have anything to so with anything e...   Sep 5 2012, 22:19
- - pisymbol   Is this the TAO (track at once) vs DAO/SAO (disc a...   Sep 5 2012, 22:59
- - 2Bdecided   There's subcode, HTOA, offsets, pregaps etc wh...   Sep 6 2012, 10:31
- - Rollin   If your drive has positive offset correction value...   Sep 6 2012, 14:09
|- - pisymbol   QUOTE (Rollin @ Sep 6 2012, 09:09) If you...   Sep 6 2012, 16:49
- - greynol   You need to take into account the offset of the bu...   Sep 6 2012, 15:11
- - greynol   Countless discussions on this forum, digital-inn, ...   Sep 6 2012, 17:31
|- - pisymbol   QUOTE (greynol @ Sep 6 2012, 12:31) Count...   Sep 6 2012, 20:15
- - Manlord   QUOTE (Rollin @ Sep 6 2012, 15:09) If you...   Sep 6 2012, 18:30
- - greynol   The greatest number of samples that can be replica...   Sep 6 2012, 18:55
- - guest0190   http://www.digital-inn.de/exact-audio-copy...se-of...   Sep 6 2012, 20:22
|- - db1989   QUOTE (guest0190 @ Sep 6 2012, 20:22) The...   Sep 6 2012, 21:24
- - greynol   Didn't we just have another discussion saying ...   Sep 7 2012, 01:51
- - hyman   QUOTE (greynol @ Sep 7 2012, 00:51) Didn...   Sep 7 2012, 08:12
|- - greynol   QUOTE (hyman @ Sep 7 2012, 00:12) From my...   Sep 7 2012, 12:30
- - guest0190   Thank you all for your answers. So if I understan...   Sep 7 2012, 16:15
|- - Porcus   QUOTE (guest0190 @ Sep 7 2012, 17:15) in ...   Sep 7 2012, 19:35
- - Manlord   QUOTE (guest0190 @ Sep 7 2012, 17:15) My ...   Sep 7 2012, 17:05
- - greynol   You won't be able to use CT to check titles ri...   Sep 7 2012, 17:10
- - guest0190   QUOTE You won't be able to use CT to check tit...   Sep 7 2012, 22:47
- - korth   Lack of programming to do cross-pressing verificat...   Sep 7 2012, 23:05

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