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RE: New drives supporting PI/PO and Jitter measurements - 5/17/2004 10:13:00 AM   
Halc

 

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Joined: 2/4/2002
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Some questions to those of you using DVD Info Pro 3.0 beta:

- Does it test for PI (PI in the program UI), PIF (PI+ in the program UI), PO (PO in the program UI) and POF (in the program UI)?
- If not, then what are PI+ and PO+ stand for (those are taken from the DVD Info Pro UI)?
- Does it report scales at all? Or are all graphs without units and scales?
- If it does report scales, does it report absolute or relative DC jitter values?

And then to answer some questions:

- kProbe scans are not "safe" and cannot be trusted for general burn quality assessment.
- More than likely CDSpeed and DVD Info Pro (and Plextools Pro) scans are not "safe" either (on their own)
- The reason for the above is (in addition to the already mentioned reasons) that PI/PO/PIF/POF measures are CAUSAL. They are not real errors (in 99% of cases) on the discs. LOW LEVEL results (Reflectivity, DC jitter, wobble, asymmetry) are what cause the causal errors when they are high enough and exceed the reading tolerances of the drive used for testing.
- In addition, none of the consumer drives are calibrated to the degree that professional test equipment is. Unit to unit variance has already been shown (in the case of LiteOn) to be quite remarkable (some test discs as crap, while other units of the same model test them out to be ok).
- Hence, there is no universal/trustworthy consumer level testing gear for CD or DVD burn quality. If there were, Datarius and AudioDev would be out of business (among others)
- The above does not mean that the scans are useless or totally untrustworthy. It's just that one cannot say from any of the above programs if the burn is A) within specifications B) readable in most players supporting burned discs. One can relatively safely deduce though, that a burn is readable/unreadable in the drive model it was tested (excluding bad units of the same model that are really whacked out reading-wise).

Now to my opinions:

- IMHO All LiteOn dvd burning drives to date are quite bad: they are very untrustworthy as dvd-burners. They will not burn almost any of the quality media within DVD specifications. Even less so on crap/cheap media. I wouldn' trust anything important to LiteOn burns myself, if I wanted those burns to be readable in the future and in other drives than just LiteOn drives. This has been proven by countless CATS dvd scans of various LiteOn model dvd burns on various different media: almost all of them are out of specifications and most of them produce horrendous causal error rates. If you don't believe me, go buy C't magazine and PC Pro back issue archives and read the test results yourself (particularly the low level data, but also causal test results).

- To date, the best performing DVD burners I've seen reliable measurements for are LG GSA-4081/4082 and BenQ DV800A/822A (and their rebadged versions). I hope to see the later revision LiteOn DVD burners tested as well with latest firmwares and the same for Nec ND2500A and Pioneer 107D. However, the publicly available reliable tests to-date only show that those four drives are reliable for general dvd burning.

regards,
halcyon

(in reply to emperor)
Post #: 17
RE: New drives supporting PI/PO and Jitter measurements - 5/17/2004 11:52:46 AM   
emperor


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Joined: 4/28/2004
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Halc as usual your comments suggestions are interesting. From ourside we try to confirm what is going on and what we should trust or not. We never told people to trust 100% the famous KProbe scans and we have used them (and still using them) since nothing else was public available...

Things are now changing and hopefully we will be able to show our viewers trusty results

(in reply to Halc)
Post #: 18
RE: New drives supporting PI/PO and Jitter measurements - 5/17/2004 12:35:10 PM   
Halc

 

Posts: 60
Joined: 2/4/2002
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Emperor,

Please don't understand that I meant to offer any criticism towards you/CDRInfo.

Like I've said, I think you are to be commended for NOT having jumped blindly on the KProbe bandwagon like so many others. You are truly pushing publicly available understanding forward with your research on this issue.

I wish I had access to CATS dvd scanner as well. Those scans (i.e. simple scans/dvd disc) cost A LOT where I live.

I was merely replying to the whole thread in general and trying to give some facts and also personal opinions about various subjects dealt within this thread.

If you want, I can also discuss these issues privately at halcy at surfeu dot fi.

friendly regards,
halcyon

(in reply to emperor)
Post #: 19
RE: New drives supporting PI/PO and Jitter measurements - 5/18/2004 12:20:13 AM   
Dolphinius_Rex


Posts: 3310
Joined: 9/14/2002
From: Vancouver, B.C. Canada
Status: offline
You know Halc, if you just setup your e-mail in the control panel, you won't have to worry about writing your address in code on the forum to avoid spam bots

I too greatly appreciate CDRinfo.com's work on debunking the reliability of K-Probe scans! I was getting very close to utilizing them on my own DVDR media reviews, but have decided against it in the best interests of keeping quality and accuracy #1 on my site. I am currently considering the Nutech drive as an option, since it is providing at least similar graph shapes to the CATS Analyzer, unlike most of K-Probe's results.


_____________________________

Canada; Leading the world in being just north of the U.S.A.

(in reply to Halc)
Post #: 20
RE: New drives supporting PI/PO and Jitter measurements - 5/18/2004 5:45:16 PM   
emperor


Posts: 7210
Joined: 4/28/2004
Status: offline
Halc there is no problem, you can speak freely about your ideas and suggestions. There is no restriction, truly. We hope soon to deliver more interesting comparisons and true tests than throwing up KProbe scans without any meaning...

(in reply to Dolphinius_Rex)
Post #: 21
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