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Tools to measure DVD+/-R(W) burn / read quality?

DVD-R/W, DVD+R/RW, DVD-RAM

Postby Halc on Thu Aug 14, 2003 5:57 pm

cfitz, thanks for the test! I didn't even notice it was adware :(

I think the exact definition is not more than 280 erroneus rows (containing at least one errored symbol or byte) in eight consecutive ECC blocks.

This is not exactly the same as not more than 280 PI errors in eight consecutive blocks, just as my previous post is trying to (badly) explain. There can be more than just one PI error per row, so 280+ errors can be less than 280 errored rows.

That is, a disc with 280+ errors in eight consecutive blocks may or may not within spec, but a disc with more than 280+ erroneus rows in eight consecutive blocks is by definition out of spec.

My understanding is from a Karr's reply that Mediatek chipset only reports errors per ecc block, not number of erroneus rows per ecc block.

It's a slight difference, and could be averaged with probability assuming random distribution of errors, but still, if we were to measure disc readability within a drive according to specs, it would be nice to have the correct measures and units.

Currently KProbe has only numbers on the vertical axis in C1/C2 and PI/PO measures. If I've understood correctly the C1/C2 measures C1 and C2 stage errors per 75 sectors while PI/PO is row and column errors per ECC block.

It appears that both Pioneer and LiteOn DVD drives cannot return exact C1/C2 and PI/PO information to calculate conformance to disc standards.

Just as we cannot calculate BLER and BERL limits from KProbe C1/C2 measurements, we can't calculate DVD disc error limits from KProbe PI/PO threads.

Of course, this is not to say the scans are not useful, of course they are, I'm just trying how accurate the reported numbers are for a parictular reader/media combination.

regards,
Halcyon

PS I found another utility, for-pay CD/DVD Inspector, that has some sort of "Disc Readability test":

http://www.cdrom-prod.com/cddvd_inspector_screens.html

Probably not nearly as useful as Kprobe, but perhaps works on a wider variety of drives (?)
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Postby dodecahedron on Thu Aug 14, 2003 9:58 pm

looking at Arrowkey's website:
CD/DVD Inspector sounds good.
CD/DVD Diagnostic appears to be a downsized version of CD/DVD Inspecor.
comparison chart:
http://www.cdrom-prod.com/productcomparison.html
CD/DVD Diagnostic costs $50, and no price is given for Inspector (call for special pricing), my guess would be that the Inspector costs much more...probably prohibitively so.

mmm...browsing the website, some of their software sounds good...too bad it costs so much...
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Postby Halc on Fri Aug 15, 2003 3:13 pm

I also found out that EclipseSuite has error checking capabilities for DVD.

However, it is obnoxiously expensive, as it's meant for the professional premastering and authoring verification work.

I wonder if anybody has experience with it's dvd error checking?
Last edited by Halc on Sat Aug 16, 2003 2:20 pm, edited 1 time in total.
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Postby Halc on Sat Aug 16, 2003 2:02 pm

Back on the subject of DVD disc maximum random error count...

I read the ECMA 267 ("120 mm DVD - Read-Only Disk") on the ECC part and it states:

ECMA 267 standard wrote:"A row of an ECC Block (see clause 18) that has at least 1 byte in error constitutes a PI error. In any 8
consecutive ECC Blocks the total number of PI errors before correction shall not exceed 280."


So, if I understand that correctly, cfitz's original definition in this thread was spot on and my ramblings were wrong.

So, apologies for the confusion and wrong information (assuming, this time, I have finally understood this right).

This would also mean that Mediatek chipset report can be used to gauge the disc random PI error count (for that particular burn/reader), if the chipset reports running sum of eight consecutive blocks at all times (like cfitz earlier stated).

Also, I wonder if that would be PI error count before or after the error correction for rows has been applied?

Now, could we encourage Mr Wang to add this information (units) to the Y axis of his Kprobe utility's PI/PO test PI chart?

regards,
Halcyon
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Postby cfitz on Sat Aug 16, 2003 2:18 pm

Halc wrote:
ECMA 267 standard wrote:"A row of an ECC Block (see clause 18 ) that has at least 1 byte in error constitutes a PI error. In any 8
consecutive ECC Blocks the total number of PI errors before correction shall not exceed 280."


So, if I understand that correctly, cfitz's original definition in this thread was spot on and my ramblings were wrong.

Hey Halc, don't back down so quickly. I didn't respond to your earlier post because I could see I would need to sit down with some documents and try to sort it out in my head to a get a clear understanding, and I haven't had time to do it yet. But I don't think the quotation you just provided rules out your earlier contention that counts should be on a row basis. In fact, I read the quotation to support your earlier view, as long as you amend your statement to qualify that a PI error is a row that is in error.

I think you were trying to explain the right idea, and your main point was correct:

Halc wrote:I think the exact definition is not more than 280 erroneus rows (containing at least one errored symbol or byte) in eight consecutive ECC blocks.

The only place you might have gone a little off course is with the nomenclature, stating that there can be more than one PI error per row:

Halc wrote:There can be more than just one PI error per row, so 280+ errors can be less than 280 errored rows.

But your general idea that errors should be reported on an aggregate row basis was right, as far as I know. And the concern that KProbe might be reporting total symbols in error rather than rows with symbol errors as required by the definition of PI errors according to the ECMA 267 standard, was and is a valid one. Hopefully we can get an exact clarification from Karr as to whether the "errrors per block" count from the MediaTek chipset he reports as PI is true PI errors per block, or symbol errors per block.

Your questions are well founded, so don't stop poking around looking for answers! :D

Personally, I still want to sit down with some documents and learn more about DVD structure and burning, but I don't have the time right now.

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Postby cfitz on Sat Aug 16, 2003 2:43 pm

By the way, from what you have written regarding Karr's reply to your question, it sounds like whether the MediaTek data he is plotting is true PI errors (count of rows in error per ECC block) or the total number of symbols in error per ECC block, that he is plotting them on a block basis.

That isn't unreasonable, but it would be neat if we could get him to add an option to plot the running 8-block sum as well. That way we could have something to compare directly against the 280 PI errors per 8-blocks standard. As it stands right now, I think we need to eyeball the average PI error value on any given area of the plot and multiply by 8 to compare to the 280 error standard.

Maybe I will post a request in the KProbe thread.

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Postby Halc on Wed Jan 21, 2004 6:11 am

Any new development in this arena, except for a new version of Kprobe and UM Doctor Pro II as an additional tool?

Does BenQ, NuTech or Pioneer have anything up their sleeve?

Official, in-house only or anything?

Inquiring minds want to know.

Personally I think this kind of testing should become standard in burning applications.

The DVD burning quality is still quite apalling, imho and most of my friends are completely oblivious to it.

They think that burn is either perfect (when it work) or crap (when it doesn't work).

Binary logic

regards,
Halc
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Postby RJW on Wed Jan 21, 2004 11:14 am

I know plextor is looking into some testing tools for DVD writers. Still you never know with Plextor if we will get it and how it will turn out for the end support.

Pioneer uses to meassure there burns on other profesional analyzers not the burner itself.

Benq and Philips use a tester based on special Philips optical pick up. Not much info is given to third parties about this.

Sony tests in house these days with there Tester codevelopped by Datarius.
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Postby Halc on Wed Jan 21, 2004 4:46 pm

RJW,

thank you again for very enlightening information. Can you name your source for these info snippets?

I'm still trying to slowly dig into the c't magazine old articles, but I'm afraid not having studied German has proven to be quite a hindrance in my quest for more information :)

It seems to me that German computer magazines do the most interestings tests. British and American magazines are utterly useless and Finnish ones do not understand this subject at all.

Well, I guess it's never too late to learna new language :)

regards,
halcy
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Postby dodecahedron on Wed Jan 21, 2004 5:08 pm

Halc wrote:...and Finnish ones do not understand this subject at all.

well, that problem is easily solved.
you should start a new Finnish computer magazine! :)
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Postby Halc on Sat Jan 24, 2004 8:55 am

Has anybody got experience with or comments about using UM Doctor Pro II to measure PI/PO on dvd discs?

I'm really itching to buy that software along with Optorite burner, but if it's already deemded not useful software, then I'm not sure it's worth it. And it's not cheap either :)

Also, has anybody seen low level drive performance measurements for any Optorite models? Esp. jitter tolerances?

regards,
Halcyon
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Postby RJW on Sat Jan 24, 2004 12:28 pm

About the SANYO design based models.(Let's name it by there name since there are some others arround possibly all made by optorite in the end but still haven't got that one confirmed so I would name it this because the original design is Sanyo's)
Well UM Doctor Pro results are currently investet by some people over here. As soon as there is news I will let you guys know.

About low level performance ?
I haven't heard about options like jitter measurement for UM Doctor.
So if it is about the drives self measuereing jitter then I'm affraid to give you the dissapointing news that they probally can't.

If you mean how the Sanyo based models react on high jitter then here is some information (which should also be there in the C't burners test data post)

C't tested the MSI-DR4A (MS-804A) - in C't number 23/03,page 176
It could read 77,2 % of the rissing jitter and failure disc with firmware 2.23.
Which starts is a DVD-R starting at 8 % jitter and is highered to a jitter of 20 %.
Now how does this compare to the pulsetec optical pick up (Used in Audiodev)CATS analyzer) and the Lite On models.
Pulstec perfomed arround 60%
Lite On 811S (firmware HS06)-80%
Lite On 411S (firmwareFS07) -98,8%
I think the 401S results should also be there in the C't burners Topic.

Just checked and that one says just the maximum readable values.
LiteOn LDW-401S (ES0G) -17,4%
MSI DR4-A (2.21) =15,9 %
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Postby Halc on Sat Jan 24, 2004 1:28 pm

Thanks RJW.

That's exactly what I mean, the jitter tolerances of the drives themselves. I did understand that Optorites only offer PI/PO checking from the Sanyo chipset, no low level data.

I just want wider testing gear than just using KProbe. I think the jitter tolerance of Sanyo drives is so different (not to mention chipset being different) that I'll get more useful results hopefully by scanning with kProbe+LiteOn as well as UM Doctor Pro II + Optorite.

I broke down and bought DD0401. Now I just have to order UM Doctor Pro II at 77 euros + tax.

regards,
Halc
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