CDFreaks Presents: Home PI/PIF scanning article

Recently in the tests of H10A@H10N and H10A@H12N I had found strange situations with very good to perfect TRTs and very bad quality scans os the burned media.

My drives capable of quality scans are TS-H552U, SH-W162C and 160P6S. All Mediatek based. All these drives show scans very similar.

Another oddity is that H10N or H12N "bad scans" in 160P6S suffer from a less than perfect TRT in 4163B.

http://club.cdfreaks.com/showpost.ph...&postcount=158

Google brings you the answer in form of a DVDInfoPro Drive Suport List. Some NuTech drives are supported.

Search Google for nutech dvdinfopro

Just for comparison I scan the same media from this post http://club.cdfreaks.com/showpost.ph...&postcount=230 with samsung SH-w162C in 8x and the bad region in 2x and 4x.

Perhaps variable results but none is good.

The original scan was done with 160P6S.

Supported drives list

*EDIT* OOopps, me missed a page, me johnny come lately!

@muchin

* * Moved thread from Blank Media forum to Media Testing/Identifying Software sub-forum * *

@ pchilson

The trends of the jitter scans given by the Plextor drive and by the Lite-On are quite similar. However the max jitter value in the Lite-On scan is about two times that in the Plextor scan, yet the reverse is observed for the PIE/PIF max. How come? A plausible explanation is as follows:

DVDScan appears to report data-to-data (DD) jitter rather than data-to-clock (DC) jitter, which is adopted by DVD specifications; the former jitter may be two times as high as the latter in extreme cases.

Interesting, Maybe No Shock For Some.

Here's The BenQ 1640 Transfer Rate Test Of The Burn Above.
Please Note That The BenQ 1640 Is Housed In A USB Enclosure Using External FW BEFB.

No suprise as it's been pointed out many times that Benqs are not reliable when reported jitter levels get well above 12% as in your scans. Below 12% and they are fine.

I Was Just Reading Wendy Collins Great Article:
http://www.cdfreaks.com/reviews/Home...o-believe.html

And Decided To Do A Little Test Of My Own.

Yeah The BenQ Sure Gets The Jitters When Scanning Discs With High Jitter.
Doesn't Seem To Effect The Transfer Rate Of The BenQ.

Interesting results, I see that all the Mediatek chipset drives indicate similar results (though actual numbers differ to a large percentage), which give a slightly different view than the Sanyo chipset based Plextor drive. The 2 BenQs however are in complete disagreement with each other, which in this particular case shows the 1650 to be closer to the other drives from a qualitative view (if you compensate for the high Jitter magnification effect).

Though, if you are looking to some correlation to ECMA compliance, they are probably nearly all wrong I suspect (maybe the BenQ 1640 would be proven to be closer.)

@ Pulsee

It will be more interesting if you would scan for jitter with the Lite-On writers.

@Muchin

Retrieved Disc From Rubbish Bin.

Scanned 4x For Jitter On A Lite-On SHW-1635S (Check Out The Huge Increase Of PIF's Being Reported When Scanned At 4x)
Getting Closer To The Sanyo Chipset Results.

Pulsee

It is hard for me to believe that the Lite-On 1635 reports PIF of 7 when the PIE is only 8 at the same position, though it is not entirely impossible. Would you also use KProbe to do the test?

Your guess may well be right. But even though the error rates given by BenQ 1640 may be closer to those of CATS device, the differences between them may still be very large, for example:

BenQ 1640 vs. CATS

Lite-On 1635 vs. CATS

There is a really unbelievable difference in those scannings.
The problem is that BenQ and LiteOn give for good discs that CATS rejects. It was better the contrary one.

mognegna:

Could you rephrase that as I'm finding it hard to understand.

It may be of interest to you to read the review of Optiarc AD-7170A & preview of Lite-ON LH-18A1P on cdrinfo.com and compare the kind of results a professional analyzer gives compared to what is posted by users using consumer drives on this forum, it's interesting.

http://www.cdrinfo.com/Sections/Revi...rticleId=18307
http://www.cdrinfo.com/Sections/Revi...rticleId=18774

My Lite-On 1635 Will Be Off Loaded Friday To Make Room For A New Generation Drive. (It's Been A Great Drive. )

Sorry, I mean that it's not a good thing that LiteOn and BenQ give good PI/PIF values of discs that have high PI/PIF values with CATS. I would always prefer with them worse PI/PIF values than CATS.

Wendy Collins Review Of A Plextor PX-760A For CD-Freaks:
Has The 7 High PIF's And Low PIE's On BenQ Daxon AZ3 DVD+R 16x Too.

http://www.cdfreaks.com/reviews/Plex...rformance.html

Here's A Screenshot That I've Borrowed From The Review

The recent CDRInfo reviews using the DaTARIUS analyzer show that (almost?) all DVD fail the tests in some ways, and I can't remember a single disc in a single drive reviewed that didn't have out-of-specs PIE, PIF or POF when burned at 16x or 18x - only some of the DVDs burned at 8x in the Plextor Blu-ray burner stay within those ECMA specs for PIE, PIF and POF.

So the DaTARIUS is much pickier than most consumer drives. Does that mean that the DaTARIUS is right and the consumer drives are wrong, or does it mean that the DaTARIUS is wrong and (some of) the consumer drives are right?

No it doesn't mean either of those things. It only means that you get different results when scanning in drives with different reading behaviour. Current consumer drives are better readers than the original 1x generation of drives, so even if a DaTARIUS scan or CATS scan says that a disc is unreadable or nearly so because of Parity Outer Failures, the disc might be easily readable in current consumer drives. If OTOH a disc passes a DaTARIUS or CATS test then it should in theory be readable in any non-defective drive.

EDIT:

Just to clarify, this does NOT mean that I think that all consumer drives are as reliable or useful for scanning CD/DVD media as DaTARIUS and CATS scanners.

But it means that I think that no drive, whether it's a consumer drive or professional scanning equipment, has any monopoly on the "truth" about the quality of a CD/DVD. Such a "truth" does not exist in my opinion, since the quality is not an objective measurement but rather the result of interaction between drive and media.

It also means that I think CD/DVD media could still be readable on many consumer drives even if the media fails a DaTARIUS or CATS scan.

And finally it means that in my experience, it's possible for a CD/DVD to produce disc quality scans on consumer drives that are within ECMA specs, and the same disc can still be unreadable in some other drives.

Thanks to muchin for pointing out the possibility that my statements above could be misunderstood.

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Last edited by DrageMester; 29-11-2006 at 22:15. Reason: Added clarifying comments

Hi Drage
- probably the reason why I have to resort to tests putting more stress on the reading process (= scanning @12X or 16X) to achieve some sort of predictability for my standalone DVD players.. but not for my PC drives, which will all easily "eat" a disc passing a 4X, 5X (Nec) or 8X scan in any of my drives.

Yet, I'm more or less convinced that our burnt discs aren't nearly as good as we come to think by scanning them in Liteys @4X. ECMA standards were published at a time when our drives weren't so good readers (as you just -implicitely- pointed), and professional scanning devices could well still be, nowadays, calibrated to reflect this 'old' behaviour.... so are ECMA standards numbers to be applied 'as is' in home scanning? I highly doubt it. Though I don't see how we could introduce a different standard for error levels...

So one approach (the one you explain) is to consider that as drives are now much better readers, such bad results as shown by Datarius don't mean much in real-world, and Litey (or Benq) scans @-forum-standard-speeds (4X, 8X) can be trusted for most uses.

Another approach is to consider that our scanning drives are too good readers to properly reflect a burnt disc's potential reading quality in a wide range of drives, particularly in older (or cheap) standalone players. With this approach, one will not rely on a single testing drive but use at least two 'scanners', and/or put more stress on the reading process by scanning at higher speeds.

Both approaches are legitimate, and in fact reflect different necessities.

Personally, I use both.

For data/backup discs, a good-looking scan in a Benq or LiteOn or Nec (3540A ONLY - all other models highly suspect) @-forum-standard-speeds + a passed (= prefect) TRT in at least one drive and I'm good.*

For video discs, on the other hand, I scan in at least two drives, and at higher speeds. Only this way can I be (99%) sure that the discs will play flawlessly in most standalone players, including older ones.

*(Since scanning takes time, even for the data/PC discs I first use higher scaning speeds. Then if the error levels skyrocket at the end of the disc, I re-scan this area @ lower speed.)

-

Added clarifying statements to my post #122 above.

DrageMester:

Could you clarify that, within ECMA as measured by a consumer drive which can be agreed by a calibrated professional analyzer or something else?