Checking burn quality with non-liteon drives

k i’ve got an nec 3500a and i just gave my bro my liteon 851s.

as far as i’m concerned, the nec doesn’t support P0/P1 error checking/scanning. how would i go about checking the burn quality with my nec without having to rely on a liteon or a drive with P0/P1 capabilities? i can’t afford to buy another drive just for testing and i don’t have any more free ide slots. are there similar tests out there that will let me test out my burns?

I have seen nothing yet that will do PI and PIF but based on my experience and those of others you will either have to have something seriously wrong with your drive or you will have to be burning to the worst trash in the world before you will get a bad burn. I have seen nothing yet that is not a great scan.

I would keep my eye on the scan section of this forum and avoid anything that looks dubious. On the good stuff I saw there I got the same results.

Yo-

Get a Sony LiteOn 166 or Sony 1621 DVD-rom drives - and achieve two things:

#1 have a kprobe compatable drive-

#2 have a more reliable reader that takes some burden off the 3500

All for around $25-

Mike

While you may differ, I have yet to see a reliable ROM drive that will do Kprobe scans. The error rates are way too high and they are not proportional to reality. They also create mistakes in being better than is accurate as well as worse. I am not alone in these observations. If you want to read PI/PIF get a burner.

There is a long thread here in this forum about the Aopen 1648 DVD-ROM reader. Some feel it is a reliable scanner using Nero CDSpeed. Others disagree. Read the thread and decide for yourself.

I OWN this Aopen and I have seen nothing that would lead me to believe that it is a reliable drive for use with Kprobe or CDSpeed quality scans. I have done numerous comparisons and the results are meaningless…

You cannot compare absolute values of scans between different drives, but the profile of a good or bad burn should still show up.

Some of CDRINFO’s Plextools scans show PO (or PIF) error higher than PI, which seems completely wrong as compared to a typical Liteon scan.

CDRinfo is misinformed comparing PO to PIF they are not the same. Thier reviews are flawed by this. PO in plex will show higher than PIE that is normal. To perform a PIF test you need to choose 1ecc test.

chas0039,

can you share data on those tests you’ve done. How are the results ‘meaningless’?

Matth,

scan profile of a disc can vary sigfnificantly from drive to drive, even to the degree that there is no correlation with scan profiles.

Which drive is then ‘right’?

Also, POE (byte level error at outer parity stage) is not PIF (row level correction failure at inner parity level).

Jamos,

CDRInfo is not misinformed. They use POE to indicate POE correctly. It was actually posters at CDFreaks who originally spread the PIF=POE confusion (because Karr had it mislabelled in kProbe). So, CDRInfo reviews are not flawed in this respect.

Just to correct the confusion, no harm meant.

best regards,
Halcyon

PS ObOnTopicTip: To the original poster:

There is not much you can do with Nec alone. You can do transfer speed tests, but those can be misleading as well (Nec is not the best reader). However, doing a transfer rate test in CD-DVD Speed is better than nothing. At least you’ll be able to spot some of the worst offending burns (for Nec as a reader, anyway).

I consider a scan meaningless when it fails to meet the following criteria:

A scan from a ROM drive should be proportionate in error rate across the scan when compared to a generally accepted Liteon scan. A Liteon scan would be accepted when multiple people are getting comparable scans from the same media burned on the same drive.

It should not show any anomalies in the shape.

It should correctly and proportionately indicate the difference in quality between two different burns on two different media.

It should indicate changes in error rates at the same sectors as the Liteon scan.

In other words, it should look like a Liteon scan just farther up the scale, never lower.

I, and others, have found that this is not true, in general, for ROM drives. I have found it not true on my 1648 AAP nor on my 167T. I do not dismiss the possibility that there is somewhere out there a ROM drive that meets this criteria nor do I consider it impossible for my particular ROM drives to be below others in quality. I just don’t feel it is worth the $30 difference when there is a generally accepted drive that works. I am also well aware of the fact that Liteon scans from a $60 drive are no where near the difinitive standard of measurement. However, people with significantly better equipment than I will ever own have seen Liteon scans that were reasonable indications of burn quality when measured against the industry standard. That is all I expect for my sixty bucks. ROM drives don’t seem to give that.

chas0039,

There is no guarantee that alls scans will always be proportionally similar to a kProbe/LiteOn scan. However, this is no proof that (either) scan is wrong.

There is much that is left to the implementation of the dvd drive, when one looks at how dvd discs should be read. Also, while the high level error correction mechanism is the same, the chip level implementations are not all the same.

These two factors alone bring about differences between drives (and their respective scans on same discs).

I have very high consistency with BenQ DW1620 and AOpen DVD-1648/AAP scans.

Also, scan to scan consistency (same drive, same disc) is very high on both.

Does this prove that they are more accurate than LiteON DVDRW drives? Of course not. They are just different.

I see no reason to trust 1648/AAP less than a LiteOn DVDRW scan (LiteOn dvd-roms are a different matter).

Let’s not the fact that the PI/PIF scanning got off on a big scale in the enthusiast community on LiteOn drives be a misleading proof to the fact that LiteOn drives are somehow a reference standard on how discs should measure. They are not that anymore than any other drive type.

Just fyi.

regards,
halcyon

If it works for you, great. I’ll stick with what I and others have found to be reliable.

That’s a very practical approach, albeit not scientific :slight_smile:

But I respect it. If it works for you, stick with it.

That’s what matters in the end to most: does it play back or not.

However, I’m after something more elusive: what is disc quality? what is burn quality? what is burner quality? how can they be repeatably/verifiably/accurately measured.

To this date I have no clear answers, although it is quite easy to disprove the hegomony of LiteOn as the only (and as such universal truth).

I am sorry you don’t get it, but my approach is scientific.

If you need help determining how to measure disc quality look at the site below. They have done a very good job making comparisons between scans from Liteon and other drives to scans from commercial equipment. It will take some time but if you really want to know it is worth it.

http://www.cdrinfo.com/forum/tt.asp?forumid=88

I have read all of the above. I respect CDRInfo authors. Like I do those, who sweat over the details here at CDFreaks and at CDRLabs. However, I think that several people here and elsewhere have quite reasonably shown that we don’t have a trustworthy universal disc quality scanning device at our disposal yet. Most mods here do understand this fact and most likely knew it before I did, even if for different reasons.

I have also read ‘Digital Audio Technology’ (Focal Press, 2001) and ‘DVD Players and Drives’ (Newnes, 2003) plus a couple years worth of ODS Magazine dvd tech articles.

Not that it makes the difference. Understanding the issue is what’s important.

However, rather than repeat my arguments here at length, I suggest you read:

http://tinyurl.com/4h4d4

It will take quite some time, but if you really want to undertand the issue, it could be worth it. It will not tell you everything, but it should dismantle the idea of kProbe/LiteOn as a useful ‘de jure’ measurement standard (de facto standard it could not be to begin with).

If you want to understand how dvd player reading implemenation works, I suggest the Ibrahim book (2003) above. ODS Mag articles are also quite useful in detailing how focus/offset tracking and slicer implementation are left to the reading drive (as is RSPC handling on chip level as an interplay with error correction and optical tracking control).

Also, as a last point, let us not forget that a scientific view on the error rate scanning data would require modern statistical analysis of the results, something which is yet to be done by any author here or elsewhere.

friendly regards,
halcyon

PS Your link was to the ‘firmware’ forum, but I assume you meant the ‘writing quality’ forum, which I’m quite familiar with, as you will see from my posts there.

Discussion over. Oh, and just so you know, my minor field of study for my Ph.D. was statistics and measurement. I know how to compare things.

Have a nice day.

chas0039, one of the problems with your position is that you keep saying “liteon scan” as if there were one magic Liteon drive for scanning. This is simply not true. If you scan with different Liteon models (811s versus 812s versus 1213s) you will get different results from Kprobe. If you stick with the same model, but change firmware, your Kprobe scan results will (sometimes) change dramatically.

My Benq 1620 is giving better results when scanning than my Liteon 1213@1633. Probably because the Benq is a better reader, so it reports fewer errors? The generally accepted wisdom here seems to be that the results of a scan from a particular reader should only be directly compared to results from the same reader.

Halcyon, I don’t think he is going to listen with an open mind to anything you have to say. People who say “Discussion over” when they don’t like what you have to say do not have an open mind, and are usually incapable of learning.