Trying to understand pi errors

iam trying to understand pi errors and pi failures…i have tested my verbatim’s 2.4x +r and what numbers should i be watching? e.g what is a bad number for pi errors and should i be looking at total errors or average? thanks

Here and here and here are good places to start.

Hi Raymond, before you even try a scan, how those the TRT look for those discs?

TRT is just as important if not more than an error scan. If you look at one of my threads you will see what is a perfect 4x scan of a disc I burned. In fact, it’s bloody spectacular! But with a problematic TRT and 16x scan that shows errors, it proves something was not burnt so perfect on that disc and it may give trouble to ultra fussy players.

Basically trying to understand the errors never actually works. You just gotta hope they are pretty much within spec and fully readable by your drives via a TRT. Determining actual playability of a disc with a scan is not possible. Bad scans can work better than good scans, so never get too worried about what you see.

As errors reported are not a measurement of what is on the disc, but a mere report of reading errors, the drive used for scanning plays a part (sometimes important) in the numbers reported: a so-so reader (example: NEC 4550) will report more errors, in these tests, than a good reader (example: LiteOn 20A1P), sometimes dramatically so.

Then, there’s the scanning speed: usually, higher scanning speeds make that more errors are reported (the reading process being more stressful) - though there are exceptions to this rule.

Then, add to this that some drives don’t report according to ECMA standards, notably NEC and PIONEER drives. So PI errors reported by these drives are not what LiteOn, Benq or Plextor report report as PI errors.

Then, some scanners are looney and report just senseless numbers, or wildly variable numbers from scan to scan (notably NEC drives with the exception of the 3540A).

Then, it is generally considered that numbers reported by DVD-ROM drives are not to be taken seriously (though there is some debate around that - I personally use a LiteOn 16P1S DVD-ROM for scanning purposes in controlled testing conditions, but that’s another story).

My point being: [B]unless you mention the drive used for scanning and the scanning speed used, both impacting strongly the numbers reported, your question can have no answer whatsoever.[/B] :slight_smile: - best thing to do is to post the actual graph if you want more or less sound comments on the “numbers”. :wink:

And remember, scans are useful for measuring variations from the same media on different burners or the same burner on different media, even then there are fundamental problems.

i ill try a trt test…is that just a benchmark test? i have a pioneer 112l with 8.21 firmware on it but will test and post for ya.

i tried and i can not save the test is says error? and on our stand alone dvd players or t.v what speed do they read dvd’s at?

Pioneer drives are not reliable scanners in my experience. This is debatable, but at least they don’t report PIEs as defined by ECMA standards. So part of what you experience is probably due to this. :slight_smile:

How to “save” the graph: take a look atgeno888’s CD<dummytag>Speed user’s guide. The procedure is in the “main window” part of the guide.

Standalone players read @1X (or slightly faster perhaps if there is a consequent reading cache - I’m not sure).

TRT is “transfer rate test”. It’s in the “benchmark” tab if you use CDSpeed.

ok here is my test…what do you think?

It can get no better than that, within the limits of the test.

The disc is readable at maximum speed on that particular drive, unfortunately, it still does not tell you about readability in other drives.

here is another dvd i just burnt again it is verbatim 2.4x +r cmc mag r01

Looks good mate. Pioneers are relatively fussy, if you can get a good clean read on every disc like you just showed now, there shouldn’t be any problems in a decent standalone player.

And as [B]Francksoy[/B] has said - most players only read at approx 1x. If you fast forward though, and there are problems, it could be due to a poorly written disc. I for one know that some discs stop or get stuck if I fast forward beyond 8x whereas good quality discs read fine no matter how fast I fast forward.

here is a scan of a movie my friend made 3 yeas ago it is made by prodisc fo1…wow is it bad i just wanted to show you guys

So you know, that is not necessarily a bad disc. There is no reason to assume that this disc will not play all the way to the edge in a normal player.

This is where error scanning adds to the available information and would tell us more about what is going on at the edge of the disc.

From my own experience with TRTs, I personally [I]would[/I] assume that some standalone players will have issues reading this disc. Not [I]my[/I] standalone player, though :bigsmile: (it’s stunningly tolerant! :eek: )

This is where error scanning adds to the available information and would tell us more about what is going on at the edge of the disc.
Sometimes they do. But sometimes PIE/PIF scans don’t show anything special near the end of such discs which nevertheless [I]do[/I] have reading issues, specially if these scans are performed in a LiteOn @4X. In my experience, such scans don’t tell anything about the absolute quality or potential reading performance. But you already know my point of view and we both know that we don’t agree on this, and no I’m not trying to pick up a fight :flower: - just inputting a conflicting opinion for good “relativist” measure. :slight_smile: (sorry for the possible poor wording).

In my book, a disc causing a dip in a TRT in [I]any[/I] decent drive is far more suspect than a disc showing so-so PIE/PIF figures in a scan. Why? Because a TRT is a real-world [I]reading[/I] test, it actually retrieves user data, and puts into light the possible bad mechanical characteristics of a disc (marginal tilt etc…) instead of just the low-level burning quality of the disc, which is what “standard” scans (LiteOn @4X, Benq @8X…) are all about.

Granted, in most [I]quality[/I] standalone players, most discs will play, unless the media is really bad or really badly burnt. But this is not enough to excuse poor reading performance, which can be, among other things, an early sign of possible failure of a disc which has poor stability… :sad:

See, my perspective is that TRT test is [I]not[/I] a real world test, especially at the edge of the disc where the drive is spinning at 12X and above. Players read near 1X; for me, that is real world. I can’t really see the relationship between TRT 12X problems and real world 1X reading. I [I]do[/I] see the relationship between 1X reading and an increase in PIE and PIF errors and my experience seems to confirm this. I have found discs that have problems exactly where the really bad errors are located, while I have not seen the the same correspondence with TRT errors.

Anyway, differences of opinion make for an interesting forum. :slight_smile:

Not trying to shoot you down, but TRT is a real world test whether you consider it to be or not. I can see the relationship as some cheaper DVD players/fussy ones are extremely intolerant to read errors, bad burns etc. Consider that a Pioneer may be many times better than a fussy dvd player, if the Pioneer struggles, the fussier player may certainly fail at the same point, regardless of the pioneer reading @ 12x or not.

You may not see any correspondence with TRT errors because the drives you are using are just far better than your readers, which solidifies my point that some DVD writers are many times better than a DVD player. Most burns that fail or show problems during TRT almost always show large increases in PIE/PIF errors in a scan.

Basically, I’d prefer a disc with loads of PIE/PIF, let’s say like 4,000 PIF spread evenly throughout a disc and 300,000 PIE that TRT perfectly on ALL my drives including my fussy ones over a disc that has totals of 18,000 PIE and 100 PIF but TRT slowdowns on a couple drives.

Btw, I agree that discussions like this make things interesting on the forum :iagree:

That is exactly the point I am making. You can disregard this fact, but 12X is not a real test of what any player will experience.

Regardless, as is often the case, we will disagree until you can show me just how 12X reading relates to 1X reading, and is actually better than a measurement of errors. Think about it for a minute; why is the drive experiencing a problem reading at 12X? Errors? If not, then what? And how does the read problem, if it is not errors, relate to a player at 1X. If it is something like disc instability, will it be there at 1X? Will it increase over time as will errors? If it is the drive’s problem it clearly cannot be used to determine player readability.

I prefer errors because an error is just that, an error. No one in this forum will say that they prefer [I]more[/I] errors and clearly they are not good and they increase over time.

In both cases, there is a difference between what our recorders see and our players see so we are probably both blowing smoke. I still use both measures to check for problems but I consider the TRT test a gross test of readability whereas the scan is a fine test.