Analyzing scans properly

hi
i done a few scans now but lately the scans were little worse than they used to be (now i used daxonAZ3 from benq cause my burner is a benq and some verbs) and i’m asking myself if i should reburn them. i’m not at all very picky with my scans
also i done some scans from discs that i bought over the internet and most of them are terrible. much much worse than everything i ever burned.

so whats critical about a scan ? the number of spikes or the cumulative figure of PI and PIF ? what are all the limits ?
i uploaded one of the better scans of an internet-purchased disc - let me know if that one needs to be reburned

and what is the limit for PIFs (max. spikes) ? i always read it was 8 but here i read it’s 16… so is it 8 or 16? also i read that some spikes over the limit are nothing to worry about.

also i understand it’s a 50/50 % thing between proper burning and proper storing.
i just have my dvds in those paper cases and spindels stored in my closet.

That’s a scary burn! and here I was worried about my discs with PIF spikes of 5!

Seriously, though. I highly recommend you stay far way from those discs (Judging from the scans).

The upper limit specification for PIE errors is 280, and the specification limit for PIF is 4. Your PIE errors are high, but the PIF is 53 at the start of the disc. When such a burst appears at the very beginning of a scan, it can merely indicate a conflict with open programs and the drive start-up. Close all open programs and restart, and you will often find a much lower figure. However, since this burst is not at the immediate start of the disc, it may indicate physical flaws on the disc. Try another recording, and if the same burst appears, it may be due either to incompatibility with your drive or poor quality discs or both.

PIF errors higher than 4 can be resolved by many error correction systems. Significantly higher numbers make EC circuitry work harder, and at some point the drive will not be able to correct the errors. Each drive is a bit different; so the most conservative figure may be the specification of 4.

It would be nice to see a benchmark of that disc. :iagree:

That should be reburned. I think the original writer would be to blame for it. Perhaps crappy FW support made that Optodisc burn crappy.

What writer are you using right now? The benQ would be ok to use. Verbatim is also excellent media so I’d reburn with that @ 8x in the BenQ.

The most worrying thing about scans is PIFs and when the clump together. You have plenty of clumps and they’re also big. Not a good combination :stuck_out_tongue:

I think the limit for PIF’s are related to the scanning method used (its something about 1 ECC vs 8 ECC). If using 1 ECC the limit is 4 and using 8 ECC the limit is 32 (or 16).

i think mine as well as most are using 8 ECC. so is it 16 or 32 then ? i mean that is a big difference whether i should keep it below 32 or 16…
why all this bitching then when the pif a little over 5 or 6 ?

i enclosed a new scan which is a littler better from a disc i got today.
that should be ok then if the limit is actually 32… if not and i should reburn let me know

just a min ago a scan stopped suddenly : " no additional sense information"
whats that mean?


[QUOTE=torstn;1917561]i think mine as well as most are using 8 ECC. so is it 16 or 32 then ? i mean that is a big difference whether i should keep it below 32 or 16…
why all this bitching then when the pif a little over 5 or 6 ?

i enclosed a new scan which is a littler better from a disc i got today.
that should be ok then if the limit is actually 32… if not and i should reburn let me know

[B]just a min ago a scan stopped suddenly : " no additional sense information"
whats that mean?[/B][/QUOTE]

It means the drive cannot read the data from the disc

You might find what you are looking for here:
http://club.cdfreaks.com/f76/interpreting-pi-po-error-scans-80545/

When you run a cdspeed scan, look at the text window that pops up right when it finishes. It should tell you what ecc interval it is scanning at. If it is ecc1, the levels are 280 and 4. If it is 8, the error levels are 280 and 32. Acording to book standards, a disk scanned at ecc1, with error rates under 280/4, should play on the average player. The book standards only refer to ecc1, but since some drives cannot do it, you have to find an equivalent.

at ecc1, it reports the errors from 1 block. at ecc8, it reports the errors from 8 blocks. If each block has 4 errors, at ecc1 it will report 4 errors, at ecc8 it will report 32 errors (the total number of errors for all 8 blocks). The problem is, if you have one block with 32 errors, and 7 blocks with no errors, at ecc8 it reports 32 errors (not over the book standards limit if you translate the math), but at ecc1 (what book standard scanning is suposed to be done at), you will have 32 errors which is way over the limit.

In other words, mathmatically speaking, its 32, but as that will not expose some problem areas, many feel they should be lower.

[quote=ripit;1918324]…In other words, mathmatically speaking, its 32, but as that will not expose some problem areas, many feel they should be lower.[/quote] Actually there’s no single “correct” translation of the PIF<=4 limit for 1 ECC to a similar limit for 8 ECC. One such translation is PIF <= 32 but it’s not the best translation IMO.

A more detailed explanation can be found here.

hi
just curious to see if this is normal for a ORIGINAL DVD. thats a dvd from a new movie and i was amazed how bad the scan really is…


[quote=torstn;1919179]just curious to see if this is normal for a ORIGINAL DVD. thats a dvd from a new movie and i was amazed how bad the scan really is…[/quote] A lot of pressed DVDs produce thoroughly unimpressive scans, so I’d say your scan is normal, although some pressed DVDs produce better scans than this.

[QUOTE=DrageMester;1919186]A lot of pressed DVDs produce thoroughly unimpressive scans, so I’d say your scan is normal, although some pressed DVDs produce better scans than this.[/QUOTE]

ok i just thought people use pressed dvds as a reference for a perfect scan…

[quote=torstn;1920496]ok i just thought people use pressed dvds as a reference for a perfect scan…[/quote] That’s a natural assumption, but pressed DVDs (and also CDs) are not always of high quality when scanned - at least not when using consumer drives for scanning.

I have pressed DVDs as well as pressed CDs that are out-of-specs when scanned for PIE/PIF or C1/C2. Jitter is usually low however, but not all drives that can scan [I]recorded[/I] media for jitter will also scan [I]pressed[/I] media for jitter.

IIRC LiteOn DVD drives cannot report jitter for pressed DVD media, but Nexperia based BenQ drives can.

Dragemester is correct on all counts there :slight_smile:

The reason a pressed DVD can work with errors that high is that sometimes their reflectivity is just so much higher than a burnt DL media. Also look @ the jitter average, it’s around 7% for the whole disc and most burnt DL media would get around 8-9% average I believe.

The jitter lines are very spikey, which I don’t know is because of the scan speed. Perhaps DL media needs to be scanned @ 2x to make jitter look better. BenQ drives are sensitive to jitter so they also might show more errors because of jitter spikes. This is just an assumption for DL scans in a BenQ drive - I have no idea if it would make a difference. You can select a portion of the disc to scan in cdspeed if you ever wanted to try a 2x scan but didn’t want to wait an hour- just alter the “start” and “end” figures in CDspeed.