I produce DVDs for clients and quality control is important. I want to be able to test my DVDs so I downloaded Nero Disc speed.
I have looked in the Help and Manual but can't find information regarding what is a damaged disc and what isn't. Also I'd like to know if you use the scan disc and disc quality tab for testing your DVDs?
Any advice or pointers would be greatly appreciated.
DVDs use ECC (Error Correcting Codes) and so they can still play correctly even if there are a lot of unreadable bits on the drive. Even "good" disks normally have thousands of sectors where the data needs to be corrected by these codes. So the level of errors that's "unacceptable" is a rather nebulous determination. But according to the DVD specification the maximum number of allowable "Parity Inner Errors" (PIE) is 280 errors per 8 blocks.
More important in my opinion is the number of PIF (Parity Inner Failure) errors. Because of the way the ECC information is organized, you're guaranteed to be able to recover the data as long as there are no more than 4 PIFs per block, so that's the number I use for my own determination of what's acceptable and what isn't.
Most DVD drives can't report PIE and PIF error counts and so you won't be able to see them on the "Disk Quality" tab of Nero DiscSpeed. For my error scanning I use a Lite-On IHAS424 drive, which does have this capability.
I personally wouldn't have accepted that burn because the max PI failure count is more than 4. But I'm pretty anal about burn quality - disks can have a lot more errors than that and still be perfectly fine.
The real question is whether you're burning archival material to the disc that you want to be able to read in 10 or 20 years time (assuming computers still have DVD drives by then...). In that case you want the best possible burn right out of the gate to give you a bigger safety margin in case the disc degrades over time.
I would like to know your opinions on factory pressed (silver bottom) DVDs (as opposed to burnt discs) in relation to PIF's (Parity Inner Failures).
I can see that member sminlal states that a good figure is 4 or under. 5 or higher is not desirable.
Accepting that the figure of 4 or lower is the ideal my questions are these....
1) Is it possible to score a perfect 0 with PIF's?
2) Is a disc with a PIF score of 3 likely to crossover to a 4? And therefore will a 0 ever become a 1? Will a 1 become a 2? a 2 a 3? What I'm getting at is a PIF of 3 'almost' a bad disc?
3) Does it matter if the disc is a single layer DVD-5 or a dual layer DVD-9 with PIF's?
4) What sort of PIF scores do other members usually see with their factory pressed DVD-5's? Your DVD-9's?
For example members may state that 50% of their DVD-5 scans have a PIF score of 2 etc etc.
Why am I asking this? Well I'm anal with my scores but I also want to troubleshoot.
I noticed a very minor glitch on a Hollywood factory pressed DVD-5. Now the film is from 1932 so there's a strong possibility that its a glitch in the original film (Haunted Gold 1932). I received a PIF of 3 and a PIE of 19.
So technically speaking I have a healthy disc. Don't I?
So in a nutshell what I'm asking is that there a foolproof way of knowing;
Is the glitch likely to be from the source material OR an error with the disc itself?
- DVD-5 Factory Pressed flawless brand new disc.
- Zero scratches, zero fingerprints. Straight from
the factory sealed case into the DVD drive. Disc was
not loose in the case.
- Disc arrived and tested by me October 31, 2012.
I'm running this drive;
LiteOn IHBS212 12X Blu-ray BURNER
(ATAPI iHBS212 2)
I read on another Forum that the Optiarc defaults to reporting PI failures per 8 ECC blocks ... not per ECC block. So you are more likely to see PIFs of 8 than PIFs as low as 4 for good media like Verbatim and Taiyo Yuden. One poster recommended that as a rough guide, PIFs shouldn't be higher than 10. They also implied that you can change a setting option somewhere to report PIFs per block instead of "per 8 blocks". Here's a link to that Forum thread http://club.myce.com/f96/better-have-higher-pi-error-av...