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Compare Kprobe Scans of DRU-710A & PX-716A

PostPosted: Mon Feb 21, 2005 12:38 am
by VideoRoy
I was having some problems with a DVD burned in my Sony DRU-710A so I decided to burn exactly the same image in my new Plextor PX-716A. I have not tested how it plays yet but I was a little surprised at the scan results. This is when I decided an I needed some experts to comment on what I am seeing.

I used the same media and burned the disc at 4x and scanned at 4x from exactly the same files using Nero.

Here is the DRU-710A firmware BY02
Date : 2/20/2005 9:54:57 PM
Model : 1-0-0-0 D:SONY DVD RW DRU-710A BY02
Disc : DVD-R , MCC 02RG20 [Mitsubishi Chemical Corporation]
Speed : 4x
ECC blocks sum (PI/PIF) : 8/1
Scanned range : 0 - 1838637
Sampling count : 98120
Errors : 0
PI Max : 10
PI Average : 0.95
PI Total : 13594
PIF Max : 3
PIF Average : 0.01
PIF Total : 123


Here is PX-716A firmware 1.04
Date : 2/20/2005 10:14:27 PM
Model : 1-0-0-0 D:SONY DVD RW DRU-710A BY02
Disc : DVD-R , MCC 02RG20 [Mitsubishi Chemical Corporation]
Speed : 4x
ECC blocks sum (PI/PIF) : 8/1
Scanned range : 0 - 1838623
Sampling count : 101168
Errors : 0
PI Max : 14
PI Average : 1.63
PI Total : 23607
PIF Max : 3
PIF Average : 0.12
PIF Total : 1789


To me this indicates that at least on this Verbatim media at this speed that the Sony is a little better strictly on the numbers. I need to test how it plays to know for sure.

Question #1 - Is this a valid test? Basically I can I read the disc burned in the Plextor with in the Sony with Kprobe and compare the results? I would assume it is valid since I believe the drive is reading the error rate.

Question #2 - Since I am not an expert on the numbers and their scale, is this all in the "noise" range and I am just looking too hard?

Thanks in advance for your comments.

PostPosted: Mon Feb 21, 2005 4:19 am
by dolphinius_rex
re: #1

The test is not "un-valid" but testing is not so simple for it to be called "valid" either really. What the drive is reporting is only THAT DRIVE'S perspective of the disc. One drive might read that disc fine, and another might have a terrible time trying to read it. The easy way to say it would be "every drive's scans are subjective".

Sadly, since K-Probe/LiteON drives are quite limited in their reporting abilities, you can't even really compare to scans very well. For example, the first disc you burned might have had extremely high jitter, but since K-Probe/LiteON drives cannot detect this, you would never know. On the other hand, the second disc might have excellently low jitter results but very high beta levels, but again, you wouldn't know...

re: #2

To me, those two sets of test results looked mighty similar to each other. You cannot go by absolute values of the numbers, but rather by the trends of the graph. You might see 5%-10% fluctuations between scans on maximum levels, and average error levels can be even more erratic, depending on which samplings are taken from the disc being scanned.

I suppose the short answer to this would be "Yes, you may be looking a bit too hard in this case" :wink:

Media testing is VERY confusing, and even those of us who spend 8+ hours daily running test after test after test on various drives with different parameters have a hard time understanding everything!! And there is always more to learn, and more mistakes to be made (I'm pretty good at that second one myself :wink: )

Good luck!! :)

PostPosted: Mon Feb 21, 2005 5:07 pm
by VideoRoy
dolphinius_rex,

Thanks for the help. I worked with magnetic media for many years, analyzing media / failures and optical is a different beast. Some of my knowledge of drives carries over but not much on the media side.

I think I have narrowed the particular issue I am chasing to the chapter points in my video but I believe the burn on the disc is somehow making it worse.

I am going to load up alexnoe's scan application and reverse the test with my Plextor reading the media this time just for grins.

BTW do you scan media and analyze drives for a living? I appreciate your expertise.

PostPosted: Mon Feb 21, 2005 6:07 pm
by dolphinius_rex
VideoRoy wrote:BTW do you scan media and analyze drives for a living? I appreciate your expertise.


I'm not so lucky as to be able to make a living off of scanning and media testing :cry:

HOWEVER, I do spend about as much time scanning and testing media as I do spending time doing my day job :wink: ...well, when my computers are working properly that is... right now is a bit of an exception :(

PostPosted: Mon Feb 21, 2005 8:06 pm
by rdgrimes
was having some problems with a DVD burned in my Sony DRU-710A

What kind of "problems" The numbers posted are of very little use without seeing the actual graphs, but based just on the numbers they are nearly identical in terms of "playability" on the scanning drive. That does not mean they will both play equally well on another drive. So, what kind of "problems" are you having?

PostPosted: Mon Feb 21, 2005 8:22 pm
by Scour
Hello!

The values are good. But can you only burn 4x with this DVD´s? I thought it was 8x-media?

PostPosted: Mon Feb 21, 2005 11:22 pm
by dolphinius_rex
rdgrimes wrote:
was having some problems with a DVD burned in my Sony DRU-710A

What kind of "problems" The numbers posted are of very little use without seeing the actual graphs, but based just on the numbers they are nearly identical in terms of "playability" on the scanning drive. That does not mean they will both play equally well on another drive. So, what kind of "problems" are you having?


Those numbers say NOTHING of playability on that drive. Only that the drive in question reports those types of errors in those volumes. There are several other factors that could cause playback problems which K-Probe is unable to test for, such as Jitter and Assymetry. I have personally run across several discs with K-Probe scans with numbers lower then that, that were unreadable in anything I popped them in, but could still be scanned. A transfer rate test will let you know more about the playability of the disc however :wink:

Now I admit, it is likely we would know if this was the case, because it probably would have been mentioned. But I prefer to not make assumptions about things either, nor do I like to make it a habit of giving information to new users that leads to bad habits.

PostPosted: Wed Feb 23, 2005 11:04 pm
by VideoRoy
Sorry I was offline for a couple of days and did not respond.

The video problem I had was that my disc would freeze for 1 or 2 seconds every so often and I figured out it was on a chapter point I had inserted at that spot from a hidden menu. This is part of my normal editing routine so it was not anything unusual. I had burned the DVD in the DRU-710A. I had this on a couple of DVDs that I did all around the same time.

I have since burned the same image exactly in the PX-716A at 4x on 8x media and the problem seems to have gone away. I am still going to analyze this some more but have not been able to devote enough hours to it since I need to watch the videos all the way through to know for sure.

I need to resolve this though since I do not want to waste editing time just in case this is not a burn problem. My working "theory" is that the burn from the 710A was causing my old Toshiba set top player to compensate a little more and when it hit a chapter point during normal play it had some more variables to deal with an paused.

I did capture the screen shots of the scan images if you are interested but I do not have a place to host them.

PostPosted: Wed Feb 23, 2005 11:14 pm
by dolphinius_rex
VideoRoy wrote:I did capture the screen shots of the scan images if you are interested but I do not have a place to host them.


That's ok. Just keep us informed on how things turn out! :)