CD Freaks need to start using jitter tests

vbimport

#1

Recently I’ve noticed some of my discs with higher jitter 9% and above, will show great scans @ 4x. This is what cd freaks is using for their reviews. Look at the latest review: http://www.cdfreaks.com/reviews/Philips-SPD7000BD-Blu-ray-TripleWriter-Review/DVDR_RW-Writing-performance.html

I see K-probe and 4x scanning being used. When you have a disc with high jitter, scanning at 4x greatly increases the “quality scan” you perform. However when you scan at 8x or higher, things get ugly. Real ugly. Just take a look at these pics: http://club.cdfreaks.com/attachment.php?attachmentid=101213&stc=1
http://club.cdfreaks.com/attachment.php?attachmentid=101212&stc=1

Now my question is, why are CD freaks using 4x scanning only and no jitter either? I’d prefer to see a cd speed test result @ 4x with jitter or a K-probe scan with a DVDScan Jitter picture to go along with it. Just showing the PI/PIF totals is not enough in my opinion. Jitter is important, perhaps more so than PI/PIF, so why not include jitter results? The MCC004 discs I burn @ 12x on my LG4167B have horrible jitter at the beginning. They literally skip and jump in my DVD player.

Here’s another disc, different MID, different writer, -R media instead of +R. Jitter is high on this disc. It has problems playing. Yet just a 4x scan without jitter would be enough for CD freaks to say, this disc is ok, average, or maybe even good! I’d say “It’s pretty far out of spec in terms of jitter and has playback issues. Don’t use this disc with this writer”.

Do you fellow CD Freaks want more detailed scanning or am I the only one? Perhaps if enough people start asking for it, we may get some jitter scans with reviews. What do you think?

DVD scan pic of the Fuji disc: http://club.cdfreaks.com/attachment.php?attachmentid=101565&stc=1


#2

Count me in. :iagree:


#3

I agree jitter levels can really show how good a disc is going to play back so
count me in also. :wink:


#4

Another vote for high speed scanning and jitter tests.


#5

Is’nt x4 used as thats whats best for liteons ?? on at lest the earlier drive, which dont support jitter anyways. Ether way i would’nt mind seeing jitter tests added.


#6

Your dvdscan link isn’t working.

My LH-18A1P also shows a significant rise in PIE & PIF from the ~100MB point when scanning at 16x. Scanning the same disc on other drives it doesn’t show this rise. (the posted scans are more on the extreme side, on better quality scans the rise at 100MB point for 16x scans isn’t anywhere near that high, but still exists)

So my question is: Is the LH-18A1P just a crap scanner at 16x? Or are the poor 16x scans due to the jitter?


#7

I only do PIE/PIF and TRTs because it can take up a lot of time performing additional tests (but an additional high-speed scan is no problem if requested), if multiple burns are required, like earlier with a RW disc.

As for jitter scanning in reviews, maybe a Senior Reviewer will see this thread, and discuss it with the rest of us. :slight_smile:


#8

@ dicer, I have scans with good discs that don’t show big rises at higher speeds. The discs that I posted have big increases even at 6x and 8x scanning, let alone higher speeds.

DVD scan pic not working? Damn I posted it but it made the screen too big and I just posted the cdfreaks link. Guess that doens’t work. It’s bad nevertheless :stuck_out_tongue:


#9

Dicer, here are some pics of my LH18A1P and 16x scanning. The PI/PIF results actually get better with higher speed :stuck_out_tongue:

The disc was recorded with my pioneer 111L, which is a far better writer IMO than the Liteon.





#10

:iagree:
My vote is for ussing multiple drives and as much paramaters as these home testers provide.(And incase of modern lite on’s 4x is a joke without jitter !. To much problematic media falls true.)

However more data means you will have to think seriously about a good lay-out.
See Dolphinius Rex reviews on cdrlabs. Quite some info but there lay-out makes it hard to check up.

Better take the time for getting excellent reviews as rushing out those crappy worlds first §reviews (which might be slowly updated later). Don’t rush things !!


#11

That’s kinda expected with these Liteys, with good burns of good media: samples are dropped at higher speeds (check the statistics) and that’s what I came to consider as the reason why higher speeds showed lower errors in several scanning drives, but I stress the point: with very good burns.

When the disc or the burn is problematic, the higher speed putting more stress on the reading process, errors tend to raise, mainly near the outer edge.

That’s just a theory, though. :shrug: - works for me anyway. In the end that’s all I’m interested in.

Different drive models can have very different behaviours in this area, though: Recently I started scanning with a 16P1S DVD-ROM, and its pickiest scanning speed in terms of burning quality seems to be @8X. 4X, 10X, 12X, 14X and 16X give me false negatives (showing good scans of discs that stutter in my standalones and have troubled TRTs), except a the very end of the disc (assuming there is actual data burned there of course). So this model breaks the mould that I’ve been used to with Benq 1640/1650, NEC 3540A and LiteOn 1693S. There must most probably be others…!

So all this is far more complicated than it seems. :wink:

Inputting this because these considerations explain why, personally, I’m not requesting 12X or 16X scanning speeds as standards in reviews, :disagree: because it raises too many variables (number of samples, behaviour of the drive etc…). With Liteys, a 4X or 8X scan [I]combined with a TRT in a different drive[/I] is OK with me. As [B]Dakhaas[/B] mentions, multiple tests in different drives would definitly be a plus.

But if only 4X in LiteOn is used as scanning method, I can see no reason why jitter should not be reported in testing reviews. Thus the “count me in”.


#12

I would love to see that too!


#13

I think the makers of K-probe might have some sort of deal going with cdfreaks. Just a wild assumption, probably not true. I personally like the look and layout of cdspeed.

OT a little here but my H22N cannot seem to get below 9% jitter average with MCC004 no matter the speed I write at. Here’s the most recent burn. Take out the jitter and plenty of people might say “nice burn @18x!”

Put in the jitter and… it’s pretty much out of spec.



#14

KProbe was written by Karr, a LiteOn developer.
So it has the feeling of semi-officialness. :bigsmile:
But if it is preferred because of this, DVDScan should be used instead, as it has been superseded by DVDScan in its officialness. :wink:

But I prefer Nero CD-DVD Speed over KProbe too: The jitter scans, the non-hex x axis… :slight_smile:
And [B]ErikDeppe [/B]already announced that the next Nero CD-DVD Speed release will measure jitter after measuring PIE/PIF… so maybe it could measure PIE/PIF at high speeds and jitter at 4x. I want to try it right now :bigsmile:

Off-topic: What about a high-speed scan, [B]cd pirate[/B]? :flower:


#15

Damn thing took a few warm ups before it would scan at max speed! lol

Here you are :slight_smile:

Errors do increase but not too much. I watched the disc too, it works fine on my PS2. Somehow the H22N is good at burning with high jitter but making it playable :stuck_out_tongue:

There must be other factors I guess



#16

Back in the day there were “only” LiteOn and Plextor for quality scanning and both had a “dedicated” testing program and since everybody easily could obtain a LiteOn it was natural to use that option. I’d like to see jitter in Kprobe but besides that i can easily use that for QS. CDSpeed looks a lot nicer and has more features so i kind of agree it can be a better choice these days but frankly i don’t care. I never read the reviews anymore. I only watch the trends shown in this forum… and thanks for that :wink:


#17

Attack of the jitter. This PS2 backup wouldn’t load at all. Not even a loading screen. PIE a bit high, but would have expected it to play since crappy princo dvd-r’s usually do. The disc is branded SmartBuy, it’s a Prodisc made MCC004. Batch quality is ‘medium’. Usually 96-95 quality score with Benq scanning.

DVDscan -> terrible jitter!


#18

What burn speed and burner was used? Any chance that you could post a scan in a Benq as well? Thanks


#19

It was burnt at either 12x or 16x in either Benq 1640 or 1650 (I never burn any slower than that for this media).


#20

Thanks for backing me up and bumping the post dicer :slight_smile:

I recently have had some trouble with TDK003 discs. They scan a little crap, but jitter is high as hell on all burns with all my writers! No matter what, the discs skip here and there in my PS2.

As we can see on your DVD scan picture, the pits and lands are crap. Making it hard for the PS2 to read what’s on the disc. Try a 16x scan without jitter on your liteon and it may show some big increases in PIE/PIF.

I’d say jitter may be a big cause to why your disc doesn’t work well, there are probably a couple other factors as well but the main thing is that even if it did play, it would be sure to freeze in certain spots and fail to boot often.