Professional VS non Professional scanning (Full Version)

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cd pirate -> Professional VS non Professional scanning (6/6/2007 9:16:54 AM)

Just read the article. Don't know if there's a thread for it but I thought I'd start one since I can't find it.

Nice review. There seems to be little correlation between professional and non professional. I saw at the end of the article a mention about there being more comparisons like this.

I suggest for a future review on this topic that you guys use maybe only one or two media types and one burner. For example the Pioneer 112 and MCC03RG20 and MCC004 - two of the most available DVD medias. Then with the Pioneer, burn the media @ 16x 12x 8x 6x and 4x. Simply to see if results improve or decrease with the lowered speeds. It's a common belief that high speed media should not be written @ slower speeds yet this theory is often backed up only by what home based scanning results show.

I wonder if slower is really better or if faster is better for higher speed media? I personally have not had bad results even when writing @ 4x on media like MCC004. It scans a little worse in my home based drives but playback is always good, as are TRT tests in very fussy drives. It would be great if you guys did something like that.

Keep up the good work, this review has been a real eye opener [;)]



Tony Veglis -> RE: Professional VS non Professional scanning (6/6/2007 9:45:08 AM)

I should agree that testing discs burned at various speeds would be interesting.

We plan to add more measuremsnts in this article, with discs tested in different readers and other software like the popular CDSpeed.

In addition, changing the measuring speed in Kprobe for example, could give results closer in those coming from calibrated equipment. But again, the uncertainty is high when it comes to the repeatability of the results.

As a last note, heve in mind that a Pro system is used in the industry in order to monitor the manufacturing quality of a disc. For this reason, many different signals are examined, in order to easier isolate a possible factor that could affect the quality of a disc. Here, the goal is to examine how the writing strategy effects the readability of a disc, considering that the media are in perfect condition.



DrageMester -> RE: Professional VS non Professional scanning (6/6/2007 12:32:53 PM)

Thanks for the very interesting article!

Here are some comments that I also posted at CDFreaks in this thread:

10. CMC MAG AE1
quote:

Both sets of measurements report a major spike, but Kprobe shows it at the half way point whereas the DaTARIUS Analyser almost 2/3 of the way along. More importantly though, is the fact that according to KProbe, this burn is within specs, whereas the DaTARIUS Analyser clearly shows that PISum8 has exceeded the acceptable levels.


The author is not interpreting this correctly, since the X-axis on the KProbe scan and on the DaTARIUS scan don't show the same thing.

The X-axis for the KProbe scan is linear w.r.t. data (bytes) on the disc but unlinear w.r.t. to current radius from the center of the disc. The X-axis on the DaTARIUS scan is linear w.r.t. to radius position but unlinear w.r.t. data (bytes) on the disc.

The two spikes are actually in the same position on the disc, where 2/3 of the way in terms of radius position corresponds to half-way in terms of data (bytes).

15. DAXON AZ3

quote:

The measurements are comparable this time, since the result of the specific recording is very good.

Very good? The DaTARIUS scan shows a maximum PIF of 33!



cd pirate -> RE: Professional VS non Professional scanning (6/6/2007 5:31:50 PM)

quote:

ORIGINAL: Tony Veglis

I should agree that testing discs burned at various speeds would be interesting.

We plan to add more measuremsnts in this article, with discs tested in different readers and other software like the popular CDSpeed.

In addition, changing the measuring speed in Kprobe for example, could give results closer in those coming from calibrated equipment. But again, the uncertainty is high when it comes to the repeatability of the results.

As a last note, heve in mind that a Pro system is used in the industry in order to monitor the manufacturing quality of a disc. For this reason, many different signals are examined, in order to easier isolate a possible factor that could affect the quality of a disc. Here, the goal is to examine how the writing strategy effects the readability of a disc, considering that the media are in perfect condition.


Thanks for the reply, Tony. With using a different speed in cdspeed/kprobe to get closer results, I use 16x scanning at times since it can make the error levels rise dramatically on some discs which may not be very good burns. One other advantage of 16x scanning is that it's faster. [:D]

One more thing, as Drage said about the PIF max being 33 on the daxon AZ3 - Is the datarius an 8ECC PIF scanner or a 1ECC? If it's 8ECC that would explain such a difference in PIF levels.



Tony Veglis -> RE: Professional VS non Professional scanning (6/7/2007 4:17:34 AM)

Thank you for the useful comments DrageMester. You are right about the X-Axis issue, the Datarius system can either show radius (mm) or address on the X- axis.

Cd Pirate, the PIF signal is not defined in the DVD Book. PIF is the number of rows within an ECC Block with too many bad bytes to allow error correction. All bytes in the row are marked bad. Of course, it is measured in 1 ECC block.




Francksoy -> RE: Professional VS non Professional scanning (6/11/2007 3:56:28 AM)

Greetings everyone :-)
quote:

PIF is the number of rows within an ECC Block with too many bad bytes to allow error correction
... through PI error correction system. I.e. error correction can still take place through the PO (parity outer) system. ;)

That was for the record. :)

Now the reason why I'm posting here is that after having thouroughly examined all of the Datarius results you have posted in this article and in previous tests posted since you have the analyser, I'm enclined to think, from the systematically out-of-specs results for about any disc tested, that  something isn't quite right. I wouldn't be surprised that there is something wrong either with the Datarius analyser itself, or with its calibration (most likely).

Do you calibrate the analyser before each test with the Philips reference disc?

I would really like to see tests performed with your Datarius on commercialy pressed DVD-ROM and DVD-Video. This would give a reference to understand what's up.

Also you could ask the company itself if they consider the results that you get with their analyser as consistent with what other users of the Datarius system get....



Tony Veglis -> RE: Professional VS non Professional scanning (6/11/2007 6:33:49 AM)

As you realize, measurements done at a non-calibrated system are useless. The system is frequently calibrated with special test discs. Below you can see a screenshot of the signals measured in a DVD-ROM 5 disc. This is one of the discs used for calibration.






DrageMester -> RE: Professional VS non Professional scanning (6/11/2007 5:46:31 PM)

quote:

ORIGINAL: Tony Veglis

As you realize, measurements done at a non-calibrated system are useless. The system is frequently calibrated with special test discs. Below you can see a screenshot of the signals measured in a DVD-ROM 5 disc. This is one of the discs used for calibration.


Even the special test disc, which is of very high quality I suppose, shows a maximum PIF value of 11, where the ECMA standards specify a maximum of 4 PIF per ECC block!

The other values seem to be within specs.



Dolphinius_Rex -> RE: Professional VS non Professional scanning (7/23/2007 4:23:39 PM)

quote:

ORIGINAL: Tony Veglis

Cd Pirate, the PIF signal is not defined in the DVD Book. PIF is the number of rows within an ECC Block with too many bad bytes to allow error correction. All bytes in the row are marked bad. Of course, it is measured in 1 ECC block.



The PIF signal is not defined by the DVD Book, but it still a part of the specifications set down by the DVD+RW alliance I believe. DAXONAZ3 is a 16x DVD+R disc, so it should be fully applicable to the spec which requires no more then 4 PIF errors per ECC block, wouldn't it?



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