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Appeared on: Tuesday, June 05, 2007
Professional Vs non-Professional DVD Writing Quality Tests


1. Introduction

On request from our online site visitors, we have written a brief article that puts side-by side the writing quality measurements produced by Professional DVD Analysers and those from software and commercial readers. Although there are not many similarities between the two approaches when measuring the quality of a DVD recording, this article does attempt to fulfil the high interest of DVD recording enthusiasts who are seeking for an answer as to how, if at all, the two approaches correlate.

In this article, we are going to compare the results of quality measurements from our DaTARIUS Analyzer, and KProbe software with the LiteOn LH-20A1P drive as a reader. The discs that we will use in the test, were burned with two different drives, the Pioneer DVR-112D and the LiteOn LH-20A1P. The writing speeds that we used range from 8x up to 20X. Note here, that there are many drives capable of reporting the information needed to support a DVD measurement using Kprobe or Nero's CDSpeed software. However, we chose Liteon's latest drive as the reader and Kprobe software for this test, for sake of simplicity.

Since KProbe only has the capability to measure the PI and PIF error rates, we will focus only on these values. The quality measurements from KProbe were performed at 4X reading speed since this is a commonly used speed, and those from the DaTARIUS Analyzer at 2X. In addition, we have excluded the numerous other measurements provided by the DaTARIUS system, and provide only the PISum8 and PIF signals. Kprobe settings were set to PI error reporting on every 8 ECC blocks (PISum8).

The media we used is listed in the following table:

DVD+R
CMC MAG E01 000
8X
DAXON AZ3 000
16X
RICOHJPN R03 004
16X
YUDEN000 T03
16X
DVD-R
CMC MAG AE1
8X
DAXON016S
16X
MCC 03RG20
16X
TTH 02
16X

Before we proceed, we remind you the definitions of the signals we measure in this test, PiSum8 and PIF.

PISum8

The Parity inner code error is a continuously measured value, reported for every megabyte. This is the number of Parity Rows, summed over 8 consecutive ECC Blocks, containing bad bytes. Measurements are performed over 8ECC blocks. (256 kilobyte). The specifications indicate that PiSum8 should not exceed 280.

PIF

The Parity Inner code first level Fail is a continuously measured value, reported for every megabyte. 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. The signal is not specified in the DVD Book.

 


2. CMC MAG E01 000 DVD+R disc

LiteOn LH-20A1P - burning at 8X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PISum8 Max
23
92
PISum8 Average
2.73
13
PIF Max
4
19
PIF Average
0.09
1

Here we can see quite a difference in the error levels. Although both approaches report that the digital errors PISum8 are below the limits, the Kprobe software appears to be less sensitive and reports a much lower level of errors.

What is common, is that both approaches indicate that digital errors are more prominent at the beginning of the disc.


3. DAXON AZ3 000 DVD+R disc

LiteOn LH-20A1P - burning at 18X

-The reading process

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
12
608
PI Average
1.05
74
PIF Max
3
33
PIF Average
0.05
5

This time the differences are much greater. The DaTARIUS analyser reported that the disc was out of specifications, with the PISum8 reaching 608. In contrast, the Kprobe results indicate a very good burn, with some PIFs.


4. RICOHJPN R03 004 disc

LiteOn LH-20A1P - burning at 16X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
14
250
PI Average
1.86
60
PIF Max
3
106
PIF Average
0.05
4

The trend continues and again we see big differences between the results of the two methods. The disc is readable, and the two graphs for PISum8, show similarities in the general trend but the DaTARIUS analyser is much more sensitive. PIF reports on the other hand, are completely different.


5. YUDEN000 T03 disc

LiteOn LH-20A1P - burning at 20X

-The reading process

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
10
240
PI Average
0.57
21
PIF Max
2
55
PIF Average
0.01
2

Here, there's no match in the trends. Completely different results from the two sets of measurements.


6. CMC MAG AE1

LiteOn LH-20A1P - burning at 8X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
131
160
PI Average
35.02
40
PIF Max
4
55
PIF Average
0.15
7

Here are some results of interest. The PISum8 error graphs are nearly identical and levels are almost the same, while the PIF errors still show quite a difference.


7. DAXON016S

LiteOn LH-20A1P - burning at 18X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
37
334
PI Average
7.04
137
PIF Max
5
47
PIF Average
0.20
4

Big differences again.


8. MCC 03RG20

LiteOn LH-20A1P - burning at 16X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
31
149
PI Average
3.15
18
PIF Max
2
10
PIF Average
0.03
0

The trend for both PI and PIF are similar but again the DaTARIUS Analyser show that it is much more sensitive.


9. TTH 02

LiteOn LH-20A1P - burning at 18X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
443
1333
PI Average
54.27
338
PIF Max
16
332
PIF Average
0.40
16

We see here another example where the trends for both PI and PIF are the same with both KProbe and the DaTARIUS Analyser but there is again a big difference in the actual levels.


10. CMC MAG AE1

Pioneer DVR-112D - burning at 12X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
42
374
PI Average
4.48
49
PIF Max
2
279
PIF Average
0.06
33

Both sets of measurements report a major spike at the same position of the disc. Notice that the X-axis on the Datarius graph indicates radius (mm). 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.

Looking at the Nero CD-DVD Speed graph, it is nice and smooth but there is a tiny downward spike around half way which corresponds with the KProbe graph. This clearly shows that these measurements are in the main, dependent on the drive being used to do the reading.


11. DAXON016S

Pioneer DVR-112D - burning at 16X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
30
387
PI Average
1.39
50
PIF Max
2
95
PIF Average
0.02
2

The DaTARIUS scan shows that PISum8 exceeds the limit of 280, whereas although the KProbe scan does show an increase at the same point, it is well within limits.


12. MCC 03RG20

Pioneer DVR-112D - burning at 18X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
1223
3135
PI Average
29.16
366
PIF Max
63
1419
PIF Average
4.08
112

Bad writing quality and both methods report it so. There is a similarity in the graph trends but the levels are different. However, the results are closer this time than they have been with previous discs tested.


13. TTH 02

Pioneer DVR-112D - burning at 12X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
148
321
PI Average
23.01
72
PIF Max
4
92
PIF Average
0.07
7

Again, because of the sensitivity of the DaTARIUS Analyser, this disc's PISum8 has been found to be out of specs whereas KProbe shows no such indication.


14. CMC MAG E01 000

Pioneer DVR-112D - burning at 8X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
391
1716
PI Average
10.07
328
PIF Max
17
479
PIF Average
0.78
23

Both sets of measurements clearly show problem areas with this disc Kprobe gives an indication that the disc is out of specifications but again, the differences are huge. Possible quality issues in the suspicious areas are reported by both systems.


15. DAXON AZ3

Pioneer DVR-112D - burning at 12X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
13
47
PI Average
1.71
15
PIF Max
2
33
PIF Average
0.01
5

The measurements are comparable this time, although the reported PIF level from Kprobe is lower than the corresponding from the DaTARIUS system.


16. RICOHJPN R03 004

Pioneer DVR-112D - burning at 12X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
11
360
PI Average
1.48
127
PIF Max
3
74
PIF Average
0.05
5

There is huge difference in both the error levels and graph trends.


17. YUDEN000 T03

Pioneer DVR-112D - burning at 18X

-The reading process

 

-KProbe test

-DaTARIUS scan

-Comparison Chart

  Kprobe DaTARIUS Analyzer
PI Max
17
423
PI Average
2.06
50
PIF Max
5
38
PIF Average
0.08
4

Totally different results. Kprobe indicates very good burning while DaTARIUS shows problems arising at the end of the data area.


18. Conclusion

The aim of this review was to provide the results of media quality measurements performed with both a professional and non-professional equipment. Technically speaking, it really isn't wise to compare the measurements produced by a professional test system such as the DaTARIUS Analyser with those provided by a common off the market drives and PC application such as KProbe. The reason as we saw in all the results of this review, is that the latter lacks the sensitivity and accuracy.

The drive used in the DaTARIUS Analyser is calibrated regularly, leading to consistent measurements, something that is not possible with a PC drive. On a home brew PC system, the drive, no matter how good, will with time degrade in performance. Another factor is that with different drives, totally different results will be produced.

When testing a DVD disc, the reader produces an analogue HF signal, which is then processed using techniques that are highly reproducible. Although our aim may be to ‘test’ a disc when doing electrical measurements on optical media, what we are really measuring is how the drive interacts with the disc. If the drive itself introduces additional noise or defects to the analogue HF signal, these could easily be misinterpreted as a disc problem. This is a common problem with home-made DVD quality scans. The key design requirements for drives are specified in the physical format specifications for DVD, and it is critical that the drives used have a very high level of reproducibility – with the absolute minimum of variations between samples.

If the drive characteristics are not constant, then it will not be possible to have a reproducible test system to accommodate and correctly measure DVD burning quality. To do this, close attention has to be paid to the quality and consistency of the drive’s component parts and the consistency of key elements such as the actuator, optical components, laser diode, etc. A high quality of mechanical stability, especially from the spindle motor, is also required –especially for the higher rotational speeds.

We tried to keep test conditions constant in all our tests. Also, we selected the 4X speed for testing with KProbe because this value is used by many users when performing media tests at home, and also it is closer to the speed used by the DaTARIUS Analyzer (2X).

- The Results

The majority of the media measurements performed with the DaTARIUS Analyser, showed error level which were much higher than those produced by KProbe and the LiteOn LH-20A1P drive. Most of the times, the maximum value measured by KProbe, was equal to the average produced by our professional tester. There were times when the graphs for both PI and PIF errors, produced by both testers followed the same trend. But this was the exception and on most occasions, while Kprobe reported a perfectly good disc, the DaTARIUS system showed significant problems. Inconsistency issues are obvious here.

While a non-professional setup can sometimes provide us with information on where the error levels peak and where they are at a minimum, they can not give us a true image of the disc's quality. Most of the discs, while exceeding the error rate limits in the DaTARIUS test, were shown to have negligible errors with KProbe. Keep in mind, that exceeding the error limits does not make the disc unreadable by an optical disc drive, it just shows us that an increased level of digital errors are present, which can lead reading errors. Nevertheless, there were a few cases in which the measurements with KProbe approximated those of the DaTARIUS Analyser. While the difference between the two systems was expected, it was not possible to find a relation between the two ways of testing media.

In the future, we are going to expand this review and add tests with more burnings, drives and speeds, as well as other non-professional software such as CDSpeed.



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