CATS vs. Home-made scans


 

 


Article:
CATS vs. home-made scans
Reviewer:
Jan70, OC-Freak & Spath
Provided by: AudioDev (S)

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The idea of this article is to compare disc quality scans obtained using professional tools (AudioDev's CATS) with the ones obtained from standard PC drives. We will also discuss about the correctness, accuracy and usefulness of these tools when it comes to disc quality measurement. Note that the comments and conclusions of this article reflect the views of CDFreaks and not the ones of AudioDev.

 Company information:

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Before we continue with this article let us take a look at the company information and what AudioDev offers at: www.AudioDev.com

AudioDev in brief

AudioDev is a world-leading manufacturer of test equipment for quality control of optical media such as CDs and DVDs. The head office is based in Malmé¶, Sweden. AudioDev has been listed on the Stockholm Stock Exchange since September 2000. AudioDev's products are sold under the brands CATS and Go!. The products in the CATS series are high precision analyzers for quality testing for all formats on the market. The Go! series is optimised for production control. AudioDev also offers an extensive service network as well as customised training and independent test analyses through AudioDev's TestCenters.

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The industry and our customers

AudioDev's operations are focused on the market for optical media. This market consists of:

  • Manufacturers of optical media (CD and DVD).
  • Manufacturers of optical media players/drive units.
  • Content owners who use CDs and DVDs to distribute their products.
  • Manufacturers of production equipment (test equipment, line manufacturing etc).
  • Consumers of optical media.

AudioDev's client list includes all of the above groups with the exception of end-consumers. Their main customers are manufacturers of optical media, such as Technicolor, Ritek Global Media, Sonopress and MBI. Other important clients are Microsoft, EMI, Samsung, Warner, Infodisc, Cinram, Panasonic, MBI, DAI Nippon Printing, and CMC.

AudioDev's clients can be found all over the world. The main markets being in Europe, USA and Asia. USA is the main market for pre-recorded DVDs. This is explained by the closeness to the manufacturers' customers i.e. the music, film and gaming industries. Demands for CDs are declining since DVDs are expected to replace the importance of CDs in Europe and the USA. Test equipment for recordable and re-writable formats is mainly sold in Asia, the main market for manufacturing these discs (CD-R/RW and DVD-R/RW, DVD+R/RW).

It should be noted that AudioDev does not only develop and sell test machines, but also offers test services for companies who do not own test equipment yet who are concerned with disc manufacturing quality.

What's driving the market?

The market for production equipment and, consequently, test equipment is driven by the fact that new optical formats are introduced at an increasingly rapid rate at the same time as the overall demand for optical media increases. Each new format increases the level of complexity, a fact that also applies to the development of existing formats. New, more complex formats mean that demand for advanced testing is growing.

Why testing?

Manufacturers of optical media and drives (the most important component in a CD or DVD player) are the two main groups using test equipment.

Manufacturers of optical media invest in test equipment to assure the stability of their production process and to make sure that their products meet a consistent level of quality.

Drive manufacturers invest in testing equipment to verify the compatibility between the disc and the drive. This is done to make sure that a disc can be put into any player worldwide and play or record without errors.

So what do we test?

A number of parameters are specified to ensure that the quality requirements for each CD and DVD format are satisfied. These parameters are monitored using test equipment.

There are various methods for testing optical media. AudioDev's equipment performs signal tests, i.e. checks playability using a laser to follow the track. The signal test is the largest test segment, as this actually confirms playability.

The other two ways of testing are: scanning the surface to check whether the surface layer has any visual defects, and testing whether the right information has been transferred from the master disc to the replica.

To sum up: Testing equipment is used to make sure that any consumer can expect their newly bought disc to play in any player '“ it ensures playability. It is also used to give the manufacturers a verification of a stable production process. Finally, testing equipment is used to make sure that the discs meet industry standard '“ the closer to the industry standard, the better the quality. AudioDev's products are the number one product on the market as they measure closest to the industry standard.

Test machine:


 For this review we will be using a computer with the following configuration:

Hardware:

  • Motherboard: ECS Elitegroup N2U400-A with Nvidia nForce 2 Ultra-400 and nForce MCP chipset.
  • Processor: AMD Athlon XP 2800+ (Barton) 333 MHz FSB.
  • RAM: 1 GB Infineon PC2700 DDR
  • GFX: ATI Radeon 9600 XT
  • Sound: SoundBlaster Audigy
  • Hard disk: Samsung SP1614N 160 GB.

 System set-up:

DMA (Direct Memory Access) and autorun was enabled for all the test drives:

  • LITE-ON DVDRW SHOW-1633S
  • Philips DVDR1640P
  • PLEXTOR DVDR PX-712A

Software:

Windows XP professional is installed on the computer along with Service Pack 2. We will be using the following software in this article:

CATS limitations:


When testing
disc or drive quality it is first important to realize that such tests do not deliver absolute values : a PI/PO plot always results from a combination of factors, which are a given media, a given drive and a set of operating conditions. Indeed, PI and PO errors are not values read from a disc like the book type or a logical sector number, but the result of a calculation performed by a DVD drive during a standard reading of the disc; for instance, CATS tools use either a Pulstec SDP1000 for the SA300 DVD Tester or a Philips CDM4 for the SA3 CD tester. This means that the errors reported by a CATS' drive (or a PC drive) can not only differ from the ones reported by another consumer drive, but also from the ones reported by the same drive with another firmware, or by the exact same consumer drive at another time. Obviously, severe physical defects will always cause errors, but all errors are not caused by physical defects, and the same physical defect can cause different amounts of errors on different consumer drives. This is why you should never compare PI/PO plots obtained with different PC drives.

So what is the point of using a CATS device instead of a PC drive if the PI/PO errors it reports are not absolute values? First of all, CATS use well defined calibrated drives, which ensure that all the results obtained with a given model will be much more consistent: this makes comparisons much easier for big companies where tests are done on multiple sites. Multiple tests on the same disc are not only more consistent than with consumer drives, but also more accurate, since CATS architectures are specifically designed for disc scanning. Nowadays AudioDev is a recognized and well accepted reference in the optical storage world and CATS are used by about all drive manufacturers. But the main advantage of a CATS is that it reports many more information than an end user drive: on top of the usual PI/PO and jitter plots, a CATS measures about 50 other parameters like reflectivity, asymmetry, signal amplitude, etc. All these physical information are probably meaningless to end users, but they give good insight about the media and can be very useful for professionals to investigate the root causes of burning or playback problems.

We present in the following pages the results of a few discs we tested with both CATS (SA300 family with Pulstec SDP1000 drive) and various popular PC drives. When needed, the results of software measurement tools were scaled to match PI SUM8 and PIF SUM1. Values in between parenthesis denote partial results, which means that the disc could not be played until the end by the drive. The goal here is not to find out which media or drive is best (this would require many more tests), but just to compare the results we get.

 

Head over to the next page where we will take a look at test disc # 1…


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