DVD Error Correction Tests

In the following tests we examined the DVD reading capabilities of the Philips JR4DVDRW drive with scratched / defective DVD media. For the tests we used Nero CDSpeed. The reference test media came from ALMEDIO.

We also tried to check the same discs with the CDVD Benchmark software but encountered problems.

- Single Layer media

ABEX TDR-821

This is a single sided, single layer DVD-ROM with 4.7GB capacity, and its surface has an artificial scratch of dimensions varying from 0.4 to 3.0 mm.

As we can see from the CDSpeed screen shot above, the Philips drive managed to read the contents of the defective area without reporting any problems. Notice the speed at the second half of the disc, is the same with this one at the reading test with the normal disc.

ABEX TDR-825

This is also a single sided, single layer DVD-ROM of 4.7GB capacity. The data structure of the disc is exactly the same as that of the TDR-821, with the difference that there are no scratches on the surface and instead defective areas ranging in dimensions from 0.5 to 1.1 mm. There are also fingerprints with height between 65 and 75 micrometers.

Once again the drive read the disc accurately, reaching for one more time it's maximum speed. The fluctuation towards the end of the disc is logical due to the artifial fingerprints.

- Dual Layer media

ABEX TDR-841

This is an 8.5GB dual layer, single sided DVD-ROM disc with artificial scratches of dimensions ranging from 0.4 to 3.0mm, on both layers.

Both layers were read without any difficulties by the Philips drive. No error occured. The resultant output graph is quite smooth and symmetric.

ABEX TDR-845

This disc is a single sided, dual layer DVD-ROM disc with capacity of 8.5GB. The only difference between the TDR-845 and the TDR-841 is that the first includes both defective areas and fingerprints. The dimensions of the defective areas range from 0.5 to 1.1 mm and the fingerprints have height sized from 65 to 75 micrometres.

This disc was also not a problem for the drive, finishing without any errors.

ABEX TDV-541

The TDV-541 is a single sided, dual layer DVD-VIDEO disc, with a capacity of 8.5GB.The disc is based on the TDV-540 series which is designed for inspection and adjustment of DVD-VIDEO players. The disc checks the layer switch operation from layer 0 to layer 1 and also includes test pictures and test signals for DVD sound files. The current TDV-541 also checks the error correcting capabilities of the drive and includes scratches sized from 0.4 to 3.0 mm.

Looking at the output graph above, we can easily conclude that the error correction capabilities of the drive are very good. Some instantaneous drops in speed didn't affect reading.

ABEX TDV-545

The TDV-545 disc is based on the TDV-540 series. It is a single sided, dual layer Video/S-2 disc with a capacity of 8.5GB. The TDV-545 includes artificial black dots on the disc's surface, sized from 0.4 to 1.0 mm. It also has 65 - 75 micrometre high fingerprints.

In the following screen shot, you can see how easily the drive read the TDV-545 disc. No errors were reported.