DVD Error Correction Tests

In the following tests we examined the DVD reading capabilities of TDK drive with scratched / defective DVD media. For the tests we used CDVD Benchmark and Nero CDSpeed. The testing media referred, come from ALMEDIO.

- Single Layer media

ABEX TDR-821

This is a single sided, single layer DVD-ROM with a 4.7GB capacity, and its surface has an artificial scratch of dimensions varying from 0.4 to 3.0 mm. The following transfer rate picture comes from the CDVD Benchmark v1.21 transfer rate test.

The drive read the contents of the 821 test disc, without reporting any reading error. There were some speed deviations while reading the defective areas on the disc's surface.

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 of the TDR-821, with the difference that there are no scratches on the surface but defective areas ranging in dimensions from 0.5 to 1.1 mm. There are also fingerprints with height between 65 and 75 micrometers.

The drive managed to read the defective area on the disc without any noteworthy problems.

- 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.

Once again the disc was read without reading errors but some speed falls showed up, for both layers.

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 from 65 to 75 microns (micrometers).

The test finished successfully without reporting any error.

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 testing pictures and 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.

Although the drive performed well in the corresponding test with the single layer disc, it had same problems in order to read the defected scratched dual layer one. Both the beginning of the 2nd layer and the ending of the first one were not read correctly, as well as the areas from both sides of the switch layer point. However this behavior didn't confirmed in PowerDVD playback.

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 micrometer high fingerprints.

This time no errors or speed drops were reported. This disc was not a problem for TDK drive.