DVD Error Correction Tests

Ricoh MP5240A

In the following tests we examined the DVD reading capabilities of Ricoh MP5240A with scratched / defected DVD media. For the tests we used CDVD Benchmark and Nero CDSpeed . The reference test media 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.

Ricoh MP5240 managed to read the contents of the scratched single layer DVD-ROM correctly, without any errors be occurred. According to the transfer diagram, the drive gave a smooth performance and the transfer rate was gradually increased to 8X towards the outer parts of the disc (8x CAV).

ABEX TDR-825

This is also a single sided, single layer DVD-ROM of a 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 it but defected areas of dimensions ranging from 0.5 to 1.1 mm. There are also fingerprints sized between 65 and 75 micrometers.

As in the previous test, the drive ignored the defected areas and read the disc contents accurately, while the reading speed was 8x CAV, as it was expected.

- Dual Layer media

ABEX TDR-841

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

With the dual layer DVD-ROM, Ricoh DVD+RW MP5240 finished the test without reporting any read errors. The drive started reading each layer at 4.8x and reached the 8x at the end of each layer. Between the 3.300.000 and 3.500.000 sector of second layer, the drive needed to slow down momentarily in order to bypass the erroneous areas, without, however reporting any problem.

ABEX TDR-845

The disc is a single sided, dual layer DVD-ROM disc of a capacity of 8.5GB. The only difference between the TDR-845 and the TDR-841 is that the first includes defected areas and fingerprints. The dimensions of the defected areas range from 0.5 to 1.1 mm and the fingerprints are sized from 65 to 75 micro meters.

Once again, the Ricoh drive performed well and read the disc accurately.

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 upon the TDV-540 series which is designed for inspection and adjustment of DVD-VIDEO players. The discs check the layer switch operation from layer 0 to layer 1 and also include test pictures and test signals for DVD sound files. The current TDV-541 checks also the error correcting capabilities of the drive and includes scratches from 0.4 to 3.0 mm.

In this case the drive did not perform as we expected. Although the first layer was read at 8x CAV, the second layer was harder to be read and the drive slowed down to approximately 4x. The second layer was read at 4.5x~2x CAV (OTP).

ABEX TDV-545

The TDV-545 disc is based on the TDV-540 series. It is a single sided, dual layer DVD-VIDEO disc with a capacity of 8.5GB. The TDV-545 includes artificial black dots on the data surface, sized from 0.4 to 1.0 mm. It has also 65 - 75 micro meters fingerprints.

This time the drive read both layers accurately, obtaining the maximum 8x CAV speed for both layers.