DVD Error Correction Tests

In the following tests we examined the DVD reading capabilities of the TEAC drive with scratched / defective 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.

The 821 test disc was read without problems by the LiteOn 812s. The drive read the disc under CAV strategy and finished the test with an end speed of 12x. The yellow dots at around 500mb mark on the disc's surface, indicate that the drive changed speed in its attempts to bypass the defective areas, but despite this, the disc was read without any anomalies.

ABEX TDR-825

This is also a single sided, single layer DVD-ROM with 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.

On this test the reading performance of LiteOn was not as smooth as the previous test. The drive used CAV reading strategy and finished once again the error correction test with an end speed of 13x but with a slower average speed. During the reading process, the speed decreased from 9x to 5x just before the laser beam reached the fingerprints area. The LiteOn kept the reading speed at 5x for about 100mb but then was increased again to 10x. The test finished without reading errors.

- 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.

 

The LiteOn read the 841 dual layer test disc fast and without changes to the reading speed. CDVD Bencmark reported reading errors in the first layer of the disc at a point just after the defective area. On the second layer there were more speed changes as the drive tried to bypass the defective regions, but the overall process was not effected by this.

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 microns (micrometres).

 

So far, the drive has performed brilliantly and seems to be an excellent DVD reader with defective media. Here we can see a number of speed fluctuations where the defectiver regions are, but also a lot of activity around the layer switch.

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.

NeroCDSpeed reported that the LiteOn read the disc under CAV and as shown by the screenshot below, the reading speed of the drive was decreased momentarily at the beginning of the second layer but not during the switch layer operation. The test ended successfully without read errors.

 

 

 

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 micrometres high fingerprints.

 

The reading and error correction capabilities of the LiteOn with the Abex TDV-545 was perfect. NeroCDSpeed screenshot shows smooth reading under CAV strategy.