5. DVD Error Correction Tests
AOpen COM5232 / AAH - Page 5
DVD Error Correction TestsIn the following tests we examined the DVD reading capabilities of the tested device 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
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 first test disc from the Abex series was not a problem for the AOpen combo drive. The drive finished the error correction test with a fast end speed and CDVD did not report any read errors. Notice however, in the region with scratches of larger dimensions, the drive changed speeds often (dense collection of yellow dots a little after the 1.000.000 sector) in its attempt to overcome the defects
ABEX TDR-825This 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.
Once again the AOpen COM5232/AHH finished the test without errors and with fast reading speed.
- Dual Layer media
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 above screenshot comes from CDVD and shows that the tested device read the effected dual layer DVD-ROM without producing any read errors. In first layer the drive encountered a bit of a problem half way through the defective region but managed to overcome this. The second layer which has the same defects as the first, was read without any deviations to the reading speed.
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 (micrometers).
Here too, very good error correction performance. The screenshot shows temporary changes to reading speed at the beginning of the test and smooth reading process until the end. The overall performance of the AOpen could be considered as quite acceptable.
ABEX TDV-541The 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 CAV reading strategy with fast average speed. During the error correction test, no errors occurred but the drive changed reading speed momentarily after changing to the second layer.
ABEX TDV-545The 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 micrometers high fingerprints.
Fast and smooth reading process without reading errors, as the above screenshot shows.