Kiss DP-1000 DVD Player - page 3

Error Correction Tests

Here, we try to simulate one of the most interesting problems faced by the average user while using a DVD player, the reading accuracy of a DVD player when accessing a defective or scratched DVD or CD disc. Of course, the performance of the drive here has to do with the quality/precision of the mechanical parts (Optical Pickup Unit, sufficient servo control, etc) as well as with the drive's reading strategy under abnormal conditions, controlled by the main chipset and firmware commands.

So, in order to test the abilities of the Kiss player against several types of defects, we used the ABEX series from Almedio which offers a good indication of the error correction capabilities of a CD/DVD reader. In addition, we used the SBC444A test disc from Philips and the CD-Check test disc from Digital recordings.

DVD-Video

• Abex TCD-545

This is a single-sided, dual layer (S-2 type, OTP) disc with 8.5GB capacity. The disc can be used for checking the layer switching operation from layer1 to layer 0. The disc also includes test pictures and test signals for Dolby Digital, linear PCM (48kHz/24bit, 96kHz/24bit) and others to check for high quality picture and sound. The disc contents is an MPEG-2 NTSC DVD-Video file. Apart from the disc contents, the TCD-545 includes defects on the disc area (black dots and fingerprints). The size of the black dots varies from 0.4mm to 1.0mm. Fingerprints are sized from 0.065mm to 0.075mm.

Although a graphical presentation of the transfer rate when reading the test disc is always enlightening, it is not an easy task when you test a non-PC DVD player. As a result, we used the test disc as a normal DVD-Video disc and checked whether it is recognized and played correctly, with detailed navigation through the tracks and forward/reverse operations. Note that the size of the defects increases as we sequentially play the tracks.

The Kiss player managed to playback the disc successfully, with no skips, picture stills or glitches. This good behavior is also prominent amongst most PC DVD recorders/players. We proceed to the next test disc, the Abex TCD-541.

• Abex TCD-541

This disc is exactly the same as the Abex TCD-545 tested previously, except that the defect is a scratch of dimensions varying from 0.4mm to 3.0mm, increasing by steps of 0.2mm/step.

Once again, the DP-1000 read the contents of this disc without producing any reading errors.

AudioCD

• Abex TCD-726

This is an AudioCD disc used for measurement and adjustment of the error correction ability and tracking/focusing servo characteristics of a player against the defects included in some CDs. Three kinds of defects are included on this disc, interruption in information layer, black dots and fingerprints. The interruptions are fabricated by intentionally varying the lengths of pits in the disc fabrication area. Their size varies from 0.5mm to 1.0mm. The diameter of the black dots are from 0.4mm to 1.0mm. Last, the simulated fingerprints are small, gathered dots, of diameters sized from 65 micrometers to 75 micrometers. 160 individual black dots in total construct the artificial fingerprint.

All audio tracks were played successfully without problems.

• Philips SBC 444A

The test concept with the Philips SBC 44A is the same as in the previous test disc. Interruptions on the information layer vary from 400 micrometer to 1000 micrometers, while the black dots have a size of 300 micrometers to 800 micrometers.

This disc was not a problem for the Kiss player.

• Abex TCD-721R

Same contents as with the Abex TCD-726, but different defect. A scratch with a size of 0.4mm to 3.0mm is on the disc's surface. Error symptoms expected when playing this disc are noise, sound skips, same sector repeatedly played, start of tune cannot be detected etc.

The DP-1000 played successfully the first 5 tracks out of the 15 in total. The 5th track corresponds to a scratch size of 1.0mm. First problems occurred in the 6th track (1.2mm) with audible "clicks" while playing, which increased and were followed by sound skips and playback interruptions as the defective area was increasing in size.

• CD-Check

We finish this testing cycle with the CD-Check disc from Digital Recordings. Five audio signals (5 tracks) in combination with disc error patterns to rate the player's ability to read music and reproduce it completely. The five tracks contain a sequence of progressively difficult tests.

- Check level 1 (track 1): Standard manufacturing errors
- Check level 2 (track 2): 0.375mm scratch
- Check level 3 (track 3): 0.750mm scratch
- Check level 4 (track 2): 1.125mm scratch
- Check level 5 (track 2): 1.500mm scratch

Any clicks, interruptions or looping during audio reproduction indicate failure of a Check level (audio track). Below you can see the test results:

The player had very good performance since it managed to reproduce the first four level without problem. During the 5th track, which is the most difficult for all players, including PC recorders, we heard only one click for each time played, and then nothing else.

Overall, we can say that the error correction capabilities of the Kiss player are very good.