Jari Ketola
7 Nov 2000 13:38
Lately there has been alot of discussion in Usenet newsgroups as well as DVD-discussion forums about a phenomenon called DVD Rot. The effect is similar to what was known with Laserdiscs as Laser rot. Movies that play flawlessly when bought turn unplayable all of a sudden. The deterioration is probably caused a production flaw which in turn causes oxidation on the disc.
All the problem discs found so far have been so called RSDL (Reverse Spiral Dual Layer) discs and manufactured by WAMO (Warner Advanced Media Organization). Problems have occured atleast with region 1 and region 4 movies.
Some of the affected discs are:
-Casablanca
-Contact
-Deep Blue Sea
-From the Earth to the Moon
-The Maltese Falcon
-Message in a Bottle
-The Music Man
-My Fair Lady
-Pee-Wee's Big Adventure
-What Dreams May Come
-... and many others
The DVD rot effect appears as heavy MPEG pixellation and blockiness after the layer change, which is usually located about half-way through the movie.
Although there's no reason for panic, DVD rot is definitely something to worry about, because it's both consistent to WAMO-produced discs and affects discs fairly quickly (after only 4 or 5 viewings). Of course there has not been any official word from WAMO about the issue (and there probably never will be), and there's no guarantee that defective discs will be replaced. It's still probably a good idea checking your discs for signs of rot using the following two links as a guide.
More on DVD rot:
Frame by frame view of the DVD rot -effect in action
DVD Dual-Layer deterioration with pictures of a "rotten" disc