HD DVD

What about DVDs which play movies in DVD format? Can I watch my favourite movie from a HD DVD?
You might not know this but almost all movies on DVD you purchased until recently are not in HDTV quality. DVDs have a standard resolution of 480i which on some progressive DVD players can be played as 480p. On the previous pages you have seen that standard HDTV resolution is 720 or even 1080 horizontal lines. With the advent of HDTV there are some technical solutions of upscaling the DVD picture to match the HDTV pixel count but still these DVD players or recorders do not play or record in genuine HDTV.

What is the problem? one might ask. Why do these movie giants like Disney, Time Warner etc. not jump into this new market and make their DVDs more attractive with HDTV and a dramatically increased picture quality?

The problem is mainly a technical issue. Recording a movie in 480p resolution there is a data stream of approximately 4 MB/sec. It follows that about 4 hours of video can be fitted on a double layer DVD of 8 GB.  Recording a movie in HDTV quality would require 20 to 24 MB/sec. The maximum transfer rate of a usual DVD is 9 MB/sec. A 2 hours movie in HDTV would take 20 GB of disc space, too much.