I have the complete collection. The only one that is actually on a HD DVD is the sampler which is Living Landscapes the World's most Beautiful Places which features about 15 mins from each of the other titles. The other titles are all on 3X DVD's 8.5GB DL DVD. They are in HD but not near the bit rate of the HD DVD sampler disc. The audio is not selectable so you have to listen to the boring music over the nature sounds. I believe the later Blu ray releases have the option of removing the music.

I do not understand your post to be honest.

So those HD DVD videos were not released on HD DVD media, ist that your point ? Because I do not understand you sorry hehe

Yup, you could press HD-DVD content onto regular DVD disks...

One of the original HD-DVD ideas, pushed by the studios, was for a 9GB HD-DVD standard using regular DVD disks. Wikipedia has some good stuff on it. It was an idea a bit ahead of it's time, perhaps... but the same evolution in codecs that would have made red-laser HD disks worthwhile also made 1080p streaming work, too... as long as you have a good enough ISP!

Blu-Ray wasn't in it's modern caddyless form at that point, it took TDK's development of the anti-scratch coating to make it a practical consumer disk.

Think of it as an AVCHD disc for your Blu ray player, but it's for your HD DVD player. Both are burned on DVD's.

A number of p0rn titles are also on standard DVDs- including Camp Cuddly Pines, one of the Jack's Teen America volumes (which shows noticeable compression artifacts as a result) and Jesse Jane: Sexual Freak (that disc also has an authoring problem which on some players causes the main menu's video to play with no overlaying graphics so you can't access anything else on it! My modded A35 has that problem, but not my modded A2 so I have to keep that hooked up just to play this disc! ) Method Man Live is also on a standard DVD.

Oh, thank you for the very interesting information ! Method Man Live on a DVD disc. Interesting !