Now that I own an HD DVD player, I’ve started reading more of the forums about the two formats. This page on Wikipedia gives a full overview of the differences between the two formats.
Everyone is quick to point out that Blu Ray has a higher capacity and supports higher bitrates in the audio tracks—which is true. However, since they both use the same codecs for video compression, that means that we’re actually just talking about having 8.5 hours on a Blu Ray disc versus 5.1 hours on an HD disc. So really, that extra space is only going to be useful for TV series and the like where you’d end up being able to put the entire series on, say, three discs instead of four.
You’ll also note that both formats support lossless audio formats. When there are lossless options, who cares what the bitrates are for the lossy formats? What we really need is hardware to decode the lossless formats. This is required of all HD DVD players, but optional (and therefore not implemented) on any Blu Ray player.
Those are the major bones that get picked at, but for me there are two other issues that are just as important. First, while both standards implement the AACS copy protection, the Blu Ray standard adds another layer called BD+. Fox has recently pulled almost all of their scheduled Blu Ray releases, and it is widely speculated that they are waiting for BD+ protection to be added to before they begin releasing titles again.
If you read about BD+, you’ll see that the current version of the standard (1.1) hasn’t yet been implemented in any of the existing players. Moreover, version 2.0 of the standard will require an internet connection, suggesting that they will need to authorize media each and every time you want to play it. That’s right: some multi-national organization is going to know what you play, when you play it, and decide if you are trustworthy enough to be allowed to play it. Sounds an awful lot like the draconian failed DVD competitor Divx to me…
The other line that is frequently overlooked is the Region Coding. If you are familiar with internationally released DVDs, you know that there were several different region codes and that players were not supposed to play movies from a different region than the player was coded for. Region coding aside, there were technical problems with playing foreign movies domestically due to differing video standards (NTSC and PAL) and languages.
HD source material does not have to deal with differing video standards, so there is no technical reason for region codes any longer. Blu Ray still maintains region codes; HD DVD has done away with them. That means that I can (and did) order the British version of Harry Potter 4 from Amazon UK and watch it without any problems in my home.
I know I’ve been picking at the details here, and the truth is that both formats are going to look amazing on a true High Definition television. That said, I think that if you look beneath the surface, it’s clear that HD DVD is a much more consumer-friendly format, and that Sony has a bit of a Trojan horse here. Within those cavernous Blu Ray discs hides a phalanx of restrictions, limitations and gotchas that only a multi-national corporation could love.