Here's something I wrote about this subject on another forum... good parts are in
red:
OK, for a long time I was torn between these two formats... but what I just heard yesterday has convinced me that Sony has BLOWN IT with Blu-Ray and that HD-DVD is the superior format.
Here's the skinny:
- Blu-Ray does have higher video throughput rates and per-layer video storage rates than HD-DVD. BUT, Blu-Ray disc makers (i.e., movie companies) are all using the 10 year old MPEG-2 video codec, which is not as efficient as the new VC-1 codec that HD-DVD makers are using. So Blu-Ray is using an older codec that requires MORE disk space and MORE video throughput than HD-DVD to produce the same results. HD-DVD discs are all using the latest technologies, so they're using the space they have more efficiently; Blu-Ray is wasting its advantages by using older technologies.
- Because HD-DVD disc makers are all using VC-1, HD-DVD movies actually do look better than Blu-Ray movies. Blu-Ray movies, since they are using MPEG-2, actually don't look much better (if at all) than standard DVDs. (Did you know that 95% of the original bits of a movie are eliminated during the authoring process? That's how good the codecs for DVDs and HD discs are... 1 terabyte of uncompressed source data is being compressed down to 8.5 GB of space.)
- Right now, dual-layer HD-DVD discs (15 GB per layer x 2 layers = 30 GB per disc) are in production, and you can actually buy movies on dual-layer HD-DVD. Blu-Ray discs are all still ONE layer (25 GB per layer)... Sony can't get the dual-layer Blu-Ray discs to work.
- HD-DVD discs are MUCH more scratch resistant than Blu-Ray discs, because of the construction of the discs. HD-DVD discs contain their bits further inside the disc (at least .6 mm below the surface), while Blu-Ray discs contain data a mere .1 mm inside the disc. If you scratch a Blu-Ray disc, or even get fingerprints on it, you can ruin it.
- Also, because of their design, it's possible (and practical) to make hybrid DVD/HD-DVD discs, where one side of the disc is a regular DVD and the other side is an HD-DVD. This is NOT POSSIBLE with Blu-Ray.
- And the HD-DVD spec includes a lot of MANDATORY technologies, such as built-in Ethernet (so your HD-DVD player can communicate with the Internet for downloads, updates, and even live connections to new disc content), persistent memory (so you can bookmark clips from HD-DVD discs), and dual video-decoders (so you can do PIP off of a single disc... the main movie running normally, with a PIP of the director giving commentary, for example). These technologies are all OPTIONAL on Blu-Ray and none of them are in use in any available or announced Blu-Ray player.
Anyway, based on this, I've decided to back HD-DVD. I'm going to wait for the HD-DVD add-on for the Xbox 360, since it's only going to cost $200 and it'll be much easier to incorporate into my home theatre system... if it works well, then I'll consider a standalone HD-DVD player when there's more choice of players on the market (right now only the two Toshiba models are available).
Go HD-DVD!