Here's the thread to dissect the formats... Let me start off by saying I can't stand the BluRay Disc format. I believe it's a complete rip-off to consumers and that it doesn't contain any features other than "gimmicks" above HD-DVD. I believe the things that matter are the following:
Disc Standards:
Capacity:
BD: 25 & 50GB
HDVD: 15 & 30GB
Mandatory Codecs:
BD and HD-DVD - Video: MPEG-4 AVC (H.264), VC-1, MPEG-2
BD - Audio (Lossy): DD (640 Kbit/s), DTS (1.5 Mbit/s)
BD - Audio (Lossless): PCM
HD-DVD - Audio (Lossy): DD (504 Kbit/s), DTS (1.5 Mbit/s), DD+ (3.0 Mbit/s)
HD-DVD - Audio (Lossless): PCM, Dolby TrueHD
Optional Codecs:
BD - Audio (Lossy): DD+ (1.7 Mbit/s), DTS-HD High Res (6.0 Mbit/s)
BD - Audio (Lossless): Dolby TrueHD, DTS-HD Master Audio
HD-DVD - Audio (Lossy): DTS-HD High Res (3.0 Mbit/s)
HD-DVD - Audio (Lossless): DTS-HD Master Audio
Secondary video decoder (PiP) & Secondary audio decoder:
HD-DVD - Mandatory
BD - Optional ... Mandatory from 31/10/07
Internet support:
HD-DVD - Mandatory
BD - Optional
Region Coding:
BD: Yes
HD-DVD: No
Copy Protection:
BD: AACS, BD+, BD-ROM Mark
HD-DVD: AACS
We have here, plain and simple higher specifications that HD-DVD players must conform to - they must support more audio codecs, as well as PiP - and all discs sold world-wide. The downside to BD is that their players must artificially segment market by region, and include BD+, which forces consumers to update their hardware every 18 months to continue watching BD discs, and consumers will have to pay for these updates.
Furthermore, HD-DVD's of the same movies as BD's currently contain more special features, due to Sony using a Java-based scripting language which is notoriously difficult to master. Because of this the reality is that in the current short term period, BD players will be region-locked, contain lower capabilities then HD-DVD players (none of the initial BD players support PiP, internet access - or the advanced codecs all of which are mandatory on HD-DVD players). BD has a higher specification for Dolby Digital - but as the lowest quality codec this has little meaning to audiophiles, they contain lower specifications for every other audio codec compared to HD-DVD (with the exception of DTS-HD High Resolution which is an Optional codec on both formats).
And finally, I am deeply concerned about disc integrity. As we all know, there's not a CD or DVD in the world that will "last forever". As we've learned from experience, pressed CD-ROM or DVD-ROM discs outlast all recordable discs, whether CD-R/RW or DVD+/-R/RW by a long margin - and CD-R's outlast DVD-R's by a long way as well.
It's hard to understand why this is if you're not a complete geek, but I suppose the simplest explanation is simply that CD-R's and DVD-R's use a different material to pressed commercial discs (ie recording dyes) - and these dyes are not equal to the quality of the recording layer in a commercial disc.
BD uses exactly the same technology as HD-DVD, make no mistake. The Laser Wavelength is 405 nm, and as such is capable of picking up exactly the same amount of information as the other format. HD-DVD's 15GB single-layer is pushed to the maximum - it's not a lower technology disc then BD's 25-GB single layer. The difference is the disc structure of the BD is designed to facilitate the laser picking up more material by exploiting the disc's integrity. Instead of the protective plastic layer, they spray on a "hard-coating" layer.
On the surface it sounds just fine, except that this "hard-coating" was designed so the disc could be exploited - the disc wasn't designed to facilitate it, it was designed because it was necessary for the disc. To say it's "paper-thin" is an understatement, this "protective" layer is far thinner then paper. In fact it's so thin that it's only a fraction the width of a human hair - and I do mean fraction as in 1/20th or so. And because it's propriety, some manufactures have decided to use "their" own, for instance Verbatim uses their own formula instead - for better or for worse.
Disc Standards:
Capacity:
BD: 25 & 50GB
HDVD: 15 & 30GB
Mandatory Codecs:
BD and HD-DVD - Video: MPEG-4 AVC (H.264), VC-1, MPEG-2
BD - Audio (Lossy): DD (640 Kbit/s), DTS (1.5 Mbit/s)
BD - Audio (Lossless): PCM
HD-DVD - Audio (Lossy): DD (504 Kbit/s), DTS (1.5 Mbit/s), DD+ (3.0 Mbit/s)
HD-DVD - Audio (Lossless): PCM, Dolby TrueHD
Optional Codecs:
BD - Audio (Lossy): DD+ (1.7 Mbit/s), DTS-HD High Res (6.0 Mbit/s)
BD - Audio (Lossless): Dolby TrueHD, DTS-HD Master Audio
HD-DVD - Audio (Lossy): DTS-HD High Res (3.0 Mbit/s)
HD-DVD - Audio (Lossless): DTS-HD Master Audio
Secondary video decoder (PiP) & Secondary audio decoder:
HD-DVD - Mandatory
BD - Optional ... Mandatory from 31/10/07
Internet support:
HD-DVD - Mandatory
BD - Optional
Region Coding:
BD: Yes
HD-DVD: No
Copy Protection:
BD: AACS, BD+, BD-ROM Mark
HD-DVD: AACS
We have here, plain and simple higher specifications that HD-DVD players must conform to - they must support more audio codecs, as well as PiP - and all discs sold world-wide. The downside to BD is that their players must artificially segment market by region, and include BD+, which forces consumers to update their hardware every 18 months to continue watching BD discs, and consumers will have to pay for these updates.
Furthermore, HD-DVD's of the same movies as BD's currently contain more special features, due to Sony using a Java-based scripting language which is notoriously difficult to master. Because of this the reality is that in the current short term period, BD players will be region-locked, contain lower capabilities then HD-DVD players (none of the initial BD players support PiP, internet access - or the advanced codecs all of which are mandatory on HD-DVD players). BD has a higher specification for Dolby Digital - but as the lowest quality codec this has little meaning to audiophiles, they contain lower specifications for every other audio codec compared to HD-DVD (with the exception of DTS-HD High Resolution which is an Optional codec on both formats).
And finally, I am deeply concerned about disc integrity. As we all know, there's not a CD or DVD in the world that will "last forever". As we've learned from experience, pressed CD-ROM or DVD-ROM discs outlast all recordable discs, whether CD-R/RW or DVD+/-R/RW by a long margin - and CD-R's outlast DVD-R's by a long way as well.
It's hard to understand why this is if you're not a complete geek, but I suppose the simplest explanation is simply that CD-R's and DVD-R's use a different material to pressed commercial discs (ie recording dyes) - and these dyes are not equal to the quality of the recording layer in a commercial disc.
BD uses exactly the same technology as HD-DVD, make no mistake. The Laser Wavelength is 405 nm, and as such is capable of picking up exactly the same amount of information as the other format. HD-DVD's 15GB single-layer is pushed to the maximum - it's not a lower technology disc then BD's 25-GB single layer. The difference is the disc structure of the BD is designed to facilitate the laser picking up more material by exploiting the disc's integrity. Instead of the protective plastic layer, they spray on a "hard-coating" layer.
On the surface it sounds just fine, except that this "hard-coating" was designed so the disc could be exploited - the disc wasn't designed to facilitate it, it was designed because it was necessary for the disc. To say it's "paper-thin" is an understatement, this "protective" layer is far thinner then paper. In fact it's so thin that it's only a fraction the width of a human hair - and I do mean fraction as in 1/20th or so. And because it's propriety, some manufactures have decided to use "their" own, for instance Verbatim uses their own formula instead - for better or for worse.