Posted Fri Sep 1, 2006 at 12:02 PM PDT by
Time again for the latest installment of High-Def Digest's Reader Mailbag,
where we answer your questions on HD-DVD and Blu-Ray, industry trends, and
our site's news and reviews.
Got questions or feedback of your own? Send
them our way, and we'll try to answer them on the site in future installments
of our Reader Mailbag.
Bitrates, Dolby Digital-Plus and You
"Hey Peter! Just read your review of 'Stargate' and I thought
I might mention something. Most Blu-ray titles are using 640kbps Dolby Digital
soundtracks as opposed to the Dolby Digital-Plus ones you'll find on HD DVD.
Warner is using 640kbps Dolby Digital-Plus and Universal has been doing 1.5Mbps.
Roger Dressler of Dolby has already stated that there is no difference audibly
between 640kbps Dolby Digital-Plus and Dolby Digital.
The way Blu-ray works is it only requires Dolby Digital-Plus when it goes beyond 5.1 channels (i.e. 6.1 or 7.1 soundtracks). This is different from the authoring of HD DVD which uses Dolby Digital-Plus for other things such as adding voice commentaries, button noises and other uses that Blu-ray doesn't do. But from a performance standpoint they are the same.
Dressler also concedes that there is really no advantage to the 1.5Mbps that Universal is using as the gains are minimal, if any. So your comments on them not using Dolby Digital-Plus aren't really relevant from a technical point of view.
Also, just in case you don't know, DTS-HD is the same as full bit rate DTS (i.e. 1.5Mbps) they just call it a new name (love that marketing!!) DTS MasterHD is their lossless version (which I know you already knew!)
Keep up the great reviews!!" -- Kris D.
Editor Peter Bracke responds: Thank you, Kris, for the kind comments and great
info. There certainly has been a great deal of insight coming our way on just
what the differences really are between Dolby Digital-Plus and Dolby Digital,
which is terrific -- often the technical details behind surround formats are
so shrouded in mystery or inaccuracies that it is hard to understand what each
is truly capable of delivering, and how they legitimately compare in quality.
Admittedly, I also fell into the trap early on of assuming Dolby Digital-Plus was automatically superior to Dolby Digital, without stopping to pause and consider actual bitrates and the other variables that determine the ultimate quality of a soundtrack. Indeed, many feel that because the Blu-ray releases so far have been "only" Dolby Digital, that consumers are somehow getting ripped-off, or that the quality is inherently substandard, which at least in raw technical terms is not correct.
Part of the problem has also been that the only Blu-ray player currently on the market is the Samsung BD-P1000, which does not offer any sort of bitrate meter or onscreen display, at least that I've been able to find. Hopefully, manufacturers will support such a feature on future Blu-ray and HD DVD players, and the studios will also begin to label bitrates on the disc packaging itself. Unfortunately, with no indication on the packaging nor any way to tell via the player what the actual bitrate of a soundtrack is, a lot of assumptions have been made. Wrongly, in many instances.
In any case, we've gone back and updated all of our Blu-ray versus HD DVD comparisons regarding the bitrate issue, and we will also note it on all future Blu-ray reviews that "only" contain 640kbps Dolby Digital tracks.
Lastly, regarding Universal encoding their Dolby Digital-Plus tracks at 1.5mbps,
it is a shame the studio will likely never release an HD DVD with both 640kbps
and 1.5mbps Dolby Digital-Plus track, if only so we could do a true apples-to-apples
comparison. Of course, in our estimation, what early adopters most likely really
want is Dolby TrueHD and/or DTS-HD Master Audio soundtracks on all HD DVD and
Blu-ray releases. Not that I'm holding my breath...
No 'Corpse Bride' for HD DVD?
"I'm disappointed that Warner has chosen to release 'Tim Burton's The
Corpse Bride' on Blu-ray only.
Also, I don't understand why Warner releases some titles as combo and charges quite a bit more when the high def version is included. Who wants to pay more? I don't buy those.
Keep up the good work. I enjoy reading your site!" -- Gabe L.
Editor Peter Bracke responds: Well, Gabe, I can certainly understand your frustration
when a title you've been dying for is finally announced for high-def release
and... it's on the wrong format! Sadly, though, I think this is going to be
a fact of life for early adopters for the time being, at least until the format
war settles itself out.
But I wouldn't worry too much about 'The Corpse Bride.' Warner has so far been quite good about supporting both formats. Though they did jump into HD DVD earlier as the format launched ahead of Blu-ray, they have been consistently announcing more and more Blu-ray titles, and I fully expect the day will soon come when they will release discs on both formats simultaneously. As for 'Bride,' I suspect that as with 'Good Night, and Good Luck' -- which hit Blu-ray about three weeks ahead of the HD DVD -- we are only a few weeks away from an announcement for the Tim Burton flick on HD DVD. I can't imagine Warner will not release the title sooner rather than later on both formats. So hold tight.
As for combo releases, I'm with you - and if email from our readers is any indication, ours is a sentiment shared by most early adopters, who clearly don't like the idea of paying more for a high-def disc because it also includes a standard-definition version of the same movie. Clearly the combo approach is geared toward the mainstream consumer, who may be more inclined to purchase a combo title to "future proof" their collections, if and when they decide to jump into the high-def arena.
It's a pity that at the same time those high combo prices serve as a deterrent to purchase for those of us who've already made the step up. Hopefully, production costs will soon go down quickly enough that the studios won't have to charge a premium for combo titles much longer. Until then, let the frustration continue...
Pre-Recorded vs. Broadcast Comparisons?
"I appreciate your frank reviews; however, I don't have a reference
in which to interpret them. I have an HDTV that does up to 1080i, and some of
the few shows I watch are 'CSI,' and basketball and football in high def (all
from broadcast stations only). When you reference grain, etc. on Blu-ray movies,
how are they comparing to the broadcast I am used to enjoying? Is the quality
comparable, or is a grainy Blu-ray movie still good to the point where it is
untouchable by broadcast HDTV? I haven't adopted yet, so I have no way of knowing.
Thanks for your time." -- Dave B.
Editor Peter Bracke responds: Thanks for the great question, Dave. You certainly
bring up some very, very valid points in this day and age of over-the-air HD.
And you are not alone in your confusion. Many potential consumers interested
in Blu-ray and HD DVD have only recently been introduced to the glories of high-def
via broadcast and satellite, and so have no other reference point.
However, it is very hard if not impossible to accurately compare prerecorded high-def programming, such as on a Blu-ray or HD DVD disc, with broadcast HD. There really is no reference point! How the major and cable networks encode and transmit their HD content is quite different in intent and presentation than what the studios are trying to deliver on disc, even if the underlying technology is the same.
For example, satellite services such as DirecTV and Dish Network have to squeeze many, many channels into a very narrow bandwidth, and thus pick a compression codec optimized for low bitrate applications -- just the opposite of the approach of the Blu-ray and HD DVD camps, which don't have the same level bandwidth crunch to worry about. As you've probably seen, problems such as rampant macroblocking are just a fact of life with broadcast HD, as are a host of other artifacts that just aren't nearly as much of an issue with pre-recorded high-def content.
Also, the type of equipment one is using (such as your HD set-top converter box) has a huge impact on the quality of the HD you're seeing. As can the path a broadcast signal has taken to reach your home. I've heard horror stories of local affiliates totally botching the transmission of HD from the major networks, with intermediary image processing that can render a high-def broadcast if not unwatchable than scarcely superior to a crappy DVD. So trying to compare the quality of an HD program on, say, DirecTV versus that same program on a Blu-ray or HD DVD disc is if not impossible, than so far from apples-to-apples as to be futile.
However, I will give you my completely subjective opinion. I have watched quite a few movies now in HD via satellite and recorded them on my Dish Network DVR, then compared them directly to their Blu-ray or HD DVD counterparts. And in all honesty, I'll take even the worst Blu-ray or HD DVD disc I've seen over broadcast any day. Grain or the occasional artifact on a disc aside, just the amount of macroblocking I've seen with broadcast (which is always at its worst with fast-action) really gives the pre-recorded formats a huge advantage. I also prefer the consistency of Blu-ray and HD DVD, as well as the fact they are a more "controllable" technology. Of course, no format is perfect, but again, with so many variables in the broadcast chain between point of origin and ultimate destination, I always feel far more confident that what I'm seeing on HD DVD and Blu-ray is going to be far closer to the original master.
That said, I would urge you to go and visit the most reputable electronics store in your area and see demos of Blu-ray and HD DVD for yourself (hopefully you have more than just a local Best Buy around!). You will really want to see some pre-recorded high-def in action before you take the plunge with Blu-ray and/or HD DVD, and as always, the best judge is your own eyes. Hope this helps.
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