Originally Posted by darinp2
This response makes it looks like "The Polar Express" on HD DVD has this feature....--Darin
I was going to comment on your question regarding branching, and then someone sent me this related link: http://www.avsforum.com/avs-vb/showt...&#post10125991
Originally Posted by darinp2
This came up a while ago. One of the people who was involved in HD DVD back when they decided their minimum 1.0x spin rate that led to their current bandwidth limitations, and who brags about how the HD DVD camp didn't overdesign their format, didn't understand this and thought that the extra languages not being played didn't affect the bandwidth left for video, other audio, PiP, etc. Along with not understanding what branching was at the time (according to what they said here), I can understand how they wouldn't have had a problem with HD DVD deciding on a 1.0x minimum spin rate instead of a 1.5x minimum spin rate. I wish they had actually understood how things worked back when that decision was made. It may have changed that decision, as they might not have been so smug about how their side wasn't overdesigning things, if they had known how things really work. I have a strong feeling that the decision about spin rate would have been different if they had known then what they know today. --Darin
If this doesn't make me the classic village idiot, I am not sure what does
. In the middle of all that though, you do bring up some new topics which I have not covered before so I am going to take a shot at commenting on them first. Hope you forgive me for that.
As the sole representative of HD DVD format here, I think sometimes people give us way too much credit for everything going into that format. Yes, we had our finger in a few things (see list below). But nowhere close to level of influence assumed in the post. Please let me provide some needed perspective here.
Microsoft was not involved in the development of either format until later stages. HD DVD was invented by Toshiba and NEC from what I recall, in a similar manner to which BD was designed by Sony/Matsushita. Neither was a committee invention in the way MPEG-2/MPEG-4 are for example. The spec is provided to the forum which then reviews and refines it before approving it.
From a timing perspective, the standardization of the original AOD (HD DVD) format was well under way while we were busy making WMV-HD discs and running around making technology for the Internet. We got involved because of two factors: 1) advanced codec testing and 2) to break the logjam in DVD Forum over the new format. On the latter front, the BD companies were blocking the approval of the working group HD DVD physical specification (remember, they have majority vote at the board level). Clever decision was made to add new (then neutral) members leading to Disney and us getting elected to the board. By the time we showed up (or in the previous meeting, I don't remember), the physical format was already approved. So historically speaking, we had no say or involvement in the creation of the physical specifications, where the data rate, capacity, physical characteristics, etc. came about.
Trust me, I wish I could take credit for this wonderful format called HD DVD, but we just can't
. The history simply doesn't allow it. If you want to blame us for bad things in this space, here are the areas you should go after:
1. Pushing for adoption of VC-1 and advanced codecs in general. We did this for both formats.
2. Matters related to copy protection (including region coding) and unification of both formats around a single technology (AACS)
3. Getting both formats to use the same (UDF) file system and (PC drive) interface language.
4. Helping create the original pillars of AACS and its full specifications.
5. HD DVD interactivity.
6. To some extent, mandatory features of HD DVD logical (i.e. above physical spec) layers.
7. Creation of authoring tools for VC-1 and to some extent HDi.
8. Helping studios drive state-of-the-art in compression technology/tools.
9. Helping companies like Toshiba ship HD DVD products.
There are probably a few other things we are guilty of but this is all I can remember screwing up so far
. All of this happened after we had a physical specification already approved. And also why people say we added a lot of software (logical) layers to HD DVD.
I think your second point is that because I didn't know everything about everything, somehow the spec wound up being suboptimal. Well, that isn't so either. I love you all so I spend a lot of time here personally to answer your questions. But that doesn't mean that I do the same low level work in other areas I manage. Indeed, I have not once set foot in a working group at DVD Forum where all the technical work occurs. So if there is something of concern there, it wasn't my doing. Heck, if I were involved, there would surely be more areas to criticize
Fortunately, I have people who know more about optical formats than anyone should be allowed to know. These are the people who attend the technical working groups and drive discussions in the forum. I have been in a few board meetings and voted on things but have not done that for two years now. My ignorance of some topics only serves to create embracement for me here and not much else I am afraid
The third point you make is that HD DVD is underdesigned due to my ignorance of its applications. I addressed the ignorance part above. But I will not accept that HD DVD is underdesigned. HD DVD has 3X the data rate of DVD. It uses advanced codecs which provide up to 2X the efficiency of MPEG-2 used in DVD. Multiply the two and you get up to 6X improvement over DVD format. 1080p has 6X the resolution of DVD which happens to match this number. But those pixels are highly correlated and we don't need anywhere close to 6X the bandwidth of DVD. As otherwise, all of those BD MPEG-2 titles would have to have the average data rate of 30 mbit/sec, which we know none do.
Should people have done more on the physical spec? Good engineering says you push a design up to a magical line, after which it gets too difficult/expensive to manufacture things. We feel that HD DVD has done exactly that. I am sure people will argue about where that line is and I won't go into it here. Suffice it to say, for a format to have increased capacity by 3X and yet, allow full backward compatibility with both replication equipment (HD DVD lines can make DVDs) and user equipment (combo/twin disc capability), shows great depth of design. HD DVD also mandates advanced features such as networking and persistent storage -- something competing group decided was too complex to make mandatory. So HD DVD is anything but a conservative design. It is both elegant and complete.
Your key argument above continues to be the need for more audio tracks because ultimately you may run out of bandwidth if you keep adding them. On paper, and with limited vision of where the format is going, one may think you have a point there. But let me explain how we see this.
As I stated previously, HD mandates both networking and storage. This in a nutshell, gives you another source of bandwidth. HD DVD allows up to 15 mbit/sec data rate coming from persistent storage because it does not incur any seeks to get to that data. This is above and beyond the bandwidth coming from the optical media. Given this, a much more elegant solution exists than stuffing everything on disc whether someone values it or not. You can put the core experience on the HD DVD, and leave the rest to be downloaded by the user to persistent storage. Given the fact that the video still comes on disc, you don't have long download times to deal with. You not only gain extra bandwidth this way, but you also let people decide more of what they want, than one size fits all.
No, this doesn't mean we ship movies without sound
. DD+ at 640kbps outperforms the DVD's audio quality, yet only takes 2% of the bandwidth. Even 5 languages can be served with just 10% of the total. DD+ at 1.5 mbit/sec rivals lossless audio and yet, it still only takes 5% of our capacity. Lossless take more bandwidth but we can fit one in there as we have shown across multiple titles. And IME on top of that. This means we can still ship a rich package on the HD DVD disc itself.
Yes, it is tempting to think old fashioned and assume everything has to be stuffed on the original shiny disc because that is the way good old DVD worked. But why? We use the internet all the time to add to our multimedia collection. Why design an optical format today, and not have the same capability be there for it just the same? OK, so it makes the system more complicated. But so does 0.1mm recording of the alternative format
. Someone wants a lossless track for some foreign language? I say let them download it at their convenience. No need to spec a system just for the optical media and stay within those confines. Heck, we could offer dozens of languages this way.
Then there is the home media distribution scenario. Using managed copy, once you rip the content to the server, you can add all the other elements to it with zero regards for bandwidth. After all, even a laptop hard disk has data rates exceeding 2-5X of BD let alone your desktop/server hard disk. You would use the disc for instant gratification but from there on, you can update it in place. No longer are you stuck with a read-only ROM format in this vision of the future. You can have 100 audio tracks to really make you feel good
. Given the more frugal encodings of HD DVD, we can store more movies in the same storage space. And stream them around the home much easier with half the peaks of typical MPEG-2 BD movie. Or stream more channels at the same time. Being efficient this way has a lot of value which may not be so obvious to folks thinking these technologies as simple DVD replacement.
So there you have it. While we didn't invent HD DVD, we helped make it better." People had no business inviting us into the forum, if all they wanted was another DVD format