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WB poor choice in audio for Terminator 3 (1 Viewer)

Robert George

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Yes and no.

Yes, the audio quality of the HD DVD and Bly-ray will be, for all practical purposes, the same.

No, the "+" in Dolby Digital Plus is more than semantical. DD+ is a different codec from Dolby Digital. It just so happens that at this bit rate (640 kb/s), the two codecs achieve essentially the same performance.
 

Adam Barratt

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Michael, Dolby Digital Plus is similar to the DTS-HD variants in that it's a core and extension system (but unlike DTS-HD not always based on a directly backwards compatible core: on HD DVD the core is an E-AC-3 program stream and on Blu-ray a conventional and fully backwards-compatible AC-3 program stream). In the case of HD DVD, Dolby Digital Plus decoding is mandatory in all players, so the extension data can be used to enhance the resolution of the main channels with the knowledge that there will be a decoder that can understand and process the data being received. However, Dolby Digital Plus decoding isn't mandatory on Blu-ray machines, only legacy Dolby Digital.

The core program stream of any Dolby Digital Plus soundtrack on Blu-ray must therefore be a fully contained AC-3 entity, and encapsulate everything that a listener with a conventional Dolby Digital decoder would need (ie. six channels of audio). There cannot be anything in the extension that is essential for reproduction of these channels (including any content which if removed would result in coder unmasking), and this includes anything that could also be used to enhance their resolution. Therefore, on Blu-ray, the extension data must be regarded only as secondary, disposable data that will in many cases be discarded.

Essentially what this means is that any Dolby Digital Plus soundtrack on Blu-ray will have only as much resolution across its main channels as the 640kbps AC-3 core datastream itself is capable of delivering. The E-AC-3 extension data present in addition to this core can still be used to expand the number of channels available, or even to entirely replace channels, but there won't be an overall gain in resolution equivalent to that possible on HD DVD at the same data-rate above 640kbps (or 1.024Mbps if the core AC-3 data is replaced entirely by the extension packet).

So, while the resolution and sound quality of Dolby Digital Plus can vary on HD DVD in relation to its bit-rate, the same isn't true of Blu-ray, and the only guaranteed means of increasing resolution at higher bit-rates is to switch to a different format altogether, such as PCM. This is a side-effect resulting from Blu-ray's lack of mandatory support for any advanced audio formats.

Adam
 

Ron-P

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Every HD-DVD and every Blu-ray disc should have some sort of lossless audio track, the disc's have the space for it so there's no reason, none at all, that they should lack it. This is HD media, right?

I've limited myself to buying only those titles with lossless tracks unless it something I really, really want and one reason why I support Blu more-so then HD-DVD, most all their discs have at least an LPCM track. I'm willing to bet that down the road a lot of these HD movies out now with crappy audio tracks will be re-released with lossless tracks. Multiple releases of the same film is what studios do best.
 

Michael Reuben

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Thanks, Adam. For a relative latecomer like myself, this kind of explanation is invaluable.

Does TrueHD on Blu-ray suffer from any kind of similar problem? The question occurred to me recently when I noticed that Warner's Kubrick releases have TrueHD as their lossless option on HD DVD, but PCM on Blu-ray.

M.
 

Dave Moritz

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I own both formats and that is the one thing I have a problem with. :angry: I do enjoy my HD-DVD's so do not get me wrong. But I hate seeing the HD-DVD trailer at the begining of many of these discs. The problem I have is where they say up to 7.1 channels of Lossless sound! They do not say that some titles may contain up to 7.1 channels of Lossless. They say up to 7.1 channels of Lossless sound, giving the impression that HD-DVD is stricktly lossless. Now every Blu-ray may not have a lossless track but I would say a large majority of them do, alot more than HD-DVD. But I also do not like it when a Blu-ray title does not get a lossless track ether.

Just about every HD-DVD has a lossy DD+ track and I hope that starts to change, and change soon. I would like to see alot more lossless audio track being used on HD titles.

I would like to give a :emoji_thumbsup: to Disney, Fox and Sony for placing a large majority of lossless tracks on there HD releases. I would also like to give Universal a :emoji_thumbsup: for releasing Bourne Ultimatum with a lossless track as well.
 

Adam Barratt

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Yes, there are parallels with TrueHD on Blu-ray. Because TrueHD decoding isn't mandatory for Blu-ray players (together with Dolby Digital Plus, DTS-HD HR and DTS-HD MA), and there isn't a legacy core to extract, TrueHD soundtracks on Blu-ray are accompanied by a 'hidden' Dolby Digital soundtrack.

If a particular Blu-ray player doesn't support TrueHD, but its operator selects the TrueHD soundtrack on a given disc, the hidden Dolby Digital soundtrack is played instead. This can lead to quite a bit of confusion, as owners can easily assume that their machine is playing back a lossless track when it isn't.

TrueHD support is mandatory on HD DVD players, so there isn't a need for a parallel Dolby Digital soundtrack 'just in case'. However, because only two-channel TrueHD support is mandatory, HD DVDs with TrueHD have always included a separate Dolby Digital Plus 5.1 soundtrack as well, ensuring that there is at least some type of six-channel discrete option for all users.

Adam
 

Michael Reuben

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Another possibility is that Blu-ray discs with "lossless" tracks in a format other than PCM will have to be re-released with lossless tracks we can actually play. Or we'll have to get new players. Or maybe both.

M.
 

DaViD Boulet

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What are you talking about? Virtually every BD player sold today can decode TrueHD, or be upgraded to do so. And several new players are being sold with decoding for DTS-HD MA out of the box (and the PS3 will be upgraded to decode that as well). Considering that no HD DVD player offers decoding of DTS-HD MA (even though the codec is used on many discs released in Europe), it would be inconsitent to criticize BD hardware for being slow to adopt full decoding of adavanced-DTS packing. Also in the case of DTS, they were late in the game getting their specs released... so decoding manufacturers, BD player, and HD DVD player manufacturers haven't had very long to incorporate the specs (and firmware updating may fix that for many of them).
 

DaViD Boulet

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Exactly.

In the case of why some Warner titles chose TrueHD for HD DVD and PCM for BD, it's probably because at the 16-bit level there's plenty of room to spare for PCM and it's just easier to compress/author given that they just can't port over the TrueHD from HD DVD given the authoring differences (as you note with the companion DD stream for BD). Warner has provided TrueHD on BD without PCM enough times for me to suspect that they don't have a strong desire to use PCM out of compatibility concerns for BD listeners with older gear.
 

Robert George

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Remind me again of a single Warner title on Blu-ray with TrueHD.

Warner does not use TrueHD on Blu-ray because it is an optional format. PCM is mandatory so Warner uses PCM on those Blu-ray titles that include lossless/uncompressed audio.
 

Douglas Monce

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Toshiba HD DVD players transcode DD+ to (I believe) 640kbps DTS signal to be sent over the optical connection.

Doug
 

Adam Barratt

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The first generation models converted to 1509kbps DTS, and some second-generation machine converted to 640kbps Dolby Digital. I have heard (but haven't seen first-hand) that newer machines allow users to choose either format.

Adam
 

DaViD Boulet

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Adam. I don't know where your information is coming from. Roger Dressler (from Dolby) and Amir have talked a great deal about Dolby Digital on DVD and HD DVD and Roger has stated that the way the data packets are stored on DVD/HD DVD limits the bit-rate in "standard" form (I was wrong about the max rate of standard DD on HD DVD, it's actually 504 kbps, not 448 like on DVD, thanks for clarifying).

By Roger Dressler of Dolby: (bold facing mine) Note his comments on how the disc structure and "packetizing" of data affect the various bit-rates possible with conventional Dolby Digital streams (I'd be very interested to learn more about the SD DVDs you mention with 640 kbps DD audio given Rogers following comments):

http://www.audiodesignline.com/18442...N2 JVN?pgno=3



By "none" I'm assuming you're not including the Samsung player:

http://www.highdefdigest.com/news/sh...ter_Audio/1012

The PS3 is also confirmed by Paidgeek to be upgradable to DTS-HD MA decoding (estimated early 2008). It's also very likely that Toshiba will be able to release firmware updates for many of its HD DVD players to provide DTS-HD MA decoding as well.
 

Adam Barratt

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This player isn't decoding DTS-HD MA. It sends a bitstream out, just as other players (such as the Panasonic DMP-BD10 Blu-ray player, and Toshiba's newest A35 HD DVD player) are now capable of with DTS-HD MA/HR, Dolby Digital Plus and TrueHD soundtracks.

Adam
 

DaViD Boulet

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My bad! Must be why Sony is waiting to release the firmware update for the PS3... they don't want to steal any stand-alone manufacturers thunder at CES for bringing internal decoding to market.

BTW, do any of the HD DVD players stream DTS-HD MA over 1.3 for external decoding? It pisses me off that the PS3 can't do this (hardware limitation).
 

DaViD Boulet

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Adam. I was admitting an error about the 448/504 remark. You know... how some of us admit error when we realize we were incorrect about something? ;)

But that doesn't negate the rest of the comments. My post was also sharing Roger's comments why HD DVD can't do native 640 Dolby. Wasn't that the original point we were talking about (not quibbling over 448/504)? Roger is giving clear insight as to how the differing physical structure and "frame size" affect bit-rate of Dolby differently on the two formats.
 

DaViD Boulet

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Then what were you talking about? I thought you made a comment that there was no technical reason why you couldn't put 640 kbps on DVD?


Roger's comments suggest that there are technical reasons why you can't go above. But you also mention some DVDs with 640 kbps DD audio? Maybe the reason they didn't work with existing decoders was because of a problem with encoding/flagging or something in the bitstream that confused the decoder? In any case, I've heard of no problems with any decoder accepting the 640 kbps DD from BD players.
 

Adam Barratt

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No one brought up Roger Dressler but you. No one said HD DVD could transport 640kbps Dolby Digital (or, I imagine, cares that this is the case). No one said HD DVD was restricted to 448kbps but you, and the quibbling was to correct a point that you chose to bring up entirely yourself.

Adam
 

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