DTS-HD and Dolby TrueHD

Dolby TrueHD:

Will connecting the 5.1 channel analog outputs from a HD-DVD player produce a 7.1 surround sound track if Dolby Prologic IIx is used? At first it made since to me but know it doesn't. What confusses me is that if a 7.1 experience can be derived from a 5.1 signal why can't S/PDIF (optical or coax) also be used with Prologic IIx to create a 6.1 or 7.1 signal?

Source (Dolby):
http://www.dolby.com/consumer/technology/trueHD/avrs/trueHD_avrs_1.html


DTS-HD:
Can DTS-HD be passed via analog connections like Dolby TrueHD can? I thought that DTS could only be tranmitted digitally. I'm asking be cause I want to be clear about how DTS-HD will be backwards compatible with current DTS implementations.

Thankz,
Ced

 

Some good questions there, and I have no idea about the Dolby True HD off the top of my head, but will find out & post back.
Dolby True HD will not give a 7.1 stream if used with a so-called "legacy" decoder though, under any circumstances.
The way it works is to incluyde the older Dolby Digital & MLP Lossless assigns in what is called the "core" stream. All extra streams will require a suitably equipped True HD decoder. Just getting an HD DVD player will not really give you what the thing is capable of unless the player can decode the bitstream internally.
DTS-HD will be able to go out from the player through analogue outputs as long as the player can decode the bitstream internally.
If it can only pass the bitstream in "passthrough" mode, like some of the cheaper standard DVD players do, then you will need a digital output to a suitable decoder.

I will go ask my friends at Dolby & DTS, then post back.

 

Thankz wilkes, If anybody can get to the bottom of this it you!

According to the Dolby web page the HD-DVD and Blu-Ray players "must" decoded the streams internally if HDMI 1.3 isn't being used.



Ced

 

This just came in directly from DTS Europe.

Still waiting to hear from Dolby.
However, as I suspected, you will only get audio from the analogue outputs when the HD DVD player is equipped with a DTS-HD decoder internally.

 

So I guess the "Core part" is the a standard 5.1 DTS mix?

Thankz for the DTS-HD info!
Ced

 

DTS-HD is just one audio track, with a standard 48kHz 5.1 DTS Core audio part (usually at 1.5Mb/s) and rest of the stream containing extensions for everything else i.e. all frequencies above 48k and all extra channels for 6.1 or 7.1. So there's no redundancy of information in the stream, it really is just one audio track. Which makes it much more efficient than the Dolby "True" HD alternative.
(BTW, the Dolby "True" HD stream is actually two streams AFAIK: one MLP and one standard Dolby Digital (at 448kb/s I think ). That's two full audio tracks, each with the same information, just encoded in different ways and bundled together).

 

Wow, ok that helps me with understanding it all.

Thankx some more,
Ced

 

The normal operation for both HD-DVD and Blu-Ray is that the player should decode TrueHD and DTS-HD to PCM, even when you later get players with HDMI 1.3. That's because you should be able to mix that audio with for instance a Director's Commentary Track (downloaded over Internet after the disc was pressed) and some cheesy Button Sound Effects. Because of this Sony had to drop SACD, while it isn't really perfect to begin with it loses the benefits and only keeps the drawbacks if you just convert it to PCM.

But there may be many Blu-ray and HD-DVD disc without glorious lossless 5.1 or 7.1 audio, the specs for Blu-ray doesn't really demand anything new and I believe HD-DVD is content with highres stereo.

I think the max datarate for Dolby Digital+ is raised from 448 standard Dolby Digital has, to something like 620. But DD+ should be backwards compatible with DD.

 

Well the Dolby page explains all of the methods very well (except the S/PDIF explination). I just want to know why; if I connect the 6 channel analog outputs to a Dolby Pro Logic IIx DSP I will get 6.1 or 7.1 (if it is available); if I connect the S/PDIF connection carring the same 6 channel info digitally to the IIx DSP why will I only get 5.1 and not 6.1 or 7.1?

Pro Logic IIx...
http://www.dolby.com/consumer/technology/prologic_IIx.html

Ced

 

That sounds like a firmware issue in the player to me.
Could easily be wrong though - I only just really started in DPL II, and have not done much in the format as yet.

SP-DIF is certainly capable of carrying 8 channels at 24/48 rates, so I really don't know.
I'll try to find out...

 

No no I was refering too page two of my source (http://www.dolby.com/consumer/technology/trueHD/AVRs/trueHD_avrs_2.html) which only list S/PDIF as an option for 5.1 but not 7.1 audio.

I thought S/PDIF could carry 6-8 channels of PCM audio like HDMI (1.0+). The page only lists FireWire and HDMI as having that ability.

Ced

 

In that case, the core of Dolby True HD is obviously not allowing SP-DIF use.
Dolby True HD is far less efficient compared to DTS-HD.
As I already said, it carries 2 streams, not one. This could be the problem.

Dolby True HD is still in beta though, and is far from finished.

 

Yea, I noticed that both the Toshiba HDA1 and Sonys Blu-ray player only support 2 Channel Dolby TrueHD while DTS-HD is fully supported.

But can S/PDIF support 8 channel PCM audio at 24/96?

Ced

 

No.
at 24/96 you cannot get more than 4 channels - and there are no players that can get around this.
Some have mod boards available to allow 6 chjannels at 24/96 through CoAxial, but this immediately invalidates warranty.

DTS-HD is the way forward IMHO.
It is the ONLY HD multichannel spec approved for both Blue Laser formats.

 

Hi -
I'm new to this thread but have a queston that it looks like you guys could answer - I'm upgrading my home theatre setup - I currently have a Yamaha Receiver that does only does Dolby Digital - I'd like to buy a receiver that can support Dolby TrueHD and DTS-HD. SInce I dont see anything out there yet, is it a matter of waiting? or am I missing something and the new receivers do support it?

Also when does HDMI 1.3 actually start getting implemented? My goal is to pick up a Sony SXRT 60" with a 1080P HDMI input, eventually buy a Blueray or HDDVD player and interface them with my receiver.

ANy help would be appreciated - I'm building a custom cabinet and need tomesh out as much of the requirements as I can.

Thanks for your help!

 

Does your receiver have Multi-Channels inputs? If so use them. If your receiver doesn't have them then your going to have to make an upgrade.

Ced

 

HDMI 1.3 is still "vapourware" and there are no final specs as yet, never mind actual hardware.
DTS-HD and DTS-HD Lossless are different animals too.
Both BRD and HD DVD are required to support - fully - DTS-HD, including Core, DTS-ES and DTS 96/24.
DTS-HD Lossless is optional.

Dolby True HD is mandated in HD DVD ONLY, and in STEREO only.
It is claimed by Dolby that Multichannel Dolby True HD will be implemented in "most future" HD DVD players.
Right now it isn't.
Dolby True HD is only optional in Blu Ray.

The only mandated audio codecs for Blu Ray are
Dolby Digital
DTS-HD.

Advice?
Don't bother right now.

 

HDMI isn't that important and wanting a receiver that decodes Dolby TrueHD or DTS-HD is even less important. Having the ability to pass raw audio streams to an audio processor isn't need and often is impossible with the new HD disc formats.

Why? Because everything is transcoded internally in the player to PCM (at the ratio of the source up to 24/192). Passing that PCM stream needs to be your only concern. Use the Multi-Channel outputs or HDMI 1.x to pass 6 or 8 channels of PCM audio to an audio receiver.

See this page for more info on Dolby advaced codecs and your old receiver...
http://www.dolby.com/consumer/technology/trueHD/AVRs/trueHD_avrs_1.html

HDMI 1.3 has been finallized as o June 22nd

HDMI.org press release...
http://www.hdmi.org/press/pr/pr_20060622.asp

Are you sure? I know that the current HD-DVD players only support stereo but Dolby has stated for a long time that HD-DVD and Blu-ray can support up to 8 Channels of Dolby TrueHD @ 24/192.

Dolby TrueHD Faq...
http://www.dolby.com/assets/pdf//tech_library/TrueHD_FAQ_10925_Final.pdf

I also found this to be intresting.

Dolby Whitepaper on future audio technologies...
http://www.dolby.com/assets/pdf/tech_library/DPlus_TrueHD_whitepaper.pdf

As far as DTS-HD I've only seen support for core DTS and DTS-ES from both camps although DTS claims to have lossless support in both formats. In any case DTS-HD isn't new altogether. As long as your receiver can decode DTS-ES and DTS 24/96 then your ready for DTS-HDMA.

Ced

 

According to Dolby Labs, the information I have is that MANDATED codecs for Blu Ray are
Dolby Digital up to 640kb/sec
DTS-HD
All others are optional. There is no guarantee at all that Dolby True HD, DTS-HD lossless or DD+ can be decoded in Blu Ray.

HD DVD mandatory
Dolby Digital
Dolby Digital +
DTS-HD
Dolby True HD -mandated in stereo only, multichannel is optional.
MPEG audio
Multichannel PCM

DTS-HD is the format formerly known as DTS, and incorporates DTS as the core stream, DTS-ES and DTS-HD High Resoolution (DTS 96/24).
DTS-HD Lossless is another extension, and support in both HD formats is optional.

The beauty of DTS-HD Lossless over Dolby True HD is the single stream nature of it.
DTS-HD will always decode to the highest quality the decoder is capable of. The core stream is always there, the extra channels & resolution are carried in the extensions.
With Dolby True HD, you get 2 streams. One is the DD/DD+ the other is what was called MLP.

Dolby are saying now that "in future, we expect all HD DVD players to be capable of decoding multichannel True HD streams." (my italics).
Note the wording "expect".

For best, guaranteed compatibility across both BRD & HD DVD, DTS-HD is the only codec that makes any sense.

Appreciate the HDMI 1.3 details. When I was at a DTS presentation the other week it was still all up in the air, with no final specs available.

 

Dolby talks about TrueHD a little differntly. The faq draws a thin line between it and MLP. What I don't get is where Dolby's Matrix extensions come in. If they can do everyting in (page 3 of) this white paper why is DTS so far ahead of them. Also why would Dolby need two streams. It would seem like both of these technologies are very similar on paper but only DTS is really doing it.

Dolby Audio Coding for Future Entertainment Formats...
http://www.dolby.com/assets/pdf/tech_library/DPlus_TrueHD_whitepaper.pdf

What do you mean by that. Isn't lossless always lossless?

Dolby is respected in the industry, why don't you think TrueHD will have industry wide exceptance one day? I'm sure its not mandatory because it wasn't final when either of the formats where final. I think it will be common for HD-DVD at least.

Ced