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DTS-HD and Dolby TrueHD
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diabolos
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5. April 2006 @ 15:26 |
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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_...
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
This message has been edited since posting. Last time this message was edited on 5. April 2006 @ 22:01
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Senior Member
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6. April 2006 @ 02:36 |
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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.
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diabolos
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6. April 2006 @ 08:27 |
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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
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Senior Member
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7. April 2006 @ 05:34 |
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This just came in directly from DTS Europe.
Quote:
DTS-HD can be passed can be passed fully lossless via HDMI 1.3, or up to 6 Mb/s via HDMI 1.1 or 1.2. It can also be decoded in a player equipped with a DTS-HD decoder and passed via analog outs.
Additionally it is backwards compatible and the Core part of DTS-HD can be passed via SPDIF (unlike Dolby "True" HD)
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.
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diabolos
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8. April 2006 @ 18:06 |
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Quote:
Additionally it is backwards compatible and the Core part of DTS-HD can be passed via SPDIF (unlike Dolby "True" HD)
So I guess the "Core part" is the a standard 5.1 DTS mix?
Thankz for the DTS-HD info!
Ced
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Senior Member
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10. April 2006 @ 07:11 |
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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).
This message has been edited since posting. Last time this message was edited on 10. April 2006 @ 07:12
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diabolos
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10. April 2006 @ 13:29 |
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Wow, ok that helps me with understanding it all.
Thankx some more,
Ced
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jjolson
Junior Member
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11. April 2006 @ 14:43 |
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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.
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diabolos
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11. April 2006 @ 17:10 |
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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
This message has been edited since posting. Last time this message was edited on 12. April 2006 @ 13:30
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12. April 2006 @ 09:09 |
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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...
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diabolos
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12. April 2006 @ 13:16 |
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This message has been edited since posting. Last time this message was edited on 12. April 2006 @ 13:29
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Senior Member
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13. April 2006 @ 01:19 |
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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.
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diabolos
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13. April 2006 @ 03:39 |
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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
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Senior Member
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13. April 2006 @ 04:53 |
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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.
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jeremybe
Newbie
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18. April 2006 @ 11:19 |
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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!
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diabolos
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4. June 2006 @ 21:20 |
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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
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Senior Member
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4. July 2006 @ 01:31 |
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Quote:
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.
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.
This message has been edited since posting. Last time this message was edited on 4. July 2006 @ 01:31
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diabolos
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4. July 2006 @ 03:16 |
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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_...
Quote:
HDMI 1.3 is still "vapourware" and there are no final specs as yet, never mind actual hardware.
HDMI 1.3 has been finallized as o June 22nd
HDMI.org press release...
http://www.hdmi.org/press/pr/pr_20060622.asp
Quote:
Dolby True HD is mandated in HD DVD ONLY, and in STEREO only
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_Fi...
I also found this to be intresting.
Dolby Whitepaper on future audio technologies...
http://www.dolby.com/assets/pdf/tech_library/DPlus_TrueHD_whitepa...
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
This message has been edited since posting. Last time this message was edited on 4. July 2006 @ 03:21
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Senior Member
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4. July 2006 @ 07:17 |
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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.
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diabolos
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5. July 2006 @ 18:48 |
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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_whitepa...
Quote:
DTS-HD will always decode to the highest quality the decoder is capable of.
What do you mean by that. Isn't lossless always lossless?
Quote:
Dolby are saying now that "in future, we expect all HD DVD players to be capable of decoding multichannel True HD streams." (my italics).
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
This message has been edited since posting. Last time this message was edited on 5. July 2006 @ 18:58
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6. July 2006 @ 05:31 |
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Quote:
Isn't lossless always lossless?
Yes. Naturally lossless is always lossless, but DTS-HD isn't necessarily lossless. That's the whole point.
The DTS-HD stream can be anything from "standard" core DTS right the way up to DTS Lossless - through DTS-ES and DTS 96/24 along the way.
You get a single file that contains the "core" at 24/48 or 16/48, depending on source. The extended frequency response, the additional channels & the lossless component are all taken care of in the extensions.
So one stream doesall - and the decoder will always decode to the highest quality it is capable of.
So, for example.
Suppose I take a 7.1 surround stream, at 24/96 resolution, and encode to DTS-HD Lossless.
If your amplifier cannot decode the DTS-HD Lossless stream, or the 2 additional channels, but is capable of DTS 96/24 then you will get out a 5.1 stream at 24/96.
If you have a really early decoder that cannot handle the ES or the extended frequency responses, you'll get a payload output of 5.1 at 24/48.
Quote:
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.
I'm not saying it won't have industry-wide acceptance. What I'm trying to say is that I can see other problems that so far are not being addressed by Dolby:
1 - Only HD DVD has mandated support for Dolby True HD, and that is mandated for stereo only, not multichannel.
Dolby are arguing that future players should be capable of decoding multichannel lossless True HD, but there are a lot of mights and maybes in there.
(It's not mandated for Blu Ray at all - it's purely optional.)
DTS-HD is fully mandated on both formats, although the lossless extension is again optional only.
2 - Dolby True HD uses 2 streams, so it has the core stream in Dolby Digital and what was MLP. The DD+ is in the extensions (and also, it must be said, optional for BRD) - but we still have 2 streams here where DTS are doing it all with one single stream.
DTS are just making things a lot simpler - one stream does all, across all formats.
In all honesty, I have yet to actually see the Dolby encoder. It's Mac OSX only right now, and whilst they hope to get a PC version, it's not on the cards as yet.
I will be getting the DTS-HD encoder as soon as it's available.
It's also much, much cheaper too.
DTS-HD MAS will be around $1500, and that gets you the full encoder, plus a player & a set of editing tools as well that will include restriping capability, editing, splitting & joining of streams, all sorts of goodies.
Dolby True HD, on the other hand, is a whopping $11,000+
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diabolos
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6. July 2006 @ 10:49 |
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Ok I understand what you mean.
So DTS-HD's lossless codec is an extension instead of another stream. While TrueHD has the DD core with DD+ extensions and then a 2nd stream for MLP.
In the white paper Dolby says that doing it there way is better because sound artifacts are not audible in the lossless stream that would be if it was simply matrixed as I understand the DTS-HD lossless stream is. Is it safe to assume that you diagree with Dolbys claim? My response to Dolby would be, "if that where true then why has the DTS camp done it that way and had more success (thus far) with DTS-HD than you have with TrueHD"?
Thanks for the clarifacation Wilkes,
Ced
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Senior Member
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7. July 2006 @ 01:52 |
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I'm not too sure what Dolby mean by "matrixed" - from a mix engineer & Surround producer's viewpoint the term "matrixed" means something like this:
There are 2 types of surround stream, discrete & matrixed.
Discrete is where each channel is encoded individually, and plays back as mixed.
Matrixed is like the old Quad SQ/QS system, or LCRS, or Dolby's own ProLogic/ProLogic II system, or SRS Circle Surround, where what you end up with is a matrixed stream that plays in stereo on a stereo system and decodes back into 5.1 in a surround system.
The trouble is that what gets decoded isn't discrete, and you get artifacts like crosstalk, panning issues (Try panning 2 sounds in opposite directions and matrix encoding. The soundfield will collapse into very narrow field)
What it appears Dolby have done is split the stream into 2 - one is the traditional Dolby Digital stream, the other is the lossless MLP stream. They also use extensions to the stream to get the Dolby Digital + component across.
My guess as to why it has been done this way - and it IS a guess - is because Dolby Labs didn't invent MLP. Meridian Audio did, and I strongly suspect that the requirement of an independant stream here is for one (or both) of 2 reasons:
1 - The licensing agreement with Meridian Audio states that the Lossless stream stay independant to maintain integrity
2 - The decoders require the stream to be independant.
I may be well wide of the mark - this is a guess.
DTS used a different approach.
Nothing is matrixed in the DTS stream at all. At least, not according to the usual meaning of the word when applied to surround encoding.
Also, remember DTS developed this algorithm over a period of time, and chose to make things fully bavckwards compatible by adopting the extensions approach. I Think this was the right way to go, as one stream does all resolutions and all formats all at the same time.
I've not used the DTS-HD Lossless encoder as yet, the best I can do right now is DTS 24/96 or DTS-ES 5.1/6.1 where there is a hint of matrixing going on, as with DTS-ES 5.1 you can elect to matrix the Cs channel into the Ls/Rs channels as opposed to the DTS-ES 6.1 method where the Cs channel is truly discrete. That is as far as DTS matrixing goes.
Finally, as an interesting aside, it is mentioned earlier that "Dolby have an industry-wide reputation".
So do DTS!
DTS marketing is that good I have recently run across a lot of DVD-Audio owners who have been playing the DTS stream over the MLP stream because they actually believed the DTS stream was the highest quality option on the disc
This message has been edited since posting. Last time this message was edited on 7. July 2006 @ 01:54
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Senior Member
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7. July 2006 @ 02:03 |
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Now I am looking at that referenced white paper.
Interesting.
Dolby are using the same approach as DTS with parts of this.
They too are using the "Core plus extensions" approach in the Dolby Digital & Dolby Digital + codecs.
I see nothing in there that convinces me it's any better than DTS-HD Lossless is.
If anything, DTS-HD Lossless is actually even more advanced.
I'll try to dig out some white papers.
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diabolos
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7. July 2006 @ 06:27 |
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Quote:
DTS marketing is that good I have recently run across a lot of DVD-Audio owners who have been playing the DTS stream over the MLP stream because they actually believed the DTS stream was the highest quality option on the disc
That's intresting. People can argue DTS vs Dolby all day long but DTS better than MLP, now that is something.
Quote:
I'll try to dig out some white papers.
Awsome I love Whitepapers! (j/k)
Ced
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