HD DVD - audio

Vaughn,

Unless things have changed in the last couple of weeks I don't think anything has been ratified yet.

From what I'm reading DVD-A and SACD will probably NOT be included.

M

The new high definition DVD formats will be bringing new audio formats with them. In fact HD-DVD has already launched and the disks you can buy today already have one or more of these new formats on them. In summary, the new formats are: Dolby Digital Plus (7.1 channel, lossy compression), DTS-HD (7.1 channel, lossy compression) and Dolby TrueHD (8 channel, 24bit/96Khz per channel, lossless).

Actually being able to hear these new formats to their full potential is a bit of a can of worms at present. No 1st generation player will do everything needed to give you what these formats are capable of providing. There are two ways of getting at these new formats, either a) decode internally within the player and output through analogue connections. Unfortunately the 1st gen players only have 5.1 channel analog outputs. Alternatively, b) pass the digital stream from the player to an external decoder. As the bit rates of all these formats is greater than SPDIF can handle, the way this will be done in the future is via a HDMI version 1.3 connector, which won't be available on any consumer device until the end of this year. The way Toshiba get around this is to re-encode DD+ or DTS-HD into normal full bit-rate DTS for transmission down the SPDIF connector or the HDMI version 1.1 connector. Blu-ray players will do something similar but I believe they will re-encode to normal Dolby Digital.

I've heard Dolby Digital Plus from HD-DVD re-encoded to DTS by the Toshiba HD-DVD player and decoded by a TAG AV32 and it sounded pretty good to me, better than standard DVD in the system I heard it in. From other user reports I've read from serious home cinema enthusiasts HD-DVD is providing not only the best vision but also the best audio they've ever had in their cinemas.

For more information try www.dolby.com/promo/HD/

Allan

Allan,

Am I right in thinking that nothing has been officially ratified? That certain algorithms are almost certainly shoe-ins, but that manufacturers are currently taking their 'best shot'?

M

No, thats not right, these are the standards and they are ready now. HD-DVD disks already use them, Blu-ray will use them (eventually). The only areas of doubt are when they will appear on Blu-ray disks and when HDMI 1.3 will appear. It's HDMI 1.3 that isn't ratified yet but will be very soon (if not already in the last week or two) which is why silicon isn't available to incorporate in HD players or processors. Current low yields of dual-layer blu-ray disks means that initial blu-ray titles will be on single layer disks. Given the resulting capacity constraints something will have to give and these titles will probably only have legacy DD and DTS soundtracks.

Please post a link if you've seen anything to the contrary.

Allan

Allan,

It wasn't a URL but Barry Fox a couple of months ago in Hi-Fi News....I think.

If I get any time I'll do some digging, although finishing my bathroom is my current priority!

M

M.

What it would be suggesting if that article was in any way current is that HD-DVD and Blu-ray are launching without agreed audio formats. If that was true then a player bought now may not work with future HD-DVD or blu-ray disks or that early HD-DVD or blu-ray disk won't work in future HD-DVD or blu-ray players. This is bizare in the extreme and if true would be splashed all over the press and the internet. The HD-DVD and Blu-ray formats represent a core set of standards. All players and disks must support at least that core set in the same way that a DVD player bought at launch will still play a DVD disk bought today and vice versa, ie a DVD disk bought at launch will still play in a player bought today.

Here are a couple of published reviews of the Toshiba HD-DVD players. Please read, if there was any doubt that the audio formats were still not agreed then these articles would be telling you about it:

Sound & Vision Magazine

Secrets of Home Theatre - Kris Deering's Review

Allan

Allan,

I don't think that is what BF was suggesting. I believe that he was saying the the compressed audio standards, such as HD-DD and HD-DTS are in place...but there is no solid pronouncements on HD-Hi Res formats.

He also ponts out such things as: the increased crypto making hacking the regional coding more problematic; More issues with Digital Rights Management; Lack of final sign up to a parts of the digital standards - such as regional coding (which I THINK has now been confirmed as being introduced); Lack of clear information by the various bodies; Possible issues with such things as HDMI versions .....and so on.

Martin

Ah, with you. You're talking about the equivalents of DVD-A and SACD, which are essentially standalone audio-only formats based on DVD type technology (in terms of storage capacity and bit-rate), in a HD-DVD / blu-ray world. Whereas I'm talking about the audio tracks available on HD-DVD movie/video disks.

I think though, to be fair, if you read the original posters question he's asking about the possibility of higher quality audio tracks on HD-DVD video disks. If not, I hope the info is useful anyway.

Allan

Martin,

Just to add to the above, if you check out Dolby TrueHD (as mentioned above) and DTS-HD Master Audio (An optional audio format on HD-DVD and blu-ray and the DTS equivalent to Dolby TrueHD) you'll see that these are lossless high resolution formats, probably equivalent to DVD-A yet also available as the soundtrack on a video disk.

Allan

Thanks Allan,

I'll go and have a read now....

M

Allan,

Before going into some of the detail around the articles above I just want to recap the current Hi-Res formats; if only for my benefit!

Currently in terms of common non-compressed formats on SD-DVD we have:

LPCM
http://www.digitalpreservation.gov/formats/fdd/fdd000011.shtml
Sample size to 32bit
Sample rate to 192 KHz
Uncompressed representation of the recorded waveform.

MLP (DVDA)
http://www.dolby.com/assets/pdf/tech_library/63_MLPLossless.pdf.
Way of compressing PCM losslessly.
On CD can deliver 24 bit at up to 88.2KHz
On DVD 24/192, up to 64 channels - but number rapidley declines as resolution goes up (9624 = 6 channels)

DSD (SACD)
http://www.dsdproaudio.com/html/dsd_sacd_explained.html
Sample size is 1bit
Sample rate is 2.8224MHz
Avoids issues that require digital filtering



So how does this compare to the new HD formats?

DD Plus

Extension of DD & MLP
http://www.dolby.com/resources/tech_library/index.cfm
Can deliver lossless audio.

DTS Plus
Extension of DTS
Can deliver lossless audio. Up to 192/24

http://www.hometheatermag.com/hookmeup/406hook/


The issue with these is, I think, the delivery mechanism.

The manufacturers and IPR holders want to constrain what we, the purchasers, can do with 'their' property.

I believe that all sorts of constraints have been built into BR and HD-DVD. Some of these are yet to be turned on, but if the formats are successful almost certainly will be.

http://businessweek.com/technology/content/may2006/tc20060526_680075.htm


The companies have learned from previous mistakes and so have allowed for changes in, for instance, trhe supporting cryptography.

The possible issues around HDMI, HDCP & AACS may prove interesting, with the specifications not necc. being properly implimented by various manufacturers.

My understanding is that HD player cap the quality of the audio that they output via their unencrypted digital outputs, such as s/pdif. Currently I use an external DAC with my DVD5, now manufacturers will be presumably forced into the licencing terms of HDMI etc.


So looking at the articles:

I suppose my first comment would be that, in terms of audio, I wouldn't look at either of these sources as an arbiter of audio quality. I do respect the work KD does around picture quality, and I may be doing him a dis-service w.r.t. audio.

Looking first at the Sound & Vision Article -

...and uncompressed multichannel PCM audio from the player's digital HDMI...

The non-HDMI being capped.



The HD-XA1 delivered full-resolution HDTV from the component output — neither Warner nor Universal flipped the dreaded Image Constraint Token...

But if successful as a format I have no doubt this will end.



So, what does an HD DVD picture look like? The first key improvement over DVD was an obvious gain in detail and a reduction of digital compression artifacts...

I would hope so.
If I don't upgrade my plasma I won't notice the increased quality of the new discs; and currently I think I have great PQ!



The HD DVDs proved to also have superior sound compared with the traditional Dolby Digital track found on most DVD and HD broadcasts. All the new titles I looked at were encoded with Dolby Digital Plus...

My interest here is in Hi-Res, not the compressed tracks.



In fact, my experience with the HD-XA1 bore this out. Because the standard for the next evolution of HDMI (known as version 1.3) is not finished, this Toshiba can't send the 1080p signal on an HD DVD disc directly to any TV.

Moving target as standards are still in development / how / what is being implimented.



Kris Deering

.....including the opportunity to have true lossless 7.1 audio soundtracks!

Yep, looks like it. I wonder whether anyone will?

And if they do you will need to listen via HDMI.


Martin

Hi Martin,

Lets see if I can answer most of your points:

quote:

The manufacturers and IPR holders want to constrain what we, the purchasers, can do with 'their' property.

I believe that all sorts of constraints have been built into BR and HD-DVD. Some of these are yet to be turned on, but if the formats are successful almost certainly will be.

Most people were almost expecting them to be turned on from the start but the movie studios relented and it now appears that may not happen until 2010 or 2012. I expect sooner or later they will be switched on and we will only have access to the high resolution content via the HDMI connector. However, ICT is only a concern if you want to use analog outputs.

quote:

The companies have learned from previous mistakes and so have allowed for changes in, for instance, trhe supporting cryptography.

The possible issues around HDMI, HDCP & AACS may prove interesting, with the specifications not necc. being properly implimented by various manufacturers.

There are various 'naughty boxes' out there that will circumvent the encryption mechanism so as to allow a high resolution analogue signal to be obtained from encrypted HDMI. HDCP incorportaes a mechanism that allows the keys beings used by these devices to be made invalid. I'm not aware of any issues around AACS but HDMI+HDCP is causing a big headache for manufacturers to get right. There's a huge combination of sources, sinks (i.e. displays, receivers/audio-processors, etc.) and repeaters (e.g. scalers) and meshing all this together, especially when mixing different manufacturers kit, is proving problematic. But this is nothing new and it's not specific to HD-DVD. Even today, no HDMI = no upscaled DVD.

quote:

My understanding is that HD player cap the quality of the audio that they output via their unencrypted digital outputs, such as s/pdif. Currently I use an external DAC with my DVD5, now manufacturers will be presumably forced into the licencing terms of HDMI etc.

The s/pdif/toslink connection can not handle the bit-rate rate required by the new audio formats so it has to be down-ressed. To get the full digital resolution of these formats requires a higher bandwidth digital connection which is/will be HDMI version 1.3

quote:

So looking at the articles:

I suppose my first comment would be that, in terms of audio, I wouldn't look at either of these sources as an arbiter of audio quality. I do respect the work KD does around picture quality, and I may be doing him a dis-service w.r.t. audio.

I'm sure that's fair, I just posted those links not to illustrate the audio quality of the new formats but to indicate that if there was any issue with the audio formats for HD-DVD (and blu-ray) not being agreed you would expect these articles to mention it.

quote:

Looking first at the Sound & Vision Article -

...and uncompressed multichannel PCM audio from the player's digital HDMI...

The non-HDMI being capped.

Yes, for the reasons stated. The spdif outputs a full bitrate normal DTS signal derived from the Dolby Digital Plus (or DTS-HD) track and actually works remarkably well as I've heard and the article confirms.

quote:

The HD-XA1 delivered full-resolution HDTV from the component output — neither Warner nor Universal flipped the dreaded Image Constraint Token...

But if successful as a format I have no doubt this will end.

Agreed, but if I use HDMI it won't be an issue. For some maybe, but at least they have a few years to purchase a HDMI ready display. And if they don't want to, fine, they don't have to buy into the format or they can use the 480i/576i outputs. I know that sounds rough but those are the rules and no-ones being forced to play.

quote:

So, what does an HD DVD picture look like? The first key improvement over DVD was an obvious gain in detail and a reduction of digital compression artifacts...

I would hope so.
If I don't upgrade my plasma I won't notice the increased quality of the new discs; and currently I think I have great PQ!

It's fairly well confirmed that HD displayed on an SD display still looks better than SD on an SD display. For one thing you are dealing with a lossy format, DVD is not encrypted with lossless pixels at 1024x576. The higher bandwidth of an HD signal will still put more data on your screen even when downscaled.

quote:

The HD DVDs proved to also have superior sound compared with the traditional Dolby Digital track found on most DVD and HD broadcasts. All the new titles I looked at were encoded with Dolby Digital Plus...

My interest here is in Hi-Res, not the compressed tracks.

Some HD-DVD disks already have high resolution lossless audio tracks, Phantom of the Opera and Training Day are two examples, there may be more but its early days (we're about six weeks in now from launch)

quote:

In fact, my experience with the HD-XA1 bore this out. Because the standard for the next evolution of HDMI (known as version 1.3) is not finished, this Toshiba can't send the 1080p signal on an HD DVD disc directly to any TV.

Moving target as standards are still in development / how / what is being implimented.

Blu-ray and HD-DVD disks are encoded at 1920x1080p@24Hz (USA), 25Hz (Europe). The limitation of not being able to send 1080p but only 1080i is a limitation of this first generation player only. Even this isn't actually a limtation as a 1080i signal at 60Hz sourced from 1080p at 24Hz contains all the information in the original progressive signal. In fact a 1080i/60Hz signal has so much room to spare, some of it gets sent twice . With an appropriate de-interlacer, the original 24Hz progressive frame can be re-assembled from the interlaced signal. HDMI version 1.3 is a transport standard and won't be available on consumer devices until the end of this year. It has no impact on the encoding of the disks only that you can't yet get at everything thats on there using 1st generation players and/or pre-processors without HDMI 1.3 connectors.

quote:

Kris Deering

.....including the opportunity to have true lossless 7.1 audio soundtracks!

Yep, looks like it. I wonder whether anyone will?

And if they do you will need to listen via HDMI.

I mentioned a couple of disks earlier that have lossless audio soundtracks but I believe these are 'only' 5.1. The HD-DVD and blu-ray standards allow for up to 7.1 lossless and I'm sure once the studios have gotten to grips with the new audio and video codecs we'll see them get more ambitious. It's a new format and I'm sure it will be pushed to the limit in time. HDMI connector? yes, of course.

Phew, hope I managed to answer all the questions and points you raised. Slightly seperately, prototype blu-ray players and specs for those players are beginning to appear. I'll post more on this tomorrow but a couple of the 1st gen players appear a little disapointing in terms of the audio features supported.

Allan

Hi Allan,

Seems that we agree on a lot of points.

To go through the contentious ones:

Encryption, HDMI, HDCP et al:

My issues around this is that I believe in 'fair use', despite the fact we have none in English law.

I want to buy my software, not rent it. If I buy some music in format A I don't want to have to buy it again in format B.

For instance: I buy a lot of music. I do not choose to keep original CDs in my car. I could fit multiple CDs on one CD in MP3; and protect my original investment.

I am sure this is a view that would not be shared by the IPR owners.

DRM is being introduced, as far as I am concerned, to screw me down.

The s/pdif/toslink connection can not handle the bit-rate rate required by the new audio formats so it has to be down-ressed.

Mmmm, think this needs more detail.

My s/pdif is currently playing me a stereo soundtrack at 24/192.

That is the max bit rate of the new HD DD & DTS.

Of course that is stereo, not multichannel.

I can listen via 5.1 - but the DACs are better in the Benchmark than the DVD-A card in the DVD5; and some of the sound mixing on certain albums is strange to say the least!

HDMI 1.3 allows the simple transfer of 7.1 channels PLUS DRM......and potentially introduces lots of jitter. Is 1.3 here yet?

It's fairly well confirmed that HD displayed on an SD display still looks better than SD on an SD display.

I knew you'd pick up on this!

The issue I was alluding to is that when you play a SD player through a HD screen you'll more clearly see the shortcomings.

When I watched VHS through my CRT TV I was very happy with it. Through a plasma it looked dreadful.

From what I am reading the gap between DVD & HD is not so great as VHS to DVD - and some articles state it is small.

I don't intend to upgrade my plasma in the near future, and so the 'gap' will not be accentuated.

Some HD-DVD disks already have high resolution lossless audio tracks, Phantom of the Opera .....

Trying to find a statement of the audio on the Phantom HD-DVD is as bad as SD DVD!

Lots say TrueHD 5.1, but none state the sample rate or frequency, one article states:

Warner's first batch title Phantom of the Opera is encoded with a 5.1-channel TrueHD track that will have to wait for at least a second generation player to be heard in all its potential glory.

But is that as 16 bit/44.1?? I'm sure it's not but I can't find out in a 30 minute trawl.


Martin

quote:

For instance: I buy a lot of music. I do not choose to keep original CDs in my car. I could fit multiple CDs on one CD in MP3; and protect my original investment.

AACS (ie "managed" copy) should be finalised this month. Let's see what this allows.

quote:

DRM is being introduced, as far as I am concerned, to screw me down.

I did say on this forum a couple of years ago, perhaps slightly jokingly, that the new fledgling HD video formats were all about better copy protection, fantastic image quality was just the bait. To be fair, you should also be blaming the pirates for this situation. If we were all perfect and honest, DRM would not be necessary.

quote:

The s/pdif/toslink connection can not handle the bit-rate rate required by the new audio formats so it has to be down-ressed.

Mmmm, think this needs more detail.

More details on this and loads of other stuff audio related re. the Toshiba HD-DVD player:
Answers to HD-A1 and HD-XA1 Audio Questions. Mentions this in the first post, about 4th paragraph down, as being bandwidth related but no figures unfortunately.

It looks like this method of re-encoding the DD+ and DTS-HD soundtracks into normal DTS is so far unique to Toshiba. The early blu-ray players from Samsung and Sony will only output the legacy DD and DTS core embedded in the DD+ and DTS-HD streams.

Something nice I've picked up on regarding the way the Toshiba handles 7.1 DD+ and DTS-HD is that it converts it to 5.1 LPCM for output on the HDMI version 1.1 connector (so similar to DVD-A). Not that I have a processor with a HDMI 1.1 input but there is kit out there that does, such as the Arcam AV8 and AV9 processors.

quote:

HDMI 1.3 allows the simple transfer of 7.1 channels PLUS DRM......and potentially introduces lots of jitter. Is 1.3 here yet?

Not ratified yet. Should be this month or early next.

quote:

From what I am reading the gap between DVD & HD is not so great as VHS to DVD - and some articles state it is small.

I would agree and say the difference is not quite as great as VHS to DVD but when you see it it will remind you of that feeling all over again. The difference is not small though, it's clear and very obvious. It's not too difficult to get that 'looking through a window' effect on a good 42" plasma with DVD, imagine being able to sustain that effect on a screen 6ft wide.

quote:

I don't intend to upgrade my plasma in the near future, and so the 'gap' will not be accentuated.

You have every right not to watch films in high definition if you don't want too

quote:

Lots say TrueHD 5.1, but none state the sample rate or frequency, one article states:

Warner's first batch title Phantom of the Opera is encoded with a 5.1-channel TrueHD track that will have to wait for at least a second generation player to be heard in all its potential glory.

But is that as 16 bit/44.1?? I'm sure it's not but I can't find out in a 30 minute trawl.

Don't know for sure, but as the spec for Dolby TrueHD states "Supports up to eight full-range channels of 24-bit/96 kHz audio" I'm going to take that as meaning disks encoded with fewer channels are still at 24/96 per channel. Just a hunch but I'd guess that is how Phantom has been encoded.

Allan

Allan,

I think this is the end of the road for me on this thread.

Enjoyed it.

Cheers,

M

Yes, me too. I hope Vaughn3D got the information he was looking for

Allan

thanks everyone.

I think Allan put it best, I guess I am just hoping for higher quality audio tracks on HD-DVD video disks. I don't need 45 channels of sound but was hoping for the simple correlation of HD DVDs having significantly more room to house data, and better stereo sound. But I guess since my hifi drifts somewhere between a music and movie system, thats the price I pay.

Here you go Martin, HDMI 1.3 specifications announced today. HDMI 1.3. There's something in there for you.

quote:

New HDMI 1.3 capabilities include:

Higher speed: HDMI 1.3 increases its single-link bandwidth from 165MHz (4.95 gigabits per second) to 340 MHz (10.2 Gbps) to support the demands of future high definition display devices, such as higher resolutions, Deep Color and high frame rates. In addition, built into the HDMI 1.3 specification is the technical foundation that will let future versions of HDMI reach significantly higher speeds.

Deep color: HDMI 1.3 supports 30-bit, 36-bit and 48-bit (RGB or YCbCr) color depths, up from the 24-bit depths in previous versions of the HDMI specification.
- Lets HDTVs and other displays go from millions of colors to billions of colors
- Eliminates on-screen color banding, for smooth tonal transitions and subtle gradations between colors
- Enables increased contrast ratio
- Can represent many times more shades of gray between black and white. At 30-bit pixel depth, four times more shades of gray would be the minimum, and the typical improvement would be eight times or more

Broader color space: HDMI 1.3 removes virtually all limits on color selection.
Next-generation “xvYCC” color space supports 1.8 times as many colors as existing HDTV signals
Lets HDTVs display colors more accurately
Enables displays with more natural and vivid colors

New mini connector: With small portable devices such as HD camcorders and still cameras demanding seamless connectivity to HDTVs, HDMI 1.3 offers a new, smaller form factor connector option.

Lip Sync: Because consumer electronics devices are using increasingly complex digital signal processing to enhance the clarity and detail of the content, synchronization of video and audio in user devices has become a greater challenge and could potentially require complex end-user adjustments. HDMI 1.3 incorporates an automatic audio/video synching capability that allows devices to perform this synchronization automatically with accuracy.

New lossless audio formats: In addition to HDMI’s current ability to support high-bandwidth uncompressed digital audio and currently-available compressed formats (such as Dolby® Digital and DTS), HDMI 1.3 adds additional support for new, lossless compressed digital audio formats Dolby® TrueHD and DTS-HD Master Audio™.

Products implementing the new HDMI specification will continue to be backward compatible with earlier HDMI products.

“The dramatic increase in maximum speed achieved in HDMI 1.3 will enable HDMI to stay far ahead of the bandwidth demands of future high definition source and display devices,” said Leslie Chard, president of HDMI Licensing, LLC. “As the de facto standard digital interface for the high definition and consumer electronics markets, HDMI is implementing the most innovative technologies today to fulfill the demands of tomorrow’s consumers.”

The latest HDMI specification can be downloaded at no cost by visiting www.hdmi.org.

Auto lip-synch. Thank goodness!

I had heard about the colour changes. The thing for people to remember is that this is only true for HDMI 1.3 displays! Standard HDMI displays (ie pretty much anything you buy this year) will still be limited to 16M colours.

quote:

New lossless audio formats: In addition to HDMI’s current ability to support high-bandwidth uncompressed digital audio and currently-available compressed formats (such as Dolby® Digital and DTS), HDMI 1.3 adds additional support for new, lossless compressed digital audio formats Dolby® TrueHD and DTS-HD Master Audio™.

Thanks Allan.

As we know these have a max. data rate of 96/24, although over more channels. Doesn't mean they will supply data at a high rate; such as the depressed quality of DualDisc, in spite of the specs.

They carry the HDMI overhead; which can introduce jitter, and certainly means a fully encrypted feed to get the full data rate - plus other DRM, so my current DAC will not
be usable.

The possible Hi-Res musical content of HD-DVD & BR will have no bearing on the success or failure of these formats.

I do not believe the the 'big guns' have any further interest in Hi-Res following the failure of SACD/DVDA.

What they are interested in is control, control of us and what we do with what they see as their property - despite whatever media we purchase; read the Microsoft Licence agreement recently?

.....But I'll follow the new format war(s) with interest.

Martin

Very interesting article here on the Dolby website regarding audio connectivity between the new format HD players and AV Amps / processors:

Dolby Technologies

It contains a couple of surprising elements:

• Additional audio features like commentary tracks, player generated sounds (e.g. button clicks) and on-line content (additional commentary / audio tracks streamed from the internet via the player's ethernet port) can only be accessed when the main audio track is decoded internally in the player. The separate audio streams are mixed internally by the player and output via analogue connections or as multi-channel LPCM via HDMI of any flavour, ie 1.1, 1.2 or 1.3.
  
  
• It will be 'normal' for the DD+, Dolby TrueHD, etc. bitstream to be copy protected, preventing decoding externally in an AV amp / processor, forcing the use of internal decoding by the player and transported digitally to the amp in LPCM format (or via 6/8 analogue cables)
  

On the face of it, this kind of blows away the theory that we need HDMI 1.3 to access DD+ and Dolby TrueHD digitally. All we really need is a current day processor capable of decoding multi-channel LPCM via HDMI 1.1 (or 1.2). I'm sure manufacturers of Av processors aren't going to turn down the opportunity to sell us replacement boxes emblazened with all the new logos and a HDMI 1.3 connector so I'm not sure how much of this copy protection of the raw bitstream will come to pass when commercial interest is at stake.

Allan