Sony's "multichannel uncompressed audio" - huh?

[Giles]

So what does Sony mean by this

"multichannel uncompressed audio"

for their releases of The Last Waltz and The Fifth Element

??

[awmurray]

So what does Sony mean by this

"multichannel uncompressed audio"

for their releases of The Last Waltz and The Fifth Element

??

I assume it means that the audio track (DD 5.1 or whatever) is stored on the disc uncompressed. Meaning it will not have any loss due to compressing it to make it fit on the disc...

[Premise]

Both HD DVD and Blu-ray Disc are establishing audio standards for their respective disc formats. Based on reports elsewhere, there are hints concerning the audio formats we might expect, and there’s good news and a bit of bad news. Both formats have endorsed Dolby Digital Plus, an enhanced extension of the Dolby Digital format. DTS will likely be offered on both formats, and DTS has also created an extension in the form of DTS-HD. Both Dolby Digital Plus and DTS-HD are lossy, but each should provide improved fidelity and accuracy. But best of all, both Dolby and DTS have devised new lossless digital audio formats that promise to convey every single bit found on the studio masters for greatly improved fidelity: Dolby TrueHD and DTS++.

So the good news is that as high definition DVDs are introduced, fidelity should enjoy a significant leap upward; the sound quality should be noticeably better than the finest DTS or Dolby Digital track you’ve ever heard from DVD. The bad news is that with respect to audio, technological progress is going to force investments in new equipment. Your existing decoders are not programmed to deal with the new processes, and I’d be surprised if any could be updated with new algorithms; I suspect that the processing power required to deal with the new digital audio formats will exceed your processors’ computational abilities. But don’t throw that expensive decoder or receiver out the window just yet; our friends at Dolby and DTS have made their new audio formats backward compatible.

You will be able to feed the digital audio S/PDIF bit stream from the new high definition players into your current decoder or receiver and the fidelity you’ll experience will be no less than you perceive today, possibly better. And if you have a system that supports proper bass management when driven from its analog inputs, the first wave of high definition disc players are expected to have multi-channel analog audio outputs to provide full fidelity audio decoded with the new algorithms.

So unlike the studios’ potential requirement to have early adopters purchase new displays equipped with HDCP-compliant HDMI inputs to view full resolution high definition video, you will not have to rush to purchase a new digital audio decoder. The difference in urgency between preparing for the video and the audio stems from the differences in video and audio improvements found on high definition discs; unlike the dramatic improvement over standard resolution video you’ll see in high definition images, the new “high definition” audio formats’ improvements will be subtler. You’ll eventually want to upgrade your audio path, but Dolby and DTS have been kind to us. Backward compatibility is assured. Now, if only the studios would be as kind with the video.

[Giles]

so it sounds like I won't have to upgrade my receiver then - phew

[roomservice]

Will copy protection stand in the way of using outboard decoders with the new high-def audio signals?

If not, are there any companies releasing information on upcoming units for the nee high-def audio formats?

[Spiky]

They already have HDCP all set up for movies, the audio would be within that protection.

Are you suggesting DTS++ or Dolby TrueHD audio-only discs may come out? That would be interesting. Perhaps they would use HDCP also, if they ever exist. I wonder how those formats match up with current high-rez SACD and DVD-Audio discs for audio quality.

[Todd B.]

I was intriguiged by all these new audio formats, so I did some reading on the web. I'll share my findings for your benefit.

<b>Dolby Digital Plus</b> vs. current Dolby Digital
Supports true discreet 7.1 channels (technically, up to 13.1, but HD-DVD and Blu-Ray only support 8 audio channels)
up to 6 Mbps (vs. 448 Kbps)
can downconvert to Dolby Digital for backwards compatibility
mandatory for HD-DVD. optional for Blu-Ray
S/PDIF does not have enough bandwidth to carry it. HDMI and FireWire can.

<b>Dolby TrueHD</b>
large number of channels (unspecified)
lossless
supports metadata including dialogue normalization and dynamic range control.
mandatory for HD-DVD, optional for Blu-Ray

<b>DTS-HD</b> (which is the new name for DTS++, Premise)
virtually unlimited number of channels
can downconvert to DTS for backwards compatibility
can encode either lossless or lossy
Optional for Blu-Ray and HD-DVD

Spiky, regarding using these for music, as best as I can tell, Dolby TrueHD uses the same MLP compression for lossless audio as DVD-Audio does, and it also matches the 24/192 fidelity of DVD-Audio. So, it looks like a disc authored with Dolby TrueHD and a DVD-Audio would probably sound the same. Dolby TrueHD gives the potential for more channels, I suppose (though it looks like if you do more than 6 channels, you might be limited to 96 KHz, instead of 192). I think DTS-HD would have similar advantages. So, I don't think either format provides significant improvements over the current high-res audio choices.

Sony's release of "multichannel uncompressed audio" is encoded with neither, simply being uncompressed Linear PCM tracks. That's very expensive, bit-wise, and I'd imagine that future releases will use the lossless compression advantages of Dolby TrueHD and/or DTS-HD, once they become more widespread (and released).

I was worried that HDMI might not have enough bandwidth for all these new audio channels and high-def video, but my fears were unfounded. HDMI has enough bandwidth for 1080p video, 8 uncompressed audio channels, and room to spare for future expansion.

[flashburn]

Very informative post, Todd. Interesting to see that none of the new HD formats are mandatory for Blu-Ray. I hope that doesn't mean the best we will get on some releases is a full bit-rate DTS or DD track.

[joshd2012]

Blu-Ray has yet to release the finalized specs for Blu-Ray (which were signed off on a few days before CES started). Once those get released, it is expected that they will make at least a few of those manditory.

[Spiky]

I was intriguiged by all these new audio formats, so I did some reading on the web. I'll share my findings for your benefit.
...

Spiky, regarding using these for music, as best as I can tell, Dolby TrueHD uses the same MLP compression for lossless audio as DVD-Audio does, and it also matches the 24/192 fidelity of DVD-Audio. So, it looks like a disc authored with Dolby TrueHD and a DVD-Audio would probably sound the same. Dolby TrueHD gives the potential for more channels, I suppose (though it looks like if you do more than 6 channels, you might be limited to 96 KHz, instead of 192). I think DTS-HD would have similar advantages. So, I don't think either format provides significant improvements over the current high-res audio choices.

Sony's release of "multichannel uncompressed audio" is encoded with neither, simply being uncompressed Linear PCM tracks. That's very expensive, bit-wise, and I'd imagine that future releases will use the lossless compression advantages of Dolby TrueHD and/or DTS-HD, once they become more widespread (and released).

Great info, thanks. I believe DVD-A is only required to be 24/96, so that still matches. And the stereo 24/192 tracks found on many DVD-A discs are straight PCM, also. They can be played on certain DVD players that are not DVD-A (MLP) players. Probably very similar to what you found about Sony's uncompressed audio. So it does sound like it is all the same technologies, which is probably best. They are all quite capable of great sound, no reason for another new format.

[flashburn]

Blu-Ray has yet to release the finalized specs for Blu-Ray (which were signed off on a few days before CES started). Once those get released, it is expected that they will make at least a few of those manditory.
Okay, thanks. Hopefully we will get some good news.

[flyersfan]

Great info, thanks. I believe DVD-A is only required to be 24/96, so that still matches.

Actually, there is no such requirement on DVD-A discs. I have a Crystal Method DVD-A which includes a 24-bit/48khz 5.1 MLP DVD-A stream, 24/48 6.1 DTS-ES, and 16/48 2.0 LPCM.

On a tangental note, I'm surprised and disappointed that the new HD-DVD/Blu-ray players don't include SACD or DVD-A support. My 5.1 analogue inputs are already in use, so I'll need a switch box to take advantage of the new audio formats on the hd discs.

[chente]

I was intriguiged by all these new audio formats, so I did some reading on the web. I'll share my findings for your benefit.

<b>Dolby Digital Plus</b> vs. current Dolby Digital
Supports true discreet 7.1 channels (technically, up to 13.1, but HD-DVD and Blu-Ray only support 8 audio channels)
up to 6 Mbps (vs. 448 Kbps)
can downconvert to Dolby Digital for backwards compatibility
mandatory for HD-DVD. optional for Blu-Ray
S/PDIF does not have enough bandwidth to carry it. HDMI and FireWire can.

<b>Dolby TrueHD</b>
large number of channels (unspecified)
lossless
supports metadata including dialogue normalization and dynamic range control.
mandatory for HD-DVD, optional for Blu-Ray

<b>DTS-HD</b> (which is the new name for DTS++, Premise)
virtually unlimited number of channels
can downconvert to DTS for backwards compatibility
can encode either lossless or lossy
Optional for Blu-Ray and HD-DVD

Spiky, regarding using these for music, as best as I can tell, Dolby TrueHD uses the same MLP compression for lossless audio as DVD-Audio does, and it also matches the 24/192 fidelity of DVD-Audio. So, it looks like a disc authored with Dolby TrueHD and a DVD-Audio would probably sound the same. Dolby TrueHD gives the potential for more channels, I suppose (though it looks like if you do more than 6 channels, you might be limited to 96 KHz, instead of 192). I think DTS-HD would have similar advantages. So, I don't think either format provides significant improvements over the current high-res audio choices.

Sony's release of "multichannel uncompressed audio" is encoded with neither, simply being uncompressed Linear PCM tracks. That's very expensive, bit-wise, and I'd imagine that future releases will use the lossless compression advantages of Dolby TrueHD and/or DTS-HD, once they become more widespread (and released).

I was worried that HDMI might not have enough bandwidth for all these new audio channels and high-def video, but my fears were unfounded. HDMI has enough bandwidth for 1080p video, 8 uncompressed audio channels, and room to spare for future expansion.


Great post. Answered all my questions. Thanks.

[Todd B.]

With all the new disc announcements, I had to go back and read my own notes to refresh my memory on these new audio formats. In any case, here's the latest state of home theater HD audio, as far as I could determine.

HD-DVD Players
------------------
Dolby Digital Plus - mandatory
Dolby TrueHD - mandatory
DTS - mandatory
DTS-HD - optional

Blu-ray Players
-----------------
Dolby Digital Plus - mandatory
Dolby TrueHD - optional
DTS - mandatory
DTS-HD - optional

The reality is that probably within a year, all players will support all the audio formats. Then, it's just a matter of what discs have what, and if you have a receiver that can decode it.

[Sanitarium]

What's the point of the HD audio formats? Just an added feature of HD disc formats because aren't the tracks on DVDs already what was played in theaters?

[Qui Gon Jim]

The audio on DVDs are compressed to fit onto the disc. The new formats may have room to include an uncompressed soundtrack. Many here say that some Laserdisc audio tracks sound better than even the best DVD tracks.

[Giles]

Many here say that some Laserdisc audio tracks sound better than even the best DVD tracks.


raises hand.