DTS? Core? HD-MA? huh??

chuckg · 03-04-2008, 02:59 PM

Alright, ya'all are making me feel stupid!

Could someone point me to a reasonable, concise, and meaningful description of all these new digital formats on these new high-def disks? I'm hoping to get permission from "the boss" to spend some money on a Blu player after the tax rebate and the bribe from the feds, so I need to know what I'm talking about when I check the specs!

thanks....from an old Auld school guy.

ErichH · 03-04-2008, 05:11 PM

Basic - just like the old Dolby Digital & DTS - Studios include 1 or 2 types on a film along with
good old Dolby from the Standard DVDs. Most sound better, but not all (SOS Man)

Linear PCM (LPCM) - up to 8 channels of uncompressed audio. (mandatory)
Dolby Digital (DD) - format used for DVDs, 5.1-channel surround sound. (mandatory)
Dolby Digital Plus (DD+) - extension of Dolby Digital, 7.1-channel surround sound. (optional)
Dolby TrueHD - lossless encoding of up to 8 channels of audio. (optional)
DTS Digital Surround - format used for DVDs, 5.1-channel surround sound. (mandatory)
DTS-HD High Resolution Audio - extension of DTS, 7.1-channel surround sound. (optional)
DTS-HD Master Audio - lossless encoding of up to 8 channels of audio. (optional)

Plenty of discussion on all the forums - one example

BD Player Audio Support Comparison - AVS Forum

Much discussed here as well

Have fun

sptrout · 03-04-2008, 05:57 PM

You can also go directly to the horses mouth by looking at Dobly Labs & DTS' web pages. Good stuff at both places, including "pdf" documents (at DTS anyway).

JeremyErwin · 03-04-2008, 06:35 PM

All of the dts soundtracks have a core, which can be interpreted by the most basic dts decoder, and extensions, which add extra channels, higher sampling rates, etc, by "correcting" the core.

An analogy:

There are 365.2425 days in the Gregorian year. But fractional days have their problems. So we assume that the year has 365 days and add a leap year every four years, except when it's the end of a century, unless the century is divisible by four.

365 is the core data-- the leap days correct it.

If the player only decodes the "Core" portion of DTS-MAHD, it's not giving you anything special-- it won't be lossless, it won't be 192/24, it won't be 7.1.

chuckg · 03-05-2008, 10:14 AM

Thanks everyone!

Well, this is pretty crazy stuff. While I understand digital audio reasonably well, I think I will need to do a bit if studying to understand why there are so many formats! For instance, if Uncompressed Linear PCM is on the disc, what benefit do we get from "lossless" encoding? I'm guessing it is a higher sample rate, greater bit depth, or both.

My poor simple mind wrestles with the notion. Why not simply have 8 channels of 96 kilosamples per second at 24 bits and be done with it? The bit rate would be kinda high, I suppose

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Jack Gilvey · 03-05-2008, 10:42 AM

DTS - We Bring Entertainment Alive!

Camper · 03-05-2008, 10:43 AM

Never mind!

Scott Jentsch · 03-05-2008, 10:44 AM

Some time ago, I wrote up these documents to try and put the technology into more approachable language:

These documents don't cover PCM, but they may help you sort through the differences between the compressed formats.

If anyone has suggestions for improvements to make to these documents, I'm open to feedback!

Jack Gilvey · 03-05-2008, 10:48 AM

Quote:

Originally Posted by chuckg

My poor simple mind wrestles with the notion. Why not simply have 8 channels of 96 kilosamples per second at 24 bits and be done with it? The bit rate would be kinda high, I suppose

All these "formats" are just ways to save space, to pack PCM data for storage. "Lossless" codecs, like TrueHD and DTS-HD MA, don't discard any data and when unpacked/decoded are a bit-for-bit identical copy of the encoding master. There's no advantage to this, although it's certainly possible to fit a higher-quality compressed/packed soundtrack than might otherwise fit as PCM.
You can't listen to any of these "formats" in their native form any more than you can read a zipped file, they all originate as PCM and must be decoded to such before processing and D/A conversion. With HD-DVD and BD, this can happen in the player or AVR, a single HDMI cable is required either way.

chuckg · 03-05-2008, 12:34 PM

Ok - starting to get it...must....think...harder....!

I want to make certain that when I have the spare cash (come on, tax rebate!) that I get a Blu player that will decode the latest and greatest, and send it out through analog connections. It may be a while before I can justify a new rcvr or pre/pro setup with HDMI inputs!

ErichH · 03-05-2008, 02:09 PM

Quote:

Originally Posted by chuckg

Ok - starting to get it...must....think...harder....!

I want to make certain that when I have the spare cash (come on, tax rebate!) that I get a Blu player that will decode the latest and greatest, and send it out through analog connections. It may be a while before I can justify a new rcvr or pre/pro setup with HDMI inputs!

Many of us are doing just that. BD to Receiver/pre with 6 or more cables.
Then it's on to the wonderful world of levels.

You'll love it - trust us