# HDMI versions and Lossless codecs



## Wayde (Jun 5, 2006)

Hi, quick question.

Here's what I believe, please correct if I'm wrong. 
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_At least HDMI version 1.1 or greater is required to pass uncompressed PCM translated TrueHD or DTS-HD audio from player to receiver._
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That means if you have a next gen disc player and receiver w/ HDMI 1.1 or greater and the player can decode the new lossless audio formats, it'll pass it in PCM to your receiver over HDMI connections. 

That means original HDMI 1.0 cannot do it adequetely and HDMI 1.3 is not required to accomplish this objective.

*However*, I'm reading an article that implicitly seems to state that HDMI 1.3 is required to pass the encoded TrueHD/DTS-HD audio signals from player to receiver. Why is that? Is encoded TrueHD/DTS-HD larger (requires more bandwidth) than the same number of channels PCM?

Why wouldn't they just put the movie soundtracks on BD/HD DVD in PCM, why use a codec at all if it's not saving space?

Perhaps I misunderstand something. :blink:


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## Kal Rubinson (Aug 3, 2006)

From the horse's mouth: http://www.hdmi.org/learningcenter/faq.aspx#hdmi_specification


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## lcaillo (May 2, 2006)

Good, informative link.

I might add that we have this and a number of similar resources listed with links in the Manufacturer and Vendor Reference Information forum in the thread

http://www.hometheatershack.com/for...reference-information/4797-organizations.html

Lots of horses' mouths in that one and the other sticky threads there for those who want to do some reading.


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## Wayde (Jun 5, 2006)

I appreciate the horse's mouth. 

Here is the link I was looking for:

http://www.hdmi.org/learningcenter/faq.aspx#q2

What I'm interested in is what manufacturer's aren't liable to tell you, but HDMI.org seems to have no problem letting the cat out of the bag.

*Soylent Green is PEOPLE!!*

oh, yeah... actually -
You don't need HDMI 1.3 for Dolby TrueHD or DTS-HD.

Since HDMI 1.1 supports 8ch pcm @ 192kHz/24bit, if you decode from the playback device you're in good shape.

The fact that 1.3 _supports_ TrueHD & DTS-HD is of considerably less consequence than is likely to be advertised by manufacturers.

Thanks for the link. I've read HDMI.org in the past, I was about to take a look this morning too but you beat me to the punch Kal, thanks again


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## Hunter844 (Apr 22, 2007)

I can't tell the difference anyway. I think my XBOX 360 attachment might just suck in this regard. It says it's decoding to Dolby TruHD but to me the receiver doesn't sound any different than it would normally sound with a DD track. Do I have to select a PCM setting on my Onkyo 604 because it immediately goes to DD-EX?


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## bobgpsr (Apr 20, 2006)

Hunter844 said:


> I can't tell the difference anyway. I think my XBOX 360 attachment might just suck in this regard. It says it's decoding to Dolby TruHD but to me the receiver doesn't sound any different than it would normally sound with a DD track. Do I have to select a PCM setting on my Onkyo 604 because it immediately goes to DD-EX?


It is really a very subtle difference between good DD+ or dts versus lossless (TrueHD or PCM). The XBOX must convert to a legacy lossy codec format of 640 kbps DD, 1509 kbps dts, or 1509 kbps WMA in order to get 5.1 multichannel audio to your Onkyo. You set the lossy codec type used in the XBOX HD DVD add on player application. The HD DVD playback can decode the selected audio track on the HD DVD (DD+, TrueHD, etc) but must mix the audio with button sounds, HDi commentary audio and then re-encode to the lossy output codec chosen. Some users have the opinion that 1509 kbps dts is a better choice than 640 kbps DD. Users (with WMA capable AVRs) and Microsoft feel that WMA is the best lossy codec choice if their target receiver/AVR can handle it.


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## Wayde (Jun 5, 2006)

Interesting Bobgpsr...

That the Xbox360 even does any sound at all when the disk is set to TrueHD is amazing. The volume is definitely higher ... but like I said I don't think the sound quality is any better.


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