Audio through HDMI - Prelude/Xonar cards: when?? Plus other Questions

[Jamo218]

As the title suggests, has anyone found any information relating to when new cards with such features may be brought out?

Additionally, if passing out lpcm audio via a soundcard to an amp via hdmi, am I right in thinking that this bypasses DAC's and therefore should I not worry too much about the quality of the DAC's??

I'm leaning towards an asus card in any event with the recent bad press that Creatives driver support has received. Whether this has an impact on the likes of Auzentech i'm not sure, but I wouldn't be suprised.

Thanks in advance,
J

[meansizzler]

There is no DAC conversion by the soundcard so is passed out straight to the AMPS DAC, I hear Asus is bringing out such a card that fits your requirements, not sure when though

[ukle]

Also there is a Prelude addon with the functionality being brought out.

Which is why I assume he asked about Prelude and Xonar and when the cards / add-ons with this functionality will appear.

To that its anyone's guess, I would expect the Prelude add-on to be out before the new Xonar's though, but the new Xonar's look VERY impressive, just I expect them to not be cheap

[Jamo218]

Yeah my understanding is that there is an add-on for the prelude, and a new xonar card, just not sure when this will happen.

[dogbert]

hdmi should be reasonably cheap once it hits the mass market. asus and especially auzentech are heavily overpriced, and I wouldn't be keen to beta-test their first generation hdmi stuff.

[Jim_b0b]

Could anyone explain to me (in lamens terms! hehe) the difference between the audio going through HDMI v using SP/DIF for the output to be processed by the a/v receiver ?

Am I right in thinking that to use this functionallity in HDMI you will need HDMI version 1.3? and subsequently an a/v receiver with version 1.3 ? I kind of find it all a bit overwhelming and am trying to get my head around it all.

Thanks, and sorry for hijacking the thread!

[james.miller]

Originally Posted by Jim_b0b

Could anyone explain to me (in lamens terms! hehe) the difference between the audio going through HDMI v using SP/DIF for the output to be processed by the a/v receiver ?

Am I right in thinking that to use this functionallity in HDMI you will need HDMI version 1.3? and subsequently an a/v receiver with version 1.3 ? I kind of find it all a bit overwhelming and am trying to get my head around it all.

Thanks, and sorry for hijacking the thread!

well, hdmi has far more bandwidth available. thats the important bit really. as far as the diffeent hdmi versions go, you only need hdmi v1.1 for multi channel PCM transmission -thats uncompressed pcm, same as a CD but up to 8 channels instead of two. where audio is concerned, you only need more than HDMI V1.1 when you want to send or receive DD TrueHd or DTS: MA in bitstream formats. An amp for example needs o be v1.3 to recieve DTS: MA and be able to decode it internally for example.

as long as you have v1.1 you are good to go. with v1.1, the player can (software permitting) decode the HD audio (TrueHD or DTS: MA) and then output that as multi channel PCM instead, which is what the ps3 does for example

[Jim_b0b]

Thanks for the reply!

Im trying to make my HTPC as future proof as possible (not easy with the rate of change in the IT industry), am I right in thinking that when you say

as long as you have v1.1 you are good to go. with v1.1, the player can (software permitting) decode the HD audio (TrueHD or DTS: MA) and then output that as multi channel PCM instead, which is what the ps3 does for example

that is a bit of a work-around and is not quite as good as passing the actual stream through HDMI ?, or am I misunderstanding things a little ?

I would like to be able to play blu-ray discs on my HTPC and enjoy the full sound capabillities on the disc, so am trying to plan for exactly what I need, rather than buy something now and then upgrade it something better in a couple months time.

Is there any solution at the moment to actually passing the audio stream through the HDMI cable from my HTPC, or currently is the available technology only allowing us to stream the video by HDMI and the audio via phono / SP/DIF ?

Also, when you say DTS: MA. what do you mean by the MA bit? sorry for being a bit dumb!

Sorry for all the questions, any help appreciated to finally get my head around it all!

[nickf3]

Originally Posted by Jim_b0b

Thanks for the reply!

Im trying to make my HTPC as future proof as possible (not easy with the rate of change in the IT industry), am I right in thinking that when you say

that is a bit of a work-around and is not quite as good as passing the actual stream through HDMI ?, or am I misunderstanding things a little ?

I would like to be able to play blu-ray discs on my HTPC and enjoy the full sound capabillities on the disc, so am trying to plan for exactly what I need, rather than buy something now and then upgrade it something better in a couple months time.

Is there any solution at the moment to actually passing the audio stream through the HDMI cable from my HTPC, or currently is the available technology only allowing us to stream the video by HDMI and the audio via phono / SP/DIF ?

Also, when you say DTS: MA. what do you mean by the MA bit? sorry for being a bit dumb!

Sorry for all the questions, any help appreciated to finally get my head around it all!

Jim,

DTS-HD MA – Master Audio. This coding system can produce audio that is bit-for-bit identical to the studio master with 7.1 channels at 96k sampling frequency and 24 bit resolution. On Blu-Ray, the overall data rate is 24.5 megabits per second. Take a look at the DTS site:

http://www.dtsonline.com/dts-hd/dts-...-and-hddvd.php

Current S/PDIF technology cannot handle this bit rate so it is not possible to get the raw data out of the PC using optical or co-ax S/PDIF. HDMI1.3 has been designed to support this rate but current HDMI PC graphics cards have the audio data supplied to the card from a S/PDIF socket on the motherboard. What we are waiting for is a new generation of graphics card which can pick up the HD data from the PC bus and feed it directly to the HDMI socket. This can then be decoded externally with a suitable AV amp with DD True HD or DTS-HD MA decoders on board
.
The current options are to reduce the resolution from 24 bit to 16 bit and output the lower data rate via S/PDIF or to do the decoding and D to A in the PC and output via multi-channel analogue. I have chosen to go for the second of these options at present and use a good sound card – RME in my case. This has good DACs which can handle the 96k/24bit competently.

What is unclear at present is just how the codecs supplied by the likes of Cyberlink handle the decoding. Some believe that even PowerDVD does some downgrading of resolution.

So the short answer is that, at present, you can’t future-proof your HTPC.

Nick.

[Jim_b0b]

Thanks, really appreciate the effort taken to reply.

What im just thinking at the moment though is, say in the future (when all this stuff is implemented and working), is there any point og having a fancy soundcard? I mean if video & audio are to go through one hdmi cable how does the soundcard come into this ? Would you have a link from the soundcard to the graphics card to output both through the one HMDI cable?

Im thinking of in the future, playing games that may take advantage of DSP effects or such like on the soundcard, im just not sure how the soundcard fits into the equation.

[drummerjohn]

Originally Posted by nickf3

Jim,

HDMI1.3 has been designed to support this rate but current HDMI PC graphics cards have the audio data supplied to the card from a S/PDIF socket on the motherboard. What we are waiting for is a new generation of graphics card which can pick up the HD data from the PC bus and feed it directly to the HDMI socket. This can then be decoded externally with a suitable AV amp with DD True HD or DTS-HD MA decoders on board

The ATI cards using HDMI don't take the audio from the SPdif. They are able to pass LPCM. However, I am not sure if they can pass DTS HDMA and the likes of.

[Jamo218]

Originally Posted by drummerjohn

The ATI cards using HDMI don't take the audio from the SPdif. They are able to pass LPCM. However, I am not sure if they can pass DTS HDMA and the likes of.

I thought the ati cards just passed AC3? That's what i've read on the spec-sheet for my card.

If it will pass lpcm through hdmi is this easy to set up?

[as5606]

The ATI cards (like my 2600XT) will only pass 2.0 LPCM so not much use really. Even the latest, greatest and most expensive ATI card only passes 2.0. To get TrueHD or DTS MA you will need the card to pass 7.1 LPCM which is why we wait with baited breath on these Add-On cards or the Nvidia 8200 chipset motherboards.....when....when....when