[Damage]

Quote:

Originally Posted by 3rdoptic i found what i needed in the audigy online manual.. so it does do multi channel surround through digital out..this is good.. lol what about chaintech av-710 which im getting shipped to me

And if I'm not mistaken, its neither Dolby Digital nor DTS stream (it was mentioned that only Creative Speakers have this propriatary connection, and this would most likely be it).

Currently, only nForce1/2 mainboards with MCP-D or MCP-T (respectively) mainboards can do proper surround sound encoding via S/PDIF (digital out). That multi channel output through digital output is more or less only for Creative speakers. Or, if you ever have the urge to hook your PC upto your HT in the future, you're boned.

 

[rsaavedra]

Quote:

Originally Posted by Damage And most competent sound cards should be able to allow digital pass through for DD/DTS streams.

That is more related to my question.

Mr Radar, I wasn't questioning any of SPDIF specs. What I was wondering was what the source streams were like, and what the final goal was. If you have a digital "multichannel stream" in your computer, most likely it's already DD or DTS, e.g from a DVDV or from a video game. What the card needs to do is to just pass *that* bitstream through as is, whether DD or DTS, through the digital out, for an external receiver to decode.

My intention was precisely to bring out the issue that most likely you don't have 6 PCM channels as in DVDA to start with, so the fact that SPDIF won't get more than 2 PCM channels across was irrelevant to the thread creator, and to my point. More relevant was the fact that you don't need the card to have DD/DTS encoders to get multichannel DD/DTS streams through the digital out, and most likely the source multichannel stream was already DD or DTS.

Anyway, I'm not arguing at all, my first post here was just to try to understand in more detail what was being discussed.

 

[Mr.Radar]

Unless they've liscenced the Dolby Digital encoder, games only produce PCM surround sound (and even if they did encode DD, for the Audigy to apply EAX effects it'd have to decode them to PCM anyways, and the Audigy doesn't encode DD).

 

[3rdoptic]

i am going to sit back and wait to see what doom3 needs in terms of sound.. hmm just waiting on my av-710 for musical playback as well as DVD movies etc..i cant really justify a purchase of a soundcard (audigy2) just for some sound acceleration.. that wont take too many frames anyway.

 

[rsaavedra]

Quote:

Originally Posted by Mr.Radar Unless they've liscenced the Dolby Digital encoder, games only produce PCM surround sound

Well in the PC realm not sure, but I can say my Jak II game for Playstation 2 can produce Dolby Prologic II surround sound through the digital out of the PS2.

 

[Rempert]

Quote:

Originally Posted by rsaavedra Well in the PC realm not sure, but I can say my Jak II game for Playstation 2 can produce Dolby Prologic II surround sound through the digital out of the PS2.

If I understand correctly, Prologic II is just a complex conversion from 2 channel to 5.1 (like mirroring the front channels to the back in a four speaker system, only a bit more involved). So if you are going from game console into a surround receiver, and the surround receiver is using any Dolby Prologic mode, you will be getting surround sound out of the receiver but the signal going into the receiver is just stereo. You should be able to play a redbook CD in emulated surround sound the same way.

Anyways, with computer games in general, it will just be generating PCM signals. If Doom 3 will do it's own Dolby Digital encoding (it might but I don't know for sure), it will be one of the first if not the first computer game to do so. The main reason is simply that this is not how people are expected to use their computers (although that is probably changing quickly). Most people are still using game -> soundcard -> 2 channel analog out -> 2 speakers or headphones. Some people are using game -> soundcard -> 6 channel analog out -> 5.1 computer speakers. But at this stage, it is pretty rare for someone to be running their sound from the computer's digital out into a multichannel receiver.

 

[rsaavedra]

Quote:

Originally Posted by Rempert If I understand correctly, Prologic II is just a complex conversion from 2 channel to 5.1

Well you have a point there, Dolby Prologic II is not PCM, but it's not 5.1 as in Dolby Digital either.

 

[GokieKS]

Pro Logic II, at its source, is only 2-channels... it's just a stream encoded in a specific way so that the decoder (say, the receiver) can create 5.1 seperate streams using it. The Gamecube, for example, supports PLII, and it's done through the normal output using RCA connectors.

As for DooM3, there's been a lot of reports that it will have DD5.1 audio, but nothing definite. I would imagine that even if it did, it would still have a "regular" 5.1 mode as well - as mentioned, the number of people who have digital receivers as audio equipment for their computer is quite small (I do, and I think I'm the only one I know of in person that does).

~KS